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A couple years ago I had grease leaking out of my rear wheels. I posted here the steps I took to replace the seals for the torque tube at the transmission as well as installed new style bearings in the axle. I recently filled my transmission and now I have grease coming from the passenger side rear wheel. Does this mean my seals have gone bad again?

That is most likely your problem.

Have you checked the fluid level in the differential? If overfilled this could possibly happen.

Hello Vetteman61,
If the rear end is overfilled when you go to check the level in it again, then the torque tube seal isn't working so well that is located rearward of the universal joint and driveline connection. Both the driveline and the rear axles may be worn where the seals are, so even new seals may seal loosely and allow seepage. Adjusting the seals to a new location may help with sealing. If the rearend is not overfilled, the axle seals may still be sloppy or there may be a buildup of pressure blowing past the seals when all gets warmed up driving if there is no rearend breather.

I haven't checked the level in the differential but I did just fill the transmission right before this happened, so I have to assume the diff is probably overfilled from the trans leaking back. I have not put a vent hole in the rear diff and have read the many yea/nay about whether I should or not. I did put newer style, sealed bearings in the rear axle the last time and from what I remember it may be necessary to add a vent tube because these newer, sealing bearings don't allow the rear end to breath and allow pressure to build up. It's curious to me that it only leaked out the passenger side and not the driver's side, when the last time it leaked out of both.
I can't really remember much about what it was like or what it looked like when I replaced the rear trans/torque tube seal, so I can't visualize that.

Hello Vetteman61,
To review the torque tube seal and bushing removal and installation, go to the Filling Station website. Tech Articles-Mechanical-Torque Tube Bushing Replacement. It's the second to the last article. It also discusses later model years, but towards to end has good info, so make sure to read it all.

Through my trial and error time, I have replaced bearings with double sealed type, still leaked, replaced inner seals and outer seals and finally took top bolt out of diff cover and drilled 1/8" hole through it and my problem of leaking is over. I do get an occasional seepage through that top bolt hole but it is minute and easily cleaned off. I feel it is necessary to relieve the pressure in rear end.

Jim.

I had the same leakage problems on my 32 with sealed bearings and the only cure was to vent the axle housing. I did that by adding a vent near the lh spring perch and have noticed it is the same as on my 51 which I believe was a factory installation.

My 1951 Chevy has the same axle housing vent as well.

Thanks guys for the responses. What process did you guys use to put a vent in your axles? (I know it's not technically the axle, but it sounded weird to say how did you vent your rear end) JDV, I know you said you drilled the top bolt in your diff cover. For the other vents, did you drill and tap and add a fitting with a rubber hose? Was there a reason it was on the left hand (driver) side? Do you have a picture of where it is drilled?

Thanks,
Brandon

Brandon --

You only need one vent in the rear end assembly. I chose to drill a hole in the top bolt so that I didn't have to worry about metal filings in the rear end when drilled. You can vent the axle housings also for the same result. Some guys on this chat site have drilled a hole and than dropped a 16 penny nail in the hole also. All kinds of different opinions here and they all do the same thing.

Best too ya

Jim.

I visited a wrecking yard near me and took a vent off of a 49 Chevy diff. I drilled and tapped a hole in the axle housing and screwed it in. I put an old piece of vacuum hose attached to it and used a black tie wrap to hold the hose on the top of the axle housing. Since I have replaced all the seals etc on my 32 rear end and axles and put the vent on, I have no leaks...

Good luck,

Mac

You can buy the identical vent from a Mack truck dealer for a lot less money.

Differential Vent from Currie

Here is the exact same vent for less than $5, plus shipping. I just ordered it.

It seems perhaps there's not only one correct location for this. Could someone explain a little more exactly where this piece goes. Is it on the exact top of the housing? Would it be possible for me to drill it without draining all the fluid and taking the rear end apart? If I can't get the drill on top of the housing with the body on would it be possible to put the vent slightly clocked to the side without causing problems?

Thanks,
Brandon

Yes.



Yes.



If you can't mount the vent directly on top of the axle housing then your next best option is to drill a vent hole in the top bolt that goes in the rear cover as mentioned above. That method will work just as well.