Transmission dilemma (long post, sorry)

[jicaino]

Hey guys

'00 540i with 140k miles
dealer replaced shortblock in '08 (threw a rod) got a 4.6 shortblock under the stock M62B44TU upper half

Transmission has never been serviced. (ZF 5HP24 with green label) When I started usng it as a daily driver after a long period (4 years) of semi neglected storage with very little driving, the trans threw codes and occasionally went into failsafe a couple of times, sporadicly. Codes were ASC/DSC Can timeout DD and Gear Monitoring. INPA said symptom 49 - sporadic failure last time, but it didn't went into failsafe, it lose traction momentarily between 2nd and 3rd. and engaged violently when it gained traction again, chirping tires a little.

The 2 times that it went into failsafe, I stopped the engine, removed key, floored the gas pedal, turned ignition to position 1 and it cleared right away, and kept on shifting fine and no power loss or weird shifting patterns. The couple of times it lost traction between 2nd. and 3rd it was on normal mode and happened in the same way: I accelerated in a subtle maneer, removed the throttle pressure all away and then not floored it but spet on it heavier than normal. It didn't turn any lights on or behaved oddly other than "hesitating" between those gears (the 2 times while being still warming up, a few blocks away from my garage)

I consulted a trans expert and he wanted to drop the entire thing and rebuild the TC and the valves body and replace clutches and so... he refused to change fluid and filter which was my initial request. He said that it wouldn't fix anything. I insisted saying that if it cured it it was fine and that if not I understood that it had a service coming on anyways. He was so determined that I feared he'd screw something up so he would have to drop it anyways.

The transmission shifts good most of the time, it just feels a tad slow reacting to dramatic throttle pressure changes (like as if my way of driving is out of what the computer would interpret as a single individual span of right foot mood) and acts "surprised". It doesn't downshifts hard, oil temp is normal, and this symptom happens only in normal mode. Sport or manual it feels stttttrong, no increased slippage or tardiness in reaction.

I know that it says "lifetime oil" and all, but being a machinist I'm inclined to replace trans fluid and filter and replace differential oil...

Ipunt please? thanks!

[edjack]

"Lifetime lube" is a fantasy. You have nothing but time and materials cost to lose by changing the the lube. If that doesn't cure it, the rebuild is the next step.

Get a second opinion, too.

[YourE39]

Id say go for the oil change, there is no such thing as life time fluid.

[jicaino]

Is there anyway in which I can dynamic flush it? I mean, replace oil until it's all fresh? I was thinking something along the cooler lines, get the trans to working temperature, then pump fresh fluid into the return line until the sending line spurts all new and fresh fluid... (instead of do 2 partial changes) but I'm sure somebody else may have come up with a better idea.

Seeing the way this particular trans is built, I'm more than confident that this is in no "rebuild right now" shape.

[rf900rkw]

Your transmission man is absolutely correct. Changing the fluid will do nothing good.

[larrym3711]

There are some indy's that will do a complete "transmission flush". By that I mean it is NOT a forced flush...they disconnect the lines from the cooler and let the natural tranny pump out the old fluid....while...at the same time (!)...new fluid is being sucked into the tranny. This continues for some time and eventually the COMPLETE system (tranny, TC, lines, cooler, etc) is all flushed and has new fluid. I have used this service twice now....on a BMW ('01 540i) and a Lexus ('01 GS430). I have been extremely happy with the results. I have used only BG tranny (synthetic) fluid...it meets (no...exceeds) virtually all automatic transmission requirements, including BMW, Mercedes, Toyota, etc. It DOES cost more than just a 5 quart (drop pan, change filter, replace gasket and reinstall pan, put in more fluid) change most offer as a transmission service. Both trannys act like new...very smooth, no slip, etc. That statement is no exaggeration. Those that know transmission fluid will validate the quality of the BG fluid. Please note: If you have a bad transmission part (bad pump, etc), NO transmission fluid will fix that. Period.

Hope this helps...

larrym3711
2001 540iA Sport

[rf900rkw]

There is a lot of bullshit hype about those machines. There is no suction on a cooler line. The out line is waste oil from the converter, the in line is pressurized lubrication. The machine has to push against the nature lube pressure. Would you change engine oil by screwing an adapter onto the oil filter and using a machine to "flush"? Same exact thing here.

