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Hello everyone,

I am going through my T56 which is out of a 2000 Camaro. I bought the transmission used about 5 years ago and 6th gear has always required some finesse to engage. A month ago I lost 6th completely and decided to pull it apart.

The keys in the synchronizer were all broke and attached to the magnets in the case.

I have a few rebuild kits picked out that come with upgraded billet keys and the 3-4 steel shift fork since I do occasionally beat on it and the car makes around 450whp.
thegearbox
txdrivetrain
hawksmotorsports

I believe someone was in this transmission before since the shift forks have bronze pads on them already and from what I have read they would all by a black nylon material stock.

While pulling the transmission apart I noticed that the bearing which rides on the mainshaft (42) goes on and off without any effort. The main shaft itself looks great but the inside of the bearing looks weird like it got hot and was spinning (pic attached).
Can anyone get the diameter on the shaft so I can mic it to confirm its good? I have a tremec rebuild manual but there are no specs for shaft tolerance in this location.
Also confirm if the bearing should be pressed on. I was able to persuade it off with a dead blow and minimal effort and now it just drops back on with no effort.

Secondly, the 2 races for the input shaft and counter shaft which are installed in the front adapter easily rotate. Again this might be normal but I have never rebuilt a T56 before so I want to confirm.

Other than these few issues everything seems to be in great condition (minus the 5-6 synchronizer assembly).

Can someone confirm these couple questions before I go and order a bunch or parts?

I was going to replace all the bearings but they all look great except for the one I mentioned above and even in Tremec's manual they mention for certain bearings not to replace them unless they show signs that they are damaged.

There are also a few snap rings which Tremec recommends to replace which I also will be doing.

Here is a link to the online manual which has a parts diagram

Thanks!
Shane
 

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The bearing on the main shaft is a press fit. If the shaft looks ok get a new bearing and press it on.I don’t have a shaft to measure. The races in the front cover are not a press fit, they just fall in,making it easier to change the endplay shims.
 

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All the above is correct. You can look up the bearing online via the number on the one you have. Tremec doesn't make bearings. It'll list the inside diameter in MM. Its a firm press fit so that will get you started. I also do not have a Camaro mainshaft, or a bearing to measure for you.

Breaking the keys comes from trying to shift the transmission faster than it can. The big problem is the main shift rail is too small in diameter, it "humps up" in the middle. Bronze fork pads are a mixed bag, most of the ones I see arent hard enough and theyre worn through in the middle pretty often. Its a darned if you do, darned if you dont scenario. The bronze is more capable in a shift-collision scenario, but wears through in daily driving; the black plastic is more long lived on the daily but less capable in racing. The best answer was a very high end plastic called Vespel. Some Vipers and SRT10 trucks had these. Theyre grey/green in color if you can find them.
The OEM iron fork is TNEC0843. You may already have it. It showed up first in the Viper, and if your box was rebuilt, it might already have it. I see no need at all for you to "upgrade" to an aftermarket fork if you have a TNEC0843 in good condition, other than current availability.
All the usual suspects you listed Shane, but I'll also throw Bob @ Hanlon Motorsports and Guffey @ RPM in Indy.

Been awhile Shane

Nate Huxtable @ Auto Gear (Syracuse NY)
 

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Discussion Starter · #4 ·
All the above is correct. You can look up the bearing online via the number on the one you have. Tremec doesn't make bearings. It'll list the inside diameter in MM. Its a firm press fit so that will get you started. I also do not have a Camaro mainshaft, or a bearing to measure for you.

Breaking the keys comes from trying to shift the transmission faster than it can. The big problem is the main shift rail is too small in diameter, it "humps up" in the middle. Bronze fork pads are a mixed bag, most of the ones I see arent hard enough and theyre worn through in the middle pretty often. Its a darned if you do, darned if you dont scenario. The bronze is more capable in a shift-collision scenario, but wears through in daily driving; the black plastic is more long lived on the daily but less capable in racing. The best answer was a very high end plastic called Vespel. Some Vipers and SRT10 trucks had these. Theyre grey/green in color if you can find them.
The OEM iron fork is TNEC0843. You may already have it. It showed up first in the Viper, and if your box was rebuilt, it might already have it. I see no need at all for you to "upgrade" to an aftermarket fork if you have a TNEC0843 in good condition, other than current availability.
All the usual suspects you listed Shane, but I'll also throw Bob @ Hanlon Motorsports and Guffey @ RPM in Indy.

Been awhile Shane

Nate Huxtable @ Auto Gear (Syracuse NY)
Thank you for the info!

I have spoken with 2 local transmission shops and they both said similar things about the bronze shift pads but it is what is being provided in the couple "stage 2" kits that I have found so would prefer to use what is provided and not mix and match.

I did some digging for those vespel pads and they are not cheap.....

This unit definitely has a stock aluminum shift fork.

I measured the main shaft and it was right about at 1.500-1.501" According to different sources online the Timken bearing (25572) is supposed to be 1.5000" so I really hope the main shaft does not need to be repaired. I am going to call a few places tomorrow and see if I can get a definite on the dimension. I believe TXdrivetrain can weld up the shaft and regrind it if needed.
 

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From the looks of the bearing, it appears worn, and if it was spinning on the shaft there is a good chance it wore some too.......but you should be able to tell visually if that happened. I would order a replacement bearing no matter what and see how it fits. Then it either fits properly or you need to do something to the shaft. Replace the shaft.....or ******* it with some punch marks and some red locktite. No, thats not a best solution, but if your new bearing isn't tight on the shaft, you have to create some interference/tightness on the existing shaft, or replace it.
There are industrial ways to change shaft size, but they would be more expensive than a new shaft. (The stars omitted the word "red-nec* . I consider myself to be one of those, so don't know when that became unspeakable..........I'm proud of it myself. I consider it a compliment. The ability to come up with a non-traditional solution based on the unique application of technology. My license plate on my truck contains the famous "Last words of a RN" Hey Bubba............Whachis :giggle:



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Hopefully this may help some.
 

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Man I haven't seen the name Joe Hunneycutt in a LONG time. This man was supremely talented mechanically; day to day operations kinda killed it for him.

I disagree with some of the opinions in the article expressed as facts; from a gearbox design standpoint. The "paper" lined ring is more of a cloth-backed friction material than literal paper. They worked fine for the design requirement (350hp street car) and last a lot longer than the compressed carbon (not what people think of when they hear "carbon fiber" ) which will "take a set" and become much less effective.

The newer 6-speed the so-called T56 magnum (model is actually a TR-6060 or TR-6070) went through several iterations of synchros, settling in on a ZF-style bronze composite ring system.

Shane! I still owe you a hockey game and a few beers man
 

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Man I haven't seen the name Joe Hunneycutt in a LONG time. This man was supremely talented mechanically; day to day operations kinda killed it for him.

I disagree with some of the opinions in the article expressed as facts; from a gearbox design standpoint. The "paper" lined ring is more of a cloth-backed friction material than literal paper. They worked fine for the design requirement (350hp street car) and last a lot longer than the compressed carbon (not what people think of when they hear "carbon fiber" ) which will "take a set" and become much less effective.

The newer 6-speed the so-called T56 magnum (model is actually a TR-6060 or TR-6070) went through several iterations of synchros, settling in on a ZF-style bronze composite ring system.

Shane! I still owe you a hockey game and a few beers man
I had that saved and thought it might be helpful. If you have any tips or disagree with anything in the article....or anything I said, point it out. I always try to post accurate (from my viewpoint :)) info. If anything is incorrect or you know a better way, correct me. To me its all about getting correct info when you can. I usually know just enough to be dangerous.......
 
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