Follow-up on old "OD not disengaging" Issue...

Back in June I posted a problem where the OD on my recently resurrected car would not reliably disengage when the switch was turned off, and was possibly engaging on its own.

See original thread: http://www.mgexperience.net/phorum/read.php?1,1477499,1477499#msg-1477499

Never got around to putting ATF in the tranny as some many recommended, but then yesterday, on the way to finally getting my inspection sticker (yippee!!), I noticed the O/D was getting a mind of it's own, and was engaging itself without the solenoid being activated (I have a light on the line, so I'm 99.999% sure no power was getting there...). Was a real problem when I needed to back up...

Anyway, swapped the NT 30W oil with ATF today, and after a 10-15 mile test drive, it seems to be working wonderfully! Initially it still took a bit of an accelerator "blip" to trigger the disengagement, but by the end of the ride, it was switching in/out instantly with the switch. We'll how it does again tomorrow, but just wanted to let all those that offered advice that the ATF seems to have worked. I may switch back sometime later, but I'll let this run for awhile.

Thanks!
Bob

Hi Bob,

is the OD still working with ATF or did you change the oil later? I have a similar problem: my OD doesn't disengage on the first 12 to 14 miles. I can flick in the OD quickly, but it doesn't disengage, not by switch in the 4th gear and not by changing to 3rd gear (it's a V8 - no OD in 3rd gear). Changing to 2nd gear or stopping the car helps. After the first 12/14 miles the OD is working smoothly - may be warm oil?!

Ciao,
Marcus

John Twist has a 3 part video on over drive problems chinging the filter, cleaning the pump and releif valve, and solnoid.

Hi,

I already changed the three O-rings, cleaned the solenoid and the control valve, changed the filter (sludge on the magnets on the cover plate under the filter) and filled up with new gear oil (Penrite 40). The old gear oil was really black. I changed the gear oil last year and drove about 10.000 miles without any problems since then. After my maintenance the OD flicks in more quickly, but it still doesn't disengage with cold oil on the first 12 to 14 miles. Electrically seems to be everything well. The solenoid is working (I can hear the click), the OD turns off electronically if I change from 4th gear to 3rd gear (checked with a test lamp) or if I turn it off by switch in the 4th gear. What I didn't do so far is cleaning the oil pressure relief valve and the oil pump, but I thought the OP relief valve and the pump are not responsible for disengaging, wrong? Any ideas?

Ciao,
Marcus