Is it possible to swap the 4-speed auto gearbox of a 850 T5R with the 5-speed auto gearbox of a C/S/V70R.
The idea is to chiptune the 850 T5R to 300+ HP and to me a 5-speed seems to be better to handle the power and torque.
What I found on the internet is that the engines are the same, but the question is: Does it mean you can swap transmissions?
Anyone any idea or experience?

 

Your better off posting this on Volvospeed..
There is alot more non traditional swap junkies over there
I think its been done but im not sure, I know guys have put the M66 6 speed manual in the 850's and of course M56 swaps.

 

I like my automatic and I've asked it on a few forums but haven't run across anyone who has done it or anyone offering any help or recommendations.

From what I researched it should bolt up. I didn't research what or if the wiring diagrams are different. I'm sure you'd need the TCM for the 5spd but it's likely you'd have some wiring differences.

The biggest draw back with keeping the automatic is there is no option I've found to equip it with a limited slip or posi track type differential. So you have a higher horsepower engine that is still only driving one wheel.

 

I think lucky is working on launch control options, and on of the guys over on VS is working on a plug and play paddle shifter setup for the auto.. It looks promising he has a couple vids up on youtube.

but what you say my friend is true regardless of the trans if its an auto there is no LSD option. a 6 speed swap with a gripper or a qualfie would be his best bet.

But as you know there are a couple guys here that have LSD's in their M56 5 speeds.. That would be the least of a headache when it comes to installation.