Lehman straight axle pinion seal

[dsifford]

I have a differential leak, finally narrowed it down to pinion seal, I think. GL1800, Monarch II. Does anyone know if you have to pull the diff to replace the seal? I was told yes, and it does not appear to have much room otherwise.

Thanks. After 7,000 mile trip it got really nasty, had not noticed it so bad before.

[Lee H. Mann]

I have a differential leak, finally narrowed it down to pinion seal, I think. GL1800, Monarch II. Does anyone know if you have to pull the diff to replace the seal? I was told yes, and it does not appear to have much room otherwise.

Thanks. After 7,000 mile trip it got really nasty, had not noticed it so bad before.

Questions:
Does yours have WING EFX and if it does, do you still have the center stand ?
If you have no longer a center stand, do you have the Rear WING EFX support kit ?

If you have a center stand or the support kit, you can use a paddle jack to raise only the rear axle enough to get a pair of jack stands under the body support frame far rearward as possible, maybe across the rear of the trunk area between mufflers.

The stands are just to keep the trike from see-sawing while on the center support.

You can remove the u-bolts from the u-joint and remove the caps.

Do not remove the driveshaft, leave it in the swingarm. Remove the lower stabilizer bar completely and remove the differential cover and drain the fluid from the rear axle assembly.

The 4 bolts that attach the rear axle to the swingarm can be removed one side at a time.

If you undo the right side you can start to shift the rear back enough to get the driveshaft away from the pinion.

Unbolt and remove the pinion flange and the old pinion seal.

Inspect the seal and flange.

Removing the 2 bolts on the left will allow you to move the rear axle assembly far enough back that you can rotate it 90 degrees so that the pinion faces downward.

There are 3 different type of pinion leaks.
1) Between the pinion shaft splines and the flange
2) Between the pinion flange surface and the seal
3) Between the pinion seal and the snout of the rear axle housing

All three of these conditions trace back to the original construction of the axle assembly by outside vendors.

Unfortunately the discovery of these failures took months and years to figure out the exact causes.

NOTE: You should take caution when doing this repair and consult someone familiar with rear differentials and axles. They can kinda look over your shoulder and maybe help guide you. It is an exacting job and should be left to someone who has experience here.

[dsifford]

Questions:
Does yours have WING EFX and if it does, do you still have the center stand ?
If you have no longer a center stand, do you have the Rear WING EFX support kit ?

If you have a center stand or the support kit, you can use a paddle jack to raise only the rear axle enough to get a pair of jack stands under the body support frame far rearward as possible, maybe across the rear of the trunk area between mufflers.

The stands are just to keep the trike from see-sawing while on the center support.

You can remove the u-bolts from the u-joint and remove the caps.

Do not remove the driveshaft, leave it in the swingarm. Remove the lower stabilizer bar completely and remove the differential cover and drain the fluid from the rear axle assembly.

The 4 bolts that attach the rear axle to the swingarm can be removed one side at a time.

If you undo the right side you can start to shift the rear back enough to get the driveshaft away from the pinion.

Unbolt and remove the pinion flange and the old pinion seal.

Inspect the seal and flange.

Removing the 2 bolts on the left will allow you to move the rear axle assembly far enough back that you can rotate it 90 degrees so that the pinion faces downward.

There are 3 different type of pinion leaks.
1) Between the pinion shaft splines and the flange
2) Between the pinion flange surface and the seal
3) Between the pinion seal and the snout of the rear axle housing

All three of these conditions trace back to the original construction of the axle assembly by outside vendors.

Unfortunately the discovery of these failures took months and years to figure out the exact causes.

NOTE: You should take caution when doing this repair and consult someone familiar with rear differentials and axles. They can kinda look over your shoulder and maybe help guide you. It is an exacting job and should be left to someone who has experience here.

Good to hear from you Jim.

Hope you are doing well.

Does 8 hours sound reasonable for the repair.

I have a local Lehman builder that says he will do it. Personally never done any differential work before. I have the wings and support bar no center stand. If I had know you were back at work I would have contacted you while I was in the Arlington VA area 2 weeks ago. Once out can NAPA identify the necessary part needed?