And let me add to my statement before. Changing the fluid will do nothing good. If the fluid is low, getting it to the correct level can fix somethings. But the OPs symptoms do not match a low fluid condition.

This isn't to say the transmission needs internal work. Without experiencing and diagnosing the problem, there is no way to tell if it's inside or outside the box.

[jicaino]

Hey Randy, thanks for the input.

Now, I fail to see the loggic in this: are you telling me that a 15 years old fluid still has the same properties as the day they poured it into the tranny? I mean, debris, shavings and all aside, do you believe/know from experience that the fluid hasn't deteriorated in 15 years and 150k miles? I'm genuinely asking here, I have no experience with this type of auto transmissions, my last auto was a 70ish dart with a Torqueflite A-904 in it which was certainly another ball game

If the transmission would act up when hot I'd understand the dropping it and the useless of an oilchange, but it acts up sometimes (less than 1 out of 10) while dead cold, after not having seen action in a couple of days. And it's like ONE time (when it does the thing) and from there it wouldn't do it again.

Sure, if I drop it and rebuild it top to bottom it will cure this slight fail that annoys me. But i'm not convinced that this transmission needs a full rebuild right NOW.

The transmission shifts and puts out power far better when hot than when cold. This tells me that pehaps the fluid is "sludgy" and or the filter is restricting the flow partially, and maybe the level is a little low. It doesn't look brownish or smell burt. It looks a tad "milkier" than new fluid (as in same color, less transparency)

(Edit: I edited so the post would look less ranty or moody, I re read it and it sounded like a madman trying to win a swordfight with a fork : )

[rf900rkw]

As a matter of fact, I have had old fluid analyzed. Changing it at 150k is my normal recommendation. With the understanding that this is a feel-good PM maintenance only. It will not fix anything. Nor will it prevent the standard failures.

[jicaino]

OK so it's not going to do any good, but it ain't doing any harm!
What about the switch that goes on the shifter plate? have you heard of trans misbehaving on account of that piece of electronics?

[jamesdc4]

Top off the old fluid with some new if it makes you feel better. Personally from Randy's track record, he knows what he's talking about. He practically long distance diagnosed my tranny problem to the T.

[rf900rkw]

Now that I'm on a real keyboard... new and exciting typos not generated by autocorrect.

If you were low on fluid, you would be complaining of slow engagments and falling out of gear in 1st and Rev.... especially cold.Since you are not having any problems there, then the fluid level has to be high enough. It can not cause a 2-3 problem. On the 2-3 shift, the E brake is released, and the D brake is applied. The transfer has to happen smootly and evenly.What is likely happening in your case is the D brake is not coming on when it's supposed to. There are several possible causes of this, but we won't get into that yet.

Modern fluids are an amazing thing. Fluid viscosity is very steady, and doesn't change much over the life of the fluid. The change that does happen is towards thinning. Sludge just doesn't happen. Not at any reasonable temperature, anyway. And if the transmisssion got hot enough to damage the fluid... then the transmision is shot.... lifetime fill achieved.

Same thing goes for the filter. IF there is something restricting the filter, it's because the transmission is DONE. There is no spare material. If somethign failed and put up enough debris to plug the filter, replacing the filter and fluid will not bring it back. The new filter will be a temporary fix at best.

The point of all that rambling is that if the fluid is bad, it's because the transmission failed, and changing just the fluid is not a fix. Lifetime fill as in the fluid will be fine as long as the transmission is, and when the trans goes poof, so does the fluid.

By switch on the shifter plate, are you talking about the range sensor bolted to the side of the trans? The computer does what it's told by that switch. If it goes wrong, the trans will shift incorrectly or not at all. But, the same screwy signal that would confuse the computer will also confuse the dash display. The last one I saw bad was displaying "S4" on the dash... on a Steptronic car.

[jicaino]

Top off the old fluid with some new if it makes you feel better. Personally from Randy's track record, he knows what he's talking about. He practically long distance diagnosed my tranny problem to the T.

Yes, I value everyone's opinion, that's why I edited out, keep in mind that while my english may be fluent enough I'm not a native speaker.

[QUOTE=rf900rkw;27356464If you were low on fluid, you would be complaining of slow engagments and falling out of gear in 1st and Rev.... especially cold.Since you are not having any problems there, then the fluid level has to be high enough.[/quote]

Now that you mention, some of the issues I described can be constructed as "slow engagements". I'll check level. I still cannot believe the trans doesn't come with a dipstick! I read a couple of different recommendations as to how level shoud be check. I'm going with bringing it up to operating temperature, run the selector thru all the gears and check if fluid is on the lower edge of the plug, right?

