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| This is the Heavy Duty reverse piston retaining plate and springs we use on our race transmissions. The stiffer retainer and springs make the release of reverse more consistent and reliable. The reverse piston and seals are also shown. |
When I checked the reverse clutch pack clearance on this transmission during disassembly it had .055” clearance with 5 frictions and 7 steels. I prefer .080” to .100” so it will not drag when it is released. I measured the “stack height” of the steels and frictions of the clutch pack I just removed, it was 1.085”. To get the clearance I wanted I needed a “stack height” of 1.060” to 1.040”. I ended up at 1.045” after using 6 new frictions and 6 new steels and having .050” cut off the
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| The reverse piston and retainer in position in press to have snap ring installed. This will finalize the installation of the reverse piston. All we do now is plug in an airline and give it an air check to make sure the seals are in place. |
face of the piston in a small lathe.
Note: When assembling the Reverse clutch pack start with a steel against the piston and alternate them. You can have either a steel or a friction as the last piece into the reverse clutch pack. If it is a friction just sand the thick retainer on a flat surface to make sure it is flat and free of any nicks. After getting the clutch pack into the case and the large snap ring on measure the reverse clutch pack through the access hole in the bottom of the case to make sure it is the way you wanted it.
The Planetary Gear Assembly.
I will not go into the rebuilding process of a planetary gear assembly. They are rebuildable and are also available from many different aftermarket companies. There are basically two OEM planetaries to choose from.
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The 1.82 is a light-duty gear-set that is best suited for non-transbrake equipped transmissions or light weight cars (under 2400) pounds with less that 500 H.P. TCI and BTE sell some reinforced 1.82 planetaries but I do not recommend them for serious bracket racing.
The 1.76 is probably the most popular OEM transmission part ever made. This gear set has evolved over the last 10 years and can now be purchased from aftermarket companies, TCI for example, in all forms of durability. From stock carriers with hardened gears and pins to complete assemblies made from special steel alloys. Still one of the most popular planetary assemblies, the 1.76 is available from aftermarket suppliers in a price range of $400.00 to over $1,000.00 depending on the durability your combination requires.
The next generation of planetary assemblies are the straight-cut gear assemblies. The straight cut gears offer increased durability and a slightly different selection in gear rations. The most popular straight-cut planetary is the 1.80 ratio. It has proven itself over the last five years or so to be able to withstand the abuse dished out by 1,000 horsepower for several seasons. It is my personal choice and we have them in both transmissions in our dragsters. Costs range from $995.00 to $1,000.00 depending on manufacturer. From the 1.80 straight cut there have been some other ratios made available, the 1.64 is
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| This is the popular 1.80 straight cut planetary assembly. This one is the “shorty version” for dragsters. These planetaries come with one and two year warranties depending on the manufacturer. |
gaining popularity as it reduces the torque multiplication on the start line and helps the big horsepower cars to get more consistent traction. The jury is still out on durability but we are going to try one on the 950 horsepower “Project 4-Link” dragster this summer.
The “Power glide Handbook” goes into great detail on planetary assemblies and rebuilding them. If that is your interest I recommend you get a copy of that book.
High Gear (Direct) Clutch Assembly.
This part of the transmission is always undergoing constant development and upgrades. Primarily this evolution on high gear is because of the popularity of more and more horsepower in bracket racing and Super class racing. The stock high gear drum can still offer reliable service to all but a few Powerglide users.
