Pinion shaft seal leak

[lowndes]

'99 R1100S with only 13K miles, bought 5 months ago with leak from the pinion shaft seal. PO had let sit for several years, then replaced the rear wheel drive lube with synthetic.

Question: is it possible/feasible to replace just the pinion seal WITHOUT removing the threaded ring??

http://store.bobsbmw.com/microfiche/DisplayImage.aspx?Size=Full&Type=Z&ImageID=153867

This looks do-able by removing the nut (#1) and compression ring (#2), then hooking the seal (#4) out. Some P-80 will get the new seal in easily. Doing this will not upset the pinion-ring gear lash or require the 33 1 700 tool.

Not sure if it would be best to remove the threaded ring (#3) and then the bearings and shaft for inspection with this few miles, or leave it alone except for the seal.

Anyone ever do this??

Regards

 

[PAS]

Sometimes synthetic oil will leak where as a dino oil wont. Cant help you with the seal question.

 

[gsaddict]

'99 R1100S with only 13K miles, bought 5 months ago with leak from the pinion shaft seal. PO had let sit for several years, then replaced the rear wheel drive lube with synthetic.

Question: is it possible/feasible to replace just the pinion seal WITHOUT removing the threaded ring??

http://store.bobsbmw.com/microfiche/DisplayImage.aspx?Size=Full&Type=Z&ImageID=153867

This looks do-able by removing the nut (#1) and compression ring (#2), then hooking the seal (#4) out. Some P-80 will get the new seal in easily. Doing this will not upset the pinion-ring gear lash or require the 33 1 700 tool.

Not sure if it would be best to remove the threaded ring (#3) and then the bearings and shaft for inspection with this few miles, or leave it alone except for the seal.

Anyone ever do this??

Regards

The seal cannot be replaced without removing the threaded ring. It is pushed in from behind.
FYI A chevy 4wd axle nut tool will remove it (most parts jobbers stock 'em for under $20)
The ring is very tight and can be a bear to remove.
The jig below holds the pinion from turning when removing the hexnut as well holding the FD in a vise to remove the threaded ring.
When replacing the seal it is recommended to replace the compression ring as well.
Be sure to apply sealant to the threaded ring threads as well. Many leaks blamed on the seal are actually oil creeping along the threads.
Note that items 9 & 10 on the fiche which appear as an O ring do not exist on the fiche parts list or on any FD I have ever serviced.

 

[lowndes]

GSAddict, THANK YOU, sir, for the quick and very helpful reply. I could not tell that the seal only accessed from the inside of the threaded ring. That is very helpful bad news.

I have the Hylomar M on order, as well as Stauberags paste for the splines, already have the seal. Need to get the compression ring on the way. Thank you for that info.

I can see how the jig will be necessary to remove and torque the threaded ring. Can make that from bar stock and pipe nipples.

The Chevy 4WD axle nut tool is very welcome news. The plan was to attack a deep well socket with a grinder, but was not looking forward to it.

What is your recommendation on moly additive to the 75-140GL5, or not, for the refill??


Lowndes

 

[PGlaves]

What is your recommendation on moly additive to the 75-140GL5, or not, for the refill??


Lowndes

That viscosity is out of spec for that drive. Put in 80w90 dino oil and watch the seal be just fine, probably. And I do run a moly additive in all of our final drives and transmissions.

 

[gsaddict]

That viscosity is out of spec for that drive. Put in 80w90 dino oil and watch the seal be just fine, probably.

Agreed. 80w90 dino or 75w90 syn.

 

[saddleman]

Most of the compression rings are tapered on both sides. If yours is you can just flip it over if it has any wear on it. I preheat my final drive rebuilds to 240 degrees F in a toaster oven before I remove the nut & threaded ring.

Most of the threaded rings had a lip & the seal has to be installed with the ring removed. I have seen some threaded rings with no lip. If yours has no lip make sure you measure the installed seal depth before you remove it. It can also be hard to get the seal square on the ring without the lip.

If it is a small leak I wouldn't bother changing the seal. Also make sure it isn't the transmission output shaft seal leaking. I roll up a white paper shop towel & put it up the bottom of the swing arm as far as I can.

 

[lowndes]

THANKS, y'all!!

PGlaves, GSAddict (again), Saddleman, THANKS!! I do appreciate the collective wisdom!! No need to reinvent the wheel, right?? Thank you for your altruistic contributions to everyone here.

The 75-140 GL5 lube came from the Chris Harris vid:https://www.youtube.com/watch?v=L0_j8SuiFQI Mile post 31:45. He sure sounds confident in his recommendations, but then....

Considered changing the oil to see if it helped. Read several items about synthetic oils hardening the seals. Thought about an additive to soften the seal. Might try that first. This is a winter day job, plenty of riding weather before then!! Will try out these easy ways first and report back.

Saddleman, the "compression ring" is a static "spacer", correct?? Wear or deformation??

Regards, gentlemen,


Lowndes


Lowndes

 

[saddleman]

The compression ring is solid steel & does not compress. The compression ring turns inside the seal & can get a wear groove.

 

[gsaddict]

Parts in question. The compression ring in this case could be re-used