E70 ZF8HP45->ZF8HP70?
 

Does anyone know if a ZF8HP70 can be swapped for a ZF8HP45 in a 2011 xdrive35i? I'm getting a little slippage at peak torque, tuned, and the only transmissions I'm seeing for a decent rate on eBay are ZF8HP70s.

Would the transmission bolt up to the N55? Can the mechatronics be swapped over? Has anyone done this?

Thanks!

Never heard of it being done.

Would be shocked if it works- as a 'bolt up'. Could it be engineered? *ANYTHING* is possible, only a matter of money

Why ebay?

Have you looked into rebuilding yours?

Check out xhp flash tool on Google, they sell tuning for our transmission which increases torque limits and clutch pressures. Some tunes misreport the torque so that the trans doesn't dial back power but can slip with stock maps.

Does this work with ZF8HPs? The web site only says ZF6HP.

My local Bimmer shop said they wouldn't at all be "surprised" but asked me to see if someone else had attempted it.

I need higher torque holding than the stock tranny allows, hence looking at one from a 50i. I've got a Pure Stage-1 turbo and a dyno Tune by Cobb, and I'm hitting 406WTQ and every so often, I get slippage before it grabs.

I don't know if they do 8hp yet. You can ask them or look up your year and model on the site.

Have you changed the fluid and filter? Old fluid can cause issues, especially if the level is slightly low.

I believe there are a few shops that can do a rebuild and beef it up at the same time. Shop in Portland as I recall?

I am sure you know this, but when YOU can sense slippage in the trans, it has been doing damage before that point....

Fluid and filter were changed about 10k miles ago.

I'd rather not deal with the logistics of shipping my transmission to PDX. I'm in Austin, TX.

Informing me that my transmission is likely already damaged isn't helpful. This is why I spawned this thread and am looking to have it replaced.

So this brings us back to the original question - Can a 70 replace a 45? Rebuilding is beyond the scope of my question as I'd rather go with a transmission that's beefier than what I've got, if that's an option.

Nobody has done what you are asking, and posted here or on bimmerfest in the E70 forums about that experience.

And I recall I was specifically speaking of shops that could rebuild to beefier specs. Not just fix yours so it fails again....


Finally I might have suggested that you call IPT in Hawthorn NJ, but there is that logistics thing again. (Never mind that they might be able to answer your question...) Plus here I am NOT answer the question you asked. Im telling you who might know, but again- that is NOT what you asked.