early years. These gearboxes took hard drag-race launches better than the Muncie gearboxes. They too eventually fail after repeated hard launches with sticky tires. It just takes a little longer.
This Tech Tip is From the Full Book, CORVETTE C3 1968-1982: HOW TO BUILD AND MODIFY. For a comprehensive guide on this entire subject you can visit this link:
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Because you are concerned with performance issues, the emphasis is on replacement gearboxes with the latest technology. The majority of performance car builders know that you want versatile vehicles that can get your heart rate up and still cruise the interstates. The following information covers the serious race options and the street performer build concept.
Today’s purpose-built streetable units can handle up to 700 ft-lbs of torque with ease. The latest transmissions have geartrain tolerances that are much tighter than the OEM transmissions on the C3s. Many have roller bearings supporting the components. The tight clearances and better bearings require lighter-viscosity fluids in many of the latest manual gearboxes. The smelly high-viscosity gear oil of old also slows gear changes in the heat of battle. Those early loose gearboxes required the high-viscosity oils to fill the bearing and gear voids. Using 75W90 gear oil in a latemodel gearbox makes shifting very difficult, especially at cold temperatures.
Old-school transmissions used tapered brass synchronizer rings on steel cones to slow down the gears during shifting. The brass synchronizer rings dragged on the cones, acting like brakes to aid in gear shifts. The synchronizer was forced onto the cone’s taper, and this slowed down the gear for a smooth shift. That is, until they wore or broke, causing that inevitable gear grinding.
Today synchronizer blocker rings are lined with fibrous materials so they act as true friction braking components. Automatic transmission–type friction materials in the latest synchronizers help slow down the gears much better for smoother shifting at high RPM. In fact, many late-model manual transmissions use Dexron fluid, which complements the friction materials used on the synchronizer blocker rings. Bearing clearances are also much closer for precise shifting at high RPM.
One of the best innovations is the internal rail shifter most late-model gearboxes use. Having the shifter mechanisms internally lubricated keeps the shifting process smooth for many years with minimal service. The shifter rails are supported well internally, and this further enhances shift control.
In the early days of the C3, the Hurst aftermarket shifter was a common and welcome replacement for the Muncie-supplied sloppy factory shifters and light-duty shift linkage. The internal shifter is one step above the superior Hurst shifter, which has changed the shifter marketing plan for the aftermarket suppliers forever. No more adjusting shift linkages as they wore or if transmission servicing was performed. Shifter mechanisms, shift knobs, and sticks are about the only items available for the latest transmissions.
When someone says they have a higher numerical first-gear ratio, they have a better mechanical advantage. As the ratio numbers get higher, less effort is required to get the wheels rolling. Conversely, lower-number gear ratios require more torque to get the same effect as the higher number.
Torque multiplication of the transmission and differential gearing aid in vehicle launch. Here you have to be more concerned with mechanical torque multiplication factors, without having an automatic transmission’s torque converter aiding in vehicle launch. To achieve the automatic transmission’s 2:5.1 torque converter multiplier effect, you need a steeper or higher numerical first gear in your manual transmission to help get the Shark rolling at the same velocity.
Here’s the Math
To arrive at the gearing torque multiplier number when figuring total mechanical advantage, multiply the first-gear ratio by the differential ratio. For example, have a manual transmission with a 3.06:1 first-gear ratio and a differential ratio of 3.08:1. The torque multiplication is 9.42 (3.06 x 3.08 = 9.42).
Now let’s factor in the engine torque output factor. Let’s say your engine develops 200 ft-lbs of torque. You multiply the torque by the torque multiplication figure (9.42) to get the output factor. In this case it’s 1,884 (9.42 x 200 = 1,884). When your clutch fully engages, your rear tires should have 1,884 ft-lbs of torque applied to them.
That may seem like plenty of applied torque at the time of clutch engagement lock-up, but remember the typical Shark Corvette weighs 3,500 pounds or more. About 400 ft-lbs of torque sure sounds better in theory with 9.42 x 400 = 3,768 ft-lbs of torque applied at launch.
