Transmission problem for BMW 740 IL 1994

[manceros]

I need help. I'm a new member and I'm the owner of a 530 I 1995 and a 740 IL 1994. For the 740 IL, the transmission is giving me some problems. It works fine when I have it on Sport Mode, If I switch it to Auto, it takes a little longer to switch it in gear, specially when is cold. I also have a leak in the power steering. I can't find where the leak is coming from. Please advise if you have any suggestions.

[Dick Schneiders]

Is this a new car for you, or a new symptom? Most BMW auto trannys will hold their gears longer when the engine is cold, for a few minutes of driving until it warms up. Every one I have owned does this and it is a common question that comes up from new owners. This is the way they were designed.

[manceros]

Actually I have more problems when is cold. Looks like when is in Auto it does not move at all for a while. If I switch it to manual, It moves right away, but it makes a little noise until it gets a little warmer. I really hope that thisis not a big transmission problem. Do you have any ideas???

[muleman]

In Dec 97 BMW issued Service Bulletin 240394 "Transmission Control Module EPROM Update". Do you know if this was done?
I had some similar symptoms, the tranny was searching for the correct gear and not always shifting at the right time. I had the EPROM replaced last month, along with the addition of 1 liter of transmission fluid. Problem appears to be solved. Cost $147. May be worth investigating - BMW told me at the time that if this did not correct the problem, they would suspect the valve body (>$3000) so I am keeping my fingers crossed....

How long have you had the car?
Muleman
1994 740iL
1991 318is

Originally Posted by manceros

Actually I have more problems when is cold. Looks like when is in Auto it does not move at all for a while. If I switch it to manual, It moves right away, but it makes a little noise until it gets a little warmer. I really hope that thisis not a big transmission problem. Do you have any ideas???

[libertylover]

Muleman's advice seems sound and I'm going to check it out for my '93 740iL.

Also, have you changed the transmission fluid? In the Owner's Manual it claims the transmission has a "lifetime" fill. However, the manufacturer, ZF Industries (German), now says the fluid should be changed at 100,000 miles. The special fluid is very expensive and it'll cost you several hundred dollars to change it. I suggest buying the fluid and a new filter from Jaggi Transmissions (http://www.jie.com/bmwtrans.htm) or some other ZF dealer and then pay someone local to do the messy work.

Also also, there is a known problem in the valve body with reverse. If memory serves you can buy a rebuilt valve body resonably priced ($500?) from Jaggi and also a rebuild kit (less money, more work) if you want to go that route. When I had my fluid changed I could see the valve body and it looks easy to change though very messy due to dripping fluid.