Rear drive / bevel box rebuilds
Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
First off, regardless of what you want to do to your rear drive, read both of Pete Roper's articles (hosted at the Guzzi Power website). Better yet, read through them a few times to get a really good understanding of what these boxes are designed to do and how to repair them.
Now, I'll try to provide some insight from a first-timer's perspective. This information is only intended to supplement Pete's articles.
Items you will want to replace, regardless
- MG# 90403850 - The small outer seal (these are the same for all big twins)
- MG# 90407085 - The large inner seal (these are the same for all big twins)
- MG# 90706490 - The large O-ring that goes between the pinion carrier and the rear drive housing
- MG# 12352600 - The paper gasket that goes between the pinion carrier and the rear drive housing.
- MG# 12352900 - The paper gasket that goes between the pinion carrier and the swing arm.
- MG# 12350700 - The paper gasket that goes on either side of the shim between the flange and the body of the rear drive.
- Replace all of the washers and bendy-tabs with Schnorr washers.
Items you may want to replace, depending on condition
- MG# 92249225 - Pinion carrier bearings.
- MG# 92201070 - Large ball bearing pressed into the flange.
- MG# 92254340 - Needle bearing.
Special tools that are very helpful if not required
- Half of an old, worn out U-Joint - If you don't have one in your own stash, check with your local dealer or with friends.
- Two-jaw puller - I just bought a cheap one from Harbor Freight because I ended up grinding on it to make it able to remove the inner race of the needle bearing.
- Slide hammer puller - I bought a cheap one (Harbor Freight item number 60554). The attachments are weak and mostly worthless, but end up making my own using bolts that I grind for specific uses.
- Betty Crocker Roaster Oven - The Home Depot seems to sell these each year during the holiday season for around USD $30.00. Money well spent.
- Torque wrench - Nothing fancy here, just something that goes form about 10 to 50 foot pounds is great.
- 36 mm box-end wrench (or a 1 inch box-end wrench if you can't find one of those)
Things I learned the first time around
- Get the tools listed above before you start the tear down.
- Removing the outer race for the needle bearing is much easier if you use the oven technique Pete describes. Plus, you probably won't ruin the brass ring. But, it is very stinky. I'm still in the doghouse with my wife Angela for using the oven in the kitchen. Now I have the Betty Crocker Roaster Oven and it works great.
- Forget messing around with the old bendy-tabs and lock washers...replace them all with Schnorr washers and be done with it.
- When installing the small outer seal, be sure to install it properly. As you are looking into the housing (as if it were a bucket), the flat surface of the seal should be on the bottom. If you get it backwards, your rear drive will leak (ask me how I know this).
- There is no need to use gasket sealant on any of the gaskets. My experience is that they gaskets seal quite well with just a coating of grease on them.
- Do use a high quality spline grease on all of the splines. Do not use wheel bearing grease or any other typical grease. It will only heat up, turn to liquid, and get flung all over your rear wheel (ask me how I know this). Instead, use something like Amsoil Fifth Wheel and Open Gear Compound.