Well I got it off. Still not sure what it up. It had to be pryed off.

 

I have a 6th gear, 80MPH, 2100RPM vibration that is bad. Shift to 5th tad better. Shift to 4th gone. No vibes anywhere else. I have ruled out everything and I am convinced its the tranny. Gone through two DS's, both rebalanced twice, no poly mounts, angles are dead on, tires are balanced.

Searching I have found where the 5/6 driven cluter gear loses its tight fit on the mainshaft and will dance under load at high speed when in sixth gear. The mainshaft has to be repaired or replaced to make the fit tight again.

Can anyone confirm this?

 

Holy ****. I thought that 5/6 gear would never come off the mainshaft.
In the end I used two propane/butane mix blow torches at the same time all over it, with the vice to help hold everything in place, whilst using a big breaker bar on the 3-jaw puller. That's a lot of heat and force, but it's off, and smoking!

 

I killed my 5-6 gear trying to get it off. I wound up heating mine as well to get it off.

 

Both Tick and TDP have both told me that some of the 5/6 gears can be pulled off by hand on some rebuilds. I will be doing this soon.

 

Just pulled my 5/6 gear off very easily by hand. I hope this is the source of my vibes.

 

In some cases 5/6 driven gear does come off by hand.

When I press the loose ones back on, I use some Locktite 609 that's for Press Fit applications.

Don't know if it's the cure all, but should not hurt anything.

If 5/6 is loose on the main shaft, the gear can walk back on hard accel in 5th gear.

Usually you tear up the snap rings on 1/2 > 3/4 syncro's taking them off.
So you should always grab a snap ring kit. There usually around $20.

 

I got my 5/6 gear off by hand, but it had to be tapped back on wiht a long peace of pvc pipe and a rubber mallet, don't hit it hard you will f*ck up your bearings!

 

Valuable "do not do this" tip.
Do NOT press the 1/2 syncro on with the caged roller bearing in the 1st gear. I just did and slightly bent the cage and now its useless. I pressed the syncro on using the gear, without the bearing just fine.

 

I need someone how to remove the main shaft bearing i want to replaced

 

OK been a while since my rebuild, I replaced all the bearings myself, you should really invest in a press, or get e machine shop to do it for you, anyway.

As I recall the main shaft has two bearings one on the front and one on the back, the inner race for the front is in the input shaft and the inner race for the rear one is in the main case, so which one needs to be replaced or do both of them need to be?

To replace the input shaft inner race... this is a chore.. use a dermal or a die grinder with a reverse tapered die cutter in it, an carefully cut two diagonal slots on opposite end in the old race, without cutting into the base material! than it should just slide out. To install the new one heat the shaft a bit with a hot plate.. old waffle iron etc.. and keep the inner race in the freezer for a while, put a bit of trans mission assemble lube on the out race, hold the shaft in a vise, don't clamp it on the gear or any bearing surfaces, and using a socket the right size tap it squarely into place

alternately and preferred you could press the inner race in cold. with a hydrolic press this is what I did!

use a bearing splitter (two piece tapered halves that slide behind a gear or bearing with two bolts two pull them together) and either use a long puller two pull it off,or use a press two press it off. Than use the press and a socket the right size to press it back on, alternately you could use the hot and cold method and tap it on, I don't recommend this however.

repeat for the rear main shaft bearing. there may be a cir clip that you have to remove first can't remember?

As for the main case inner race it's a real pitta as well! Remove the spring clip with a small flat bladed screw driver heat the the case with a propane torch , try and use the point of the blue flame hottest part and keep the heat as close the the surrounding race material as possible, try not to heat the race itself at all, remember we want the aluminum to expand and the race to stay cool. Than tap it out side to side with a long punch on the back side of the race. To install heat the case, freeze the race, and again use trans lube and tap it into place, have the cir-clip ready, so you can install it right a way, and this way you know you are in far enough!


Good luck and don't even think of using a new bearing on a old race, as tempting as it may be.. trust me they are a matched set you would be better off keeping the old bearing and race set in there.

