leaking rear main seal: 5spd tranny

[7277]

just peeked under my '72. it has 81-83ZX 5spd. noticed a tiny puddle of oil at the rear of the trans. is the rear seal replacable in-situ without a removal/rebuild of the whole trans? if so, any how-to tips would be appreciated. i did a trans gear oil change about 1000miles ago, checked for overfill, and it didn't leak at all since yesterday...

thanks!

..must be the Brit car gods getting back at me on my post about Brit car vs. Z in Open Z car discussion

[sblake01]

It could likely be done with the trrans in the car but I've always dropped the trans to replace the rear extension housing seal because I would do the front cover gasket and seal at the same time.

[7277]

It could likely be done.....

has anyone tried it? any special tools to get the seal out?

-thanks again

[blue 72]

I've got a '78 5-speed and had to replace the output shaft seal a few months back. Nothing tough at all, just remove driveshaft, pop out old seal, clean, install new seal, grease seal and reinstall driveshaft. Might want to drain the gear oil first just incase you don't like leaking all over the place.

[7277]

hey blue72. thanks! i'll climb under there today and pull the shaft... 'pop out old seal...'

pair of needle nose pliers or something? pardon my ignorance, but i wouldn't have thought it to be that easy.

thanks again!

[7277]

hmm...perhaps i posted a tad prematurely... climbed under there and inspected the area...to my surprise the speedo cable was wet. unscrewed the collar, and found the little 'hat' shaped seal to be crusty. hopefully i can fab up a new seal and it will fix the problem

[240ZMan]

There's an O ring on the outside which is easy to see. There is also a seal inside the speedo collar that you might not see if you don't go looking for it. If it's leaking you may find gear oil under your dash. Ask me how I know...

[sblake01]

Been there...done that. That's how I found out that threre really isn't a seal on the speedometer end of the cable so if the seal in the collar leaks and the o-ring holds, the only other place the oil can leak is behind the guage.

[7277]

think i got it! pulled the drive gear and check the 'o-ring' the unit came out snug and pushed back in ok..didn't seem to be faulty.

the 'hat' shaped seal was crusty, but cleaned up ok. it also didn't quite cover the edge of the male collar threads (on the gear drive-off the trans) and looked crimped and a bit folded. i added a 'custom' flat rubber seal to the front of the 'hat' seal. then tightened down the collar good and snug. took the car out for a 20 minute spin....waited 30mins.................crossed fingers and looked under there.................................................dry !! whoo hoo (hope it holds...)

thanks everybody

[240ZMan]

Hey, good for you, hope it holds. Still I would suggest that the next time you order from MSA or Courtesy Nissan (and with an older Z, it's "when" ) that you order replacements. They're cheap (cost less than shipping) and as you now know, not hard to change. Compared to the alternative of the delightful smell of gear oil in the cabin AND cleaning it up, it's a worthwhile investment.

[7277]

hey daniel...yeah i know..it's probably a $0.20 seal,....the other consideration is that it's an 81-83 trans and the cable is a 72, so the new 'hat' (for a 72 cable) probably wouldn't fit as didn't the original one. the flat one i made gets squished between the 'hat' and male gear drive threads. as if the 'hat' now has a wider mating flange to the gear drive. i made it just slightly oversized to cover the edge of the male threads, but not too big in diameter that the collar wouldn't fit on. l also made the hole in my flat seal a tad smaller than the (actual) male speedo cable shaft. so it is now double sealed there...

[cegrover]

Is there a particular trick to getting the inside seal out of the pinion gear carrier? I'm in the process now and it doesn't want to budge with various screwdriver tricks, etc. I'll keep digging at it, but I always worry a bit about excessive force!

EDIT: Okay, I got it. It just took more time with a jeweler-sized screwdriver. I also found a reference to the drill bit method, but didn't have a bit the right size...

Edited July 9, 2011 by cegrover