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post #1 of 3 (permalink) Old 11-15-2012, 02:21 PM Thread Starter
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T56 Rebuild advice

So if anyone has followed my saga on this transmission you all know, it finally came to an end. :-( After changing the fluid, then the slave cylinder, then the master cylinder, the car locked itself into 4th gear and had to be towed home. It's still stuck in 4th gear and at this point, I know I'm stuck needing to get it rebuilt.

I was looking at using Texas Drivetrain Performance (Texas Drivetrain Performance) and doing their stage 2 build, and probably requesting that they go ahead and replace all of the gears, etc. just to be safe. My brother suggested that I should request straight-cut gears instead of angle cut. As he explained it, angle-cut gears are quieter, and straight-cut gears create a slight whine, but the straight-cut gears are a bit more forgiving of rough handling than angle-cut. I could use a bit of forgiveness from the car....

Is he right? Also, is there anything else that I should request done to the transmission while it's out and getting rebuilt?

Also, for pure curiosity, is it better to send the tranny off for rebuild or to do it myself at home?

1995 Z28, 6 speed, Boosted and Supercharged. Lots of problems. No, the car isn't a lemon, the driver is.

Last edited by indigorhages; 11-15-2012 at 02:39 PM.
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post #2 of 3 (permalink) Old 11-20-2012, 03:10 PM
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Location: McDonough, GA
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Unless there's evidence of excessive wear or damage, don't replace the gears. Replacing undamaged gears gets expensive quick. The only exception is 2nd gear, which is commonly upgraded to the Viper and newer F-body design with longer clutch teeth.

Straight cut gears are overkill for a street driven car, plus there will be a noticeable whine. Unless you will be using the car for strictly racing, there's no need for it. The stock gears are easily good for well over 500hp, and can be treated to go even higher (cryo, micronite, REM, etc.). For extreme street use, there are kits available that utilize a lower angle helical cut gears (22 deg., I believe), which are stronger, thicker, and are still pretty quiet, that can take you to the 1000hp mark and beyond. But be prepared to spend $3500 for 1-4 gears alone, parts only.

You can do the work yourself with only a few special tools and it is a very rewarding experience. If you are mechanically inclined and enjoy that kind of work, go for it. You'll save some money and learn a lot on the way.

1995 Firehawk #528 resto-mod underway

Planned 383 rebuild: 195cc competition LT4 AFR heads, custom cam grind (still debating specs), 6" or 5.85" rods, forged internals

Upgraded T56: Viper mainshaft and 2nd gear, steel 3/4 shift fork, Billet keys 1-4, bronze shifter cup, internals Cryo'd and REM'd
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post #3 of 3 (permalink) Old 12-17-2012, 10:55 PM
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I rebuilt mine myself. I would not bother changing gears unless your transmission has over 160k miles or you plan on putting crazy power down..

If I were you I would go with just a basic OEM rebuild, with the small basic upgrades to make for a solid street driven transmission. Billet synchro keys, new blocker rings, steel 3-4 shift fork. (aluminum ones tend to wear out, especially on higher powered vehicles. That was the failure in mine)

I'm willing to almost guarantee your car is stuck in fourth because the factory synchronizer keys broke/snapped.. it's happened on both my T56's and caused them to lock into a single gear. The stock stamped ones are crap. they cause a synchro to stay stuck in a certain position.

I would recommend giving it a shot yourself. It's really not all too difficult of a procedure. There's a few how-to's online.

1994 Pontiac Trans Am "Boosted Turd"

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