Think twice about the main shaft front bearing, it took me nearly four hours to get that inner race out of the input shaft! Good luck!

 

use a bearing separator...Youll destroy the old bearing but it will come right off. Getting the new one one without a press.....that will be your challange. If I didnt have a press id leave it on if its an option.

 

i have what seems to be a bent 3/4 shift fork and bad synchros. i am either going to have to buy a rebuilt one or just do it myself... i have done Everything else myself (LS2 Miata) so id like to fix it and learn... will i be having to tear it all apart to do this or can i just open it up, replace the shift fork and only go down to the 3/4 synchros? seems people have a hard time when it comes to rebuilding the entire transmission.

 

You won't have to strip it all the way down. Pointed out in the pic is mainshaft divider; the splined gears and synchro hubs are pulled from their respective sides. 3/4 synchro is on right. 4th is on the *** end of the input shaft and has got a race that rides on the far right bearing. You may as well do brass pads and shifter bushing while you're in there.

 

Once you get the case off and tailhousing off, the mainshaft, countershaft and shift fork/rails will all lift out as an assembly. And, they can all be put back in just as easily. In you want to get at the 3/4 synchro where its shown in the pic you made need to start pressing stuff on/off. But if you have access to a press and a bearing seperator and puller....well its really not any more complicated than a big heavy set of legos. Pretty easy if you can follow some steps.

 

What do you recommend ?
Mike

 

Just take it easy and it wont get damaged.

 

Just rebuilt my t-56 (gto) and this write up really helped ALOT thanks guys for putting this together.
But... i have a problem

Ever since i installed the trans. it seems like the shifts have been rough. I tried bleeding the slave and initially it helped. However a short time later the shifts became rough again. So, i tried bleeding the hell out of the slave to no avail.
So.....
Pulled the trans. last night and double checked the measurements i made to make sure i didnt need a shim, slave looks fine measurements all fine, and im at whits end
please help guys in input is appreciated

 

Shifts are rough? That's pretty vague! With the engine off does the shifter move freely in and out of each gear?

With it running are they notchy? Perhaps the clutch isn't releasing 100%, or the tranny is shimmed to tight internally? Did you check end play?

If you jack the rear of the car up (securely on stand front wheels blocked) and start it put it in 1st release the clutch and then depress the clutch do the wheels stop pretty quickly? If they take along time to stop or they never stop your clutch isn't release all the way.

This can be caused by a verity of thing;

-Bent clutch disk

-warped flywheel or pressure plate

-weak slave cylinder, low clutch fluid, not bled properly

- not enough slave cylinder shims.

What kind of a "air gap" do you have space between slave and pressure plate (measured with salve spring removed, and fully compressed, pressure plate and clutch disk-installed and torqued down)

Recommended gap is 1/16"- 1/8" I shoot for 1/16". If you have say 1/4" gap your clutch won't fully release.

Hope this helps.. good luck!

 

Shifts are rough (in all gears) when the car is moving only. With the engine off it does slide freely into every gear. I didnt jack it up and start it to see if the wheels turn but i tried puting it in & out of gear with the engine running while holding the clutch. The idea being if it wasnt sliding freely into gear then the clutch is not releasing.

i did check endplay and shim the mainshaft to whatever tremec recommends in their service manual i cant remeber ATM. But how would it being shimmed too tightly cause hard shifts?

I just pulled the trans. again to double check the air gap between the slave and pressure plate, and its almost zero.

i have the trans. out still so ill get on checking the flywheel and pressure plate although they seemed fine before.

The weird thing is when i bled the slave it initially shifted fine but the next day it was back to its old ways. I have since tried bleeding the little **** but it doesnt seem to do any good.
Im wondering if the slave is bad already (i just replaced it 3 months ago) or if theres a small leak in the clutch hydraulics somewhere. I just dont know how to go about determining which it is...
Thanks for the input it is very much appreciated