So I have the parts to do my transmission oil pump and while I'm playing under there for a few hours I thought I'd do the rear wheel bearing as it's started to rumble now. Off I go to the store and start to get the bearing, what axle is it they ask, so I think it's OK, there's a code (B4) on a 91 EXT AWD 4.0 that was no help, so I run back home, look on this informative site and low and behold, withing 30 secs I'm armed with the answer, so under the van I go looking for a tag with the number and it's not there, so what now, I know that the diff cover does not have the fill plug if thats any help, anyone got any ideas as it would help to know if I need a puller or a diff cover gasket. I couldn't find any other information on the search function so any further information on identification would be helpful.
Adie

 

Welcome to FTE!
Aerostars use a 7.5" rear end with 28 spline axle shafts. The axle is a semi-floating variety meaning the shaft turns on the bearing which can cause that portion of the axle shaft to wear.

The axle shaft(s) must be removed to access the bearings. This means opening the differential and pulling the C-clip(s) securing the axle. Withdrawing the axle shaft(s) will also drag out a puddle of hypoid lubricant so have your brake shoes removed and a drip pan under the end of the axle.

There are two styles of replacement bearings - the original style and an offset style for use when the shaft is worn. This often called a 'replacement bearing' in parts store lingo. Getting the old bearing out requires a large slide hammer with puller tips or the special puller that folds up to allow it to pass through the bearing axle shaft hole. Once through, it is weighted and the swivel end drops down forming a "T" that fits the backside of the bearing race. Either way, it takes considerable effort to extract the old bearing. You will also need to fit a new seal(s) when replacing the bearing. No gasket on the diff cover, just scrape the old RTV silicone off and run a small bead of new around when replacing.

On edit: Here is a link to a picture of the "special" puller mentioned above. Not recommending you purchases these as you may be able to get one from your local parts store 'free' tool loan program. http://www.drivewerks.com/catalog/sh...CAT407_pg3.htm

 

You star, thanks a lot, i have a puller that I can use I just wasn't sure if I needed to take off c-clips or just drift the shaft out, didn't know about the seal so i will grab one of those at the same time, youve just saved me a load of time wondering where to start, thanks.
Adie