my 89 bird has a t5 that i got out of an 83 camaro (cast in 82!) the thing is a little tired, i believe the counter shaft bearing cap?? dunno the official name but if you look at the front of the tranny there is a little round cap just under the input shaft bearing retainer.. anyways, that thing leaks out all the gear oil in the tranny. No gear oil= hard shifts, and whining.
I also have an 84 Z28 with a t5, however, it has a problem, 3rd and 4th gear are non existant. It feels like theres nothing there, if i move the shifter to the middle position it will flop back and forth between third and fourth as if nothing is moving inside. I looked at an exploded view of the tranny and Im guessing since there is no grinding and it feels like nothing is there, that the 3rd and 4th shift fork is somehow damaged or disconnected. Does this sound like the case?
Id like to swap transmissions between the two cars if i can repair the one in the 84. If im not mistaken, the 84 t5's no longer use gear oil but use ATF. It would seem to me this would be the better transmission being that the lube isnt so heavy (free up a few hp). I understand also that t5s recieved better features every year to make them stronger etc.
The t5 in my 89 stinks, it requires too much effort to shift quickly and is a real detriment to my ET's since i cant powershift it.
Say i remove the t5 from my 84, how can i inspect the syncros to see if they are in good or bad condition? Is changing the syncros a difficult task? (will i need special tools?)
what could be the cause of the third/fourth problem.. what holds the 3/4 shift fork in place?
any information would be appreciated. Id just like a tranny i can shift quickly without it fighting me

 

THe thing yuo see in the front of the case is the actual bearing itself. The reason it leaks is because the case is stretched, which is of course unrepairable. So, that one is ready to move on to the big transmission parts shelf in the sky. Plus, if it has been run dry, the teeth on the clutch gear and teh counter gear where they meet are almost certainly toast. So those parts most likely can stay with the case.

I think you dignossis of the shift fork thing is probably dead-on. That sounds to me like the fork is simply broken. There's no way for it to become disconnetced. You can take the whole cover off the one with the stretched case and put it on that one, and maybe make one good one out of the 2.

Use gear lube. GM went through several swaps back and forth between the 2 lubes, without there being the slightest internal difference. There are no "incremental" improvements whatsoever, all the parts are absolutely identical, so don't base your fluid selection or parts choice on their age. The real deal is: the "World Class" version of the trans has composition clutches on the 1st and 2nd synchros (why 1st and not 3rd is beyond me) and therefore should have ATF. The rev 1 box has brass synchros so it doesn't require ATF; synthetic gear lube will help it survive longer. If you can avoid any shock loading of the trans at all you can use ATF in any of them. I don't think that's wise if you're going to pound on it.

Power shifting is the cause of death. The shock loading is what spreads the case. I would avoid doing that if at all possible: shift as fast as you can, but don't let the engine speed flare up between gears. That, and dumping the clutch at the line, destroy the case in a hurry.

The T-5 (both rev 1 and "WC" rev 2) are the quickest-shifting trans I have ever had. They make a T-10 or a Muncie feel like a dump truck by comparison. You should be able to get one to feel slick. One thing that will help is using a relatively light clutch disc, since that's where most of the enrgy the synchros have to deal with is coming from. They have to slow down the clutch disc during the shift as well as the gears. I don't know of any one kind that's any lighter than any other, but when you're buying clutches, research it a bit. I run the CF DF which si at least no heavier than any other I've had. In fact, a 4-speed might shift a whole lot better if it had a 10.4" clutch instead of the 11"-ers I've always used with them.

------------------
"So many Mustangs, so little time..."
ICON Motorsports

 

thats good info RB, thanks a whole lot
my birds tranny is definately not slick shifting. My first car, an 84 mazda 4cyl pickup truck felt like the onlything i was working against was the weight of the 1 lb stick, i could shift that with blazing speed
my t5 is tricky, to shift fast you need to muscle the stick into each gear, but, too fast and it will grind badly
with only using the 1 and 2 shift of the other car as an indication, it seems to shift more easily than the one currently in my car.. that might also have to do with the fact it has FLUID in it.

Just to be sure, when i open it up, how can I inspect the syncros? what should they look like.. ive never seen inside a tranny like this but is it anything like an engine bearing that turns into a brassy color when worn? Also, while i have it out, is changing the syncros easy enough to do to just do it for insurance?
I just wanna be sure im not swapping my junky tranny for an even junkier one

 

The synchros have teeth on the outside which should be sharp and on the inside there are grooves which should be sharp---these grap the chrome "cone" part of the respective gear to synchronize the speeds. The 4th gear synchro comes out after you remove the input shaft. THe others need to be removed after pressing the gear selectors off the mainshaft.
The best thing that ive found is to shim the trannys to proper spec with regards to the mainshaft and countershaft. Shim the mainshaft to 0.008-0.012" preload by placing shims under the bearing race in the input shaft retainer. I shim the counter shaft by using shims under the rear thrust bearing in the tailshaft housing. Try to get this down to 0.010-0.015". I bought 0.005" shims from McMaster Carr (any industrial supply Co will work, ie Grainger, MSC) which are 1.5" OD, 1" ID. You can only fit about 2-3 of these before the race wont seat properly. Make sure you use a new countershaft thrust washer too. When you have all the clearances right, it should shift well. Also, as far as I know, RB has broken and rebuilt more of these than anyone, and therefore gives good advice .

------------------
1984 L69, IROC look, tangerine orange
305 from 87 IROC, tossed peanut cam,
replaced with LT1 cam.
Uses gas as fast as i can pump it!

 

Here's what I did when my non-WC V8 T5 started leaking badly...I tore down a deceased V6 tranny to the bare case and refitted it with all the V8 components; I was replacing the countershaft at the time and figured while I had it totally apart, I would swap cases, theorizing that the V6 case hadn't been abused (or stretched) by nearly as much power as the V8 unit.
Next time the tranny is out of the car, I'm gonna swap the O/D gears to get a .63:1 ratio instead of the .73 it currently has.

Pete

------------------
Pete's Place
HiOutput Tech Page
83 SC
205+k mile LG4/5-speed
14.935@94.14

 

thats interesting pete.. good idea actually

I was wondering this.. if the cases are the main reason for failure because they stretch, why not have extra metal welded to the case?