Continuing pinion seal leak

[taylorpjones]

I’m hoping you guys can help me. I’ve got a 54 CJ3B and have replaced the front pinion seal twice and it’s still leaking fairly good. I was careful to utilize the gasket and also a little rtv around the edges of the seal but no joy. I am greasing the inside of the seal as well before sliding the knuckle back in. I inherited this jeep from my Dad and am still learning. Is there something I’m doing wrong? I tightened the pinion nut to 150 ft lbs per Mr. Walcks advice. But I keep reading about shims and did I mark the drive shaft before I took it off? Does the drive shaft have to go on a particular way, hence the admonition to mark it? Are my bearings bad inside the differential or maybe the front drive shaft is out of balance? I can’t believe it would be since this Jeep was just totally rebuilt 1000 miles ago. Thank you for any help you can provide! Taylor

PS forgot to say the knuckle is new so there is no groove worn into it by the seal

[Rus Curtis]

I’m hoping you guys can help me. I’ve got a 54 CJ3B and have replaced the front pinion seal twice and it’s still leaking fairly good. I was careful to utilize the gasket and also a little rtv around the edges of the seal but no joy. I am greasing the inside of the seal as well before sliding the knuckle back in. I inherited this jeep from my Dad and am still learning. Is there something I’m doing wrong? I tightened the pinion nut to 150 ft lbs per Mr. Walcks advice. But I keep reading about shims and did I mark the drive shaft before I took it off? Does the drive shaft have to go on a particular way, hence the admonition to mark it? Are my bearings bad inside the differential or maybe the front drive shaft is out of balance? I can’t believe it would be since this Jeep was just totally rebuilt 1000 miles ago. Thank you for any help you can provide! Taylor

PS forgot to say the knuckle is new so there is no groove worn into it by the seal
« Last Edit: Yesterday at 11:15:53 PM by taylorpjones »

taylor,
Leaks are hard to find sometimes.  On your front axle, it's leaking out around the pinion seal?  That piece you slide on before torqueing is a yoke end for the universal joint on the propeller (drive) shaft. 

So far, I haven't had the displeasure of putting up with this leak.  However, I can think of a few ideas.   You mention you've replaced it twice so far.  The inset where the seal sets, is it smooth or does it have gouges in it?  When you put the seal in does it face the correct way?  Have you tried smearing a little RTV on the teeth of the pinion/yoke where they mesh before attaching with washer/nut?

Do you have an Oil Slinger in place under the seal?  What kind of gear oil are you using?  How much? Is the dust shield with felt wick in place behind the yoke?

I don't know how much you've taken apart but the shims shouldn't be accessible with what you're doing on the seal.  Marking the propeller (drive) shaft keeps the u joints clocked so they aren't out of sync. Google "phasing a drive shaft"

Lastly, do you have a Service Manual?

[Chuck W.]

Did you check the yoke for wear? If there is a wear groove in it where the seal lip runs, you may need to repair with a speedy-sleeve or replace the yoke with a new one.

[taylorpjones]

Thank you guys for your advice! I’m going to look into several of your suggestions.

[Bruce_W]

  When the yoke is in place and the nut is torqued to 150 ft.lbs, is there any movement up/down or side/side possible?
BW

[taylorpjones]

The yoke is new and has no discernible wear. There is also no lateral or vertical movement. I checked all that thanks to you guys suggestions. It got me to thinking maybe I should call Mr. Walck back and he said I should be running 140 weight vice 90 weight oil as that is what they’ve been doing for years. He also said to take the pinion nut and wager off and put some rtv on the splines and then put the washer and nut back on. After I do both of those, I’ll let you all know the results! Thanks again for all the suggestions! Taylor

[taylorpjones]

Okay for all who may have the same issue. Mr. Walck suggested I switch to 140 weight as that is what they use. He also said to take the pinion nut and washer back off and to put some rtv on the end of the splines then put the washer back on and rd tighten the pinion nut to 150 ft/pfds. I did that earlier tonight and so far have no leaks. Prayerfully if the creek don’t rise, this should do it but I’ll update my post after a few days. Thanks to all! Taylor

[Rus Curtis]

The yoke is new and has no discernible wear. There is also no lateral or vertical movement. I checked all that thanks to you guys suggestions. It got me to thinking maybe I should call Mr. Walck back and he said I should be running 140 weight vice 90 weight oil as that is what they’ve been doing for years. He also said to take the pinion nut and wager off and put some rtv on the splines and then put the washer and nut back on. After I do both of those, I’ll let you all know the results! Thanks again for all the suggestions! Taylor

Okay for all who may have the same issue. Mr. Walck suggested I switch to 140 weight as that is what they use. He also said to take the pinion nut and washer back off and to put some rtv on the end of the splines then put the washer back on and rd tighten the pinion nut to 150 ft/pfds. I did that earlier tonight and so far have no leaks. Prayerfully if the creek don’t rise, this should do it but I’ll update my post after a few days. Thanks to all! Taylor

fingers crossed!

[Earl Baker]

A pinion flange leak can be caused by seepage along the pinion splines and can be sometimes corrected by applying a sealant to the splines before attaching the pinion/ driveshaft flange

[Earl Baker]

I found this on another site and it agrees with me that the pinion leak may be from the splines of the pinion itself I have on many types of equipment I have worked on found this very beneficial. I also googled ( oil leaking from rear differential pinion nut) and found that oil leakage is fairly common from this location and completely separate from the pinion seal. It is a good practice to apply RTV to the pinion spline and loctite to the nut while re-assembling.Jul 27, 2014

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