Let’s take this a step further. If your 327-ci engine develops torque at higher RPM or your engine is down on torque, you need to use a higher first-gear ratio to help your Shark get moving. Your 327-ci engine may have 3,768 ft-lbs or more of torque available. However, your camshaft does not provide peak torque until 3,000 rpm, so this limits your available torque unless you do a full-throttle launch.
Many do not want to drive a Shark that way, and it’s not feasible if you drive on city streets. Either you increase the transmission first-gear ratio or you replace the differential gear set with higher numerical pieces to get your Shark rolling.
On the other end of the spectrum, a 427-ci Shark with plenty of low-end torque works better with a lower numerical first gear. Here it makes sense to use a 2.87:1 transmission first gear with a 3.23:1 differential gear set: 2.87 x 3.23 = 9.27:1 combined ratio.
The original Muncie 4-speed and Turbo-Hydramatic 350 are antiquated by today’s standards. There are many high-performance transmission options for the Shark today whether you feel like shifting manually or letting the transmission select gears for itself.
Let’s begin with GM units that are available for a Shark. Tremec (formerly BorgWarner) T5 5-speeds were found in S-10 pickups and 1985–1992 Camaros.
The 1983–1987 T5 versions are dubbed non-world-class and only capable of handling a wimpy 265 ft-lbs of torque. The 1988–1992 models are world-class and have better main shaft support, so the torque rating is 300 ft-lbs. Parts are available and some specialists are upgrading them to handle some serious torque in excess of 600 ft-lbs. That is questionable, though: the cases are not that tough and the gear designs do not withstand the elevated torque even with superior materials.
If you decide to go the T5 route upgrade, parts are available from places such as Medatronics Corporation and D&D Performance. Each supplier has its own opinion as to what is best for a high-load T5, which means you have to do some serious investigating to make this decision. Because of the lower cost of this unit compared to other Tremec and Richmond offerings, it makes sense to buy a complete assembly. The readyto-go box is a safer bet unless you are well versed in the innermost workings of this gearbox.
Camaros equipped with V-8s and T5s had two first-gear ratios available. The Throttle Body Injected (TBI) engine had a first-gear ratio of 2.95:1, while the Tuned Port Injected (TPI) engines had a ratio of 2.75. Both had a 1.94 second, 1.34 third gear, and two possible overdrive ratios. The TBI engines had a .63 ratio and the TPI used a .74 final-drive ratio. T5s were also used with 4- and 6-cylinder engines with first-gear ratios as low as 4.03, but be careful not buy one of these for your Shark. They are too fragile to withstand 200 ft-lbs of torque.
One consideration is that the T5 is lighter and fits easily in the tunnel with less overall installation work. They have smooth-shifting internal rail shifters for consistent shifts. The 2.95 TBI first gear and .63 overdrive gear make them a smart decision for a lower-torqueoutput long-distance cruiser, not a highperformance Shark with torque loads in excess of 350 ft-lbs.
General Motors used a Tremec T56 6-speed in a number of vehicles between 1993 and 2004. This transmission is a popular swap for any Shark with those who want two overdrive ratios. General Motors engineers specified a 2.66 first gear, 1.78 second, 1.30 third, 1.00 fourth, .74 fifth, and a high torque requiring .50 final gear for the 1993– 1997 Camaros. Due to demand, Tremec offered an aftermarket T56 application that has a 2.97 first gear, 2.07 second, 1.43 third, 1.00 fourth, .80 fifth, and .62 sixth gear.
As discussed earlier, the 1993–1997 Camaro gear ratios require a steep differential gear set (4.10:1) or a high-torque engine to use the transmission effectively. The aftermarket T56’s gear ratios are middle of the road for an engine that produces its torque at higher RPM.
