After Trans oil Change/harsh downshift now

[andrewwynn]

If I had a similar situation I may look into AT-205 treatment. If the sloppy shifting is from the seals getting hard that stuff is supposed to make the rub we softer and seal better.

In fact I'm planning to get some and may try before I do the filter change on wife's X5

[crystalworks]

Good info Rockit. Thanks for the update. I'll add that I just used liquid moly's substitute for the zf lifeguard 6 that these trans call for. It is also very thin. If I hadn't changed the bridge seal and the 4 rubber sleeve seals I'd be very worried.

This was on a 186000 mile 6hp19 in a 5 series wagon. I am still in the process of the fluid fill (got 3.5 liters in so far) as I was waiting for a guibo, exhaust gaskets, and csb to come in before continuing on the trans. Will update with results here to add to the knowledge base. The vehicle had no real shifting issues before the work.

[Rockit]

Originally Posted by crystalworks

If I hadn't changed the bridge seal and the 4 rubber sleeve seals I'd be very worried.

Crystalworks, can you please document this procedure if not in pictures can you explain in detail what you changed and the part numbers. This may cure my problem.

[Rockit]

This is the link to the Youtuber Crystalworks mentioned, states why he uses that Valvoline oil. There are many ads but worth hearing.

https://www.youtube.com/watch?v=vqQxnICNJxA

[Purplefade]

Originally Posted by Rockit

Crystalworks, can you please document this procedure if not in pictures can you explain in detail what you changed and the part numbers. This may cure my problem.

Hey Rockit

I'm sure one of the guys will keep me honest, but I don't think the 5 speeds in the 02 use the same bridge seal and pickup tube setup as the 6 speed in CWs so that probably wouldn't help you too much.

[Rockit]

So an update....the problem with the trans was NOT in the trans, it was the rubber damper on the drive shaft.

So my car was shifting fine, I changed the trans oil at 125k on a 2002 and it started to down shift harsh. I'm a very good diagnostician and this got me. The rubber damper on the drive shaft was cracked
/worn and aloud to wobble and created play, very hard to spot bolted together. When the car was put on the lift it most have torn the worn part further. as the suspension went to full rebound. Every time I would put it on the lift to change the trans fluid it would change the position or align or misaligned the rubber cupler. I don't know the BMW name for it.

If you have a Hugo E53 and I would change every piece of plastic and rubber you can find. I had 2 E38's with 150k and 10 years old and never had any of these issues except for the Bear radiator top house cracking as the all did because they could not taken the heat. Bear F'ed that up and took zero responsibility.

Anyway if you have an 2002-2005 or so change them now, its age rather than mileage. You will never find this until the bolts break off eventually, I had zero drive line vibration.

[bhennrich]

Originally Posted by Rockit

So an update....the problem with the trans was NOT in the trans, it was the rubber damper on the drive shaft.

So my car was shifting fine, I changed the trans oil at 125k on a 2002 and it started to down shift harsh. I'm a very good diagnostician and this got me. The rubber damper on the drive shaft was cracked
/worn and aloud to wobble and created play, very hard to spot bolted together. When the car was put on the lift it most have torn the worn part further. as the suspension went to full rebound. Every time I would put it on the lift to change the trans fluid it would change the position or align or misaligned the rubber cupler. I don't know the BMW name for it.

If you have a Hugo E53 and I would change every piece of plastic and rubber you can find. I had 2 E38's with 150k and 10 years old and never had any of these issues expect for the bear radiator top house cracking as the all did.

Anyway if you have an 2002-2005 or so change them now, its age rather than mileage. You will never find this until the bolts break off eventually, I had zero drive line vibration.

It sounds like you are talking about the "guibo" and there are two of them on the X5. One for front and one for rear

[Attacking Mid]

The 5L40E originally came with something similar to Dexron III, so it was likely much more viscous than the Dexron VI that most are currently using. I changed mine out with the MaxLife fluid which I swear used to be a bit more viscous than Dex VI. After I had changed it out, I happened to look up the specs and it now says it's actually slightly LESS viscous than Dex VI. Unless I'm mistaken, it appears they have changed the formulation sometime in the past couple of years resulting in a lower viscosity.

It seems to be working fine in my trans, so I'll leave it in there for a while, but I may try something else like the Castrol Multi Vehicle mentioned earlier at my next fluid change. I'm not in the camp of those who believe in old, contaminated fluid being the ticket to long transmission life.

AM.

[oldskewel]

I did a total of 3x drain and fills with DEXRON VI within a few k miles of getting my 2001 3.0i. Had ~160k miles on the original fluid when I started. No problems, and very glad I did it. Smoother, faster shifting. Did it carefully, which I posted on this site back when I did it.

On the DEXRON VI vs. III, I believe the low temp viscosity of the VI is lower, and you can pretty easily see/feel this when you pour it in. But the VI is more stable, retaining the viscosity both with temp increase and with wear. So as the fluid actually operates in your AT, at temp, and after a few k miles of use, the VI will have slightly higher viscosity, which is preferred.

[Attacking Mid]

Originally Posted by oldskewel

On the DEXRON VI vs. III, I believe the low temp viscosity of the VI is lower, and you can pretty easily see/feel this when you pour it in. But the VI is more stable, retaining the viscosity both with temp increase and with wear. So as the fluid actually operates in your AT, at temp, and after a few k miles of use, the VI will have slightly higher viscosity, which is preferred.

Yep, from what I've researched, Dex VI is a superior fluid in just about every way. With an older transmission, it makes sense to me that a slightly more viscous fluid with the quality of Dex VI might make sense. I've read where some have used Mobil1's synthetic ATF that is noticeably thicker with good success. It's expensive, though!

For now, the MaxLife stuff is working fine and it definitely made it shift faster/cleaner vs. the old OE stuff I pulled out at about 125K miles.

AM.