I just installed a JDM FD and 3-4 synchro into my transmission. When I test fit the case, with the circlip in the countershaft groove, everything works perfectly. But when I torque down the case bolts, the thing binds up and I can no longer turn it over, even with 2 hands turning a clutch on the shaft. When I loosen the case bolts, it's fine again.

What could be the problem>?

 

eY!

 

Y21 Tranny

 

I'm no tranny expert but it's happened to me before also. Seems like it was not in the area that you worked on. I think it was the ring gear/ spool assembly was not completely in position. As long as the case was not bolted tight, everything was perfect. As soon as I would tighten it down, the final clearance was knocked to zero and would lock up. Look in that area first. Good luck

 

Try just bolting the tranny together with just the mainshaft and then see if it still binds. This way, you can check if you re-assembled to mainshaft back properly after changing the 3rd and 4th gear synchros.

Hope this helps. Tranny's can be fustrating.


[Modified by Rocket, 6:22 AM 4/26/2002]

 

If you don't line up the tangs on the friction collars with the holes in the gear sleeves, that will cause binding when you torque the case.

 

I did install just the mainshaft and try. It still binds when torqued down.
The collars you are referring to are the brass rings with the springs, right? I double checked the mainshaft assembly, everything looks good.

HOWEVER. The top bearing on the mainshaft sits above the end of he shaft a little (5-6mm). Is it supposed to be flush or close to flush? If so, I can't find what's keeping from dropping all the way.

One note, the 3-4 synchro hub doesn't look like it slides completely onto the grooves of the mainshaft (maybe 3/4 of the hub's height is in the splines), but it's down as far as it can go......



[Modified by sackdz, 12:41 PM 4/26/2002]

 

It should be fluch. Be sure you install the main shaft end bearing correctly, the thick side of the outer bearing race (with the serial # stamped into it) should be facing out, towards the end of the case.

Mike

 

Pefectly flush? Because I discovered I had the 5-R synchro sleeves switched, and now the mainshaft ball bearing sits nearly flush, a lot closer than before.... a nickel's thickness up. Is that right?


[Modified by sackdz, 6:04 PM 4/27/2002]

 

man, I had the same problem but I wasnt setting the c-clip correctly in the top half of the trannycase. are you sure thats not the problem?

 

Here's a pic of a S80 mainshaft. The synchro hub, sleeve, and syncrhros go in "one" way on the 5th/Reverse section.

 

What's an S-80? Is that another tranny code like Y21? Which car?

ANyways, between your pic and another, I think I got it. I had the 5th and reverse synchro sleeves reversed and it was causing the bearing to sit 2-3 mm higher. Now it is lower, not completely flush, but neither is the one in this pic or the other. I think everything should be alrite now, I have to wait for a new bearing to come in because I took the case off and the bearing fell out and blew up.

Thanks for all your help guys.

 

S80 is a hydraulic GSR.