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I recently bought an e locker from a 1997 land cruiser colorado with the intension of fitting it in my 2nd gen surf.
The locker was bought on the assumption that the actuator was in good working order, in all fairness it looked like new.
I figured if I was going to do the job properly I should remove the actuator and service it.
This was the beginning of the end for the actuator. It was welded into the diff and had to be forcibly removed.
The write up that follows covers the solution to my (very expensive) problem and my recommendations for anyone looking to
do their own.
I have fitted the locker in my surf axle and am operating it using an air actuator powered using a small compressor.
I will not be covering fitting the locker to the axle in too much depth as this has been done to death on a number of forums.
The diff was removed from its original home in a land cruiser axle and checked thoroughly for any wear or damage. All was
well (baring the actuator). I had decided by this point to convert to air actuation as it is much cheaper than electric.
For reference the cost to replace the electric motor is reputed to be around £400, the air setup cost less than £50.
It could potentially be done for around £30 if you have a friendly local pneumatics supplier.
The first job was to get the diff to lock and unlock on the bench. I removed the cover from the side of the diff. This cover
acts as a bearing, supporting the end of the shaft to lock/unlock the diff. Once removed I was able to take measurements.
Specificaly how much throw was required on the shaft to fully lock and unlock the diff. For information this was roughly 17mm.
The shaft has limited movement and will stop at either end of its throw so the air cylinder used can have a greater throw than
the shaft. I opted for this http://www.ebay.co.uk/itm/1908367174...%3AMEBIDX%3AIT .
The cylinder was stripped and a spring was fitted at the inner end to make the locker dissengage automaticaly, a failsafe.
Next I needed enough clearence for the shaft to come out of the diff. 30mm is pleanty for this. I cut a piece of 30mm plate,
milled it to 50mm x 90mm to cover the mounting area for the original end plate. The mounting holes were drilled and counterbored
and the hole for the shaft was drilled to 30mm to match the diff housing. The air actuator could then be mounted using M5 studs.
The actuator was attached to the shaft using an adaptor mad from 25mm steel bar. It has an M5 stud to screw into the actuator
and a 14mm hole to slide over the diffs shaft. An M5 hole was tapped in the side of the adaptor to grip the diff shaft.
This shaft is hardened so a dimple was ground into the shaft in line with the threaded hole and a grub screw was used to retain
it. The actuator could then be assembled onto the diff and tested. All mating faces have gaskets and are sealed with RTV silicone.
There is a hole in the front of the housing for the motor. This was plugged up using a 24mm core plug. The switch in the top can
be used to turn on a light on the dash. As mine was damaged it has been removed. It happens to be the same thread as a diff drain
plug and makes a nice filling point.
The next thing on my list was a simple onboard air system to run the actuator. I have thought about onboard air before now mainly
for the purpose of inflating tires but I havnt as yet been able to justify the cost. The air system I built cost next to nothing
to build. My only real requirements were; it needed to be able to engage the difflock and keep it there, it needed to be hidden
away and it needed to be cheap. My setup uses a 12v tire compressor similar to this http://www.ebay.co.uk/itm/New-Heavy-...item1e8d09553c
I already had the compressor so that was free. Aldi have been selling these for £12 recently. The system needed a reservoir but
not a huge one. My solution, a disposable co2 cylinder from a mig welder. All that needs doing is the valve drilling out of the
top. The fittings required for the air system are; a pressure switch, safety valve, inlet and outlet. The pump is rated at 150psi
the pressure switch turns on the compressor at 90psi and off at 110psi and the safety valve is set to 120psi. The whole system is
piped up with 6mm nylon tube and push fittings rated at 150psi. My diff will lock easily at 20psi and the cylinder is rated up to
150psi. The cylinder is controled by a pneumatic solenoid http://www.ebay.co.uk/itm/3605958412...%3AMEBIDX%3AIT
and a pair of relays handle the power. Everything fits nicely in one of the tool bins in the back. The compressor will charge to
110psi in around 20 seconds and is wired only to run when locked.
The axle had to come out next. This should have been an easy job until I realised I didn't have any stands big enough to reach the
chassis. My friend came to the rescue with some very large stands and off I went again. The axle came out easy and was stripped in
the workshop. All the cutting and welding was done using a gasket as a template. Top tip! When it comes to drilling the stud holes,
put the diff in the axle, find a drill the same size as the clearence holes in the diff and drill down them to mark the axle. Then
use your 6.75mm drill and drill through ready to be tapped. That way your in the right place and you are parrallel enough to the
diff for the studs to fit. ASK ME HOW I KNOW.... Anyway, cut, welded, ground, drilled, studs fitted and back together. Axle back
under the car and off for a test drive.
I have done about 25 miles at time of writing this and everything works fine. No nasty noises, it locks, unlocks. Perfect.
This project cost me a lot of money, mainly for the electric actuator that didn't work. If anyone wants to do their own here's my
advice.
Buy the diff on its own. No actuator, wiring, nothing. I saw one on ebay for £170.
The air system is easy. £15 compressor, £10 solenoid, free reservoir if you use a disposable co2 cylinder to weld your axle.
Pipework and fittings cost around £30, this would probably have been less from a local pneumatics supplier.
I estimate with this advice you could do yours for less than £250. Thats less than a lunchbox type locker, less than an ARB air
locker and probably safer than a spool or welded diff in the long run.
Use pleanty of RTV silicone on gaskets. The stuff is brilliant and more or less guarantees a good seal. Make sure everything is
tightened up properly. Finaly don't forget to refill your nice new diff before driving it anywhere.
