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General Information

Stormy Daniels
Not much
In the past two weeks lots of updates to the machine:

Full primitive armor kit, primitive king spring lift, torq-locker rear end, dual band mobile install, tepui tent top, 15" BFG K02s. Full size spare under the back.

We are going into a distant NF for unsupported camping. Machine is outfitted for full off track performance. King spring / spacer lift is really helping with the weight carrying. Torq-locker is much, much quieter than expected. I can only hear the "clicks" when turning right at low speed with the windows down, inaudible from the divers seat.


Torq-locker rear diff. Lift.
TM-D710ga dual band ham radio
Full underbody armor, Yakima racks and Tepui.
LED high beams.
Wheel and Tire
15" sparco Terra, 215/75R15 BFG K02


18' 2.5 Premium 6MT
153 Posts
Ive driven 130mi on rough forest service roads in the past week. The torq-locker seems to make a big difference. On a very steep route yesterday I was waiting for TC to kick in but never did. It seems like the lack of wheel slip is keeping it from activating which is good. I aired down the K02 s which I'm sure helped but I was very impressed. More to follow when I get home.

18' 2.5 Premium 6MT
153 Posts
Setup Observations after 5,381 miles of which about 275 were off road mixed dirt and rough forest service trails:
1. Wheels / Tires - BFG K02 215/75R15 on 15" Sparco Terra: I decided on the 15" wheels to maximize sidewall and improve ability to air down while still retaining as close a possible to stock overall circumference. The gearing for 1st gear is higher than I would wish as is so increasing size would only exacerbate the issue. A dual range gear box would be perfect but not a feasible option. Still, I only had to burn clutch maybe twice when getting moving up a steep rocky grade (30* angle) at over 6,000 ft ASL. For rock crawling which I don't do, an automatic would be better but otherwise the manual has more benefits in my opinion.
The tires had excellent grip, seem to have worn well managed both off-road and highway well. They are quite a bit louder but not oppressively so. The skidplate did not help with the noise due to removing part of the well liner with the stock plastic under pan. Once I arrived in the Flathead valley I aired down from the OEM recommended pressure to 23 psi front / 22 psi rear which is a mild reduction.
On the steepest and muddiest sections and some deep snow I only observed T.C. activate a few times which I attribute to the torq-locker (more on that further down).

2. Underbody armor - Full primitive racing underbody (front, mid, rear diff). This definitely added to noise somewhat but more so on the fast gravel roads. Several areas we camped were 60miles down a rough gravel and dirt road from the nearest town with sections navigable at 45mph. In turns the gravel thrown by the inboard wheels would strike the skid plate and produce a loud clank / ping but this gave me no worry as the thick aluminum certainly managed the assault better than the stock plastic. 2-3' of snow on higher elevation roads would scrape the skid plates roughly as it was compacted and icy from spring melting. I braced to scrape on some tall rocks in the center of narrow trails but crediting the lift, did not.

3. Primitive spacer / spring lift - When first installed the lift seemed huge, I measured 13" from the bottom of the door sills. This dropped some as they've settled in and definitely with the heavy load. The roof top tent added 150lbs, another 400 of camping gear and provisions, toddler / spouse / myself another 340-350. With 800lbs of load and a full tank of fuel the lift definitely helped keep the back end from sagging too low and creating a ground clearance limitation. This validated my decision to go with the king springs as a spacer only lift would not have addressed the suspension load.
Another benefit was very little body roll in tight turns (on ramps especially) despite the high center of gravity of the tent.

4. Torq-locker - This was the modification that caused me the most apprehension. User reviews are limited at present and long term reports non-existent. Never the less I decided the concept was sound and made the leap hoping for the best. Noise is a concern with this type of locker, interestingly it is only noticeable in tight turns at low speed with the windows down. The faint clicking sounds like something is broken but you will know all is good. Rarely on tight traffic circles or sharp uphill turns on pavement I would hear a clunk as the lock released, this seems to be a result of heavy throttle input required. During normal town / highway driving the locker is transparent.
Off the pavement was most interesting. My first big observation was that on the long stretches of fast dirt / gravel roads the rear end would have an 'interesting' feel. Never loose, but I could feel it come through the turn in a manner that would typically indicate the traction control was about to activate due to some lateral slip. However the anticipated TC activation I waited for would never appear, instead the car would feel solidly predictable through the turns.
To better describe the phenomenon: Driving 45mph on loose gravel and dirt approaching a tight curve which if limited would be likely 25 mph. I would let off throttle but not brake more than lightly prior to but not in the curve to avoid loosing grip. Taking said turn at 35-40 I would apply light throttle through the curve increasing during exit. The rear end would shift but not 'slip' sideways and never result in any detectable traction loss.
My hypothesis is that the rear diff would be locked in these situations, the 'slip' sensation was the result of one of the rear wheels traveling above or below speed for the radius of its arc. Because the car never detected a wheel speed variation indicating a loss of traction the t.c. never activated. To me this is preferable as the t.c. tends to induce some instability as the single wheel braking it employs is neither linear or predictable in a way that the driver can manage gracefully.
The overall sensation was 'interesting' in a good way and after a few times confidence inspiring. I am very eager to see how this behaves in snow this winter weather willing.

Despite the weight, tires, poor aero-dynamics I managed to average 23mpg over the trip which all things considered was very good.

2018 Forester Manual
348 Posts
Taking said turn at 35-40 I would apply light throttle through the curve increasing during exit. The rear end would shift but not 'slip' sideways and never result in any detectable traction loss.
My hypothesis is that the rear diff would be locked in these situations, the 'slip' sensation was the result of one of the rear wheels traveling above or below speed for the radius of its arc.
That's 100% what is going on. With a locked differential, the inside wheel is going to slip and lose traction first. That's what you were feeling. Automatic lockers like the torq locker will lock if there is any torque being applied to the center pin. So either accelerating or decelerating will cause it to lock. The amount of acceleration or deceleration will allow the springs and beveled teeth to grab more or less.

Traction control isn't kicking in because the rotation picked up by the gyroscopes isn't enough, and as far as the computer is concerned, you aren't spinning because both rear tires are spinning at the same speed.