ZF HP8 Transmission Servicing

Joined
Nov 4, 2014
Messages
666
Location
Wichita Falls, TX
Howdy y'all. I recently bought a used 2016 BMW 550i that has a GA8HP70Z transmission, a variant of the popular ZF HP8 tranny used in a lot of vehicles from the Dodge Charger to the Rolls Royce Phantom. BMW apparently considers the ATF a lifetime fill, recommending no service interval for the transmission. That seems ridiculous, as the transmission manufacturer recommends no more than 100,000 km or eight years before changing the fluid and the transmission pan, which is plastic and has an integrated filter. I'll probably service mine at about 50k miles.

Has anyone here done a DIY service of an HP8 transmission? It looks pretty easy, based on the manufacturer's instructions. The hardest part might be determining the transmission oil temp before checking the level. Maybe use an IR temperature gun for that?

I see the Genuine BMW pan/filter assembly is over $300, but ZF-branded ones are more like $100. The ZF Lifeguard fluid is over $20/liter but there are alternatives that meet the ZF specification at a fraction of the price, like Valvoline MaxLife. Anyone have experience with an alternative to the OEM transmission fluid? With a drain n fill taking nine quarts, spending $200+ on ATF seems crazy.
 
The interval you're quoting falls under ZF's "Above average operating conditions" (see page 5 HERE)

I used ZF fluid when I changed the ATF on my 335d. IMO when this procedure is done 2 or maybe 3 times during the life of the vehicle it does not make sense to use a "universal" ATF.

You can buy ZF kits from HERE or HERE / HERE

Quick Video and how-to: FCP Euro ZF 8HP Fluid Service

Technically you need a lift and a scan tool to monitor transmission temps in order to correctly fill the unit. These units are finicky.

Of course paying someone to do it who has the proper equipment can be a life saver BIMRS
 
The CTSC is a good source for parts and instructions when servicing ZF units. Definitely use the ZF pan, definitely use the ZF fluid.
 
I haven't touched the 8HP45 in my Ram 1500, but it's the same deal. I've seen youtube videos of 8HP70 owner's dropping the pan cold, measuring the amount that came out, then refilling with a few quarts until fluid starts to dribble out the fill/level check port, then idle the vehicle and add the remainder of the volume you took out.

I have yet to see anyone use the drain plug on the plastic pan. On hemi powered Rams, the drain plug runs right onto the exhaust. On Pentastar powered Rams there's nothing in the way.
 
Last edited:
Mercon SP and the ZF fluid are the same product. I wouldn't worry about the pan/filter. It's just a passive rock-catcher. The factory drain-fill procedure is based on achieving a temp range at the fill point to account for thermal expansion. You can just replace the same amount drained if it's at the proper level to start with.
 
Originally Posted by Joel_MD
With a drain n fill taking nine quarts, spending $200+ on ATF seems crazy.

Not as crazy as the cost of replacing the transmission. Like they say, pay a little now, or a lot later. Pretty sure you knew before buying it that BMW maintenance costs won't be the same as a Toyota.
 
Originally Posted by UberArchetype
Mercon SP and the ZF fluid are the same product. I wouldn't worry about the pan/filter. It's just a passive rock-catcher. The factory drain-fill procedure is based on achieving a temp range at the fill point to account for thermal expansion. You can just replace the same amount drained if it's at the proper level to start with.

I knew Mercon SP was the same as ZF Lifeguard 6 but it also the same as ZF Lifeguard 8?

The problem with using the measurement method is that all of the ATF coming out needs to be captured and at the same temp as the ATF going in and you have to account for that which runs out during the initial fill. Ya I suppose it can be done, but it's probably less than ideal and just "good enough".
wink.gif


Allegedly the plastic drain plug is a one-time use and even with the plug out the pan still retains a good amount of ATF.
 
The level-check procedure seems straight forward, even following the official ZF documentation that they quite kindly freely make available.

I'm going to be servicing our ZF 8HP45 in the coming months. My plan is to use a genuine ZF transmission pan with Comma MVATF Plus which is a universal ATF like MaxLife. Ours has 145k on the clock so I'm coming for a decent improvement.
 
Yup, plastic plan apparently is a one time use part.

