T56 Rebuild Underway!

Hello all,

I've seen a few posts over the years about people rebuilding their T56 transmissions that have caught my interest. Since my reverse synchro gave up on me a few weeks ago, I somehow convinced myself it would be a good thing to try. Soooo...I made a little roadtrip down to D&D today to get the ball rolling. I came home with a billet 3-4 shift fork, a synchro rebuild kit, a complete bearing kit, reverse synchro keys, springs and retainer (not included in kit), input and output shaft seals and a shim kit. Even more fun, I convinced a machinist that worked for me during the summer to make me an endplay tool for FREE! I've got the transmission mostly ready to come out and expect to be at the rebuild tomorrow morning (and yes, I will document every step). Think I can do it in a day? I've never tackled a T56 before, but I'm feeling courageous.

For now, here are some pictures of the parts I picked up today:

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_31_full.jpg

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_33_full.jpg
http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_34_full.jpg
http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_35_full.jpg
http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_36_full.jpg
http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_37_full.jpg
http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_38_full.jpg

I may be doing the same in the future. Good luck and keep us informed. Ken

it can easily be done in one day. they sell great manuals for these trans that have specs and great pics for less than $30. if you have never done one it might not be a bad idea

Do you want to sell the endplay tool when you are done?

JD

I'm going to hang on to the endplay tool for now...I've got a few more transmissions to do if this one goes successfully. It's honestly a pretty easy tool to machine though. Any machine shop should be able to make it for you pretty cheaply. When I talked to the guys at D&D, they said they don't even use the endplay tool anymore...they can just set the shims by feel.

As far as the rebuild manual goes, it's available for download on D&D's website for free. It seems to be very thorough. I'm excited to get started at this project.

Oh no! Disaster Strikes! After dismantling the transmission, the synchro teeth on my reverse gear are all chewed up. Anyone know where I could get a new reverse gear before the new year? I go back to school on the 3rd...

Also, I wouldn't mind a second opinion. It looks to me like the leading edges of the synchro teeth are too rounded over. What do you think?

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_40_full.jpg

Well, I've completely disassembled my transmission now and here is my final diagnosis (not exactly what I was expecting to find):

1. Isolator cup is loose in rear offset lever. I have a new isolator cup. If it does not fit tightly, I will need a new rear offset lever assembly.

2. Reverse gear synchro teeth are chewed off/rounded over on leading edge. This explains the constant popping out of reverse/grinding shifting into reverse. I will need to replace the reverse gear.

3. Reverse gear synchro hub teeth are also chewed away/rounded over on leading edge. I will need to replace the reverse synchro hub.

4. This one I didn't expect...several 5th gear synchro teeth are broken off. This might explain why I couldn't shift into fifth gear trying to pass on a few occasions. Fifth gear must be replaced. EDIT: It turns out my fifth gear synchronizer sleeve was also shot...which became yet another delay.

5. 1-2 synchro blocker ring teeth are worn out. Blocker rings, synchro keys and retainer springs must be replaced...these parts I actually have.

6. Bearing races in front adapter are scored. The associated bearings and races must be replaced...these parts I also have.

7. All shift fork pads are fairly well worn. I will replace the shift fork pads.

All in all, I'm pretty disappointed. I really wanted to have this transmission rebuilt and installed by the end of Christmas day. Due to lack of replacement parts, I can't continue with the rebuild until after the holiday. I find it somewhat amusing that most of the typical rebuild parts that I bought aren't even necessary...the majority of the synchros and bearings are fine. I will replace everything anyhow just for peace of mind. Tomorrow I'll go at all the parts with solvent and compressed air, and assemble up until I need 5th gear.

Merry Christmas to everyone!

What is D&D's site?

http://www.ddperformance.com/

Well folks, I'm finally finished this project!

To be brief with the pictures, the transmission went from this:

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_41_full.jpg

To this:

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_42_full.jpg

To, finally, this:

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_43_full.jpg

I found the actual rebuild rather interesting and have taken pictures of nearly every step. If anyone needs help with this chore/would like a picture, feel free to ask.

Obtaining the parts for the rebuild, on the other hand, was a phenominal hassle. Here are the issues I ran into:

1. I tried to purchase gears and synchros from Rockland Standard Gear. They had the parts in stock and their website clearly suggests that customers outside the US should pay with a credit card. However, when I called to order, a representative said that only bank wire transfers are accepted--impossible to do when banks are closed around Christmas time. I cannot recommend RSG based on my experience. AutoGear in Syracuse, NY provided excellent service and had my parts on my doorstep the next day.

2. D&D neglected to include several critical bearing/race combinations in my bearing kit and gave me a few parts that certainly don't belong in a T56.

Nonetheless, I'm thrilled to be finished and can't wait to get this (along with a new 12 bolt and aluminum driveshaft) in the car. If you can read, have a clean workspace and are willing to spend a few hundred dollars on some shop tools, this is a very doable project.

EDIT: If you wonder how I got the case so clean, I media blasted it. I first tried aluminum-safe solvents, but those just made a horrible mess. I discovered the case casting has way too much zinc content and the chemicals turned it black.

So how much did the initial parts list cost you? I have this fear of not being able to put one back together once I got it all apart. Did you need a press for anything?

So how much did the initial parts list cost you? I have this fear of not being able to put one back together once I got it all apart. Did you need a press for anything?

