vettekidc5

I had a guy rebuild my M6 about 2 months ago and he screwed it up twice.. He left the inner hub to the 5th gear synchro out and didnt know it. Didnt catch it the 2nd time either.

I now have the works, Carbon fiber blockers, billet keys, steel 3/4 fork, Bronze slider pads etc.

I wound up tearing into it myself Its not too scary But be careful guys with that cluster gear Numb had trouble pulling out. Its 200 bucks!

Max01GreenMachine

No snag, harbor freight tools. 12 ton with plenty of working distance on sale now $139.99, picked one up tonight.

Numb

The latest installment:

While I'm waiting on tranny parts to arrive, I decided to take apart the torque tube to check the condition of the couplers. Before the tranny died, I had been getting a slight vibration in the drivetrain at anything above 2000 rpm. I have been operating under the assumption that it was the flywheel, since I didn't have it balanced with the clutch last time around. One thing I noticed before I took the torque tube apart is when you spin it, there is a noticeable amount of runout on the input shaft. I searched the forums, and apparently that's common, because it's attached to a rubber coupler. Supposedly, the pilot bearing keeps everything lined up, but it still doesn't give me a warm fuzzy fealing.

What everyone says is true... the snap ring is a PITA to take off... made my regular set of Craftsman snap ring pliers cry. Only thing I could find was a 9" set at Harbor Freight... cheap crap, but it did the job.



With the snap ring off, you have to tap the shaft out from the clutch side... I used a block of wood and mini-sledge on the input shaft... popped right out. Inside, I found some black shavings that look to be from the snubber contacting the housing:



You can see where the snubber has rubbed the inside of the tube:



The couplers look to be in suprisingly good shape, although there is some wear on the inside of the housing near the front coupler... the coupler doesn't look like it has been rubbed, but I don't know how else those marks got there. Buying a used car is like marrying a hooker... you just don't know what she's been up to.

Front coupler:


Rear coupler:


Inside the tube, front side:


So now I'm not sure what to think. Maybe the snubber is rubbing because the couplers are getting old and flexing too much? Maybe the car was over-revved by a past owner? Maybe the vibration problem is due to an unbalanced drive shaft? I'm thinking I need to check the balance of both the clutch/flywheel assembly and the driveshaft. The first one is easy, but there aren't many places that are setup to balance these driveshafts.

Dan_the_C5_Man

I wouldn't get too hung up on the rubber guide hitting the inside of the tube - that's more or less its purpose. The aluminum prop shaft will flex at high RPM; if that doesn't sound good to you then an LG carbon fiber shaft will fix it, although that's a lot of cash to solve a "non-issue". I would take the couplers off and carefully inspect both sides for cracks - that is the tale-tell sign they are beginning to break down. IF you can find the proper replacement items (I say IF because now it seems the BMW couplers we all thought were the answer to un-obtainable parts are softer than stock and not holding up well), I would certainly replace them as a maintenance item. Actually when I get to the point of needing to do mine I will run one aluminum and one stock coupler.

Great post BTW..

Numb

I talked to a local drive shaft shop today, and they said they can balance the drive shaft, but just the center portion - they can't do it with the input and output sections attached. Seems like that defeats the purpose. I'd like the reassurance that the shaft is properly balanced, but is it of any value if you can't test the whole thing?

Max01GreenMachine

I've taken apart four torque tubes and never have I seen an out of balance drive shaft. The only time I've seen vibrations caused is when the bearings (input shaft bearing mostly) have play or the input shaft is not true.

I rebuilt my torque tube with new bearings, two LG aluminum couplers, slapped it all back together with blue loctite and proper torque specs. It is solid!!! It took all the abuse that my transmission output shaft couldn't handle. After I took it apart this last time it spins straight as an arrow, like it was brand new, right from down unda. (They are built in Australia).

waddisme

I wouldn't mind buying a used trans and trying this myself. I am sure that will be the next thing to break in my car. I have done new rad, repl most of sc components, now just breaking in new motor, and already repl clutch. Are there enough how-tos around to DIY? It does seem pretty complicated, but it would be a great learning experience. Can you DIY with no trans experience?

