JT4x4

The Mud Pit => Wrenching => Topic started by: submrnman on October 22, 2011, 06:24:24 PM

Title: Replacing rear pinion seal...
Post by: submrnman on October 22, 2011, 06:24:24 PM
The rear pinion seal in me rear diff has just developed a slow leak... The new pinion seal and diff gasket just came in the mail the other day.n I have never done a pinion seal replacement, I know the basics of it though.  Has anyone ever replaced a pinion seal?  If so, any guidance you can offer would be much appreciated....
Title: Re: Replacing rear pinion seal...
Post by: BlacXJeep on October 22, 2011, 08:49:30 PM
I'm not an expert by any means, but it would be helpful to know what real axle you are running.
Title: Re: Replacing rear pinion seal...
Post by: submrnman on October 22, 2011, 09:05:40 PM
Oh sorry.  I'm running a Dana 35 in the rear.
Title: Re: Replacing rear pinion seal...
Post by: skibum on October 23, 2011, 01:32:25 AM
Changing a pinion seal is very easy. There is just one very important thing to know first before anything is disasembled. It is very important to put a referance mark on the pinion nut & shaft so when retighening the marks they are lined up to make sure the crush collar is not over tighened & not change the pinoin bearing preload. Hope this helps you out.
Title: Re: Replacing rear pinion seal...
Post by: Bill3753 on October 23, 2011, 03:03:16 AM
Another this you want to do is make sure you replace the nut with a new one.  They use a thread deforming lock nut on the pinion.  Basically, they are only good to be torqued once.  You can use them again, but you'll risk it backing off.  That will change your bearing preload and cause big problems in the rear.
Title: Re: Replacing rear pinion seal...
Post by: Mr Rock on October 23, 2011, 04:23:29 AM
Like skibhm says, mark it ! Then I count the turns it takes to unscrew the nut so I know how far to put it back on.

Bill is right you should install a new nut, but I have had good luck reusing the nut.
Title: Re: Replacing rear pinion seal...
Post by: skibum on October 23, 2011, 07:27:28 PM
I have replaced hundreds of pinion seals & have never seen one back off yet. You can use Lock Tite if you want the extra security.
Title: Re: Replacing rear pinion seal...
Post by: gearhead1985B on October 24, 2011, 12:44:58 AM
I have replaced hundreds of pinion seals & have never seen one back off yet. You can use Lock Tite if you want the extra security.

x2
Title: Re: Replacing rear pinion seal...
Post by: submrnman on November 01, 2011, 04:51:27 PM
Cool thanks.  I am doing the pinion seal this weekend.  What gear oil do you guys recommend?  I usually run 75W-90.  Just wondering if I could be running something better...
Title: Re: Replacing rear pinion seal...
Post by: skibum on November 01, 2011, 10:32:12 PM
Synthetic 75W90 is fine unless your towing then you should use synthetic 75W140
Title: Re: Replacing rear pinion seal...
Post by: submrnman on November 02, 2011, 01:59:28 PM
Thanks man.  It was good to meet you guys last night.  I'mm looking forward to the Nov Trail Ride.  I just have a few last minute tweaks to do to the Heep so it's ready...