white90 Posted July 20, 2006 Posted July 20, 2006 This job is the replacement of the rear transfer case output shaft bearing and rear oil seal. Normally the first you will know about this is yet another pool of oil under your truck, and with a bit of further investigation - the handbrake drum will wobble. The alloy casing behind the handbrake drum and backplate carries the oil seal and output shaft bearing. The method here is the replacement of the rear ouput shaft bearing, oil seal, and associated gaskets. Unfortunately the brake shoes had not long been replaced, and it would be wise to replace them again, but soaking in petrol removes nearly all of the oil that has soaked into them. The handbrake pulls on 4 clicks and the engine has to be revved hard to get the truck to move, so I think it'll be ok. Raise and support the rear of the vehicle and drain the transfer case. This is the tell-tale sign that all is not well:- A Transfer box overhaul set is only about £3 more than buying the individual oil seals, and you'll need to buy a couple of gaskets too. You get everything for around £7, including the seals. Remove the rear propshaft, and this 30mm nut is exposed. It's very tight and even with the vehicle jacked up, there still isn't a great deal of room to undo it. Pull the handbrake on as hard as you can and then a socket and breaker bar/foul language/etc, should see it come loose. Once you have got a couple of turns on the nut, leave it as it is and undo the two countersunk m8 screws indicated - these hold the drum to the drive flange. The drum may have a lip on the inside through wear, so you need to now slacken both the handbrake cable and adjuster in order for the drum to come off. 19mm spanner on the cable - undo it several turns until the outer sleeve of the cable is very loose in the housing. The adjuster on the opposite side - 11 mm spanner fits and undo this several turns until it no longer ratchets every 1/4 turn. The inside of the drum is soaking in oil as I expected it would be. Brake shoes and backplate are all soaked as well. The drive flange nut and washer can now be removed and the flasnge will slide off. The brake shoes, expander unit, adjuster, and backplate can be removed as one. Disconnect the handbrake linkage by withdrawing either one of the pins that make up this linkage. Like this. Ondo the 4 x 15mm bolts that hold the backplate to the bearing housing and the whole assemply will lift away. Undo the 10mm nut that retains the speedo cable and the cable should then just push out of the way. Should be looking at this now. The handbrake cable bracket is in the way now. There are 4 x 13mm bolts that hold it to the side of the transfer case. The two down the side just need to be undone a few turns. The two others need to be removed, and the loose bracket will then move off to one side - clear of the bearing housing. Because there's a danger of grit getting inside the transfer case - clean around the housing and it's fixing bolts before removing them. One bolt (at the 1 'o' clock position is longer than the others. The housing may be stuck in place, and as it's alloy and can be easily damged - there's an easy way to get it off. Screw the longets bolt in in this position - a good few turns to make sure the thread isn't going to be damaged. Then use a pry bar or large screwdriver in this position to release the bearing housing. This is what should come out. Inner bearing appears to be fine - it's oily and I can't detect any play in it at all, so I'm not going to strip the transfer case down any further. The feel of the bearing and shaft in the housing I just removed makes me confident that only the outer bearing is worn. Off down the shed to rebuild the bearing housing. Grip the shaft in a vice that has soft jaws, and carefully lever the seal dust cover off. Then lever the oil seal out with a screwdriver or similar, then the shaft can be knocked out with a mallet. The bearing is retained by a large circlip - release it and the bearing can be pressed or knocked out using a suitable drift. Take care not to damage the housing. The parts of the housing assembly. The bearing track is cracked - surprising how that has happened, as the housing is ok still. Clean all parts, this is the assembly cleaned and new bearing, oil seal, and gasket, ready to be re-assembled. Carefully press the new bearing in nice and square using a suitable drift. Bearing in the housing and circlip to retain it. The oil seal has a raised inner lip - make sure this is just below the edge of the housing or the flange will damage it. Replace the dust cover The housing back in place - new gasket and a small amount of RTV sealant as the lower part of the casing was a bit pitted. The brakes shoes, backplate, etc all cleaned in petrol to remove as much oil as possible. The drum is cleaned, and the assembly is all put back together. Handbrake now has 4 clicks and works ok. No play in the drum, and the jobs a good-un Once again thanks to Mark Jenkins - owner of this vehicle - the list iof things that need fixing is getting smaller - no, really Les.
Recommended Posts