The Camaro/Firebird and aftermarket T56 transmissions have a centerlocated shifter and the shifter location is farther back than the Shark’s original offset shifter. So, the factory console requires a custom console plate with a modified shifter opening in the original tunnel.
Lengthwise, the 1993–2002 Camaro/ Firebird and aftermarket applications place the shifter close to the original shifter access opening at the center of the tunnel. I use a sheet-metal plate to cover the existing shifter opening and mount the new shift boot after transmission tunnel modifications. An adapter plate is required to mate the 1993–1997 Camaro T56 to the original Shark bellhousing.
The Tremec GM aftermarket T56 comes with the adapter plate, allowing the use of your original bellhousing. The 1998–2002 LS engine–equipped Camaros with T56s are also compatible when an adapter plate is used. They also require the installation of a 1993–1997 T56 input shaft due to the LS engine bellhousing’s shorter length. Either application works with the original Shark or a Lakewood blow-proof bellhousing.
Aftermarket T56 6-speeds are equipped with a mechanical speedometer drive provision, while the stock T56 transmission on Camaro/Firebird OEMs are not equipped with this provision. These stock F-Body transmissions use an electronic vehicle speed sensor (VSS) that communicates with the speedometer.
Shift Works has a housing that drives an electronic VSS and mechanical speedometer cable. It’s $1,000, but it does solve the dilemma. An electronic fuel-injected engine that requires the VSS has both areas covered as it can still drive your factory speedometer cable.
In addition, you can have Bowler Performance Transmissions machine your T56 extension housing to accept a mechanical speedometer drive for $550. You have a few other options to resolve the speedometer issue. These options include replacing the factory mechanical speedo with an aftermarket electronic unit or using a CableX speedometer drive system. The CableX uses the VSS input to run an electrical motor that drives the mechanical speedometer cable.
core unit for the RS buildup allows a substantial savings.
Keisler SS 5-Speed
Keisler’s latest SS 5-speed gearbox is from a clean sheet of paper with plenty of torque-handling capabilities. The case height is lower, fitting in the Shark’s transmission tunnel with ease, plus the 700 ft-lb torque rating means these units are available for a highperformance engine. Multiple mounting fitments make this bolt directly to the original GM small- or big-block bellhousing.
Gear ratios are 2.66 first, 1.78 second, 1.30 third, 1.00 fourth, and .68 or .80 overdrive ratio. They have a 2.97 first gear ratio gear set in the works.
Richmond is another alternative to the original 4-speed transmission in your Shark. The company offers 5- and 6-speed transmissions for direct installation. One approach to the fuel-mileage dilemma is unique with its 5-speed offering. A five-forward gear set is used with a 3.28 first, 2.13 second, 1.57 third, 1.24 fourth, and 1.00 fifth gear, rather than the traditional four-forward gear choices with an additional overdriven high gear.
Off-the-line launches are better because a low numerical gear ratio differential can be used, say a 2:73.1, for lower-RPM cruising. The five forward gears without overdrive make the gear change transitions smoother with less RPM drop between shifts.
Richmond also has a Super Street version of its 5-speed gearbox with an overdriven fifth gear. The three gear ratio selections offered for first gear are 3.33, 3.06, and 2.89. The ratios for the other gears are a 1.85 second, 1.31 third, 1.00 fourth, and .77 overdrive. This gearbox is rated for 600 ft-lbs for more robust applications. All of the Richmond Gear transmissions are designed for direct bolt-up installation on a small- or big-block bellhousing.
Richmond’s 6-speed transmission has overdrive gearing available. Similar to the road race gearbox, the 6-speed has eight first-gear ratio options, starting with a 2.08:1 and ending with a 4.41:1 first gear. Two selections are available for the second through fifth gears, with two overdrive gears, .80:1 and .84:1, respectively. This makes it easier to match your engine’s torque curve without major compromises.
