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* No-Reverse Solution For GM Transmission *

638K views 49 replies 22 participants last post by  Mr Podman 
#1 ·
This doesn’t apply to everyone! Please read carefully.

Alright lets get started. A lot of threads have come up recently about no-reverse and such. Well something needs to be cleared up. At any rate, here's my story:

About 3 years ago, I bought my 2000 328Ci (automatic). I loved it, but one day I discovered that it wouldnt engage reverse. I used my trusty friend google and searched "bmw 3 series reverse gear wont engage" like any future fanatic would do. Well it led me to this site, I was told by many of you that it was my reverse drum in the transmission and that I was screwed. I mean, this could have been the case, but it wasnt. Here is the general breakdown of how E46s and transmission are distributed: A5S360R is the transmission we are looking for



323's - Mostly ZF transmission (Rare but can have GM tranny as well), the reverse drum actually shreds, causing you to lose reverse. This is the general and accepted idea of what happens. And it is true.

328's - GM transmission, (328s have the GM tranny). I have (well had) a GM tranny as I have a 328Ci. You could get under your car and check for a green label which is pictured further down the page, but I guarantee you that you have a GM tranny if you have a 328i/Ci

Now here's the main point: People will come on here sometimes and complain of no reverse, a normal situation to fanatics. But what they dont realize and what they dont notice is that the OP might just have a 328 and not a 323.

Here is why that's important: Automatic 323's are known to lose the reverse drum, that's a fact. Automatic 328s can lose reverse as well, that's a fact. But what's the crazy fact is that 328's with GM transmissions might not have actually lost the reverse drum! :yikes: GM and ZF trannies both lose reverse gear but they do it in different ways. The drum failure is the common failure on the ZF transmissions. The symptoms of the 5L40E (GM tranny) are identical, you place the car in reverse and it revs up like in neutral and does not move. And that's the point of this thread. To show you what to do if you have a steptronic GM transmission.

So GM trannies might not have lost the reverse drum? Then what is the problem you ask? There are things called solenoids in the pan of a transmission that control pressure allowing the transmission to engage gears. We all know that automatic transmissions in E46s are hydraulically driven correct? Well one of those solenoids can go bad, and guess which one? The reverse solenoid. The name which you should call it as is the "TCC and PWM solenoid"

What happens: At any rate, what happens is when the car is cold, ect, this reverse solenoid has a mesh screen on it and build up can get on the screen causing it to not be able to control the pressure to the reverse gear. This in turn is when people notice the infamous "no-reverse." Thus, people with GM transmissions wont be able to engage reverse gear and they think that their reverse drum is to blame. This is not the case!

Here's some articles that explain a little bit about the TCC and PWM solenoid:

Sonnax | Transmission, Torque Converter & Driveline Parts

http://www.zoom-tech.com/downloads/support/tranxpages/gm/5l40e.pdf

http://www.automaticchoice.com/Catalogue/5l40e.pdf

Tell if you have a GM tranny: Bentley info and Transmission Charts (Important!)

http://www.automatikoelwechselsystem.de/files/AutomatikgetriebeOelstandskontrolle.pdf

http://www.taligentx.com/passat/maintenance/atfchange/BMW_ATF.pdf

http://www.europeantransmissions.com/Bulletin/DTC.BMW/BMW transmissionfluidchard.pdf

I experienced reverse failures with my GM transmission 3 years ago but after a little bit of research that long time ago, I found that my reverse gear actually hadn't shred.

This is how I found out: I couldnt engage reverse ok, so I put my car in Neutral and rolled it down my driveway, to where I was able to engage Drive. I drove around town for a little bit, maybe to clear up the mesh screen, and then I tried engaging reverse. Lo and Behold! My reverse engaged again! This was an on and off occurrence for me for years. I never decided to replace the solenoid because I didnt really care for it. If I ever lost reverse in a parking lot, I just waited for the car to warm up and shifted around a bit. Then reverse engaged itself again.

At any rate, if you are the owner of a car that is experiencing no reverse and you have a GM tranny, try and get your car out into the open and drive around for a bit then try and engage reverse. If it comes back to life, then your solenoid is to blame. If the reverse drum was really shredded, you wouldnt be able to engage reverse again. The solenoid is in the pan and only costs around $250 to fix (labor aside). So even if you arent sure, I'd say its worth a try.

