I recently had my rear end rebuilt (10 bolt posi) in a 71 Chevelle SS with a 350/350. Since then the pinion seal in the front of the differential has been leaking. The guy that rebuilt it told me that they often leak until they are broken in. I've driven it maybe 250-300 miles since then and it leaks worse now. I referred to my repair manual and it called for several special Chevrolet tools to replace the seal and nut without damaging the gears. I got a reference from Bush Hog racing for a guy that only does rear ends and he said he would do the seal for $70.00. Does this seem reasonable? The rear end seems to be working fine. I would take it back to the guy that did the original work, but he's now a 4 hour drive away.

I've replaced several and they never leaked. Break in? News to me. How far are you from Baytown? Have you ever heard of Pyle Brothers? Give them a call (281)-421-5878, they are at 2402 W. CBYO. LYNCHBG. RD. Just off I-10 before you get to Baytown. See if they will coach you through it.

If you don't think you can replace it, let me know. I am only an hour from you and I am in Houston all the time. Its easy to fix. I'd be glad to help.

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Mike Hurta
(Aug98)
Gold#25
Clute, Texas
www.chevelles.com/feature/aug98.html (http://www.chevelles.com/feature/aug98.html)




[This message has been edited by Aug98 (edited 08-27-99).]

DO NOT I REPEAT DO NOT PAY SOMEONE 70 BUCKS TO DO THIS FOR YOU!

one of three things has happened:

1) the pinion seal was not replaced, or was replaced with the wrong one

2) the axle vent is plugged/taped/broken and when the axle heats up, pressure builds.. the weakest link is the pinion seal which is always holding back fluid (in direct contact) AND THIS DOES HAPPEN it happened to me.

To look at the vent, get behind the car, its on the passenger side of the pumpkin and just a little plastic thing sticking up... can be removed with pliers fairly easily..

3) the third thing i forgot while typing the first 2!!!

I highly recommend checking out the following links:

http://www.chevelles.com/forum/Forum9/HTML/001419.html

well unfortunately Team Chevelle doesnt keep all the old posts anymore.. http://www.chevelles.com/forum/frown.gif http://www.chevelles.com/forum/frown.gif there was an EXCELLENT thread that I started on changing the pinion seal, regarding pinion nut removal/replacing, etc... there was some really good advice from DZAUTO that I ended up taking and its worked out perfectly..


well if you need any more info, i.e. how to do it, etc... let me know id be happy to help.. it was VERY simple and I highly recommend doing it yourself assuming you have the least bit of mechanical skill.. http://www.chevelles.com/forum/smile.gif i'll go now.. thanks for your time


Mike Reeh
Gold #34
San Diego, CA

[This message has been edited by mike reeh (edited 08-26-99).]

Here is a Tech ref. I read it before I changed my pinion seal. http://www.chevelles.com/forum/smile.gif http://www.chevelles.com/forum/smile.gif

http://www.chevelles.com/archive/files/rpseal.htm

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DG
Springfield, Ohio
70 Chevelle Malibu

www.wright.edu/~adams.6/chevy.htm (http://www.wright.edu/~adams.6/chevy.htm)
Genx member (Founder 4 Ohio)
TEAM Chevelle Member #0086




[This message has been edited by DG (edited 08-27-99).]

Mike, your old post is still there. Philip

Phil show me

Thanks for all the advice. I pulled the vent tube out and it didn't appear to be plugged. I'm still unclear on how to get the flange and the yoke off without the three pronged puller. I also haven't located a pinion nut. Any idea where I can get one of those. Is it a dealer item?

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71 Chevelle SS
350/350
Spring, Tx (N. of Houston)
N. Georgia motorhead

Undo the nuts to the universal and move or hang the driveshaft out of the way unless you want to remove it out of the trans then you'll see the nut.

Mark

You can still buy the nut at a dealer.

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Mike, I stand corrected. Before I went on vacation I was reading posts that dated back into 1998. I see now that they are no longer showing up in a search. I have printed a lot of them, the info from the people here is a great supplement to the service manual. The real life experiences of what works and what doesn't can take a lot of trial and error out of repairs.

