Rear Drive outer seal replacment -1000 SP

[Rafael]

Hello again,
Unfortunately, when my trans leaked, on a long road trip, it filled my rear drive. The pressure build up damaged the, hard to get to, seal or at least it appears that way. The oil seams to be coming from the center of the splines. My question is whether the rear drive has to be reshimmed when this seal is replaced or can I take it apart and put it back the way I found it?
thanks, Rafael

 

[john zibell]

No need to re-shim. To get the race out for the inner bearing, you sometimes need the Guzzi special tool. I haven't found any generic pullers that will get the race. Sometimes you are lucky and it falls out.

 

[Rafael]

thanks John
Is 12 90 69 00 the tool your referring to?

Rafael

 

[Penis Rotor]

For that race I use a bicycle wheel bearing puller. Little three legged bugger with a 'Bridge' that goes across the bearing. Hook the *feet* under the brass washer and whoops-a-daisy out it'll come.

No need to re-shim but what I always suggest to novices is that they bolt the crownwheel holder into the box and pll the crownwheel onto it's big bearing by tapping the box on the bench to seat it and then pulling the splines *out*. Then you can feel the backlash between the crownwheel and pinnion by rocking the pinnion back and forth.

When re-assembling it is important to have the same backlash, sometimes you'll find this requires and extra crownwheel shim gasket.

Pete

 

[john zibell]

thanks John
Is 12 90 69 00 the tool your referring to?

Rafael

Yes that is the one. Like I said, see if it falls out first. Sometimes they do. Then again, Pete's bicycle puller has to be less expensive.

 

[Morizzi]

I've never used a puller, I use heat.

Put the drive in a vice with some soft patches. I have it standing so the axle would be horizontal. I then heat the casing around the race so that it expands. A brush with some water on the race can help too. You do need to get it hot but propane/butane can do it.

When it is loose enough just use a seal pick to pull it out. I have a rag underneath for it to fall on.

There is a trick to replacing that inner seal. If there is any pitting on the surface the seal runs on it may leak if you push the new seal all the way home as the lip will run on the pitted area that has been outside of the oil environment. I put the seal and washer just in a bit. I then re-assemble the drive without the bearing race and torque the bolts down. This pushes the seal in the minimum amount and allows it to run on the smooth surface that has been protected by the lubricating oil. You then pull it all apart and insert the bearing race using some heat again down until it just touches the sealing washer and seal. If the surface is too far gone you can get a shaft repair sleeve for the seal face if need be. 38mm from memory, the last one I purchased was 'Chicago Rawhide' brand.

Remember you are looking at that seal from the inside. When replacing it you should be able to see the spring.

 

[Rafael]

Back to this winter project. Well, no luck finding a bicycle bearing puller. I used to have one years ago; I think bicycle technology has changed so much these aren't used or sold any more. I found a pilot bearing puller; too small and found a 3-inch 3 legged puller; too big. I probably try the heat, if that doesn't work for me, I'll grind down the 3 legged puller to fit.

Moto Guzzi wants $241 for the factory puller. John: Does the MG puller do anything besides pull the one bearing race? Maybe help with the install?

This rear drive has some issues, I found a little play in the pinion bearing, fortunately not side to side but in line with the shaft, so I'll be reading Pete's procedure and posting further questions once I make some more progress. Thanks

 

[john zibell]

Moto Guzzi wants $241 for the factory puller. John: Does the MG puller do anything besides pull the one bearing race? Maybe help with the install?

Unfortunately that tool is a uni-tasker. It does only one job, but it does it well. Good luck on shimming the pinion bearing.

 

[Rafael]

Hate to admit it but I think it's a smart move. I sent my rear drive to a specialist for the shimming. Reshimming of the crown ring is required now the the pinion is adjusted. I don't want to mess with shimming at least not yet. Suppose when I get the proper tools I'd like to learn. BTW the race came out without a special tool. I used a seal puller and carefully guided it around the base washer and it lifted right out.