Here is the part you need, Part #4 in the diagram. Reason I say it will cost $250 to fix is because you should get a new gasket and filter:

04 Pressure regulator,convert.lockup clutch 1 24327532013 $83.5

Gasket and filter:

02 Gasket, oil pan 1 24117524707 $36.19
06 Set oil filter 1 24117557070 $132.11



Little green marker on the side indicating a steptronic GM tranny:







Some pictures of the reverse solenoid:



Reverse solenoid in the valve body



Actual solenoid



Screen that gets clogged



I'm sorry I didnt post this 2 years ago. :(


Cliffs:

I think people with the GM trannies automatically associate the ZF transmission failure (reverse drum shredding) to their GM transmissions no-reverse even though the GM transmission has a completely different no reverse issue! I think most people just dont know the difference between a GM and a ZF tranny. Most take it to a shop saying they cant engage reverse so the shop just replaces the entire transmission when all that was needed was a solenoid! If you have a GM transmission and are afraid of losing reverse, when it happens, look into replacing the TCC & PWM solenoid. You don't need to replace your entire transmission!

This is just a possibility to look into, this doesnt apply to everyone!

(For anyone interested, my thread I made nearly 2 years ago)

http://forum.e46fanatics.com/showthread.php?t=551050&highlight=tcc

And my quote from that thread 2 years ago:

I have a 2000 bmw 328Ci. My transmission has been acting up in the past year. I experienced the infamous "no reverse" problem. But its not the same as others no reverse problem. The car sometimes doesnt shift into reverse, reverse acts like a second neutral. But after i drive for a while in Drive, the reverse gear magically works again. This has happened 2 or 3 times. I have been reading and I dont think i have the ZF Transmission where the reverse gear completely strips because after i go in Drive, the reverse works again. I think its the TCC PWM solenoid. What should i tell my mechanic? Thanks in advance.
Cheers my friends




edit by B: changed some picture links as per PMed request from Neil

edit by Neil on 3/21/16 to fix some photo links
 
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9
#4 ·
intermittent reverse

Thanks for this thread, can I have some clarification. I have an '05 325iT steptronic transmission. 115000km it is still under warranty until 120000
last week I experienced a similar no reverse as neil1138, like a second neutral. restarted the car and no problem. I took it to the dealer and they couldn't find anything. Does the 325 of this year have a similar issue?
Should I mention the solenoid possibility?

I'd like to get this resolved prior to the warranty disappearing naturally.
THanks for your input
 
#5 ·
Thanks for this thread, can I have some clarification. I have an '05 325iT steptronic transmission. 115000km it is still under warranty until 120000
last week I experienced a similar no reverse as neil1138, like a second neutral. restarted the car and no problem. I took it to the dealer and they couldn't find anything. Does the 325 of this year have a similar issue?
Should I mention the solenoid possibility?

I'd like to get this resolved prior to the warranty disappearing naturally.
THanks for your input
If you are experiencing the same issues, then I would naturally assume it's the same problem. Tell your dealer about this and don't let them push you around. Even if they don't replace it under warranty, it's a relatively cheap fix, labor aside.
 
#7 · (Edited)
The solenoid/pressure regulator part Neil quotes is only for the 360/390 tranny. Here are the solenoids/regulators for the A5S325Z tranny: Anyone know which one is the reverse solenoid?
http://www.realoem.com/bmw/showparts.do?model=EV53&mospid=47725&btnr=24_0894&hg=24&fg=15



No. Description Supplement Qty From Up To Part Number Price Notes
01 Solenoid valve (SOLV) 3 03/2003 24341423368 $63.85 +core
02 PRESSURE REGULATOR 3 03/2003 24341423369 $159.49 +core
03 Bracket 2 03/2003 24341423370 $1.22
04 Torx bolt M5X12 4 03/2003 24341219933 $1.12
05 PRESSURE REGULATOR 1 03/2003 24341423461 $126.71 +core
06 Bracket 1 03/2003 24341423374 $1.22
07 Torx bolt M5X12 1 03/2003 24341219933 $1.12
 
#8 ·
The solenoid/pressure regulator part Neil quotes is only for the 360/390 tranny. Here are the solenoids/regulators for the A5S325Z tranny: Anyone know which one is the reverse solenoid?
^ The ZF transmission is a different ordeal. It isn't the solenoid that goes bad, it's the entire reverse drum gear. This thread is for the GM transmission, that's why I only listed the parts for that one.
 
