

| Subject: | Automatic Transmission, slipping when cold? |
| From: | Ezra Hall |
| Date: | Fri, 3 Mar 2000 16:18:18 -500 |
Folks, I think there is a problem with our automatic transmission, or perhaps the torque converter on our 1988 Westy. On cold days (freezing or below), it takes a while for power to be delivered to the wheels, something is slipping. I have not changed the atf fluid since purchase last fall, but the level is ok. I performed the "stall" test as described in the Bently. This test consists of applying the brakes while in Drive or 1st, and briefly flooring the engine while monitoring engine RPM's. MAX RPM's are supposed to be an indication of torque convertor and/or trany health. On our westy, RPMs reach ~2800-2900 according to the dashboard tach with a warm trany. I have to check the trany code to see if this is within spec, there are different specs for different tranys. I suspect the difference has to do with engine power more than anything else (later engines have more power), but I didn't track down the trany codes to correlate to year. The Bentley manual indicates high RPM's are a sign of slipping first gear plates (There is no difference in RPM's if in D or ist). While driving power delivery to the wheels seems ok, once the engine has idled for a minute or two or course (longer if it is really cold out). Fuel economy is ~14-15mpg. I expected fuel economy to be in that range given the vehicles size/weight/underpowered engine,etc.. but do folks see better fuel economy than this? If driving on level road at 50MPH, and I floor the engine, RPM's increase 300-400. Of course some loss will occure in the torque converter since it doesn't lock, but is this an exceptable amount (~10%)? The Bentley indicates if the "stall" RPM figure is below the spec range, the torque converter is shot. I suspect if it is slipping too much, it could also cause the "stall" RPM to be too high as well? Is the torque converter on the way out? Does the torque converter have its own fluid internally, or does it somehow share atf with the trany? If so, could changing the fluid help? Is a locking torque converter available? Perhaps from an Audi? Thanks! Ezra Hall '88 Westy '86 944 '95 Golf (soon to be sold)
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