For the past 3 years I have been driving my 85' 240 (Mt and 175k miles) only on short trips.However yesterday when driving on a major highway at 60 mph for about 15 minutes I noticed that the car would seem to loose OD gear-bog down when I would drive at speeds bellow 55 mph. If I drop to 4th Gear It drives fine. Then again at 60 Mph and steady speed the OD seems to be fine. Just for you own info the car sits most of the time and I have put about 1100 miles over the last 3 years. Is this an indication that the tranny-OD unit is dying or that is gloged because of using it rarely?

Should I use the OD or Stop using it in Case I might cause more damage?
What is the RPM at 60 Mph At 4Th gear?
Thanks
Mike

Possible damage: more of a nusance than physical damage. Fluid pressure will continue to drop off and cause such severe slip you will out of frustration stop using OD before any damage is done.

I've been so out of my manual trans but if memory serves me 70 was 2750 which would put 60 around 2500.

Duane

First, check tranny fluid level. OD shares with trans and must be very close to full to function properly. Carefully with the wrenches and breaker bars. Non access tends to lock the plugs in very well.

If OK, sometimes a fluid change (2.4 qts) will help for a little while. Maybe even longer if the O-rings are not to far gone and accept some fluid to soften them up some.

Bottom Line is most likely fluid is starting to leak past the actuating piston O-rings which get old and hard even when not being used. Eventually the fluid will blow past and you will not hvae OD at all. Just prior to this stage the OD will stutter and slip before it finally engages. It may also only engaage when cold but not after any use.

See 700-900 FAQ's under M46 for info.

Duane