#10 ·
i just got this problem on my 2000 323ci with 173000 miles first trans problem it just happend 2 days ago and keeps happening but looks like its random i check this morning and i have the gm trans, so i was wondering how do you remove the solenoid is it just pull the pin and it will come out or how do you get it removed im planing on doing it myself but dont know how do you remove it
 
#12 ·
If the solenoid didn't fix it, that could be troublesome. Cleaning out the valve body isn't easy, if you decide to take it apart, best of luck getting it back together properly. I honestly don't have advice for doing valve body work, that's over my head. For what it's worth, you could try cleaning it without taking it apart but I don't know how well that would work. We could move to simpler things like taking a look at the electronics behind the gear engagement. Take a look at your internal transmission wiring harness, I know when I took mine out, it was so brittle who knows if it was going to go bad at some point. Have you guys tried fluid changes, at the very least a filter change? Maybe the whole problem is behind there being too much gunk in the valve body and when you put a new solenoid in there, it just gets gunked again? I kinda confused here because I've never heard of this failing for so many people, there must be another underlying problem causing your no reverse
 
#13 ·
I was inclined enough to take apart my entire transmission and take photos of the solenoid which are in the first post of this thread. If those aren't helpful to you then I'm sorry for my shortcomings. If you have anything to add to this thread once you make your picture tutorial, it would be appreciated
 
#14 ·
Neil, is the screen visible once you remove the solenoid or do you have to disassemble the solenoid. I'm still curious as to why you can't just clean it if it's just a clogged screen. Again, I haven't had mine apart yet, so I'm not familair with the solenoid yet. I've seen the your pictures, thanks, but sometimes you just need to hold it in your hand to understand it. :) Also, what are your thoughts on one of the other solenoids being a possible cause for a slow catching drive on a cold start?
 
#18 ·
I only recommend considering the solenoid because if one goes in asking for a fluid flush, and the tech comes back and says the solenoid must be replaced too, then there is a good chance this is true.

I've not seen the stories of flushing the GM5 and the No Reverse problem was not solved. I've seen stories where owners of GM5s were told that the trans had to be replaced when the reality appears to be that only a fluid change -- amd perhaps the solenoid as well -- is required.

As a matter of record, I'd have preferred that my solenoid was replaced since I specifically asked for it. By the time I found that it had not been replaced, the pan had already been put back on and the car had been prepped for pick up. Now, I'm at the mercy of somebody that I pray knows more about this stuff than I do. I believe the trouble is a combination of fluid and hardware, but all I got was new fluid. I hope this does the trick, so far it's been fine. But it has only been two weeks, so the data set is very small.
 
#19 · (Edited)
The fluid pressure (due to clogged filter) is a good possible cause of no reverse, I'd do the solenoid replacement myself in the face of $5000 dollars bill, so I'm just being scientific and want to know the real cause of this problem. I give credits to Neil for starting this thread that keeps us thinking what the real cause is...
P.s I've done the fluid replacement myself, GM tranny, 1K so far so good :thumbup: (to clarify, I did not have a no reverse problem, but replaced the fluid preventively
 
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#24 ·
If you decide to diy repair the valve body, I'd recommend the ATSG 5L40E transmission overhaul manual. I have it and it's good although not very detailed. It's like Bentley but for GM transmission. It has diagrams, part numbers ,instructions how to take the slushbox apart and put it back together including the valve body. The book is like $30 online.

Meanwhile if you need a diagram or something, you can PM me and I'll try to scan a page or two for your personal use and PM you back (it's copyrighted so I do not want this stuff floating all over the Internet)

GM / BMW 5L40-E / 4L40-E Transmission Rebuild Manual
 
#26 ·
Hmmm, from looking at my valve body I dunno. When I took my transmission apart I ripped apart the valve body and I thought I might be able to figure out the best way to clean it out, well nope. You really have to rip into it to get anything accomplished. The main thing that worries me are those floating pellet thingys, I don't even know how to put it back together without messing something up horribly. I would just take advantage of Alex's offer and just hit him up for some scans on how to take it apart properly.

Rebuilding a valve body is over my head
 
#27 ·
Trans has been working flawlessly for 1 week now. I was thinking, if the screen gets caught in the reverse lockout bore, wouldn't it get dislodged eventually by it self? So this piston like thing springs into the reverse bore, it would move anything in its path. I don't see at all how this could be a "sometimes" not working scenario. If the screen is lodged in there, it would be an always not working. I doubt its the screen.

I shifted from reverse to neutral and back about 50 times in a row, and it worked every time. I was hoping maybe this would dislodge the stuck screen, if that is what the problem is.

Starless I will take you up on that offer, but I will at least wait until it fails again. I need this car for a couple weeks, but in mid May I will have time for this project.

I pretty much already mostly had the valve body out before, I am not too afraid of that. Its the opening it up that scares me.

Here is a good tutorial on completely removing the Valve body.
http://www.bimmerboard.com/forums/posts/673185

Now I need a tutorial on how to open it up and service it.

Maybe I could pay to buy a new one or have this one fixed. (anyone know price quotes on these?)

