Ok, so I drive a '92 W250 and I have noticed my transmission "appears" to be slipping. Now I'm no mechanic, but I checked my fluid level (while it was running) and the level was fine. It's a lot worse in the mornings, but it happens in the afternoon as well. I live in Georgia and I don't particularly feel that it's that cold in the mornings but I've gotten in the habit if letting it warm up for 15 minutes or so before driving which seems to help. I live about a mile from the highway so when I stop at traffic lights sometimes it doesn't go when I hit the pedal so I have to feather the pedal until I get it in gear, then I can go. I'm on the highway for about 40 minutes going to work and when I get off the highway I don't seem to have any trouble. Does anyone have any idea what's going on? Is it really slipping or is it because it's not hot? Could it be my filter is dirty? I've had the truck for about 7 months and I haven't changed the fluid or the filter. This is my first diesel so I have no idea what to do. And exactly what type of transmission do I have. It's an automatic and I think I read somewhere it's an A727 but I'm not sure.

 

When you check the fluid was the trans in neutral? It must be checked in neutral not park with the engine running. You trans is a 518 non lock up.

 

I'd change the fluid out put a new filter in, usually if a trans is slipping it will work better cold than warm because the fluid is thicker. sounds like its low on fluid to me but i'd check it and like onemoparnut said it has to be in netural. id change it anyways then it will be on your maintence schedule.

 

Also, when you first start the truck, before putting it in gear, shift to neutral and let it idle in neutral for 30 ~ 45 seconds so as to ensure the torque converter completely fills with fluid. Then shift into gear (forward or reverse).

It's a known issue with cars and trucks of these years that the converter would drain fluid from itself (internally) while parked. Most aftermarket "Shift-Kit's" include mods to rectify the issue.

Hope this helps.

 

When you dump the fluid, and change the filter, add a quart of Rislone Slip stop. It's supposed to help trans slippage.


Make sure you adjust your bands while you're in there as well. Made my truck shift a little better. Once I put the new Potentiometer in, all of my trans issues disappeared.

T.