Richmond Gear’s approach leans to the race-orientated Corvette owner; their aluminum main housing case splits in half for easy servicing or quick gear changes. Once the gear housing is split, the main and counter shaft assemblies come out quickly. During frequent race events, the transmission could be disassembled numerous times for inspection and repaired trackside if necessary.
Richmond recommends using its synthetic 75W140 gear oil in all of their gearboxes. I feel that Richmond’s transmission offerings lean toward the true racer, who uses the Shark primarily for drag or road racing.
Many clutches are available for your Shark. The Shark uses a specific clutch fork, and that’s the only significant difference for the Gen I small-block and Mark IV big-block engines. The new LS engines use hydraulic actuation systems. The clutch assembly works by clamping a disc connected to the transmission’s input shaft between the flywheel and a pressure plate to control application. Clutch designs vary from a simple onedisc to multiple discs and different compound materials.
Like the brake friction materials, as the clutch horsepower requirements grow so does clutch aggressiveness. Multiple-disc clutches are used to gain friction surface area. In many cases, this helps alleviate some of the required pedal effort to disengage the clutch. Determining how much clutch you need is the first part of the equation. Installing a clutch for a 700-hp engine on a 350-hp engine means a lot of wasted effort on your left leg in traffic. High-horsepower clutches also tend to chatter due to their aggressive nature.
Clutch pressure plates come in two designs: diaphragm and lever. Diaphragm clutch pressure plates are used by General Motors in all of their manual transmission applications. Lever-type pressure plates require more effort to disengage the clutch, while diaphragm pressure plates apply more force on the clutch disc as engine RPM increases. That means diaphragm pressure plates apply more pressure while requiring less pedal effort. Who doesn’t like that?
There is a minor problem with the diaphragm design, which causes the clutch pedal to stick on the floor, disengaged at high RPM. The same centrifugal forces that increase the pressure plate’s clamping power tend to keep the multiple pressure plate fingers from releasing. However, the correct clutch diaphragm finger positioning at WOT can prevent this problem.
Two methods are used to prevent the clutch pedal from sticking to the floor. One is to fabricate a stop under the clutch pedal to shorten the travel on hydraulic clutch systems, or you can add free-play to the clutch linkage. You need just enough clutch pedal travel to release the clutch. The adjustment takes some trial and error before you find the sweet spot.
Step 1: Install Clutch Disc
This high-torque, large-cubic-inch big-block has an aluminum flywheel for quick revving. It’s not a good choice with a smallinch engine and radical camshaft. Installation begins with a new roller bearing pilot assembly with a proper socket that fits the outer diameter of the pilot bearing. Hammering close to the center of the pilot bearing can damage the seal and cause the transmission input shaft to fit tightly, and gear clash results during shifting. Thoroughly clean the flywheel clutch disc friction surface with an alcohol-based cleaner. The line-up tool should fit easily into the bearing; if it is tight, you need to replace the bearing or get used to gear grinding when shifting. Always check the manufacturer’s install note on the clutch disc before installing the line-up tool into the clutch disc and the pilot-bearing. Carbon semi-metallic clutch discs such as this Spec Stage 3+ hold well and are aggressive on flywheel and clutch pressure-plate surfaces. All that grip and a manageable clutch engagement is what this disc is about. You can expect smooth clutch operation even when plying the city streets.
Step 2: Install Pressure Plate
Centerforce clutches are another option that work well for the occasional road-racer who drives on city streets. The weighted diaphragm clutch fingers allow for less left-leg fatigue in traffic while applying extra pressure from the centrifugal force as RPM increases. These can be tricky to balance due to the weights moving around at low engine speeds. All in all, the Centerforce weighted diaphragm clutch finger design is proven and a good choice for someone using a Shark for a daily driver or as a weekend warrior.
