rear pinion seal change

[DannyW]

Well, it's that time. I guess 216,000 miles on the original seal and u-joints isn't too bad.

Got a question about the disassembly though. I have the instructions posted in TDR sometime back about torqueing the pinion nut back exactly to its as-found position, plus just a pinch for good measure. But it talks putting a holding tool on the pinion flange (can't remember the proper name right off the bat) while breaking the nut loose. If the rear wheels are up on ramps with the parking brake cinched down tight, that will keep the pinion from turning. Or is the nut so tight that breaking it loose that way would put too much stress on something in the differential?

 

[sag2]

You need the holding tool.

 

[DannyW]

And exactly what's the deal with the differential oil level.....1/4" below the plug?? Is there any good reason not to fill it to the plug?

 

[Prairie Dog]

And exactly what's the deal with the differential oil level.....1/4" below the plug?? Is there any good reason not to fill it to the plug?

It keeps it just below the lip of the seals.
But I've always filled it up.

 

[DannyW]

What a goat roping this has turned into. First, that prior article in TDR got it wrong about the socket size. 1.375"? (1 3/8", that is) Too small. So I managed to lay hands on a 38mm 6-point (too small) and a 39mm 12-point (too big). So I haven't the foggiest what sort of socket this thing takes. I had ordered a seal from one of the online Mopar suppliers, but since I was dead in the water and wanted a backup seal when I finally got this nut off, I had the dealer order one. He had to have the VIN number to make sure he got the right one. So the seal job is at ALL STOP for the time being. An aquaintance is a Mercedes mechanic......he said, "American Axle?? Them sumb**ches dont' know WHAT they've got."

 

[DonFitzwater]

Big pipe wrench on the pinion flange works fine..........but now that you've gone to the trouble of making the tool, use it! Lol

I believe you might have mixed up Dana pinion and American Axle pinion info. 2nd gen trucks had Dana and 3rd gens run AAM.

 

[DannyW]

Nope. The article in TDR 67 is specifically about a 2004, as is mine, with the AAM.

 

[DonFitzwater]

Different axle size then?

 

[DonFitzwater]

The article in issue 67 details a front axle pinion seal change...................

 

[jhenderson]

You mean the pinion on a 9 1/2 in differential might be smaller than the pinion on an 11 1/2 in differential? Whoda thunk it?

 

[Blakers]

What a goat roping this has turned into. First, that prior article in TDR got it wrong about the socket size. 1.375"? (1 3/8", that is) Too small. So I managed to lay hands on a 38mm 6-point (too small) and a 39mm 12-point (too big). So I haven't the foggiest what sort of socket this thing takes. I had ordered a seal from one of the online Mopar suppliers, but since I was dead in the water and wanted a backup seal when I finally got this nut off, I had the dealer order one. He had to have the VIN number to make sure he got the right one. So the seal job is at ALL STOP for the time being. An aquaintance is a Mercedes mechanic......he said, "American Axle?? Them sumb**ches dont' know WHAT they've got."

View attachment 91012View attachment 91013

So what size socket finally worked on the 11.5" ?

 

[Ozymandias]

36mm 12point - use a 3/4" Tool, 1/2" will probably break.

 

[Blakers]

36mm 12point - use a 3/4" Tool, 1/2" will probably break.

Thanks. I have a 3/4" drive 1 7/16 socket. That is 1/64" larger than 36 mm. I may try that first since I have it.

 

[Ozymandias]

Thanks. I have a 3/4" drive 1 7/16 socket. That is 1/64" larger than 36 mm. I may try that first since I have it.

17/16 should work

 

[Blakers]

Well a 1 3/8 socket worked by tapping it on with a small hammer. Now my problem is getting the flange off. It won't budge. How much force should it take to come off? Is it just sealer in the splines holding it? Does it hurt to beat on it with a hammer?

 

[Blakers]

I'll probably use 1 7/16 to tighten it back up. Using a 3/4" ratchet rather than an impact wrench.

 

[Blakers]

Made a makeshift puller with C-clamps and got it apart. White sealer was holding everything together. The seal was half rusted away and the oil was leaking from around the seal, not through the seal. After a lot of difficulty, I got the seal out, scraped the mating surface clean of rust from the old seal, then installed the new seal with sealer around it. Then put sealer on the splines and installed the flange. I tightened the nut, however I can not get it quite to the point it was. It's within 5 minutes on a clock. I used a 3/4 ratchet with a cheater pipe. I'd like to get it tighter, but either can't hold the flange from turning, or my ratchet starts to bend.

 

[Ozymandias]

Do you have an Impact Drive? I usually use this for it to make the Last couple of Angel Degrees.

 

[TConver]

you really want to get it back to the original spot and then add about 5 ft lbs of additional torque to get the right preload.

 

[Blakers]

Believe me, it's tight! Since I did not mark the exact position of the flange to the shaft, the splines may not be lined up exactly as before. That could cause a difference in the position of the nut compared to originally. The spline machining could be slightly different. All buttoned up and waiting on gasket sealer to dry and then add oil.