Final Drive Project [Page 3]
I was going to leave the crown gear needle bearing alone, but remembered
that the original seals might not have been up to hypoid gear oil. The
seal is under the bearing. A little heat applied to the case and the
needle bearing fell out. I cleaned it and checked it by mounting it on
the inner race attached to the ring gear. Very smooth. It will be
replaced. Now for that pesky seal. I used to have a tool just for
digging something like that out, but can't find it right now. Oh well,
there's always tomorrow.
Saturday, Nov 27, 2004
It's been a while. I ordered the needed seals and, while I was at it, gaskets and some shims for the ring gear "just in case". I now have a complete set of those particular shims.
This image shows the new seal in the cover and, in the upper right of
the image, another new seal in the pinion retaining nut. That seal
faces the drive shaft as it's job is to keep the oil in the drive
shaft out of the final drive.
Bernd, on the /2
mailing list, mentioned removing the axle tube to make seal removal easier.
Not needed, I replied. I've got this nifty seal puller.... Well, I should
have listened for two reasons. 1) its easier to install the seal with the
tube removed, and 2) you won't scratch the tube if you remove it before
removing the seal, nifty seal puller or not. Luckily, nothing actually
touches the tube, so I get away with the scratches this time. I did dress
the tube with a fine file and some crocus cloth to make sure there were
no rough surfaces.
Installing the new seal is a snap with the axle tube removed. After the
seal was installed I heated the case again to install the axle tube, then
applied a bit more heat and let the ring gear needle bearing slip into
place. The assembly was covered to keep dirt and dust out then put
away to cool down. I'll get back to it another day -- other duties call
right now.
Sunday, Nov 28, 2004
I've got some time to spend on this project this afternoon. The Sunday morning ride was cold (SF Bay Area cold -- 40ish :-) but it warmed up enough to work in the garage, later.
I cleaned the shim for the pinion and made sure it was placed correctly,
then placed the pinion with bearing in the case and applied heat until
the gear/bearing dropped into place. It didn't take much heat. The case
was about 160 F. The third picture also shows the end of the work I did
yesterday: the axle tube and needle bearing are back in the case.
What's wrong with the second picture? I installed the threaded ring
and torqued it down to 80 ft-lbs, then put the coupling hub over the
pinion shaft and scratched my head. Something was wrong. The coupling
hub lock plate wouldn't fit. Ooops... I forgot the seal ring that
goes between the bearing and the coupling hub. Off comes the threaded
ring. I must like doing things twice. This is a good picture of
the replacement coupling I found. It's used, but doesn't have the
large step that was worn into the original part.
This picture shows the missing seal ring. I re-installed the threaded
ring, torqued it down to 80 ft-lbs, installed the coupling hub, the
locking plate, and the nut (also torqued to 80 ft-lbs) then bent a section
of the locking plate to stop the nut from loosening.
I used some dry marker on part of the ring gear to check the gear positions.
The backlash feels OK. The ring gear was loosely rubbed against the
pinion and there was dry marker transfer off the ring gear (pictured)
onto the pinion. It's a bit toward the back of the gear, which is OK
(I think) as there was zero pressure applied. These are the shims that
came out of the unit and I didn't change any of the bearings. They
should be OK. Lastly I put the big bearing on the ring gear. That's
all for today. I'll finish up next time.