Evening Gents,
having studied the design and schematics of these and looked at many of the issues people face, I’ve come to the following conclusions:
- Mega piece of kit.
- do seem to cause a lot of issues, especially on the Land Rover installation. I’ve had some of these in other classics and not had any issues before.
So, first an apology for teaching grandma to suck eggs....
The first thing to rule out with any issue is electrics. Assuming that is ok then we have to move on to the oil system. Regarding the description of the issues above (disengaged skipping):
- is the unit making pressure when in the “off” position?
- this could be caused by incorrect solenoid operation, incorrect seal fitment to the solenoid.
- some part of the “bypass” path for the oil being incorrectly assembled (there look to be some channels that have to line up with holes, etc in the previous pages of this thread)
- I think there is a good reason overdrive repairs has a pressure gauge in its “j type” parts section. Clearly, testing the unit’s off pressure is a useful thing to do.
If it isn’t this, then, yes, it is probably the springs. As I understand it, when the unit is assembled, these springs should hold the cone off the brake ring making it hard to assemble. If not, where does the preload for the “off” position come from?
I think the idea of some spacer shims is good, but these will also shorten the distance the springs can be compressed (overdrive engaged), so be careful. Longer, springs that don’t have significantly longer compressed lengths might be a better solution.
one idea to test the springs are working might be to try to see what torque the unit can take applied to the input shaft with the unit off the car and the body/output shaft prevented from moving. Not the easiest test, but fairly conclusive of what should be happening when the overdrive is disengaged.
Just my thoughts. Hope no one takes any offence.
BP