Thanks.

[Lee H. Mann]

Good to hear from you Jim.

Hope you are doing well.

Does 8 hours sound reasonable for the repair.

I have a local Lehman builder that says he will do it. Personally never done any differential work before. I have the wings and support bar no center stand. If I had know you were back at work I would have contacted you while I was in the Arlington VA area 2 weeks ago. Once out can NAPA identify the necessary part needed?

Thanks.

If they are just replacing the pinion seal, 5-6 hours should be sufficient. Axle bearings too....maybe 8.

I will give you the pinion seal part numbers.

They make a NEW triple-lipped seal that is better than the original 2 lipped seal. Get the Timken 8181NA seal.

Later and I am doing better.

[dsifford]

If they are just replacing the pinion seal, 5-6 hours should be sufficient. Axle bearings too....maybe 8. I will give you the pinion seal part numbers. They make a NEW triple-lipped seal that is better than the original 2 lipped seal. Get the Timken 8181NA seal.

Later and I am doing better.

Thanks soo much for the help after i complete the rum for ther wall next year may just have to sor in for a vists.

[Tagg]

I see that you mention 3 different type of leaks on the pinion seal. How do you tell which is which and will the 8181NA seal cover all 3 repairs ?

Thanks.

Questions:
Does yours have WING EFX and if it does, do you still have the center stand ?
If you have no longer a center stand, do you have the Rear WING EFX support kit ?

If you have a center stand or the support kit, you can use a paddle jack to raise only the rear axle enough to get a pair of jack stands under the body support frame far rearward as possible, maybe across the rear of the trunk area between mufflers.

The stands are just to keep the trike from see-sawing while on the center support.

You can remove the u-bolts from the u-joint and remove the caps.

Do not remove the driveshaft, leave it in the swingarm. Remove the lower stabilizer bar completely and remove the differential cover and drain the fluid from the rear axle assembly.

The 4 bolts that attach the rear axle to the swingarm can be removed one side at a time.

If you undo the right side you can start to shift the rear back enough to get the driveshaft away from the pinion.

Unbolt and remove the pinion flange and the old pinion seal.

Inspect the seal and flange.

Removing the 2 bolts on the left will allow you to move the rear axle assembly far enough back that you can rotate it 90 degrees so that the pinion faces downward.

There are 3 different type of pinion leaks.
1) Between the pinion shaft splines and the flange
2) Between the pinion flange surface and the seal
3) Between the pinion seal and the snout of the rear axle housing

All three of these conditions trace back to the original construction of the axle assembly by outside vendors.

Unfortunately the discovery of these failures took months and years to figure out the exact causes.

NOTE: You should take caution when doing this repair and consult someone familiar with rear differentials and axles. They can kinda look over your shoulder and maybe help guide you. It is an exacting job and should be left to someone who has experience here.

[Lee H. Mann]

First of all, make sure the replacement is a triple-lipped seal, don't CHEAP OUT HERE ! The seal will fix 2 of the 3 conditions. The one condition that the seal won't fix is the pinion spline-to-yoke or pinion flange leak.

After cleaning and running again, look to the very front of the pinion flange behind the u-joint for leakage. If leaking here the sealant used between the flange and pinion might have failed. Regardless, the pinion seal should be replace when repairing this leak also.

Clean the front snout prior to diagnosis and try to isolate the leak before ordering parts.
You may have to disassemble the pinion flange to make sure you don't need a speedy-sleeve with the seal. Sometimes the yoke may be undersized and causing the leak. This condition is usually immediately noticeable and not a usual situation.
Prior to assembly, or purchase of the seal, make sure the seal fits snug on the flange and make sure there are no grooves and scratches on the flange seal area.

[dsifford]

Thanks Jim. Turns out the pinion yolk had several rough spots on it. A speedy sleeve was used and I was assured the seal was top quality. Thanks for the guidance. Hoping I am good for at least another 30K miles.

[Papa Zook]

Great help Jim!