The OD in my '82 with M46 tranny only works when the oil is cold. When the car warms up, the OD disengages. I know this is due to bad O-rings and resulting insufficient hydraulic pressure to keep the OD engaged, and I plan to replace the OD with a good used unit when time permits. I noticed that my Triumph TR6, which also uses the Laycock J-type OD unit, uses 90W gear lube in the tranny and OD instead of ATF as recommended by Volvo. Is it OK to use the 90W in my Volvo tranny and OD? I'm sure the OD would then work all or most of the time because the thicker gear lube would "hold" hydraulic pressure better than the thin ATF. But would this destroy anything?
TIA for any help!
Colin