1988 744Ti 183K

I rebuilt the Laycock overdrive unit in this car 18 months ago at 162K. At that time I found the old pistons with Teflon seals still in place- evidently it has escaped the recall. I was prompted to remove the unit at that time because it was dropping out of overdrive and immediately trying to engage again; it would continue to "hunt" for engagement.

I installed some used pistons that would accept the normal Orings as well as replaced the other seals except the ones in the solenoid. It had a quick and solid action when 12v was applied. I don't think the problem matches the criteria of a defective solenoid.


All as been good for 21,000 miles until recently. The same behavior is displayed; let the speed drop below 60mph and the overdrive disengages and almost immediately tries to engage again.

Hasn't leaked a drop of Type F (checked today). The overdrive light stays on during these times and when the buttom is pressed the light goes out and the hunt to engage stops.

The problem has all the earmarks of worn seals on the pistons. Any other thoughts on what it might be with only 21K on a rehabbed unit?

Randy