1994 960 3ltr Sudden loss of drive when idling.

[father ted]

Seem to have a problem with auto box whilst stopped at say a red light. There is a deffinate loss of drive whilst idling in drive mode which lasts for perhaps one second and then you feel a bump as it re-engages.
This dos'nt happen often but its very disconcerting when it does. I hav'nt experienced any drive issues and the box works fine except for this niggling problem. I change the atf regularly and no leaks are visible. Its a difficult thing to describe but it feels like a valve or similar opening and closing which momentarily loses drive pressure and reinstates it almost immediatly. I have had volvo's with autoboxes for years and years but never come across this before.
Grateful for any info on this before it turns into something serious. Thanks.

[93Regina]

I know nothing, but newest ATF oil may not be compatible with older transmissions. In short, a slight decrease in pump pressure, and actual transmission damage can be the end result.

With automatics, if your pump pressure is not within spec, stuff will happen.

Here is shop manual

[father ted]

Thanks for that my friend especially the shop manual,that's gotta be helpful. Cheers.