205,000 miles and about to service transmission question.

[mm3846]

that old school thinking isn't right anymore on the new stuff. under normal driving, the ZF fluid can go 75k (according to ZF) before you change it. OEMs say 100-125k. So, double ZF's number and you get 150. Transmissions and fluids have come a long way.

It was a bigger deal with transmissions were shifted solely on hydraulic pressure, now that doesn't matter as much as its all electronically controlled. Also, D/M II and III went to **** after like 50k miles, and if the fluid ever got hot, it was worthless. Another reason (IMO) for 4L60 failures... old ass fluid, gets a little hot and it turns to water and you've got 4 neutrals.

 

[greiswig]

I would guess that a poorly-done service on an older transmission might loosen up some crud and deposit it in places where it might not have ended up had it been left alone. But IDK. And IDK whether that still equates to a "never flush an old transmission" or not. Seems likely that plenty of old transmissions have failed from neglect, too. You need that data as well to have a real weighting of the risks.

 

[mm3846]

I would guess that a poorly-done service on an older transmission might loosen up some crud and deposit it in places where it might not have ended up had it been left alone. But IDK. And IDK whether that still equates to a "never flush an old transmission" or not. Seems likely that plenty of old transmissions have failed from neglect, too. You need that data as well to have a real weighting of the risks.

Agreed. And flush =/ drain and refill. Which is what most of us are doing anyway.

 

[Rover Range]

What's high mileage in this case? And is this a fluid drain and refill, or some sort of fluid "flush?"

100k miles.

 

[Al Pizzica]

Gosh I feel like I've read this same thread on dozens of forums over 20 years.
It's like red or black at roulette with the slush boxes: are you feeling lucky?
I guess only time will tell with mine at 100k.

 

[16FujiDisco]

that old school thinking isn't right anymore on the new stuff. under normal driving, the ZF fluid can go 75k (according to ZF) before you change it. OEMs say 100-125k. So, double ZF's number and you get 150. Transmissions and fluids have come a long way.

It was a bigger deal with transmissions were shifted solely on hydraulic pressure, now that doesn't matter as much as its all electronically controlled. Also, D/M II and III went to **** after like 50k miles, and if the fluid ever got hot, it was worthless. Another reason (IMO) for 4L60 failures... old ass fluid, gets a little hot and it turns to water and you've got 4 neutrals.

I agree, fluid tech has progressed just as much as transmission tech; that’s why I wanted to preface what time frame that came from.

I’ve always been from the camp of following recommended service schedules from either the car manufacturer or component maker; that’s why I did mine at the ZF mileage.

 

[16FujiDisco]

Here is a good article from FCP Euro on the ZF 8’s

The Definitive Guide To The ZF 8-Speed Transmission (8HP45) - Specs, Common Problems, Diagnostics, & Maintenance

ZF Friedrichshafen was formed just after the turn of the 20th century in Germany. Initially, ZF was dedicated to designing parts for Zeppelins, but the quickly growing automobile industry soon became their main focus. By 1934, Zahnradfabrik Friedrichshafen had built their first fully...

blog.fcpeuro.com

 

[Al Pizzica]

Here is a good article from FCP Euro on the ZF 8’s

The Definitive Guide To The ZF 8-Speed Transmission (8HP45) - Specs, Common Problems, Diagnostics, & Maintenance

ZF Friedrichshafen was formed just after the turn of the 20th century in Germany. Initially, ZF was dedicated to designing parts for Zeppelins, but the quickly growing automobile industry soon became their main focus. By 1934, Zahnradfabrik Friedrichshafen had built their first fully...

blog.fcpeuro.com

I would die to have the ZF8 in my 2013. I had it in other high power vehicles and it is the best slush box. The 6 is a sluggish pig in comparison.

 

[ftillier]

Could the ZF 8HP from a 2014+ be swapped into a an earlier LR4 that came from the factory with a 6HP?

 

[16FujiDisco]

Could the ZF 8HP from a 2014+ be swapped into a an earlier LR4 that came from the factory with a 6HP?

I believe it can, but with the electronic controls, you’d prob have to reflash something to get the ECUs to jive