Spaceballsthelunchbox

I have an L3 91 CRX Si transmission that I replaced the OEM synchros with Synchrotech carbon fiber synchros and new springs. After reassembly, I am able to shift all 5 gears and reverse without issue but the input shaft is hard to spin by hand when I compare it to another stock Si transmission I have on the bench. Is that normal? I am worried about friction and over heating.

holmesnmanny

Too little clearance

slowcivic2k

You will need to verify your mainshaft preload, differential pre-load, and installation of parts. What was all replaced in this unit?

It would be wise to take it back apart to check at the least.

Mista Bone

If he only swapped the synchros, no need to worry about clearances.

Did you soak them in oil before installing?

Mista Bone

No diff preload to check.....

slowcivic2k

I do agree on the pre-load part. Perhaps I was being a bit vague, but..

I'm not going to assume the differential was not replaced or the case itself. These should be at the very least checked whenever the case is split. Need more information. Clearances should always be checked to determine if wear has occurred. Not doing this could result in premature failure, and you know that.

I should clarify, these should have ball bearing units but should still be clearanced and corrected if necessary.

I'm leaning towards installation error given the situation. I have personally haven't had this type of problem with synchrotech parts.

Spaceballsthelunchbox

Thank you for the replies. I posted this late last night and left out a bit of info, sorry about that. The diff was replaced with a Quaife unit. The LSD was installed with new
bearings and it was tested in the case by itself with an even bearing clearance of .005" when the case was tightened. The diff. did spin free with no binding. I am using the same case no mixing of parts. All that was replaced on the stacks was the synchros and springs.

I am going to take it apart and remove the diff, put it back together and see if that makes a difference.

holmesnmanny

When posting stuff like this you really need to be detailed about what you did. You never originally mentioned you replaced so of course the advice is going to vary based on what info you give.

Spaceballsthelunchbox

I understand, I am not looking for a fix. I simply needed to know if carbon synchros can make the input shaft hard to rotate by hand. Thank you for your help.

Mista Bone

Yes, carbon's can have high points and bind in certain spots, how I found out about soaking them before installing but still had the issue.

What I did trying to find the binding point.....