2005 TRANSMISSION FAILING.. MODLE # A5S 390R YZ

[Rockit]

The mechanical ZF transmission are pretty good.... overall.

Try this first before you start doing mechanical stuff. Unplug all electrical connections to the trans and clean and lube them. If you live in a climate of salt or if someone pulled there boat in an out of the water with the car chances the connecters are corroded.

The main connector that plugs in to the natural safety switch was my problem and made mine go into limp mode. I was then told the celinoids in the trans were bad. Simple to clean it, you can crawl under and do this, try that first. The neutral safety switch is on the outside of the transmission.

And yeah 100k change the trans filter and oil. If you do this remember to start the car, leave it running and add the final quart. The Valvoline Maxlife AT is good to use, have it in mine.

Just remember everything on this truck is monitored my millivolts, one bad connector is all it takes, even the electric fan motor can through a code.

[upallnight]

Originally Posted by c-bass

Many people use the Valvoline Maxlife ATF

https://www.valvoline.com/our-produc...ti-vehicle-atf

The transmission fill procedure is not complicated at all.

You need to have the transmission at normal operating temperature and when you unscrew the fill plug there should be a slight trickle of fluid coming out.

If you are worried about driving the vehicle then let the engine run until it comes up to temp (needle in the middle) and shift into each gear for a few seconds. R N D etc. Then check the fluid level.

Basically the trans fluid will expand when heated (like most fluid) so if you fill the transmission to the proper level while it's cold once you're driving around the fluid level will be too high.

The transmission shop that I deal with specializes in European cars and while I had my car there for a flush I was asking the guys all about the pain in the ass fill procedure. They said it's not that sensitive and proceeded to walk me through it on my car.

If you read how to do the fill procedure from the manual it sounds a LOT more complicated than what it really is.

au contraire mon ami

Not according to the TIS Bulletin issued by BMW for filling and checking the fluid level in their trans. The temp should be between 30C - 50C. If 100C is the boiling point of water 50C is only 122F. With a thermostat that is set to 195F that would be Waaaaaay over the maximum temp allowed.

Here's a link to the TIS

https://www.bimmerfest.com/attachmen...py-pdf.301615/

Watch out for the Cliff Claven on this board.

[c-bass]

Originally Posted by upallnight

au contraire mon ami

Not according to the TIS Bulletin issued by BMW for filling and checking the fluid level in their trans. The temp should be between 30C - 50C. If 100C is the boiling point of water 50C is only 122F. With a thermostat that is set to 195F that would be Waaaaaay over the maximum temp allowed.

Here's a link to the TIS

https://www.bimmerfest.com/attachmen...py-pdf.301615/

Watch out for the Cliff Claven on this board.

What does the temperature of boiling water have to do with anything?

I'm familiar with the TIS as well as had this done several times by a reputable shop that walked me through it while we were under the car.

Everything I said is basically the same procedure as the TIS you linked.

- Bring trans to temp, check for fluid seeping out of fill hole

I'm not a big fan of passive aggressive so if you disagree with my opinion of what "up to temperature" is just say so...mon ami

[crystalworks]

You'll have to get used to UAN c-bass. Very knowledgeable and usually helpful. But definitely gives out info with his nose in the air. Is what it is. There's one of two on every forum. Read past the "extra" stuff and the info in his posts is usually on point. As he is quick to point out.

[oldskewel]

Originally Posted by c-bass

... if you disagree with my opinion of what "up to temperature" is just say so...mon ami

It would be so much easier if the spec was actually to bring the AT up to operating temp, i.e., with the engine warmed up, AT and ATF at a steady-state temp, having just driven it to the garage of your choice.

But for some reason, nobody does this. ZF and GM for the BMW, and same thing on Porsche and Mercedes I'm aware of have the temperature at which ATF level is set be a temperature that is far below normal operating temp.

The reason it matters is that the ATF will expand as it raises in temp, I believe with about a half quart difference between cold vs. hot for a ~10qt capacity. I don't know how much that difference matters, but it sure does get most people's attention.

I believe for the BMW (both ZF and GM ATs) that temp spec is 30-50*C, with 35*C as the actual target. As @upallnight correctly pointed out, that is FAR lower than "operating temperature." In fact, it is stone cold in many climates at certain times of the year. I think many people here in the US, where C vs. F is like a foreign language, and having numbers involved causes some panic and lack of clear thinking, leading people to go and buy pyrometers and OBD2 systems.

EDIT - and LOL, that last sentence is probably why @upallnight mentioned the boiling point of water. It might bring some calm and rational comparitive thinking to some of us in the USA who are not used to a foreign language like that. Not completely kidding

This low temp spec makes it tough to get done properly at a shop. I can definitely believe that a shop would say operating temp is good, since that makes their job a lot faster. But it does not change the spec. It seems it would be a lot easier for everyone if the spec were at a temp closer to operating temp, and the fill hole was a few mm higher to account for that. But across all German ATs (and even the Porsche one I know of is an Aisin [Japanese] one, with a similar spec) I know of, they use the low temp spec.

I've seen on youtube where they use a bunch of fans to cool down a car+engine so they can get the guy out the door in only 4 hours. LOL. Waiting overnight will work as well.

