ZF8

DaleHeinz · 10-21-2018, 08:44 PM

Tuning and modifying my M240Xi has been fun. It's great to bring the car up to a performance level that exceeds anything in its price range.

So, just how much power can the ZF8 transmission handle? Not that I'm even the least bit worried at this point, but I'm curious to know what it can handle from a reliability standpoint.

Joe240 · 10-21-2018, 09:05 PM

The zf8 is rated for 369lb-ft, funny enough the rated lb-ft that Bmw gives the m240i/x. Reliably, I’d say stock numbers. However, there’s not a ton of high mileage vehicles with this zf8 variant in them to observe longevity, let alone tuned beyond the factory numbers. Most people, including myself, have only put about 20k miles tuned on this transmission. Still no issues thus far, but 20k miles is hardly justifiable for reliability benchmarks.

tennisfreak · 10-22-2018, 08:17 AM

Unless Wikipedia is wrong the variant used in the 2 series can handle up to 450lbs of torque.

https://en.wikipedia.org/wiki/ZF_8HP_transmission

Mr Carrots · 10-22-2018, 08:30 AM

Quote:

Originally Posted by tennisfreak

Unless Wikipedia is wrong the variant used in the 2 series can handle up to 450lbs of torque.

https://en.wikipedia.org/wiki/ZF_8HP_transmission

500nm or 369 lb/ft

They are clearly good for more but that offical rating is very low

tennisfreak · 10-22-2018, 08:33 AM

Ooops read that wrong my bad.

Zwei · 10-22-2018, 10:26 AM

Quote:

Originally Posted by Mr Carrots

500nm or 369 lb/ft

They are clearly good for more but that offical rating is very low

Not so sure. There are variants that are good for much more but they likely have internal changes that make them more durable and are not in F22's. Those ZF ratings come with extensive testing to demonstrate reliability. Anecdotal uprating, as in I modded my engine and it now has 100 hp more and the ZF works just fine, is not the same as the technical test results demanded by BMW. How many miles do you expect from your transmission without issues?

Maynard · 10-22-2018, 02:54 PM

I'd heard from an expert at a tech talk that they are identical across applications, but it was an offhand comment, might have just meant they are basically the same. Also that with higher power it pays to shorten the normal 50k service down to 30-40k and do an oil analysis. Given what a PITA the fluid change sounds like, I'd bet most are never refreshed, and I've not seen much about trans problems.

DaleHeinz · 10-22-2018, 06:23 PM

I didn't realize there were that many iterations of the zf8 out there.

10-21-2018, 08:44 PM	#1
DaleHeinz First Lieutenant 221 Rep 314 Posts Drives: M240Xi Estoril Blue Join Date: Apr 2017 Location: Washington DC area iTrader: (1)	ZF8 - How much can it handle? Tuning and modifying my M240Xi has been fun. It's great to bring the car up to a performance level that exceeds anything in its price range. So, just how much power can the ZF8 transmission handle? Not that I'm even the least bit worried at this point, but I'm curious to know what it can handle from a reliability standpoint.
	Appreciate 0 Tweet Quote

10-21-2018, 09:05 PM	#2
Joe240 Major 2924 Rep 1,303 Posts Drives: 2021 C8 Corvette 1LT Join Date: Jul 2016 Location: Pensacola iTrader: (0) Garage List 2020 GMC Sierra AT4 [0.00] 2019 BMW X3 M40i [0.00]	The zf8 is rated for 369lb-ft, funny enough the rated lb-ft that Bmw gives the m240i/x. Reliably, I’d say stock numbers. However, there’s not a ton of high mileage vehicles with this zf8 variant in them to observe longevity, let alone tuned beyond the factory numbers. Most people, including myself, have only put about 20k miles tuned on this transmission. Still no issues thus far, but 20k miles is hardly justifiable for reliability benchmarks.
	Appreciate 1 DaleHeinz220.50 Quote

10-22-2018, 08:17 AM	#3
tennisfreak Second Lieutenant 201 Rep 296 Posts Drives: M240i Join Date: Feb 2018 Location: DFW iTrader: (0)	Unless Wikipedia is wrong the variant used in the 2 series can handle up to 450lbs of torque. https://en.wikipedia.org/wiki/ZF_8HP_transmission
	Appreciate 0 Quote

10-22-2018, 08:33 AM	#5
tennisfreak Second Lieutenant 201 Rep 296 Posts Drives: M240i Join Date: Feb 2018 Location: DFW iTrader: (0)	Ooops read that wrong my bad.
	Appreciate 0 Quote

10-22-2018, 02:54 PM	#7
Maynard Colonel 3848 Rep 2,873 Posts Drives: 228iX & M2C Join Date: Mar 2016 Location: Upstate NY iTrader: (1)	I'd heard from an expert at a tech talk that they are identical across applications, but it was an offhand comment, might have just meant they are basically the same. Also that with higher power it pays to shorten the normal 50k service down to 30-40k and do an oil analysis. Given what a PITA the fluid change sounds like, I'd bet most are never refreshed, and I've not seen much about trans problems.
	Appreciate 0 Quote

10-22-2018, 06:23 PM	#8
DaleHeinz First Lieutenant 221 Rep 314 Posts Drives: M240Xi Estoril Blue Join Date: Apr 2017 Location: Washington DC area iTrader: (1)	I didn't realize there were that many iterations of the zf8 out there.
	Appreciate 0 Quote