Subaru Crosstrek and XV Forums banner
1 - 9 of 9 Posts

Registered
XV Crosstrek 2014 Limited 2.0i 5MT
Joined
90 Posts
Discussion Starter · #1 ·
I recently upgraded my rear open differential for an LSD. I don't have an absolutely logical reason as to why, except that I was looking for a new project to improve my skills/knowlege and wanted to make my XV more fun in the snow.

I found a JDM AP suretrac diff with the R160 case and 4.44 gear ratio. The initial plan was to do a full rebuild, but I choked after being quoted about 100$ CAD per OEM bearing. The unit I received was in such a good condition that it was not necessary anyway. I ended up just changing the seals, gasket and o-rings. I also brushed and repainted the case to give it a better chance against our winters.

Here's what my rear diff looked like after 7 years of sand/salt marinade.
Land vehicle Car Plant Vehicle Automotive tire

Having bought the car at 127 000 km, I assumed that none of the 100 000 km maintenance was done. I was proven right when I emptied the diff. Lots of oil was missing, and what was left was clouded with metal particles. The magnetic oil plug had a good amound of metal shavings as well. Change your oil guys...

This is my new diff after painting it with roll bar VHT
Musical instrument Bumper Wood Bicycle part Fender


This area won't be seen very often but here's what it looks like installed. I brushed/painted the diff support as well. The swap was very easy, no need to take wheels off, just jack the car and pop the axles once the diff has been lowered.
Hood Automotive tire Motor vehicle Bumper Automotive exterior


After the swap I went to a local sand pit to test it out in a safe environment.


The car is so much fun and easy to control in the snow, I love it! 馃榿 It's going to take a while before I've tested it in the many various road conditions that one can encounter during daily drives but as of now I have no regrets. This swap only works with manual transmissions though.
 

Registered
2021 Subaru Crosstrek
Joined
196 Posts
This is awesome! Where did you source the suretrac? Could you feel it engage when you were whipping around in the dirt? How does it handles regular turns on pavement? I believe with a suretrac, you won't get anything unless there is at least a little traction on the slipping wheel. Have you seen how it performs with one wheel up in the air?
 

Registered
XV Crosstrek 2014 Limited 2.0i 5MT
Joined
90 Posts
Discussion Starter · #4 ·
I got it from a guy in Ontario who imports parts from Japan and sells them on his website and Ebay. I tested it with both wheels jacked up. It acts as an open diff until one of the wheels starts loosing traction, so when you turn a wheel, the other one turns in the opposite direction. As soon as you hold one of the wheels though, they start both turning in the forward direction.

It doesn't make any more noise than the open diff (as opposed to the nightmare-inducing clicks from the Torq lockers), but I did feel it in action when I was breaking traction at the pit. It felt as if I was sitting on top of the wheels, like an ATV. 馃い That was with VDC off in a safe spot though. On the road, if I lose traction, the VDC can still correct it with ABS and throttle modulation. Improvements in road driving are very subtle and prone to exaggeration, so for now I'll only say I may have felt it help push the car in curves a couple of times.
 

Registered
Joined
29 Posts
Did your Crosstrek have the 4.44 ratio originally, or did you have to swap ratios in the front as well? I am not familiar with Subaru drivetrains, but in a normal awd.4wd you have to do both ratios at the same time or risk blowing the center differential/ transfer case up.
 

Registered
2021 Subaru Crosstrek
Joined
196 Posts
Did your Crosstrek have the 4.44 ratio originally, or did you have to swap ratios in the front as well? I am not familiar with Subaru drivetrains, but in a normal awd.4wd you have to do both ratios at the same time or risk blowing the center differential/ transfer case up.
All MT crosstreks are 4.44 afaik, so I think he just had to swap the rear diff.
 

Registered
XV Crosstrek 2014 Limited 2.0i 5MT
Joined
90 Posts
Discussion Starter · #8 ·
All MT crosstreks are 4.44 afaik, so I think he just had to swap the rear diff.
Exactly.

I got a little lucky because the LSD I found had a whole case with the ring and pinion at 4.44, so I didn't have to reajust backlash, bearing preload and tooth contact pattern. I verified that it was good, though. Most of the LSDs I found online had 3.90 or 4.11 ratios, but it's still possible to take the ring and pinion from your R160 open diff and use them with an LSD if the gear ratio doesn't fit your car's. However, you will have to work a little more to make sure everything seats properly in the case and the teeth touch at the right spot. I also read that some people had to do a little bit of grinding to fit an LSD in their open diff case.
 

Registered
2019 Canadian Sport trim (6MT // 2.0 )
Joined
632 Posts
Good job! Would be interesting for you to try the two diagonal wheels in the air test on an incline, traction control off. In principle, with open and front diffs, you won't move at ALL. If the LSD kicks in, you'd be able to...
 
1 - 9 of 9 Posts
Top