(SOLVED) Transmission slipping on reverse after more than an hour drive
 

Hi, newb here. I hope someone will give me way out from my issues.

I drive BMW 2003 X5 E53 4.4i.
Recently, after I drive more than an hour, doesnt matter drive normal or hard or on start stopping traffic, my transmission slips while in R mode when I want to park my car after drive. Well this scares me because reverse gear is needed to park the car here almost all the time. On D mode, theres no slip at all but sometimes it downshifts roughly from 2nd to 1st after around an hour drive also. My transmission had been overhauled and had all the clutches, all the seals, and everything that came with the repair kit were replaced with the original BMW's repair kit a month ago, then the mechanic filled the ZF5 transmission oil from zero to almost 12 liters which means the fluid was flushed and new. All the job done by the BMW mechanics but he couldnt figure out whats the problem. I've read this forum talkin bout overheating transmission, well I'm not sure since no one slipping on the reverse gear after an hour drive.

I hope anyone could help me, thanks.

Well if it's only been a month, I am sure there is warranty from the place you had the work done? I would bring it back, maybe they missed something. Were the solenoids and wire harness replaced as well? What about the torque convertor?

years ago I studied this website for future problems - seems the transmission starts to go around 170-180,000 miles - just replaced mine at 187k, but had been nursing it along for 3 years with 1st gear slipping in high torque situations, then 2nd gear started acting up last year.

EXTERNAL TRANSMISSION COOLER, PROBLEM SOLVED SO FAR
 

Yay I finally fixed this prob. Thanks to the post I found in this link :

https://xoutpost.com/bmw-sav-forums/...on-cooler.html

I've been driving around 1300km without problem so far, no slipping reverse, smoother gears change, better torque all time. MPG stays same.

To test this mod, last two weeks I drove really hard for 2 1/2 hours, 153 km highway on 1 a.m when only few cars on my way. Since theres no defect notice (my loud straight piped exhaust) and no speed limit enforced in my country, it's great to test car with speed. My cruising speed was 16-180 km/h, pedal was often floored to reach 200 km/h ++, no resting until I arrive and the problem was none. Total drive around 400 km that day. Couple days after I got a work project in Jakarta that gave me no choice to drive the heavy start stop traffic for more than 3 hours and get back home, total was 160 km long drive that day until I got home. Last week, I just got another work project, I drove urban driving for more than 300 km including start stop traffic, some hard accelerations when the traffic got lighter (I was bored). Everyday until today, I'm still driving really hard when the road empty, flooring pedal, caught in start stop traffic, etc. (FYI Indonesia is a strange place to drive, no defect notice, no rule, no lane anywhere on the road, only traffic light and license plate number to be obeyed, just watch youtube videos if you want to see how to drive in my place)

The test results: NO TRANSMISSION PROBLEM. Still the same like the day I put the cooler. All GREAT!! I hope this is not a problem masking.
What do you guys think?

Hi Yosia,

Nice to see there is an fellow Indonesian in this forum as well.

I have just started to slowly rebuild my 2001 e53 4.4 and currently facing transmission issues similar to what you have experienced.

May I PM you regarding this matter? I would like to obtain information about BMW workshops located in Jakarta.

Your kindness is greatly appreciated. Terima kasih.

Salam,
Radjasa

glad it helped you as well.
as BCredliner eludes to in another thread about tranny coolers used to fix problems... I wonder what the actual problem causing your tranny to act up is.

I am not positive this will fully solve the issue. I know of at least 1 board member here who has an external cooler but the symptoms came back.

CIF, oh I have no doubt this is not a solution to everyone.