Update, I found some of your posts dating back to 11/98, so it probably is still there.

Philip

[This message has been edited by 64elcamino (edited 08-30-99).]

You do not need a 3 prong puller to get the yoke off. You can tap on it from the back side with a good ball pien hammer, and it will come off.

The other thing that Mike Reeh was probably thinking of is that the rear yoke could have a groove in it where the seal rides, in which case, you may need a new yoke.

It is not necessary to replace the pinion nut. If you mark it with a punch or chisel before you remove it (mark the pinion shaft also in the same spot) and use red loctite when reassembling, you will be fine. Tighten the nut a little past the mark you left, being sure you have the same amount of threads exposed on the shaft as before you removed the nut.

NOTE!! Extreme care needs to be taken when doing it this way. If it isn't tight enough or if you over tighten it, you'll have trashed pinion bearings in no time. Believe me, as Mike Reeh has already heard from me, I've seen countless pinion seals that were not done properly, even at certified mechanic shops.

In fact, I had one the other day where a guy tried doing his own pinion seal, and ended up bringing it to me to fix it right. It cost him $130 for all new bearings, $300 for new gears, $250 for labor, $35 each for axle saver bearings (the wasted pinion bearings took out the gears, and chunks of metal from the gears got sent all over the differential). It was an expensive lesson for him. I noticed the nearly new pinion seal when I took the rest of the diff apart, and asked him if it had just been replaced and who did it. He admitted that he tried it himself with no knowledge of what he was doing.

At least you are asking the right questions, not going into it blind like this guy did.

Also, since I work in a driveline shop and do differential work all the time, every day - I have no idea where this guy gets off telling you that it's normal for it to leak until it breaks in. That is completely rediculous! I have never heard of such a thing.

Good luck!

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70 & 1/2 RS Camaro
SB406 & M20 4spd
9" Rear
70 Malibu
SB350 & TH400

Gold Member # 103

Me and scooter didnt used to see eye to eye very well but if theres one thing I agree with him 100% on, its what he said.. i literally did everything he said when i changed my seal and its been working perfect ever since.......


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Mike Reeh
Gold #34
San Diego, CA

Well, the RIGHT pinion seal is in!
Thanks to Mike , Scooter and others for the valuable advice. Some key points. I went and got some 12000# Rhino ramps (29.95) which allowed me to use my creeper under there. Also, my Chevy manual was a big help with pictures. I cleaned (wire brushed and engine cleaner) the casing before I started and this made it easier to reuse my fluid (which I strained thru a new red rag. I used Permatex A on the splines (chevy manual), red loctite on the nut, and packed the seal lips with lithium grease. I couldn't tighten the nut back to the original position because the seal I replaced was the wrong size (too short) and seated flush while the right seal was almost twice as thick and seated itself about 1/8" from flush (chevy manual). While I was under there I found two cracked fuel lines so I went ahead and replaced the lower four. I tooled it around the neighborhood and let it sit 3-4 hours with a piece of cardboard under it. Still no drops. Now not only doesn't it leak anymore but it's ready for a coat of paint on the hub.
Once again, thanks for all the advice everyone, it helped a lot!

Well, the RIGHT pinion seal is in!
Thanks to Mike , Scooter and others for the valuable advice. Some key points. I went and got some 12000# Rhino ramps (29.95) which allowed me to use my creeper under there. Also, my Chevy manual was a big help with pictures. I cleaned (wire brushed and engine cleaner) the casing before I started and this made it easier to reuse my fluid (which I strained thru a new red rag. I used Permatex A on the splines (chevy manual), red loctite on the nut, and packed the seal lips with lithium grease. I couldn't tighten the nut back to the original position because the seal I replaced was the wrong size (too short) and seated flush while the right seal was almost twice as thick and seated itself about 1/8" from flush (chevy manual). While I was under there I found two cracked fuel lines so I went ahead and replaced the lower four. I tooled it around the neighborhood and let it sit 3-4 hours with a piece of cardboard under it. Still no drops. Now not only doesn't it leak anymore but it's ready for a coat of paint on the hub.
Once again, thanks for all the advice everyone, it helped a lot!