Thanks for reading. Pics will follow.
The locker was bought on the assumption that the actuator was in good working order, in all fairness it looked like new.
I figured if I was going to do the job properly I should remove the actuator and service it.
This was the beginning of the end for the actuator. It was welded into the diff and had to be forcibly removed.
The write up that follows covers the solution to my (very expensive) problem and my recommendations for anyone looking to
do their own.
I have fitted the locker in my surf axle and am operating it using an air actuator powered using a small compressor.
I will not be covering fitting the locker to the axle in too much depth as this has been done to death on a number of forums.
The diff was removed from its original home in a land cruiser axle and checked thoroughly for any wear or damage. All was
well (baring the actuator). I had decided by this point to convert to air actuation as it is much cheaper than electric.
For reference the cost to replace the electric motor is reputed to be around £400, the air setup cost less than £50.
It could potentially be done for around £30 if you have a friendly local pneumatics supplier.
The first job was to get the diff to lock and unlock on the bench. I removed the cover from the side of the diff. This cover
acts as a bearing, supporting the end of the shaft to lock/unlock the diff. Once removed I was able to take measurements.
Specificaly how much throw was required on the shaft to fully lock and unlock the diff. For information this was roughly 17mm.
The shaft has limited movement and will stop at either end of its throw so the air cylinder used can have a greater throw than
the shaft. I opted for this http://www.ebay.co.uk/itm/1908367174...%3AMEBIDX%3AIT .
The cylinder was stripped and a spring was fitted at the inner end to make the locker dissengage automaticaly, a failsafe.
Next I needed enough clearence for the shaft to come out of the diff. 30mm is pleanty for this. I cut a piece of 30mm plate,
milled it to 50mm x 90mm to cover the mounting area for the original end plate. The mounting holes were drilled and counterbored
and the hole for the shaft was drilled to 30mm to match the diff housing. The air actuator could then be mounted using M5 studs.
The actuator was attached to the shaft using an adaptor mad from 25mm steel bar. It has an M5 stud to screw into the actuator
and a 14mm hole to slide over the diffs shaft. An M5 hole was tapped in the side of the adaptor to grip the diff shaft.
This shaft is hardened so a dimple was ground into the shaft in line with the threaded hole and a grub screw was used to retain
it. The actuator could then be assembled onto the diff and tested. All mating faces have gaskets and are sealed with RTV silicone.
There is a hole in the front of the housing for the motor. This was plugged up using a 24mm core plug. The switch in the top can
be used to turn on a light on the dash. As mine was damaged it has been removed. It happens to be the same thread as a diff drain
plug and makes a nice filling point.
The next thing on my list was a simple onboard air system to run the actuator. I have thought about onboard air before now mainly
for the purpose of inflating tires but I havnt as yet been able to justify the cost. The air system I built cost next to nothing
to build. My only real requirements were; it needed to be able to engage the difflock and keep it there, it needed to be hidden
away and it needed to be cheap. My setup uses a 12v tire compressor similar to this http://www.ebay.co.uk/itm/New-Heavy-...item1e8d09553c
I already had the compressor so that was free. Aldi have been selling these for £12 recently. The system needed a reservoir but
not a huge one. My solution, a disposable co2 cylinder from a mig welder. All that needs doing is the valve drilling out of the
top. The fittings required for the air system are; a pressure switch, safety valve, inlet and outlet. The pump is rated at 150psi
the pressure switch turns on the compressor at 90psi and off at 110psi and the safety valve is set to 120psi. The whole system is
piped up with 6mm nylon tube and push fittings rated at 150psi. My diff will lock easily at 20psi and the cylinder is rated up to
150psi. The cylinder is controled by a pneumatic solenoid http://www.ebay.co.uk/itm/3605958412...%3AMEBIDX%3AIT
and a pair of relays handle the power. Everything fits nicely in one of the tool bins in the back. The compressor will charge to
110psi in around 20 seconds and is wired only to run when locked.
The axle had to come out next. This should have been an easy job until I realised I didn't have any stands big enough to reach the
chassis. My friend came to the rescue with some very large stands and off I went again. The axle came out easy and was stripped in
the workshop. All the cutting and welding was done using a gasket as a template. Top tip! When it comes to drilling the stud holes,
put the diff in the axle, find a drill the same size as the clearence holes in the diff and drill down them to mark the axle. Then
use your 6.75mm drill and drill through ready to be tapped. That way your in the right place and you are parrallel enough to the
diff for the studs to fit. ASK ME HOW I KNOW.... Anyway, cut, welded, ground, drilled, studs fitted and back together. Axle back
under the car and off for a test drive.
I have done about 25 miles at time of writing this and everything works fine. No nasty noises, it locks, unlocks. Perfect.
This project cost me a lot of money, mainly for the electric actuator that didn't work. If anyone wants to do their own here's my
advice.
Buy the diff on its own. No actuator, wiring, nothing. I saw one on ebay for £170.
The air system is easy. £15 compressor, £10 solenoid, free reservoir if you use a disposable co2 cylinder to weld your axle.
Pipework and fittings cost around £30, this would probably have been less from a local pneumatics supplier.
I estimate with this advice you could do yours for less than £250. Thats less than a lunchbox type locker, less than an ARB air
locker and probably safer than a spool or welded diff in the long run.
Use pleanty of RTV silicone on gaskets. The stuff is brilliant and more or less guarantees a good seal. Make sure everything is
tightened up properly. Finaly don't forget to refill your nice new diff before driving it anywhere.
Thanks for reading. Pics will follow.
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