While the changes are finicky given that technical directions call for a lift and temperature readout. I still find it hard to believe that dropping the pan (cold) into a measurable container and replacing with the same amount of cold fluid won't deliver the same results. This was the method I (and many others) used with the Nag1 on the LX platform and didn't have any issues.

I understand that some users may have fluid leaks or losses caused by their particular usage, which would result in a less than full baseline, but for the vast majority of driver's I don't believe that would be an issue. I'll be doing a pan drop at 80k miles as that's when Alfa calls for the t-case to be completed, might as will take care of both at the same time.
 
Originally Posted by UberArchetype
Mercon SP and the ZF fluid are the same product. I wouldn't worry about the pan/filter. It's just a passive rock-catcher. The factory drain-fill procedure is based on achieving a temp range at the fill point to account for thermal expansion. You can just replace the same amount drained if it's at the proper level to start with.

No, they're not.

ZF8 is green and it is a new fluid. ZF6 and ZF8 are different fluids and I don't trust anyone that recommends the same fluid for both.
 
Originally Posted by dave1251
I used MAXLIFE ATF in my ZF-8 and thousands use it also. There is no reason to use ZF fluid it is nothing special.

Sure.

You prepared to replace his transmission if it fails based on your recommendation?

I wonder, do you have the same ZF8 as the OP? Are the internals the same? The programming?
 
Why in the world would a transmission fail from using a non-OEM ATF that meets the manufacturer's specifications? For years I used Amsoil universal ATF in my Saab 9-5, not taking the advice of some ninnies on the Saab forum who said my Aisin transmission would fail if I didn't use the non-synthetic ATF that the manual specifies. The Amsoil ATF met the specific Aisin spec. That car has nearly 200k miles on it and the tranny still runs like a sewing machine.
 
Originally Posted by BMWTurboDzl
Allegedly the plastic drain plug is a one-time use and even with the plug out the pan still retains a good amount of ATF.

Maybe the pans are different between ZF8's, but if you do a search for the drain plug, it looks reusable. It's threaded with an O-ring seal. I did post pics on this some time ago, but it might be somewhere else.

FWIW, I wouldn't expect to get a full drain from any drain plug removal.

I'm with you though.. I'm still hesitant to pull that plug without having a replacement pan on hand!
 
Originally Posted by Joel_MD
Why in the world would a transmission fail from using a non-OEM ATF that meets the manufacturer's specifications? For years I used Amsoil universal ATF in my Saab 9-5, not taking the advice of some ninnies on the Saab forum who said my Aisin transmission would fail if I didn't use the non-synthetic ATF that the manual specifies. The Amsoil ATF met the specific Aisin spec. That car has nearly 200k miles on it and the tranny still runs like a sewing machine.

Great, I'm happy for you. I really am. But...

Your Saab is not a BMW with a ZF8.

I trust ZF more than Valvoline in this case, and so should the OP. There's a recent post on this board of MaxLife not playing nice in an Aisin 8 speed. Valvoline says it should be fine, but it isn't. Is it really worth saving the hundred bucks? How often is he going to change ATF?
 
Originally Posted by rooflessVW
The CTSC is a good source for parts and instructions when servicing ZF units. Definitely use the ZF pan, definitely use the ZF fluid.

Yep. Spend the extra $50 and get ZF fluid. Why do people always try to save money using non OEM ATF ????

I'm getting a 10 speed auto Camaro and when its time for ATF change it will be OEM and not MaxLife for my GM.
 
VW asin transmissions (09G) have a similar method of filling the trans based on temp. What you need is a OBD scanner that can read BMW specific trans codes. Just go to one of the many BMW forums and there should be a ton of recommendations on what scanner to use, the drain and refill procedures, and the correct fluid to use. I agree that using the ZF recommended fluid is best since these transmissions are very finicky, and saving 50 or 100 bucks on fluid only to have a 5k transmission go bad its just plain stupid. Avoid being penny wise pound foolish. Also before you even start to consider the fluid change you must have a perfectly level surface and the ability to raise the vehicle so that it is level in order to get accurate fluid readings post refill. I use a bubble level to verify that the vehicle is level.
 
If you are in Europe you can try AISIN AFW+ thats made by Aisin. Its WS compatible and many SAAB and other euro brands with Aisin transmission are using it with good results. I use it on my FJ Cruiser that has Aisin A750 transmission.
 
Back
Top