Transfer box rear oil seal change

[Jon Wildsmith]

The transfer box rear output oil seal on my 100 was leaking very slightly so I changed it today. First job was to remove the rear prop shaft and this is what I do rather than match marks until it's on the bench, saves the end falling off

It was a close call with the Pro Speed exhaust running so close to the transfer box wether I'd be able to get the rear housing off without removing the exhaust section. It just about scrapes past with having to leave one of the bolts undone but not pulled out until the rear housing was pulled away and could be turned slightly.

Apart from that it's just a case of disconnecting the various electrical connectors and the earth strap and then undo the casing bolts. Took at little leverage around the edges of the casing to get it to seperate.

Take the plate off, remove the speedo speed sensor. Remove the snap ring holding the speed drive gear and the gear and then the snap ring holding the shaft in the housing.

Then push the shaft out of the housing

The new oil seal has a taller outer lip than the old one, maybe this one will last longer

Greased up and ready to be put back together

Something not really shown in the pics are the oil pump shim which I smeared a bit of grease on the back of to hold it in its recess during reassembly and the main housing shim which has no recess and is just clamped between the parts once the bolts are done up tight so I used a little bearing/stud lock to stick it to the rear housing and left it with a heavy weight on while I had my lunch. By the time I was ready to put it back together it was held firmly enough to not drop off at the slightest touch!

 

[Rob]

Looks very familiar to the 80, did you replace the output bearing as well while you were there? I did mine without the bearing about 20k miles ago and it is leaking again

 

[Jon Wildsmith]

The bearing was fine, no plans to change that. From reading on the net and past experience these seals seam to be suseptible to failure if you throw a lot of gritty muck at them and yours leaking again might just be that. I'm assuming the design change on the 100 series part is an attempt to address that and it's possible they would fit an 80, might be worth checking.

 

[Gav Peter]

Did you ever get round to doing the codeword puzzle on the bench Jon?

 

[Jon Wildsmith]

you must be having a slow afternoon!

 

[Gav Peter]

I am... Almost caught up on 5 pages of unread posts on here though

 

[frank rabbets]

Sometimes replacement seals fail because of a groove worn in the shaft on which they sit. There are very thin walled stainless steel sleeves available to make a very good repair. You just squeeze them on.

Frank