Make sure whatever clutch you use survives. Like the flywheel, the pressure plate surfaces should be cleaned with an alcohol-based cleaner to remove any oil or grease preservatives. Once the bolts are all finger tight, start tightening them in a crisscross fashion, a couple of turns at a time, to evenly seat the pressure plate and disc on the flywheel. Torque the bolts at least twice starting at 20 ft-lbs to seat the pressure plate, then finish with the manufacturer’s recommended torque (typically 45 ft-lbs). A good practice is to mark where the pressure plate is on the flywheel. If you did not have the assembly balanced you can install the pressure plate in the same position, if there was no vibration. Chances are if you’re having fun you will revisit the clutch assembly multiple times as you learn your Shark’s weaknesses.
This clutch has Kevlar pucks instead of one continuous layer of friction material. The idea is for the individual pieces of friction material to retain less heat if the clutch assembly is worked often in autocross or short roadcourse events. Following is the way the clutch assembly is installed if you choose not to modify the crossmember for removal on a 5-speed manual transmission–upgraded Shark. The bellhousing and clutch pieces are loaded on the input shaft, then the transmission is raised into position. Once the loose assembly (transmission, bellhousing, and clutch assembly) is close to the correct position, someone carefully installs the clutch pressure plate to flywheel bolts loosely. Then a modified line-up shaft is inserted into the clutch disc and pilot bearing. The shaft (with a piece of mechanic’s wire) must be removed after the pressure plate bolts are tightened. The bellhousing is then installed, and if you were able to properly line up the clutch disc, the transmission slides into place. This does not make sense for anyone building a modified Shark. Chances are you will revisit this at some point and will regret that you did not remove the crossmember.
Clutch Actuation Options
All 1968–1981 Corvettes use mechanical clutch linkage to actuate the clutch. These work effectively, so why be concerned about it? For many applications, there’s no need to modify or change what already performs well. Hydraulic clutch systems were installed on Corvettes in the mid-1980s and have become the standard all manufacturers use today. Flexibility is the key, requiring one flexible hose to connect the clutch master to the slave cylinder.
Another factor is clutch pedal effort. By simply moving the pivot point to the clutch actuator rod location, clutch effort can be highly modified. If you plan to use a clutch assembly that requires high effort, hydraulic clutch actuation should be considered.
Another reason to use the hydraulic system is a conversion from automatic to manual transmission. Welding the clutch equalizer support to an automatic transmission–equipped frame can be difficult unless major components are removed.
The 1968–1982 Corvette production run included four different automatic transmissions: Turbo-Hydramatic 400, Turbo-Hydramatic 350, modified Turbo-Hydramatic 350, and 700R4 overdrive. All of them have good track records for durability, except for the first-run overdrive unit found in the 1982 Shark.
The Turbo-Hydramatic 400 started the Shark era, then a lighter-duty TurboHydramatic 350 series took over for a number of years. In 1980, General Motors tried a modified Turbo-Hydramatic 350 with a lock-up clutch torque converter to increase fuel mileage and eliminate inherent torque converter slippage. The final year of the Shark production ended with a 700R4 automatic overdrive with a lock-up torque converter as the only available transmission.
The TH400 transmission is a stout and durable transmission for a big-block. Unfortunately, they were also heavy and required extra horsepower to make the hefty internal components rotate.
Turbo 350s were a great advancement, and these lighter-weight units were still tough and easily rebuilt. Bigblock engines appeared in a few early C3s from 1968–1974, so if you have one of these rare Sharks, you are probably going to keep the original equipment because it is so valuable. The low-compression 350s produced anywhere from 165 net hp to 235 net hp and didn’t require a heavyduty transmission.
The 1980–1981 two-year lock-up turbo 350 transmission experiment coupled a fine-working transmission with a clutch-equipped torque converter, eliminating torque converter slippage and upping fuel mileage a minuscule 2 percent. When the torque converter clutch (TCC) was applied, engine speed dropped approximately 200 rpm. One nagging issue plagued the first-design TCC operation: a vacuum switch–controlled clutch operation locking the torque converter in at 28 mph in high gear. The engine immediately bogged down when the TCC came in; the majority of owners disabled TCC operation.