Brent,

Just put down the R/C controller! lol. I spent less than $500 for everything for my tranny (steel fork, billet sliders, synchro kit, and bearing kit.) The manual states that you shouldn't replace the bearings at all unless they are bad. I didn't know this and purchased the bearing kit and ended up not using it. BTW I got all my parts from www.thegearbox.org.

Later,
Shaun

My transmission was a bit more of an investment due to the amount of damage. I ended up buying a synchronizer rebuild kit, a bearing kit, a billet 3-4 fork, reverse gear, the reverse synchro, fifth gear, the 5-6 synchro, a urethane mount, and a new inspection cover. The total is somewhere around $1200--still far cheaper than buying a new transmission and I know it's done right. I used a 20 ton shop press and a home made gear puller.

As far as not replacing the bearings, there's no way I was going to go to all the trouble of tearing down the transmission and not replace them. I'm the type of person that likes that piece of mind.

Just an update: I've put some miles on the transmission now and it's absolutely beautiful! Definitely a rewarding project.

i would like to see as many pics as you have would you mind posting them or emailing them to me? rjkutz@kag-1.net

thank you.

Sure thing. I took a ton of pictures. There are a few that might be of particular interest to you, such as the ghetto gear puller I made to pull 2nd gear and the way I rigged up my dial indicator to measure the shaft endplay. Do you have any space restrictions on your email account?

Thanks for sharing the info buddy. Additionally, there is a good article on rebuilding T-56's in the latest GMHTP mag. Or maybe it was in a different one? I can't remember now, I've got so many subscriptions. :D

It was GMHTP. I saw it on the news stand last week and thought "where the heck was this two months ago?!" I swear I took some of the exact same pictures! The article is definitely worth the read for anyone considering a DIY rebuild.

Hello, I have a few questions for you restoroc.

1) I am going to attempt the rebuild, do I need a hydraulic press if I am not replacing any bearings? Is there a way to rebuild this without one?

2) Can you please send any pictures to Marc1130@aol.com

3) If I am not replacing the bearings do I need to readjust the preload? (I don't have the special tool)

You rock brother.. I am going to attempt the same thing with increased confidence this summer after seeing your results. A quality job through and through! Thanks for documenting it for us. Sticky worthy IMO.

marc1130: As long as you don't change any of the bearings or races, you don't need to check the bearing preload. The service manual stresses that you shouldn't even replace bearings unless they need it. Having said that, replacing all the bearings was an easy job. Any machine shop should be able to make the tool you need for less than an hour's labour cost. A good dial indicator is also worth having. Digging into the transmission requires a fair amount of effort to being with. Bearings are wear parts with finite service lives and how much is peace of mind worth to you? As a caution, if you can tug on the input shaft and feel any back and forth play in it, the transmission case has stretched and the bearings DO need to be reshimmed.

As for tools, if you're not doing the bearings, you won't need a press. You can get by with a good set of snap ring pliers, a dead blow hammer and drift pin and some long-reach gear puller. I made the one pictured below out of a cheap all-purpose gear puller and some steel bar.

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_50_full.jpg

In addition, here are some shots of what you'll need to set endplay if you attempt it. The endplay tool sticking out of the case is merely a glorified handled to wiggle the countershaft. I found I could make most of the measurements with my magnetic dial indicator base stuck to the steel inspection cover on the transmission.

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_49_full.jpg

http://memimage.cardomain.net/member_images/11/web/2255000-2255999/2255863_51_full.jpg


Several months later, I'm definitely pleased with my efforts. This transmission is smooth as butter! Those wanting pictures, I'll put something together and send it out over the weekend.

Mine's apart on the bench right now! ;)

It's getting a new 2nd gear (the teeth on the gear that the synchro slides over are shot and/or missing!? :eek: ) as well as the whole 1/2 synchro assembly (again, it's completely chewed up inside the hub).

I'll be replacing all the synchro rings for all the gears while I'm in there, AND I need a new reverse synchro hub, as it's slightly chewed up inside (although the synchro ring is suprisingly NOT bad? :shrug: ).

Looking forward to finally having a smooth shifting T56 in my car :yes:. Since I put this tranny in used last summer, it never worked right from day one ... can't wait to row through the gears with ease, instead of a fight! :D

Your issues sound very similar to mine, Pete. Strangely enough, my reverse blocker ring was fine, but the rest of the synchro assembly was demolished. When you get it all back together, you'll be amazed at what you've been putting up with (I bought the car with the bad transmission and just thought it was supposed to be that way).

Yeah, sounds like you were suffering a lot of the same problems too?! :D

Weird how the reverse hub goes like that, eh? :think: I tell ya, it would infuriate me sitting in a parking lot, trying to back into a parking space, and fighting with 2 hands on the shifter, trying to get into reverse :mad:. I see now why there was a problem!? :rolleyes:

I'll try to post a picture at some point of 2nd gear ..... you gotta see how many of those small "teeth" are missing ... it's unbelievable!! (actually, amazing it even went into gear at all! :shrug: ).

Also, before the car goes back on the road, I'm swapping out the 3.23's for a set of Motive 3.90's ..... it's going to be a whole new animal!! :bow: :D

great thread. can you send me the pics at bbachmann@atitelemetry.com , thanks.

I am considering a rebuild myself. If you could send me the pictures too, it would be awsome!
Mdenz3@hotmail.com