Automatic transmission fluid leaks

[Al Gray]

I have been plagued with ATF leaks ever since I purchased my 1992 525i in March of 2000. My solution has always been to add more ATF fluid. Depending on the amount of driving I do the ATF leakage is more or less. I have even resorted to carrying an extra bottle of ATF and a funnel in my trunk in case I get the dreaded TRANS PROGRAM message when the ATF gets to low. I have replaced transmission filters and properly torqued the bolts that hold the fluid sumps. I still have leaks and they can usually be seen on the bottom of the ATF sumps and sometimes oozing down the side (drivers side) of the transmission.

I was reading my Bently manual and on page 240-17 it outlines places where the transimission can leak fluid. The torque converter seal is located between the transmission and the engine. Leaks here will usually be seen at the bottom of the bell housing. My trans does not show leaks here.

The second place that leaks can be found is the output shaft seal. This located at the back tail shaft end of the transmission and connects to the flex disk. It also entails removing the driveshaft. I don't know whether I have leaks here since most of the leakage I have noticed seem about midway back on the transmission, not the very end. But I will check it anyway.

The last place for leaks is the Manual Valve seal. It is located on the side of the transmission case and on the side of the ATF sump. Apparently this is the easiest fix because nothing needs to be removed. The instructions say to replace the manual valve seal, remove the manual valve lever from the transmission. Pry out the old seal using a small serewdirver or hooked toool. Lubricate the new seal with ATF and drive it into place. When installing the manual lever, torque the nut to 8 - 10 Nm.


Has anyone ever encountered this problem? Can much fluid leak from this Manual Valve Seal? I would appreciate any comments.

Al Gray

[632 Regal]

Hi Al, sounds like your doing the hit or miss approach with the leak. You can replace that seal, its easy enough but you should really try to locate the source. From your description it could be that seal but if not you will still have to locate the leak.

[Al Gray]

I have had a difficult time seeing where the leak is emanating. I can see the droplets of ATF where the two sumps are located and above that is the location of the manual valve seal. I am going to try that first. I don't know where else it could be.

=632 Regal]Hi Al, sounds like your doing the hit or miss approach with the leak. You can replace that seal, its easy enough but you should really try to locate the source. From your description it could be that seal but if not you will still have to locate the leak.[/QUOTE]

[ryan roopnarine]

sounds like it might be the intermediate seal between the bellhousing and the tranny, this would explain why it would be leaking between the sumps. there's a TIS bulletin for this, unfortunately, it involves taking the tranny out and doing some light or moderate disassembly. i have it posted in my webspace, at the request of sbcncsu (scott council). it is available here

http://plaza.ufl.edu/rroopnar/SI%20%...pter%20Cas.PDF

if you want to look at it and see if your leaks match its symptoms.

[shogun]

I replaced the shaft end seal of the trans rear 2 times in 11 years.
Last time last month. It is completely dry again.
http://shrubbery.student.utwente.nl/...rbox_seal.html

[Al Gray]

When I replaced my flex disk I dropped and supported the exhaust system and I was able to remove the drive shaft and replace the flex disk. It seems to me that in order to access the rear of the trans I could do the same thing. What was your procedure?

I replaced the shaft end seal of the trans rear 2 times in 11 years.
Last time last month. It is completely dry again.
http://shrubbery.student.utwente.nl/...rbox_seal.html

[BFEINZIMER]

Yea this is a stupid **** question but I think my almost newly rebuilt tranny is leaking fluid as I checked it last night and its very low. So do I just funnel more down the dipstick line or is there somewhere else to pour atf?

[Rus]

Yea this is a stupid **** question but I think my almost newly rebuilt tranny is leaking fluid as I checked it last night and its very low. So do I just funnel more down the dipstick line or is there somewhere else to pour atf?

You simply pour the fluid in through the dipstick tube. In case you aren't aware, do this with transmission warmed up and engine idling.

[BFEINZIMER]

You simply pour the fluid in through the dipstick tube. In case you aren't aware, do this with transmission warmed up and engine idling.

o alrite thanks man