The installation of the 700R4 overdrive into the 1982 Shark allowed Chevrolet to use their latest transmission creation as a test bed for the rest of GM’s lineup. The groundbreaking transmission had an overdrive gear and a TCC torque converter. An ECM engine control module controlled the TCC application, making them more desirable than their first attempt at a fuel-conscious transmission.
Like the turbo 350 lock-up units, TCC came in very early to conserve fuel, making the already anemic crossfire fuel-injected engine even more so. In the shop you modify the prom chip to have TCC come in at 50 mph, and the immediate thought is you added 50 hp.
Modify or Swap?
Your first option is to modify the original transmission. If you plan to keep close to home and ply your local streets and drag strip, modifying your original transmission makes sense. Before you start, take a long test drive on city streets to really work the transmission, shifting through the gears. Use the torque converter and run it up to stall speed to get the fluid heated up. If the transmission still has decent shifts without slipping, it is a candidate for modifying. If there is any slipping during shifts, do not expect a shift modification kit to fix the problem.
Shift kits are available for the turbo 400, 350, and 350 with TCC. Turbo Action has one that precisely and reliably shifts the C3. The easy-to-install kit replaces the separator plate between the transmission case and valve body. The company’s Positive Action for Corvettes kit requires no spring replacements or modifications. A few check balls are deleted from the original count and you are ready to go. However, other intricate kits require spring and valve modifications. It’s best to install these during the overhaul of a transmission. Tweaking the governor weights and/or springs is one method to optimize the shift timing. The governor uses fly weights to apply pressure to the shift speed control pressure valving, which regulates shift timing.
Shift kit installation is one of those Saturday-afternoon projects that require a clean work area without sand and debris blowing around. After the transmission has been assembled, the results are immediate. You experience a firm shift under moderate throttle to barking tires at WOT.
Another mod for an original transmission is a full manual control valve body so that the driver has full control over all up and down shifts. Early automatic transmission shift technology was fair with sketchy control of shift timing. As an example, when downshifting from high gear, anticipating a second gear shift and engine braking, the transmission downshifts into first gear, causing the tires to chatter or over-rev the engine. The full manual control valve body is suited for competition and aggressive driving, so it can be used for road racing, autocrossing, or gymkhana events.
Manual control valve bodies operate similarly to a manual transmission because they give you full control of shifting. You must select the gear you want regardless of engine RPM. The task is similar to the separator plate replacement. The replacement valve body bolts in place of the original with a few adjustments and you are ready to go. Manual valve bodies are available for the 350, 400, and 700R4. The price is not too stiff at $200, considering the cost of performance pieces today.
Your second option is to swap in a different transmission. Although extremely durable, the TH350 and 400 are not the best high-performance automatic transmissions for your Shark. These transmissions have higher mechanical first-gear ratios (turbo 400 2.48:1 and the 350’s 2.52:1), and therefore they are a detriment to your off-the-line launch when using a small-block engine. In addition, these transmissions do not have an overdrive gear, so they do not provide fuel economy for long-distance driving.
The 200R4 was installed in various Buick, Oldsmobile, and Pontiac models and used with various engines. Most notably, the 2004R4 was fitted to the 3.8-liter turbo V-6 in the Buick Grand National. General Motors did configure some 200R4 cases in universal form for use behind the Chevrolet small-block engine. A 2004R has a similar length to the TH350 in the 1977–1981 Sharks, so the retrofit to a C3 is much easier with this transmission than many others. In addition, the original Shark driveshaft is compatible with 700R4 for most applications.
Currently, the 700R4 or 4L60E, which is a 700R4 with electronic shift control, is the most common automatic transmission swap into a C3. Very few 2004R transmissions were found behind smallblock Chevy engines, but the 700R4 transmissions were factory installed in hundreds of thousands of GM vehicles. This makes the 700R4 the most popular choice because of the massive quantities of available units and performance pieces marketed for them.
