I think I may have converted my latest project car into a parts car. But before I completely throw in the towel on this one, I thought I'd try to use a lifeline.
I have a 2000 328i with 161K miles that a bought as a non-running project. I got it running and everything seemed fine when I started driving it around. But then I noticed an intermittent loss of reverse. I did a ton a research on the issue (well documented, by the way) and settled on my problem being worn bores in the valve body.
I was about to order a rebuilt Sonnax valve body when I stumbled upon a '99 328i with only 109K miles for practically nothing. I needed some other parts off of it anyway, so I bought that car with the intention of swapping the transmissions. But that's an awful lot of work, so I thought I'd take a shortcut and just swap the valve bodies since that's where I believe the problem to be.
Well, I did that and it seems that I made the problem worse. I now have no gears at all. There are no warning lights or faults, and the gear indicator in the instrument cluster works, but nothing happens whenever I put the car in any gear. I can hear and feel the engine load very slightly in "D" and "R", but it acts like it's in neutral.
Could I have overlooked something when installing the new valve body? Is there an incompatibility between the '99 and '00 valve bodies even though both cars have the GM 5L40E (AS5 360R) transmission?
I used the wiring harness from the donor valve body because several of the plastic clips on the unit I took out of the car broke off - even though I was extremely careful when removing them. None of the clips on the donor broke, so I used that wiring harness and never removed it from the valve body. The only connections I removed are the two for the sensors installed in the transmission body, and the one to the Park/Neutral switch. All others were left connected when I dropped it out of the parts car. But I still triple-checked all the connections before I put in the filter and bolted up the pan.
I also made sure the selector detent spring and lever were correctly aligned.
I made sure that I added the proper amount of the correct transmission fluid after I completed the swap.
I'm hoping someone has some advice, or suggestions for something I can try before just selling the car for parts.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
Sorry, I have to ask:
Was the donor car driving and reversing properly before you did your work?
And when you say you "added the correct amount of fluid", may I assume that you filled the trans through the correct hole in the side of the trans, and that you did this with the engine running, until fluid came out?
And, did you remember to put the filter back in the transmission?
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
No need to apologize. I have asked myself the same questions. The donor car has a bad starter, although the seller insisted it ran and drove fine until the starter quit. So no, I have not personally verified the transmission functionality and have considered the very real possibility that it's junk.Originally Posted by bmwdirtracer
You're assumption is correct for how I determined the correct amount of transmission fluid.
Yes, I installed a new filter when I reassembled the transmission.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
member "whiskychaser" is usually knowledgeable in these matters. He frequents the E34 sub forum
If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue
It would seem to me that you're going to have to swap the valve bodies back to know whether the problem is within two different valvebodies, or something else in your transmission.
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
I have considered that option. But it's a lot of work just to put it back to how it was before. Yes, it will be driveable again. But it will still have the intermittent reverse problem. If I decide to pull the valve body again, I'll bite the bullet and buy a rebuilt one from Sonnax.
Or, more likely, I'll probably sell the car for parts. Financially, it'd be a wash. And it would be a whole lot less work!
I was just hoping that I had missed something obvious during the swap and someone would point it out.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
First thought is that 99 and 00 boxes are not compatible. That is if yours is 1423876 and the donor is 1423182. Gear symbol means limp mode. Is that what you have?
I don't have any warning lights or faults related to the transmission. One thing I haven't done yet (but will) is to see if I can activate any of the solenoids using DIS or INPA. That ought to tell me if the computer is even talking to the transmission.Originally Posted by whiskychaser
How do I determine if I have a 1423876 or 1423182? I'm not familiar with that nomenclature.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
Sorry. Using my mobile. Those are BMW part numbers. Put your vin in realoem and it should confirm which one you have
Ah, thanks! I'll do that later this afternoon.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
OK. Just had a look at the parts diagrams. Up to June '99, they fitted valve body part no. 1423945. From then it was 7504756. And they are not compatible. Put both vins in and keep your fingers crossed
Have you considered ditching power to the TCM to create a fault? In limp mode, the pressure regulator (as well as MVs) is knocked out. So you get maximum line pressure. Something is very wrong if you don't at least get 4 and reverse
'99 VIN: FR11732
Valve Body Part #24301423945
'00 VIN: FR20945
Valve Body Part #24307504756
Well, crap. As they say, "There's yer problem!". So even though both cars have the 5L40E / AS5 360R, they aren't the SAME transmission. I wonder what the actual difference is? Visually, both valve bodies look identical.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
Wow, I'm impressed, whiskychaser! Many thanks for sharing your wisdom here!
(Um, does your familiarity extend to the ZF 6HP mechatronic gearbox? I have a weird one that just came in to the shop)
Chris Powell
Racer and Instructor since, well. decades, ok?
Master Auto Tech, owner of German Motors of Aberdeen
BMWCCA 274412
German Motors is hiring ! https://www.bimmerforums.com/forum/s...1#post30831471
Ok so upon reading this thread I did some research regarding my 5L40e trans it’s in limp mode and I can’t seem to get it out of limp mode I have changed the Tcm and that was a dud still went into limp mode..I have reset the transmission numerous times to try to get out of limp mode but still no luck..my next step is changing the solenoids and fluid..but I want to be sure before I do that..also have abs lights on could that cause it to go in limp mode? Oh and one more thing where in the heck are the speed sensors located? Thanks so much for your advice in advance..
A faulty ABS module will cause the transmission to go into limp mode - even if there's nothing wrong with the transmission itself. I would diagnose and repair the ABS fault before digging any deeper into the transmission.
1998 ///M3/4/5 | 1999 528iT | 2003 Z4 3.0i
ok, so that version of transmission is in a lot of vehicles. One of the more common issues with reverse is the TCC solenoid that fails causing the reverse problem. Other things to consider is low fluid in the sealed transmission. My suggestion would be to put back the original valve body and swap the TCC solenoid for a new one, barring there was no other shifting issues with that transmission. Those solenoids are around $30.00 bucks to replace. You can pick up a whole kit for around $130 for all the solenoids but would only recommend that on a rebuild. That transmission is a solid transmission its was also used in Honda Passports and Isuzu Troopers.
Last edited by LittleHemi; 11-21-2020 at 03:39 PM.
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