Padawan
04-18-2026, 12:59 PM
Looking for some experienced input on a T5 issue that showed up after a simple reseal.
I’ve got a T5 out of the car and open on the bench. The transmission was working perfectly prior to this. The only reason we opened it up was to fix a leak at the top cover, we measured about a 0.23 mm gap on the top right corner of the cover.
Important point:
We did NOT remove or intentionally disturb the geartrain, synchros, or mainshaft assemblies. This was strictly a top cover reseal.
After reassembly, here’s what’s happening:
Transmission binds and gets stuck in 3rd gear
With the case open, I can see that one of the synchro hub keys/struts is out of place
The synchro sleeve is not centered properly over the hub
It appears to be the 3rd/4th synchro assembly
From visual inspection:
At least one key has popped out
Concern that the internal synchro spring is no longer seated correctly
Sleeve position looks off, which lines up with the binding in 3rd
Questions for anyone who’s dealt with this:
Can the key/strut be carefully tapped back into place and the synchro sleeve re-centered without pulling the mainshaft apart?
Does the sleeve need to sit perfectly centered over the hub at rest, or is slight offset normal?
If a key has popped out, is it safe to assume the internal spring has also shifted or come out of its groove?
With the gear stack still assembled in the case, is there any realistic way to access and reseat the synchro spring?
Or is this realistically a full teardown situation where the mainshaft has to come out and the 3/4 synchro hub needs to be rebuilt correctly?
I’m trying to avoid tearing the whole thing down if there’s a safe way to correct it in place, but I also don’t want to force anything and risk damaging the hub, sleeve, or blocker rings.
Appreciate any insight, especially from someone who’s dealt with T5 synchro keys popping out like this.
228299
228300
This is a Dropbox link with all the photos and the leaking top cover: https://www.dropbox.com/scl/fo/di1j4ixgrmq5td8vtj1s1/ACMjJ30dP4qrmzzWpB7GXfI?rlkey=hozfu6i2i6g10v6aleil 1wn9w&st=w6kifm5p&dl=0
I’ve got a T5 out of the car and open on the bench. The transmission was working perfectly prior to this. The only reason we opened it up was to fix a leak at the top cover, we measured about a 0.23 mm gap on the top right corner of the cover.
Important point:
We did NOT remove or intentionally disturb the geartrain, synchros, or mainshaft assemblies. This was strictly a top cover reseal.
After reassembly, here’s what’s happening:
Transmission binds and gets stuck in 3rd gear
With the case open, I can see that one of the synchro hub keys/struts is out of place
The synchro sleeve is not centered properly over the hub
It appears to be the 3rd/4th synchro assembly
From visual inspection:
At least one key has popped out
Concern that the internal synchro spring is no longer seated correctly
Sleeve position looks off, which lines up with the binding in 3rd
Questions for anyone who’s dealt with this:
Can the key/strut be carefully tapped back into place and the synchro sleeve re-centered without pulling the mainshaft apart?
Does the sleeve need to sit perfectly centered over the hub at rest, or is slight offset normal?
If a key has popped out, is it safe to assume the internal spring has also shifted or come out of its groove?
With the gear stack still assembled in the case, is there any realistic way to access and reseat the synchro spring?
Or is this realistically a full teardown situation where the mainshaft has to come out and the 3/4 synchro hub needs to be rebuilt correctly?
I’m trying to avoid tearing the whole thing down if there’s a safe way to correct it in place, but I also don’t want to force anything and risk damaging the hub, sleeve, or blocker rings.
Appreciate any insight, especially from someone who’s dealt with T5 synchro keys popping out like this.
228299
228300
This is a Dropbox link with all the photos and the leaking top cover: https://www.dropbox.com/scl/fo/di1j4ixgrmq5td8vtj1s1/ACMjJ30dP4qrmzzWpB7GXfI?rlkey=hozfu6i2i6g10v6aleil 1wn9w&st=w6kifm5p&dl=0