An overdrive transmission provides the best balance of performance and economy for street driving. In fact, they deliver the benefits for all-around performance driving in long haulers. Also, the engine RPM reduction quiets down the drivetrain, has less heat buildup, and provides a comfortable long highway cruise. The 2004R gear ratios are 2.74 first, 1.57 second, 1.00 third, and .67 overdrive. The 700R4 gear ratios are 3.06 first, 1.62 second, 1.00 third, and .070 for overdrive. This makes the 2004R more desirable for a higher-torque engine that has a lower-RPM redline. The 700R4 is more suited for a long-duration camshaft that produces less torque at lower RPM.
installing a mechanical cable and the correct ratio TV actuator lever onto the engine’s throttle shaft.
If you choose to use a 4L60E, you also have the option of upgrading to a steering wheel–mounted paddle shifter. The factory shifter can be used for daily driving, with the addition of the paddle shifter: a couple of clicks and full manual control of the transmission is possible. Overall, the 4L60E installation is costlier than a typical 700R4 install, although the benefits are noteworthy. The paddle shifter adds cost for the ultimate package, which is certainly worth considering before you take the plunge. This is for the Shark owner who really wants to drive long distances and enjoy performance driving at multiple events and varied courses.
The 4L65E transmission fits in place of the Shark’s original Turbo-Hydramatic 400 with one minor modification. A Shiftworks modified transmission extension housing was required to drive the electronic speed sensor and the 1973’s mechanical speedometer cable. The PCM uses an electronic VSS to control idle speed, and it’s a must for an automatic transmission to shift the electronic transmission. Manual transmission–equipped projects do not absolutely require the electronic speed sensor, although it is recommended for the best idle control.
Your first obstacle is the transmission crossmember, regardless of whether you put together your own performance setup or use a kit in a box; the transmission crossmember most likely requires modification or replacement.
The 1968–1979 factory-equipped manual transmission Sharks have nonremovable transmission crossmembers, making it very difficult to install the longer 5- and 6-speed gearboxes. All automatic transmission–equipped Sharks have removable crossmembers. The majority of aftermarket manual transmissions can be installed without cutting or modifying the transmission crossmember. However, in order to install the transmission, the engine must be removed or you need to unbolt it from the motor mounts and move it forward on the frame so you have adequate room to install the transmission.
If you decide to leave the transmission crossmember welded in place, you will have difficulty servicing the clutch because there is not much clearance between the clutch and the crossmember. The smart way is to remove the crossmember; it makes the install and future servicing easier. This is one thing that I have done numerous times over the years: removing the crossmember and making it look like a factory removable automatic transmission–equipped frame.
Transmission Fluid Tips
Frequent fluid changes and minimum annual checks are recommended if you are a street/strip warrior. Always check the pan for any clutch material that shows up as flakes of what appears to be paper. Placing a magnet in the pan also gives you an idea if any needle bearings are coming out of a planet before catastrophic damage occurs. Check the magnet carefully at least annually for large metal pieces.
The pan and internal transmission pieces are eventually coated with a black film, which is normal; do not be alarmed unless the color turns brown and the film is not easily removed. The discoloration is telling you that the fluid is burning, clutch plates are slipping, or the cooler is not adequate. When the clutch plates are failing you usually find other debris in the pan (clutch plate material).
Always use top-quality fluid designed for your application. Some transmission parts suppliers recommend a certain designation, but the majority recommend Dexron IV. Never overfill the unit because the fluid becomes aerated. Aerated fluid causes pressure fluctuations and clutch damage. Installing an additional transmission fluid cooler is also an excellent idea.
Do not use old cooler lines that have been sitting around open unless they can be thoroughly cleaned. Cleaning the internals of any steel line is tough in most cases; the smart money is on using new lines. Rinse out the new lines and then blow them out, making sure no debris has found its way into the lines.
Written by Chris Petris and Posted with Permission of CarTechBooks