when does the torque converter go into lockup?

[m3f_Eric M3]

Just out of interest I would like to know what criteria are standard requirements that the 5HP18 torque converter on a 1998 M3 U.S. spec locks up?

Car is all standard, no different final drive, wheels etc.

Checked the Bentley repair manual, but no info there.

[m3f_Eric M3]

Here is some info for E36 from around page 260, shift points at ...RPM etc, different automatic transmissions and engines, technical data https://web.archive.org/web/20110516...cal%20Data.pdf

better download it, I recovered it with the wayback machine, abt 400 pages in total

[m3f_Eric M3]

here are pics, someone made a test drive with a computer https://www.bimmerforums.com/forum/s...go-into-lockup

quote

I drove my car with my laptop and DIS while in Diagnosis Request here is what I saw;

- The converter will lock up in 3rd, 4th and 5th gear.

- The load signal %(not just kick-down) has to be below a certain percentage and engine rpm or it won't lock up.

- I only took 4th & 5th gear photos.



Page 28 talks about the converter, http://www.e38.org/electran1.pdf

[m3f_egebhardt]

Looks like you answered your own question. I had 2 auto sedans. On both cars, I could go out on a nice stretch of highway and test the lock. Once locked, you can push the gas pedal lightly and the RPMs won't change. Once unlocked, the RPM does change. The torque converter definitely locks and unlocks when working properly.


Sometimes you will get Failure 111.

Fault code 111 indicates a lack of transmission torque converter lockup (i believe). I think it's a common code that comes and goes. Keep the fluid topped off.


I also read this link.

https://blog.bavauto.com/11812/bmw-t...verter-clutch/


Also, it is OK to drain and fill these trannies at any mileage. I proved it with 2 cars at 118,000 and 168,000 miles. Neither car had ever had a tranny drain and fill. I did the job and it shifted fine before and after. Lifetime fill is a bunch of BS. All fluids need to be changed sometime.


Here's how to do it: http://www.m3forum.net/m3forum/showp...0&postcount=61

[m3f_Eric M3]

Yes, ATF drain, fill and filter change is recommendable, my wrenching buddy is doing that quite often in my garage, as I have a lift+pit. He is doing a special valve body service by cleaning the valve body and checking all the parts, you can see here how much dirt sometimes is in the valve bodies, click on 5HP18 in the index http://e32b12.blogspot.jp/

there are some pics from an Alpina B3 valve body, there you can also see the small steel mesh inside the VB, when you scroll further down you can see the small ball inside the valve body, that is also smaller than original size, we replaced that too.

[m3f_M-technik-3]

I have one from my 95 M3 and it was fine when pulled if some one wants it here in the North East.