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The Hand brake or more correctly the transmission brake is situated between the transfer gearbox and the rear propshaft. It’s basically a drum brake which when operated slows down the rotation of the rear propshaft via a hub which in turn slows the vehicle down. Its not the most efficient set up as it only uses one pair of brake shoes as compared to a conventional set up which would use two pairs (one for each rear wheel). The other downside is the stresses placed upon the rear axle and propshaft when operated due to the fact
The Hand brake on my vehicle wasn’t hardly slowing the vehicle down let alone stopping it so a quick look underneath revealed evidence of an oil leak from around the bottom lip of the drum. This turned out to be a leaking rear output seal from the transfer box which was leaking oil into the drum which contaminates the shoes.
The fix is to remove the propshaft and drum and you will be left with a castellated nut with a split pin through it (see pic).
You will be left with the exposed seal (see pic), you could attempt to change the seal now but it’s far easier and better to remove the six bolts securing the housing and to change the seal on the bench. There will be some shims between this and the transfer box (or there should be) and are there so you can adjust the pressure on the Speedo drive. If in doubt just replace the shims in the order they came off. After replacing the seal, bolt the housing back on and replace the brake back plate after checking and
<< SPEEDO CABLE
that the brake is trying to slow one end of the propshaft whereas the forward momentum of the vehicle is trying to turn the other end. It’s for this reason that the transmission brake should only be used as a parking brake and for emergency's only to minimise the torsional stresses placed on the rear transmission. Continual use of the transmission brake to stop the vehicle will result in accelerated wear of components and eventual mechanical failure.
Remove these (the nut is tight) and remove the hub. Disconnect the handbrake linkage and the Speedo cable next (a right fiddly job) before removing the brake back plate complete with shoes etc.
cleaning the shoes/adjuster etc. Mine needed a new adjuster as it was seized solid! Replace the hub after cleaning it and replace the felt washer that fits under the castellated nut. Tighten the nut up to 85 lbf.ft (told you it was tight) and fit a new split pin. Replace the drum and propshaft and reattach the Speedo cable and hand brake lever linkage. (Even more of a fiddly job) Adjust the hand brake by making sure it releases and engages when its supposed to and your done. You may even find your Speedo works better now due to the castellated nut being tightened up.
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