Numb

So my transmission is broken (again)... stuck in 4th gear. This time around, I decided to do the rebuild myself... I've rebuilt other manual trannies... just not a T56. Couldn't be that hard, eh?

I pulled the tranny, and started the teardown... so far, the upper case and most of the 5th/6th/reverse stuff is out. I got stuck trying to pull off the 5-6 gear... that **** will not come off... killed my custom gear puller. I used 12ga cold rolled steel for the extensions... guess I need to use something stronger.

Pics!

Diff/tranny/torque tube/DTE brace:


Tranny


Custom tranny workbench


Upper case removed:


5-6 gear that won't come off:


Extended gear puller:


Useless!


The battle continues...

lucky131969

You might want to consider popping for the correct tools before you damage the gears.

Numb

The "correct tool" is a gear puller. There are a few super large gear pullers on the market, but they are outrageously expensive... much more than the cost of a replacement gear, and they aren't going to be any less likely to damage the gear than an extended one.

Seems I'm not the only one... here's a picture of the puller that Joe from T56 Rebuild (Sixspeeds Inc) uses in an article on GM High Tech Performance:

http://www.gmhightechperformance.com.../photo_05.html

lucky131969

While I've never disassembled a MM6, I have been present while it was done. There is a specific collar for the 5th speed gear. With any job, there are tools that are specifically made for a task. In this case, there is a specific puller/collar assembly for the disassembly of the MM6 (not ust any old "gear puller"). I know they're expensive....but that's the way it goes. Good luck

Mike94ZLT1

The stuff he is using is significantly thicker and stronger than what you are using. You have the right idea, but you are not using the correct material.

Numb

I just went and picked up some 3/16" steel stock at lunch... going to rework the puller tonight and try again.

Numb

Maybe the collar is a GM specific part? All I have for reference is the Tremec T56 service manual... if you look at page 13, they show the 5-6 gear being removed with a gear puller.

http://www.ttcautomotive.com/English...ice_Manual.pdf

I think it will work... just need to build the extensions out of something stronger.

motogib1

Wonder what the "pros" do. Perhaps they put some heat in the gear?

rubrhammer

Kudos for tackling the job yourself. I would say that even 3/16 is going to be on the light side but give it a try. Good luck and let us know how you make out.

Bill Curlee

This is a very informative post!!! Might try this one day. I would need to try on a scrap tranny first to get confident. Just so I would be familure with the procedure and R&R sequence. I have not found a scrap tranny yet! Im looking!

BC

lucky131969

It is GM specific. I looked in the service manual, and the collar is exactly what my buddy used.

lucky131969

Here you go:

http://www.flickr.com/photos/1545929...89830/sizes/o/

Numb

Update - the new and improved homemade extended gear puller worked like a champ... pulled the 5-6 gear straight off. After that, I was able to pull the main case off, and I immediately found the problem... broken 3-4 synchro key. What sucks is this is about 800 miles ago I paid a shop to upgrade this tranny to the same specs as RPM's level IV, including billet synchro keys, bronze fork pads, and a steel 3-4 shift fork. Looks like I got screwed... upon further inspection, NONE of those items are present. I'll have to press the shafts apart to find out if they even replaced the synchros.

Needless to say, I'm furious. I sent a message to the shop owner explaining the situation, and giving them an opportunity to make it right by refunding my money. Hopefully they'll do the right thing, and it won't have to escalate.

Here are the pics:

Improved gear puller:


Beefy!


Pulling the 5-6 gear:


5-6 gear removed:


Case removed:


1-2 shift fork w/ stock pads:


3-4 shift fork (NOT steel) w/ stock pads:


Part of a broken stock synchro key:

sublime1996525

Now you have me worried. I had the exact same problem. I took the tranny out myself, but the bronze pads, steel fork and billet keys and dropped them off to a tranny dealer and I now wonder if any of that was really installed!!!

I hope you are able to rectify the problem with the tranny company. Keep us informed about what happens.

Bill Curlee

WOW! Excellent work!!!!!!! How much did the self repair set you back? What was the total list of parts that were repalced?

Thanks for posting this excellent info!

BC

SuperSpeed

nice work! i have thought of doing this myself as well.

What are you doing to make it stronger? where did you get the parts?

lucky131969

That is one serious gear puller sir...

Numb

So far, it hasn't cost me anything but time... all I have done is tear it down. Once I get the shafts pulled apart, I will be able to inspect the synchro assemblies and see what needs to be replaced. I'm planning on upgrading the the parts that were supposed to be put in by the tranny shop last time... billet synchro keys, bronze fork pads, and a steel 3-4 shift fork. Other than that, I will replace all the snap rings and anything that looks worn out.

You can get all the parts from The Gear Box... I dunno if they're a forum vendor, so I won't link to their site, but you can google it.

Numb

I was starting to question even that... the 5-6 did NOT want to come off. I couldn't turn the puller with a 1/2" drive ratchet, so I brought out the 18" breaker bar... couldn't get more than a 1/4 turn out of it. I ended up having to use my earthquake impact wrench to break it loose - that is a LOT of pressure on the puller. Once it broke free, it pulled the rest of the way off easily.

Wear your safety glasses, kids!

Numb

Latest progress - I pulled the remaining pieces out of the case and got a chance to inspect everything.

The reverse gear and synchro assembly are trashed, which makes sense, because I had the transmission rebuilt in the first place because it was popping out of reverse. The reverse blocker ring looks brand new... I'm guessing the shop just tossed a new one in there and called it a day (they said they replaced the reverse gear, and charged me extra for it - doesn't look that way).

The engagement teeth on the 3/4 sleeve are pretty heavily worn... the 3-4 synchro assembly will have to be replaced. I'm going to have to press the main shaft apart anyway to replace the synchro keys. The rest of the blocker rings look to be in decent shape, but it's hard to say if they're new (should be less than a 1000 miles old)... I'll have to wait until the main shaft is apart to get a better look.

On to the pics...

Reverse gear:


Reverse synchro:


Other side of the reverse synchro - that's what it's supposed to look like:


Reverse blocker ring - looks new:


3-4 sleeve, worn teeth:


3-4 hub w/ broken synchro key:


Got my work cut out for me:


Stay tuned!