modifications > Mountune PTU Brace

Why did you put a Mountune PTU Brace on your RS?

The factory Focus RS power transfer unit (PTU) is the gearbox that transfers power from the transmission to the rear drive unit (RDU). Other AWD vehicles call it a transfer case. On the RS the PTU has a stamped steel brace with (3) bolts - (2) bolts on the PTU and (1) bolt on the transmission.

Mountune makes a replacement PTU brace out of aluminum that is stronger than the stamped steel factory unit. The Mountune PTU Brace also picks up a 2nd mount on the transmission for a total of (4) mounts compared to the factory brace only having (3) mounts. This additional support is needed for those folks that want more performance out of their RS for drag racing, autocross, lapping days, etc. To my knowledge no one has damaged a factory RS PTU yet, so we don't exactly know the weak link or limits. Only time (and more horsepower/torque) will tell us.

Date Completed:



- Mountune PTU Brace
- Loctite blue for socket head cap screws


- 1/4" drive ratchet, handful of extensions, 10mm socket, 6mm hex socket
- 10mm ratcheting combination wrench to remove (2) factory PTU bolts
- 13mm ratcheting combination wrench to remove (1) factory PTU bolt
- Allen (hex) wrenches (6mm, 5mm) for new PTU socket head cap screws
- Sweet Tea for replenishing fluids
- Pandora for tunes
*A friend for moral support is always optional.
*A freaking 10,000 lb 2-post lift would have been nice! Just jackstands today. :(


1. Install takes about 1.5 hours or so. I took my time because of taking pictures for this website.
2. Contrary to what others may have done, no turbo oil drain or intercooler piping removal is necessary. Suck it up buttercups!
3. Ratcheting 10mm combination wrench is recommended for factory top PTU bolt. Otherwise it will take days. LOL.
4. I recommend doing this swap on a somewhat cold engine. Otherwise you might get toasty a few times in cramp quarters near hot engine spots.
5. Mountune provides some instructions. If it doesn't fit don't force it. What's tighter than tight? Cross thread!
6. I recommend using a combination wrench as leverage on a 5mm allen wrench for the new top PTU socket head cap screw.
7. Easily reversible back to stock. If I sell my RS the new owner can keep this new PTU brace!
8. My bathroom scale shows weight to be exactly the same as the original stamped steel PTU brace = 1 lb.