All of those options are cheaper than a new transmission.
 
#29 ·
i just finished doing this it took me about 3 hours when i was pulling out the old solenoid it broke and i didnt force it. also the green clip that holds the wire together with the solenoid that broke i guess the plastic was toasted
my car a 2000 323ci has 178000 miles had once flush the oil when it was around 80000 miles. this time oil looked like chocolate i was looking at the oil like hum i remember putting a red color oil. my car never had the pan removed so you can imagine all that sludge in the magnet.
i want to thank neil1138 for bringing up this post and Toad21 for putting that detail picture about removing the solenoid i was going crazy when i found out i couldn't put the new one in since the old one broke when i pulled the pin
 
#30 ·
You need to get your valve body rebuilt/replaced. There are other solutions but they require special tools and aren't DIY-able (and they cost more than just getting your VB rebuilt). Cheapest solution at this point is to look into getting an entirely new valve body.

http://www.sonnax.com/tech-articles/TASC-TIP-02-09.pdf

Look into this thread, it summarizes the sonnax article and gives you different options on what you can do if the solenoid fix fails. Well written thread

http://www.bimmerfest.com/forums/showthread.php?t=458451

Unfortunately the solenoid route was found out to be one of many different problems. Sometimes it's the solution and sometimes it's not.
 
#33 ·
I stated a few months ago that I had fixed the No Reverse issue in my '00 323i. The problem has returned.

I took the car in for the solenoid (Item # 4 in the parts diagram included in the original post of this thread) but the mechanic said the screen was clean and the solenoid did not need to be replaced. I'm insisting that he go in again and replace the solenoid.

THE QUESTION i CAN'T ANSWER FOR MYSELF IS ...

How come this solenoid impacts the Reverse circuits but not the Forward circuits?


I read the write-up and some of the attached links, and found out more than I ever dreamed of knowing about TCC and PWM, and how these are implemented in an automatic transmissiion. I can't follow the description of how and what the TCC/PWM is(are) doing, and the No Reverse problem that I'm having with my 5L40-E. I am not disputing what the guys that know more about this than I do, I'm only trying to connect the dots to what they say to the problem I'm having.

Clearly, I'm missiong something. Help me out, please.
 
#35 ·
That's one of the articles that I read.

I think (and I'd appreciate a response either way -- confirm or deny) that the TCC solenoid must pull or push, depending on what it is doing, asking for forward or reverse gears. I see that the TCC is involved in Reverse, but it is also involved in Forward gear selection as well. The problem I can't get my arms around is that the TCC failure only affects Reverse gears.

This can only mean that the solenoid must activate by pulling and by pushing -- simply reversing the polarity of the electrical supply would make this possible -- and that one direction works properly while the other direction can stick intermittently causing that direction to not function.

The fluid chart on the Sonnex link is't very clear, but as far as I can see there are two passages, and one allows fluid flow to the forward gears when the plunger moves one way, and allows fluid flow to the Reverse gear when the plunger travels the other direction.

If the plunger sticks and does not allow fluid flow through the Reverse circuit, then the fix would be to replace the solenoid. But, if the trouble was the electrical signal being applied, then replacing the solenoid would not fix the problem.

Maybe I'm over analyzing this, but inquiring minds gotta know.
 
#37 ·
If you want to convince your mechanic that the reason for your loss of reverse is somehow solenoid/valve body related, I fail to see how the sonnax article doesn't cover it to your heart's content. There is nothing I can say that the articles/links here don't say. A technical article would be better to show your mechanic than my words would be :dunno:

Worst case, your entire transmission doesn't need to be replaced, your entire valve body needs to be rebuilt/replaced. Sounds like your mechanic is no good anyway... I would take it to a proper transmission shop where they can diagnose what is actually wrong within the valve body. There is no point in throwing parts at it... I would just do that instead of just replacing the solenoid and hoping it works (because it doesn't work all the time). That's the safer bet at this point.
 
#38 ·
It has been a while since I was here. I have the GM tranmsission in my 323 with a build date of July 99. I got a great price on the car because the seller was convinced it needed a tranmission, I followed the recommendations of this thread and decided that I needed the TCC Solenoid. I'm actually a pretty good mechanic, but I haven't the guts to cut into a transmission and start screwing around. To be honest, my main issue is filling it with properly when the new parts are installed. Maybe filling the transmission isn't hard, but the directions look difficult and I don't have the proper equipment to get under a car without laying flat on my back.

Anyway, sorry for the digression. I took the car to my mechanic specifically for the TCC. He said that when he dropped the pan, it was dirty but that the TCC was okay. I don't know how he could surmise that, but I went along with him. The car worked fine for weeks, but the problem eventually returned. My daughter drives the car, and she reports that the transmission fails about 10% of the time, and there's no pattern as to always cold or always hot. Reverse balks at any time with no rhyme or reason.

