Thread: Handbrake lining wear

bad adjustment from the get go and possibly a sticking expander.

pull down, give it a clean and lube and see how it moves without the drum on (wrap the shoes in some rope to give them some resistance and return motivation)

Operating mechanism is meant to be loose on the backplate but with a flat spring plate from memory so it is not "loose" (I seem to remember there are two types). This is the mechanism for equalising between the shoes. If the spring plate is missing or broken the lower shoe will probably be rubbing on the drum all the time.

John

Theoretically, transmission brake linings should hardly wear at all.But series Landy ones wear out. Why? Well, the front spring shackles are behind the axle, so when the front wheels ride over bumps the front axle moves back slightly on the shackles. In 4wd the front propshaft slip joint binds a little, so that the rearward movement of the front axle is transmitted to the transfercase which also gets pushed back on its rubber mounts. However, the handbrake bellcrank that attaches to the pullrod on the brake shoe expander is bolted to the chassis, so everytime the vehicle rides over bumps the handbrake is partially activated.A worn or dry slip joint on the front propshaft can bind even in 2wd.
Later 2As and 3s have a rubber bushed rod between gearbox and chassis that reduces transmission movement, but it still moves enough to wear the linings if the linkage is over adjusted.
Bill.

If thats happening then youve got some seriously crappy maintenance issues to sort out and the wrong propshaft fitted to the vehicle.

Originally Posted by wagoo

Theoretically, transmission brake linings should hardly wear at all.But series Landy ones wear out. Why? Well, the front spring shackles are behind the axle, so when the front wheels ride over bumps the front axle moves back slightly on the shackles In 4wd the front propshaft slip joint binds so that the rearward movement of the front axle is transmitted to the transfercase which also gets pushed back on its rubber mounts. However, the handbrake bellcrank that attaches to the pullrod on the expander is bolted to the chassis, so everytime the vehicle rides over bumps the handbrake is partially activated.A worn slip joint on the front propshaft can bind even in 2wd.
Later 2As and 3s have a rubber bushed rod between gearbox and chassis that reduces transmission movement, but it still moves enough to wear the linings if the linkage is over adjusted.
Bill.

Bill,

The slip joint on the rear propshaft is very badly worn (replacement propshaft needed) but I haven't checked the front yet.
Engine/gearbox mounts were all rooted, the gearbox mounts had been packed up with spacers because the mounts had compressed so much that the rear PTO shaft was touching the hole in the crossmember it runs through. Three of the four mounts had de-laminated.

Ex farmers car (prior to the last owner) so fixed rather than maintained.

Maybe the new mounts and a replacement propshaft will get rid of the problem but I also need to look at the operating mechanism to find out why it's loose on the backplate. Looking forward to spending the weekend underneath the S2 degreasing etc.



Colin

Originally Posted by Blknight.aus

If thats happening then youve got some seriously crappy maintenance issues to sort out and the wrong propshaft fitted to the vehicle.

No , just some seriously crappy vehicle design issues.
On the tediously long 'To Do' list to properly sort out a series LandRover, is a cable actuated handbrake or a transmission mounted handbrake lever, No other manufacturer in the world to my knowledge, including LandRover since the Stage Ones.and first RangeRovers uses a lever/bellcrank/rod linkage mounted independantly of the transmission.
Bill.

Originally Posted by gromit

Bill,

The slip joint on the rear propshaft is very badly worn (replacement propshaft needed) but I haven't checked the front yet.
Engine/gearbox mounts were all rooted, the gearbox mounts had been packed up with spacers because the mounts had compressed so much that the rear PTO shaft was touching the hole in the crossmember it runs through. Three of the four mounts had de-laminated.

Ex farmers car (prior to the last owner) so fixed rather than maintained.

Maybe the new mounts and a replacement propshaft will get rid of the problem but I also need to look at the operating mechanism to find out why it's loose on the backplate. Looking forward to spending the weekend underneath the S2 degreasing etc.



Colin

Colin, as John mentioned, the expander mechanism is designed to slide on the backing plate to balance the movement of the brake shoes.Don't quote me but from memory the nuts on the wedge type brake adjuster according to the manual is also intended to be tightened and then slackened off slightly before bending over the lock tabs.
Make sure your new front propshaft has a grease bleed hole in the end cap of the slip joint, otherwise suspension movement will push the transmission around too much.It's a bugger of a high maintenance design though. Once the front suspension is fully compressed, all the grease gets squeezed out the hole, and the remaining grease on the splines gets dispersed and the splines wear unless you regrease them regularly. Coil sprung propshafts dont have bleed holes because the slip joint telescopes instead of plunges with suspension movement.
Bill.

Originally Posted by wagoo

Colin, as John mentioned, the expander mechanism is designed to slide on the backing plate to balance the movement of the brake shoes.Don't quote me but from memory the nuts on the wedge type brake adjuster according to the manual is also intended to be tightened and then slackened off slightly before bending over the lock tabs.

A good point to remember, if I don't forget by the time I get to it.

Coil sprung propshafts dont have bleed holes because the slip joint telescopes instead of plunges with suspension movement.

That needs a little more thought, if the spline pulls and lengthens, then where does it go? It must return and compress the air inside that spline and what does this high pressure air blast do to the grease?
I might look at my prop shaft's again. ( the underneath of my bus needs a polish anyway ).
.