Numb

I'm not sure. I had help from someone who really knew their stuff the first couple times I rebuilt a transmission. There is a wealth of information out there, and the T56 manual is a good resource, but I'd say it's still pretty brave to dive in solo. It would certainly be a good learning experience!

tricep

Its kinda cool that your squat cage is truly "multi-purpose"...




Looks a lot like my gym.

Max01GreenMachine

Here is how my rebuild is going. I took everything apart today to get ready to assemble the new mainshaft. I'm waiting for my new clips and seals in the mail But after today I'm going to need a new tapered bearing (22) and race (11) as I pulled it off wrong.

All in a days work. Check out the old shaft and new.


Look familiar....thats how it starts


Bearing seperator pressing off 2nd gear and syncro


Pressing off 3rd with syncro


Later,
Max

SteveDoten

Max, that snubber wear mark on the TT is normal, I haven't seen one w/out it, how it's only on part of the snubber? I do not know, but's it's common

dbirdz06

Man this is some awesome info. I've thought about tearing into mine to fix a few things that are bugging me.

Max, have any updates?

Blue Angel

Nice work, too bad about the screwing for your last rebuild.

I rebuilt my '02Z tranny three years ago, had no issues getting my 5/6 off, came off easy (just lucky I guess). Did all the same upgrades, steel 3/4 fork, bronze pads on ALL forks, billet keys on ALL sliders, also installed a new 1/2 slider/hub assembly (was having issues going into 1st at rest, fixed the problem temporarily, but now it's back again).

Rebuilding a tranny is no problem if you have some basic mechanical ability and the right tools. The manual helps, too, since there are so many sub-assemblies to keep track of. Always good to see someone doing their own work.

After all the upgrades the tranny felt "tighter", and I felt I got better feedback while shifting (probably due to the bronze fork pads). I had a Hurst shifter at the time, so there was no rubber between me and the tranny. It felt nice, shifted well, I was pleased.

One note: when you're putting the tranny back together, make sure the pin in the shifter shaft goes in and stays in the right place as you lower everything into the front cover... that little pin is what couples the shifter shaft to the centering spring. Without it the shifter won't center properly!

Good luck, and GREAT work!

ajg1915

I would check the bearing on the TT as that is what keeps it all lined up.

I'm not sure what kind of power you're making, but the TT's are known for flexing (Whipping) under certain conditions.

Nice work and pictures.

lucky131969

The snubber is there to protect the driveshaft. The fact that it has rubbed might suggest that the the previous owner had downshifted at high speed(or at least higher the recommended). So, if that was the case, it did exactly what is was suppose to do.

Numb

Well, a lot of time has past, and I have gradually accumulated all the parts I need to put the tranny back together.

Last weekend, I pressed apart the main shaft and replaced the worn 3-4 synchro. While I was in there, I also swapped in the billet synchro keys on 3-4. I learned something new, and that is the Corvette 1-2 synchro comes with billet keys from the factory. Camera was dead... didn't get any pics of this step.

I fragged the bearing on the mainshaft while pressing off the 3-4 synchro... I don't think there is any way to save it. Here is the new bearing:


And pressed back on:


Closeup of how the 4th gear input shaft mates up to the main shaft:


Since I had to order the new bearing anyway, I went ahead and picked up billet synchro keys for 5-6, as well as bronze pads for 5-6 and reverse. I want the tranny to stay together this time!

Pressing the countershaft extension apart to get to the 5-6 synchro:


Countershaft extension disassembled:


Billet 5-6 keys installed:


Bronze pads installed on (left to right): reverse, 5-6, 3-4, 1-2 forks:


Comparison between the steel 3-4 fork and the stock aluminum 3-4 fork:


That's it for tonight. All the shafts are assembed, and the next step is to clean up the cases and put things back together. Planning on knocking that out this weekend.

fst85vtt

LBZ51girl

This is one of my favorite post!!! Keep up the GREAT work and posting excellent pictures!

Bill C

Nver2loud

I actually talked to Kevin at the gearbox today and he let me know the corvette 1-2 keys werent billet, even though they are solid and may look like billet they are powdered metal, i ordered billet 1-2 keys and i thought they looked very similar but are a bit different.

Numb

Hmm... D&D Performance (the other T56 parts supplier) was who told me that the Corvette 1-2 keys were already billet. If they're still accessible, can you take pictures of both the stock and billet 1-2 keys? I'm curious to see how they compare.