I'm restoring an '88 brougham and I drove it home about a couple months ago, no problems with the transmission. The brake lines were trash, and the fuel tank had pin holes about three quarters of the way up.

Anyway i just finished changing all the brake lines, and i checked the tranny fluid and it was real low. Before I could get some and add it my dad moved the car about 5 or 6 feet. Now the engine just revs when the car is in reverse. It will drive forward though.

Is the transmission shot? Any idea if I will I need a full rebuild on the 200r4? and how bad of a job that will be?

I have a th400 sitting around from a '77 deville should I put that in or try to rebuild the 200-r4 first?

just looking for some advice.

There is a laundry list of things that will kill reverse: binding throttle valve cable, misadjusted manual linkage, reverse boost valve binding in bore, blown lo-reverse clutch, or cracked direct clutch housing.

The car moves forward in drive. The direct clutch is also used in drive, so a cracked direct clutch housing is more than likely not your problem. A binding throttle cable or misadjusted manual linkage would more than likely effect more than just reverse.

To test the lo-reverse clutch, put the transmission into manual 1st gear and see if it will move. A faulty boost valve would also effect 1st gear, so to test the boost valve, select manual 2nd gear (2nd is still boosted, but the lo-reverse clutch is not applied).

The fluid passages to the lo-reverse clutch are probably blocked and this problem can be solved with a transmission flush. If it turns out that the internals are damaged, there is no way of repairing it without pulling the transmission. My recommendation is to have it professionally serviced.

As for the TH400: It doesn't have overdrive, which will kill your gas mileage (I lost overdrive in mine once and went from 16 to 11mpg). If it has been "sitting around" then it may need reconditioning to be ready for service; a cost which may top the rebuild bill for a 200, because of its age.

Sorry for resurrecting an old thread but I'm still trying to deal with this problem.

I tested all the things you suggested, and I ran through all the Oil Pressure tests for the 200r4 in my '84 master shop manual, and all the Info pointed to internal damage...Then today I figured WTH I might as well fire it up and try again, as I was downshifting I accidently shifted past Reverse and into Neutral, and the car moved forward! checking the shop manual the only things it said for that were: Cross Leakage, Forward Clutch issues, and a Misadjusted Manual Linkage, which is the only crossover problem to no reverse.

I looked at the linkage where it attached to the tranny, and appeared to only attach one way, so my question would be how do I adjust this? or is it possible/likely I have 2 different failing systems in my car?

Yes. It is possible to get more than one system failure. Cross leakage problems are usually in the valve body, which is the brain of the transmission. Allot of the work in the valve body is done by fluid pressure unseating check balls, which allows the hydraulic pressure to operate different functions of the transmission. It is possible that one of the check balls is not seating properly, because of dirt build up, and is allowing pressure to bleed to the wrong components. This is another thing that may be solved with a decent transmission flush.

My OEM manual doesn't give any procedure on adjusting the Manual Linkage. It only says that the parking pawl should be "freely" engaged in park, and that the engine should start in park and neutral.