Me, doing it myself in my driveway, my method is basically to
- day 1 - first purposely overfill the AT slightly, taking my time, with no concern about temp.
- day 2 - morning (relatively colder starting point) - Level set, much simplified procedure.

The day 1 overfilling is made possible by jacking the rear slightly higher than the front, so the fill hole (on my GM AT, on the left side towards the rear corner) is higher than the center of the pan.

Then, the next morning after everything is cold and the AT and ATF have shrunk, I do the following abbreviated procedure to set the level:

• Quick spin around the block, in all gears,
• in the driveway, jacked up level,
• idling, fill bolt out, and idle it until 35*C is very quickly reached (during this time, some ATF will be leaking out as it expands due to the temp rise), at which point I put the fill bolt back in.

The point of doing it that way is that the actual setting of the level is a much simpler procedure. No ATF needs to be added. Just removing the fill bolt (which did not even need to be tight) is simple enough that I can stop things as the temp rises through 35*C.

[upallnight]

Originally Posted by c-bass

What does the temperature of boiling water have to do with anything?

I'm familiar with the TIS as well as had this done several times by a reputable shop that walked me through it while we were under the car.

Everything I said is basically the same procedure as the TIS you linked.

- Bring trans to temp, check for fluid seeping out of fill hole

I'm not a big fan of passive aggressive so if you disagree with my opinion of what "up to temperature" is just say so...mon ami

The trans fluid cooling is usually tied in with the radiator. If the coolant from the engine at operating temp is 195F. than the atf fluid at the radiator is close to the temp of the coolant mon ami.

Originally Posted by c-bass

Many people use the Valvoline Maxlife ATF

https://www.valvoline.com/our-produc...ti-vehicle-atf

The transmission fill procedure is not complicated at all.

You need to have the transmission at normal operating temperature and when you unscrew the fill plug there should be a slight trickle of fluid coming out.

If you are worried about driving the vehicle then let the engine run until it comes up to temp (needle in the middle) and shift into each gear for a few seconds. R N D etc. Then check the fluid level.

Basically the trans fluid will expand when heated (like most fluid) so if you fill the transmission to the proper level while it's cold once you're driving around the fluid level will be too high.

The transmission shop that I deal with specializes in European cars and while I had my car there for a flush I was asking the guys all about the pain in the ass fill procedure. They said it's not that sensitive and proceeded to walk me through it on my car.

If you read how to do the fill procedure from the manual it sounds a LOT more complicated than what it really is.

The normal operating temp of the trans is NOT 30C to 50C temp. It is a lot hotter. Like you stated ATF expands when it is heated and contracts when it is cooled. So if you do your check at "Normal Operating temp" the ATF would have expanded considerably and if you let it dribble out, by the time it contracts when it has cooled, the fluid level will be LOW mon ami.

Like I warn people watch out for the Cliff Clavens on ths forum.

[upallnight]

Originally Posted by c-bass

What does the temperature of boiling water have to do with anything?

I'm familiar with the TIS as well as had this done several times by a reputable shop that walked me through it while we were under the car.

Everything I said is basically the same procedure as the TIS you linked.

- Bring trans to temp, check for fluid seeping out of fill hole

I'm not a big fan of passive aggressive so if you disagree with my opinion of what "up to temperature" is just say so...mon ami

If you think that was "passive aggression" don't go into the Political forum. Just pointing out to a Newbie that is having a problem that you need to take any advice here with a grain of salt.

[c-bass]

Originally Posted by upallnight

The trans fluid cooling is usually tied in with the radiator. If the coolant from the engine at operating temp is 195F. than the atf fluid at the radiator is close to the temp of the coolant mon ami.



The normal operating temp of the trans is NOT 30C to 50C temp. It is a lot hotter. Like you stated ATF expands when it is heated and contracts when it is cooled. So if you do your check at "Normal Operating temp" the ATF would have expanded considerably and if you let it dribble out, by the time it contracts when it has cooled, the fluid level will be LOW mon ami.

Like I warn people watch out for the Cliff Clavens on ths forum.

Here I was trying to make it simpler for someone to do a quick fluid check

P.S.

Everyone hates the French

Do Cliff some justice and spell his name right at least Amigo

[upallnight]

Originally Posted by c-bass

Here I was trying to make it simpler for someone to do a quick fluid check

P.S.

Everyone hates the French

Do Cliff some justice and spell his name right at least Amigo

So do you order "Freedom Fries" when you go to Mickie D?

[andrewwynn]

When the engine just reaches operating temp the mass of steel and aluminum will make for the transmission taking a good while to get up to the same temp if it's just acting as a heatsink. It wouldn't surprise me at all if the transmission would coincidentally hit 30-35 C right as the ECT hits 90c.

Of course every engine and every transmission will have different results, so unless you are *sure* that coincidence doesn't happen, the scientific approach is to do a measurement and find out.

My scanner will show transmission temp (I think the sensor is in the wiring loom setting in the oil pan), but I don't know if I can read the ECT at the same time.

As mentioned above, there is a very good chance that coincidentally the xm reaches 30-40C right when the coolant reaches 90.

I seem to recall reading 60c from transmission after driving around and the engine was full temp.