Hi Guys, I'm new here and joined to seek some advice regarding transmission fluid change on my 640d

I've heard a lot of hype about the ZF8 gear oil, but have been looking for some alternatives solely due to the cost of the damn stuff.

Millers claim they produce the same spec ZF8 oil and its literally half the price. I've used Millers many times over the years in some high performance cars and always respected their fluids but has anyone had any experience with their ZF8 gear oil or can anyone recommend an alternative to the crazy priced genuine ZF8 oil 

also just noticed Smith Alan also produce one of the same spec called 'Trangaurd ATF8'

Any help or advice would be appreciated 

Morning James

I have no experience of Millers products though I am fully aware of their products and they are a well established Company

I do however some experience of four failed ZF boxes (3 auto and 1 manual) on friends and neighbours cars where alternate Fluids had been used in service. My last service on my X5 4.6is ZF 5 speed cost £340 Fluid and filter and seals I always flush the torque converter too.

So I would guess around £500 to £600 for parts and fluid for the 8 speed plus labour if your not a DIY fan 

For me it is about balancing the cost of a ZF OEM service against a rebuilt or new box. I trust it is a service as a fluid change wont fix a fault.

Just my thoughts

Dave

Hi Dave, thanks for the reply.

yes it is just a service, I’ve owned the car for around a year now and the car has now done 85,000 miles and through further research people are advising fluid change for price of mind as there seems to be conflicting advice on when the fluid needs changing so I wanted to be safe than sorry. 
 

thanks for the heads up about alternative fluids. Like you said it may just be worth going for the ZF oil as they seem to offer a service pack with the oil and filter/pan for around £250 which I don’t think is too bad.

 

im pretty handy with the tools, would you say it’s fairly easy to do yourself with the correct torque wrench and oil pump? 
 

also how do you flush the converter? 

Morning James

About 2hrs to do the X5 fortunately mine has a cast alloy sump so less danger of distorting it.

The ZF manual recommends service at between 80000 and 100000 kilometers depending on use. Sadly BMW used to say "sealed for life" so many cars out there have never had the box touched.

Great price on the ZF service kit

Dave