Rear axle retaining bolts

I recently replaced both rear wheel bearings after the right side one failed. At the same time I also replaced the axle seals. Well apparently the seal on the right was either defective or failed somehow as I am now leaking differential fluid on that side. When I removed the tire to inspect what was going on I also discovered that the axle retaining nuts were loose even though I had torqued them to the recommended 35-40 ft. lbs. Now I am wondering if these four nuts and bolts had to have some type of thread lock applied before being torqued down. I’ve ordered new seals but should I also order new axle retaining bolts and nuts too? Just curious what others have done after changing the bearings.

I can only suggest you double check your torque readings and make sure your bolts are long enough for full thread engagement with the nut. NyLock nuts will help although the nuts and bolts should be fine thread.If you feel your torque wrench is not accurate tighten the nuts really good and snug.
Before you install the axle coat the lip of the seal with just a touch of wheel bearing grease so as to not "burn in’ the new seal.
If everything seems to be proper and a seal leaks the axle may be worn just enough where that seal rides.You can try another axle or FederalMogul/Moog/National Redi-Sleeve, a brass sleeve designed to take up the slack in that worn area.It slips right on but you’ll need to know if the axle is a 28 or 31 spline piece. 28 spline part is 99820. Part known also as “Speedi-Sleeve”.From NAPA it was like$60.00ish but it has worked for me.

Go with new bolts and check it often to make sure it doesn’t loosen up on you again. The bolts shouldn’t loosen up unless some damage was done when the bearing failed. The bolts holds the retaining plate and the plate takes up the side load from the axle when going around a corner. No other load should be applied to the bolts. Does the new bearing fit in the rear end tube snug? Do you have any vibration? Put the axle on a set of V blocks to check it for straightness. Do what is suggested above if you need to stop the lube from leaking. In the race car I run inner seals that keep the lube in the differential vs going down the axle tubes.

My thoughts on this would be, the bearing were never fully seated, and after driving the car it slid the rest of the way in causing the bolts to be loose.

This has happened.

cyclonelou - your point about applying grease to the seal prior to installing the axle might have been the culprit. The axle was dry when I installed that side. Weeks later when I did the drivers side I distinctly remember that there was still fluid on the axle when I installed it.

Brian - On Friday morning of the Springfield show I had the axle out again by 6:30 am and made new backing plate and retaining plate gaskets thinking they might be the problem. I had everything back together by 8:30 am. The leak was considerably less when I arrived in Springfield but still there. When I returned home I removed the tire again and all the nuts were tight but I was still able to apply additional torque to get back to the original 40 ft. lbs. However gasket compression might have been the reason for that. As for vibration there is none. After I install the new seal I’m wondering if I could double nut the retaining bolts to lock them in place. I see no conflict with any of the brake components.

I appreciate the help provided.

You might have a bent axle.

You should not need to double nut those bolts and if torqued properly those nuts should not back off.
You’ll have to start at square 1 and find out what’s wrong and it may be something right in front of you. It’s happened to all of us.


You have two separate but related problems.

  1. Oil leak, The gasket you made that goes between the retaining plate and axle housing. The purpose of that gasket is just to keep dust and dirt out of the bearing. It’s purpose is not to seal and retain oil. The bearing is sealed and should have no rear end lube reaching the bearing. The oil is retained by the lip seal that goes before the bearing in the axle tube. Take it back apart and see if the seal is damaged from being dry or damaged when installed. It’s very easy to deform that seal when installing. (I’ve done it a few times).

  2. Retaining bolts. Their should be no reason to double nut or do something other then stock on the retaining bolts to keep them tight. As Catlover suggested maybe you didn’t have the axle/bearing seated in all the way so the bolts were never completely tight to begin with. I’m running stock retainer bolts on the road-course race car which is loading the retainer plate 10 time more then it will ever happen on the street with no issues.

With no vibration I highly doubt you have a bent axle.


It’s possible that I did not get the bearing seated completely if the bearing retainer was not completely pressed on. I had a local shop install them for me. The other thought I’ve had since I wrote this is I might have been given the 31 spline seal instead of the 28 I ordered. If the shaft diameters are different then I’d assume it would leak. I had picked up the seals on different days and I could see a mix up at the Napa store. I’ll take some pics when I get the new seals and replace the one in place now.

Ok, new seal has been installed and the only thing I noticed was considerable wear from the axle bearing retaining ring on the old seal. So I might not have completely seated it when I initially installed and when I put the axle back on and tightened the retaining nuts the bearing was not properly seated. So after driving for a while it worked itself in place and that’s why the nuts were lose??. Anyway here are the pics I took. Note the old seal (silver) is only deformed from removing it.

I’ll drive my car for a week and see what transpires with the new seal and retaining bolts and nuts. Thanks again for the opinions and help.

Another thing to consider for the leak is that your axle vent is plugged. Pressure build up is forcing oil past the seal.

Mike, I did check that but forgot to mention it earlier. The vent had a little dirt but wasn’t completely clogged. I did clean it.

Something don’t look right, it looks like the bearing retainer is not pressed on far enough, and another thing, the bearing retainer should not rub the seal as this one looks like it did.

Hard to tell for sure from the picture. But yah, it does look like the bearing and retainer aren’t pressed on all the way.

Here is the pic of the original failed bearing and retainer. It looks to me to be positioned the same as the replacement. When I inserted the axle into the housing it slid right up to and past the flange the drum brake attaches to. The angle I took the pics are not the same but it appears to be very close.

Mike, In the picture where you show the two seals, new and used one, the used one sure looks like the bearing retainer had been rubbing, if this is what it looks like, then either the seal was not seated in the tube or the bearing and retainer is not on far enough.
I am just trying help you get it right . good luck

catlover - I do appreciate the help. That being the first axle seal I had installed it is entirely possible I did not get it completely seated. So yes that might have lead to all my issues regarding the leak and loose nuts. I’m holding off claiming success on the new seal until I’ve driven my car for a week or so to see if any leak reappears.

Follow up - After 12 days and over 400 miles later, today I removed the tire and brake drum and applied my torque wrench and the four nuts had not loosened up at all. Also no noticeably diff fluid leaking anywhere. So I’m confident that it was my failure to properly seat the first axle seal that was the cause of my fluid leaking and the axle retaining nuts coming loose. My thanks to all who offered recommendations and assistance.