Rear pinion seal leaking

[indianajoel]

I changed my diff oil this weekend but my pinion seal is leaking. I wonder, do you guys usually find a bad bearing when there's a bad oil seal?

If so, can I pull the bearing out the front of the diff (after I pull out the seal) or do I have to remove the cover and take the whole thing apart?

Thanks.

I didn't see any info on this in my Haynes book.

-Joel

[JimKshortstep4x4]

Usually the bearings are not bad. Are you getting any noise out of the differential?

If the bearings are bad it is a complete teardown to get at both bearings. You will want to make sure the vent is not plugged as pressure buildup will force oil to leak out. To replace, pull the yoke to get at the seal. Some oil will run out. After replacing the seal retighten the nut on the yoke back to where it was.

Make sure the yoke seal surface is good otherwise the yoke will need replacing.

Jim

[msgross]

yep, no need to pull it apart... rasie the front of the truck so the pinion isn't pointing down, remove driveshaft, use an impact to remove yoke, use a gear puller (free rental from autozone) to pull yoke, replace seal, reinstall everything...

doesn't hurt to buy a new yoke nut and apply flexible sealent around the splines...

[Huck]

Biggest chellenge will be breaking that pinion nut loose so expect a bit of a challenge here. I've bent 1/2 drive breaker bars with a 3' pipe trying to get one loose. You might consider having it done as I have taken this course and have had it done for under $100.
The seal is cheap but the labor is a pita unless you have the right tools. Huck

[Monte Carlo Man]

You might have a tough time even with a 3/4 inch drive ratchet and socket.

I never did get the pinion out of my truck.

[grs]

I was quoted $160.00 to replace the seal. I was told the back lash had to be set right. The nut has to be torqued correctly. Not sure if I was lied to or not.

[hayhauler71]

Not a big job, just make sure you mark the nut and pinion so you put the nut back on in the same location

[leddzepp]

Easy job. Click on my build thread below for pics and a description of the process.

[indianajoel]

Thanks for all the fast replies guys!

I got my driveshaft apart today and the pinion nut and yoke were pretty loose.
I had my impact driver out and was prepared for a fight, but it spun right off easily and the yoke fell off. no puller needed. I had the wrong seal too....one for a spicer rear end. The new seal went in too loose...without pounding. I must have a GM H033 or H035 diff (according to the parts stores' pages. 8 7/8" ring gear).

Anyway, I'll go get the right seal and put it in. My bearings look good.

But how can I know how much to torque the pinion nut down?
My Haynes says if you have "full-floating axles" to mark the position of the nut, remove it, and put it back to the same spot. (like some of you said)
I have that type of axle (axle housing bolts to wheel hub)
With the other type, "semi-floating axle" you measure the torque required to spin the axle, remove the pinion nut, change oil seal and replace the pinion nut so the torque required is 1-5 in.-lbs. more than it was before.

But both of these methods rely on the thing being set up properly before I took it apart. What if it wasn't? (I could wiggle the yoke a lot by hand before I undid the pinion nut.)
I wish there were just a number I could take it to. or a neighborhood. like really f-ing tight...over 150 or 200 ft.-lbs. I assume that's where it should be if you all had to pull out your 3/4" drive or couldn't even get it off.

Any tips?

then I just have to separate the middle yoke from the rear shaft to put on a new center support bearing, and I will have renewed everything on the driveshaft.

also, is there any way to tell what diff I have from the outside appearance of it?
I doubt I have a tag on it still, but I could look.


Thanks for all the good info.

-Joel

[msgross]

that loose huh?

I'd buy a new nut and reinstall... i'll have to check the torque in my service manual... It needs to be tight though... I also used a flexible sealent on the pinion splines when I put the yoke on, just in case any oil tried to slip through that way...

Best way to check axle ration is remove the rear diff cover and check the numbers on the ring gear. There should be a ratio stamped like 41:11 or 3.7272_ (3.73)

[David67]

[67 C-10]; We got the seal off, but the pinion won't come out of the Diff. housing (or from between the two bearings on it). 11:41 is stamped on the ring gear. Housing says GM13. 12 bolts on cover, 12 bolts on ring gear. Is there a standard 12 bolt, or is this something different?

1) How to get pinion out (or is it needed...bearings seem smooth, but have small amount of axial play)?
2) How to clean axle tube interiors?
3) Does anyone have the replacement pinion seal spec or part number? Parts houses can't seem to get it right!


Thanks!

Originally Posted by msgross

that loose huh?

I'd buy a new nut and reinstall... i'll have to check the torque in my service manual... It needs to be tight though... I also used a flexible sealent on the pinion splines when I put the yoke on, just in case any oil tried to slip through that way...

Best way to check axle ration is remove the rear diff cover and check the numbers on the ring gear. There should be a ratio stamped like 41:11 or 3.7272_ (3.73)

[msgross]

send a pic of the axle and cover....

[indianajoel]

David-

When looking for my pinion seal I found 2 types. I first ordered the one for a Spicer rear end, part # 5778. It was a hair too loose, so I looked it up again and got the one for a GM rear end, part # 8460 at Advance Auto Parts for $6.50.

(On that note, if anyone could use the 5778 seal I'd mail it to them.)

You didn't get the pinion out? But you did remove the yoke that the u-joint bolts to, right? I don't think the splined shaft that comes out of the diff will come out...you have to access it from the back cover. But I was able to slide the outer bearings out and make sure they looked good. the pinion shaft should be loose when the pinion nut's removed because it's the pinion nut that holds the tapered bearings tight.
...if I understand it right...