Tranny info 6HP26

[Lwilliams]

Are all the facelift E53's fitted with the 6hp26?

[Emory39]

Originally Posted by Lwilliams

Are all the facelift E53's fitted with the 6hp26?

I
don't know about the 3.0L but the n62 4.4 and 4.8 yes.

[Lwilliams]

nice one

[JdBn]

Would it be possible that a solenoid starts failing from a certain temperature? In M-mode my car sometimes does not upshift into 5th under load (will go into sort of neutral until you take the throttle back, then it catches 5th), but it seems to only do that when the gearbox temperature is something like 80degC or up.

[Emory39]

I would look into a fluid and filter change, reset adaptations and go for a long drive. What's you miles or kilometers on your odo? ZF recommends fluid flush at 60K miles or 96.5k kilometers. I have never experienced what you described, solenoids fail and you get a hard shift up or down. But never heard that neutral thing in 5th.

Originally Posted by JdBn

Would it be possible that a solenoid starts failing from a certain temperature? In M-mode my car sometimes does not upshift into 5th under load (will go into sort of neutral until you take the throttle back, then it catches 5th), but it seems to only do that when the gearbox temperature is something like 80degC or up.

[SlickGT1]

https://www.thectsc.com

I got all my stuff here. All of it fit perfect. And their customer service was nice enough to explain a few things when I had questions. I got everything remotely applicable when going for the solenoids. Sleeve, bushings, filter, oil, solenoids, etc. Dont remember whole list, but essentially bought everything that went as deep as the mechatronics unit. I figured if I’m going in, I’m going in so that I don’t have to go in again.

By the way, there was no sign that any of the extra parts that I replaced were worn or were going to fail. Just saying.

[JdBn]

Oil and filter were changed not too long ago, not because of any problems but more as a maintenance thing.

I did speak to ZF about this issue and they indicated that it might actually be the MAF... So that is the first thing that is going to be replaced tomorrow. I’ll drive it hard in the coming week and see if it goes weird again.

[ArchE53]

The MAF... how interesting. Let us know how it goes.

I just realised yesterday that I've been filling my trans wrong - the trans needs to be level, not the car. I've potentially been under filling it causing it to behave badly.

I've been thinking about rebuilding the valve body with the sonnax zip kit. I now have a spare 6hp26x sitting in my garage to practice on.

Any experience here with improvements post zip kit?

[wpoll]

Originally Posted by ArchE53

... I just realised yesterday that I've been filling my trans wrong - the trans needs to be level, not the car. I've potentially been under filling it causing it to behave badly....

I'm pretty that they are same thing . i.e. the trans. and the car are on a similar plane - if the car is level, the trans. is level.

I just now ran out to check but as I have a 3.0d, there is a big plastic cover over the trans and I cannot see it but I recall noting the last time I was under there that the trans. sump edge was pretty close to parallel with the body seam.

[JdBn]

Originally Posted by ArchE53

The MAF... how interesting. Let us know how it goes.

That kind of was my reaction as well when the guy from ZF said it might be the MAF causing issues. However, the MAF is pretty important as the DME calculates the torque&power based on the incoming air. Wrong measurement of the incoming air could mean incorrect torque from DME to TCU causing it to not use the correct line pressure to cope with the actual torque.

It just seems so illogical when you hear it without thinking it through