I took the car back and got the fluid flushed for free and paid for the TCC. We got the car back on July 15 with a new TCC and 6 quarts of ATF. I paid for the fluid and the part, the mechanic covered the labor because he didn't put the part in when I asked.

I'll keep tabs and post back.

Basically, I hit a bases loaded home run on buying the car unless I have to do major transmission work -- and then I only hit a single that didn't bring anybody home.
 
#40 · (Edited)
Wow. This is the solution to fix the GM trans no reverse due to faulty valve body.

http://www.bimmerfest.com/forums/showthread.php?t=458451


Long story short;

Option 1: you can spend $700 for the tools and parts to fix it yourself (Sonnex Kit + Tools)
Option 2: Spend $500 to ship it off to a professional shop that will install the Sonnex kit for you
Option 3: Buy a re-manufactured one for around $500


So your thinking, what do I need to do?

1. Put your car on 4 jack stands
2. Drain Transmission
3. Remove Transmission Pan
4. Remove Valve Body
5. Ship Valve Body to a shop or Install re-manufactured one. (Needs to be Sonnex capable)
6. Wait for 1-2 weeks (not if you choose remanufactored)
7. Reinstall

I am guessing it will costs 700$ all said and done. Shipping will be 30$ each way, and the fluid is 100$.
 
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#41 ·
I had this no reverse problem on my 99 323i about a year ago and so I replaced the solenoid and that seamed to fix the problem, for the most part. I drove my car everyday over the summer and only had the reverse fail 2 times. I am now away at college and only get to drive my car a couple times every 3-4 weeks. Now, every time I am home, the reverse fails at least once within the first couple hours of driving (but never on the first start-up). Anyone else have this similar problem? I am now looking into getting a new valve body over the summer. Hopefully that will fix it.
 
#42 ·
I seem to have the same problem on my 2000 323ci. When I put it into Reverse and give it some gas, the car rolls but does not accelerate while the engine rolls. I am fairly sure it is a ZF transmission, but what is the best way to know if its ZF or GM in order to be sure? Also if it is a ZF transmission and the drum is shredded; what is the best way to go about fixing this problem (considering that I am not a mechanic and will have to go to the shop no matter what). Any insight would be greatly appreciated!! Its a beautiful car that I don't want to lose without a fight =)
 
#44 ·
Your 00 323 will have the GM5 transmission IF the car was built before MAR. 2000, otherwise it will have the ZF transmission. Look on the driver side door jamb, there is a sticker that will give the production date of the car. YOU CANNOT DETERMINE THE LOGICAL COURSE OF ACTION UNTIL YOU KNOW THE PRODUCTION DATE.

Assuming the car is built before 03/00, you should be able to fix the No Reverse problem on your car by flushing the fluid and replacing the TCC solenoid. The symptom set is that the car will randomly refuse to go into Reverse when selected.

I bought a 323 built in 09/99 that had the No Reverse problem. I scored a very good price on the car because the seller was told that it needed a transmission. I gambled on the solenoid as the problem, and so far the gamble has paid off. I didn't feel like dealinig with the transmission fluid -- I haven't got the proper facilities and didn't want to lay on the floor in my garage -- so I took the car to a BMW mechanic in my town. He flushed the fluid and that helped for a few weeks, but before long the car was up to its old tricks again. I confronted him with the fact that I really wanted him to replace the solenoid when he was replacing the fluid, and since he didn't do the primary job I wanted, then he should repeat the task but not charge me labor for the second time he flushed. He finally agreed that he should have done the job I SPECIFICALLY asked for, and now he will do it for free -- no labor costs. I paid for the solenoid and some more fluid, and the car works perfectly now. It's been more time and miles on the second attempt than it was on the first, but I admit that the jury is still out on the fix. So far it's looking good.

If you car is from 03/00 or later, then you have the ZF transmission, and it should not ever go into reverse again until the transmission is rebuilt/replaced. When the reverse drum fails, this is generally a fatal condition.

In addition to the Production Date printed on the sticker in the door jamb, there is a tag on the transmission that gives the make and model. You can open the door and look at the sticker, or you can crawl under your car and read a greasy metal tag. The tag should be the definitive information, but odds are very good that the transmission is still original and the door jamb will suffice to figure out what you have.

If you elect to flush the fluid yourself, BE SURE TO SELECT THE PROPER FLUID. There are far too many fluid options for my tastes, so read the chart carefully and get the right fluid.
 
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