It can not cause a 2-3 problem. On the 2-3 shift, the E brake is released, and the D brake is applied. The transfer has to happen smootly and evenly.What is likely happening in your case is the D brake is not coming on when it's supposed to. There are several possible causes of this, but we won't get into that yet.

I'm sure it's this. ( Brake=Solenoid? ) I thought seals at first, since it felt like something was bleeding back (some channel that was supposed to have fluid in it, bleeding back into the pan. Not saying it was this, I thought it was this as my understanding of valve bodies and general auto trans function is limited by my hands on experience , and as I explained, it was a torqueflite 904)

Modern fluids are an amazing thing. Fluid viscosity is very steady, and doesn't change much over the life of the fluid. The change that does happen is towards thinning. Sludge just doesn't happen. Not at any reasonable temperature, anyway. And if the transmisssion got hot enough to damage the fluid... then the transmision is shot.... lifetime fill achieved.

OK, I know a thing or two about modern lubes and I know this to be true, but didn't have any first hand experience on an auto transmission, and since the car was in a flood I thought maybe water could have sludged or mayo'd the fluid. Now that I think of, it would have killed the transmission alltogether, so most likely this wouldn't be the culprit. Operating temperature is within normal parameters and it shifts better when hot, and car never towed anything. It has been high speed road traveled a lot, but not abused subbing as a hauling truck. I'm not concerned about temperature related damage. Could level difference between cold and regular operating temperature hint us as the condition of the fluid?

Same thing goes for the filter. IF there is something restricting the filter, it's because the transmission is DONE. There is no spare material. If somethign failed and put up enough debris to plug the filter, replacing the filter and fluid will not bring it back. The new filter will be a temporary fix at best.

The point of all that rambling is that if the fluid is bad, it's because the transmission failed, and changing just the fluid is not a fix. Lifetime fill as in the fluid will be fine as long as the transmission is, and when the trans goes poof, so does the fluid.

OK so it makes more sense to drop the entire thing and rebuild it, and get another 15 years of dependable service, rather than taking a shot in the dark and replace fluid and filter?

By switch on the shifter plate, are you talking about the range sensor bolted to the side of the trans? The computer does what it's told by that switch. If it goes wrong, the trans will shift incorrectly or not at all. But, the same screwy signal that would confuse the computer will also confuse the dash display. The last one I saw bad was displaying "S4" on the dash... on a Steptronic car.

I checked that one and it's ok. I was referring to the piece of electronics that go under the shifter plate inside the car. It's not just leds, if you don't have the cables connected the transmission doesn't go into manual or sport mode. You can have no lights there and get it fully working as it has 2 cables, one powers the lights and the other is the one that would not allow the tranny into S or M mode if it ain't plugged. Have you ever seen a bad one there?

[jicaino]

I'm almost embarrased to report that the transmission was missing a whole quart of ATF. I have to put some miles on her since I just topped it off, but it feels like another car. Going thru the gears is almost instantly now, regardless of the throttle pressure, and R engages RIGHT AWAY like in no delay at all. Also the car idles quieter. I hope I didn't burn the juice box, I should have check'd level the day I got the car instead of going all fancy on diagnostic equipment. What bugs me is that trans guy didn't even want to check level for me (although I offered him his basic service fee for doing it!!!!!)

So if you have sympotms like "hesitation" but not so much engagement delay, and your trans act up while cold, you might want to check level. Mine didn't even went out of temp range, and the oil was the same temperature as reported by inpa (checked it with a thermometer in the actual fluid while reading the inpa gages and it was within 2°C.

[rf900rkw]

Ah, there you go. There was more going on than just the 2-3 shift. Glad it turned into being something that simple.

[jicaino]

Now that I have it full I can check the difference, there wasn't that much to speak of before. The only thing I could tell it wasn't normal was the 2-3 (this trans starts off 2nd on normal, so it was the first gear change) and the R took a little bit more than I expected to engage, but I thought it was normal for this transmission. I pumped a little bit more into it just to push old fluid or at least a mixture of old and new) out. It didn't smell burnt or look dark brown. I'm crossing fingers.

[philipj1]

Hope it works out for you