Torsen rear diff selection (2 Viewers)

[gluaisrothai]

Hi all,
Differentials are a bit of a dim spot in my automotive knowledge. Can anyone help point me to the most straightforward Torsen rear diff conversion for a 2021 LC rear axle? I’m not looking for an air or e-locker, really just looking for the high torque bias LSD performance of Torsen.

Thanks!
Ken

 

[TimCFJ40]

I've not seen a Torsen unit for the 200 series platform, but it may exist. A few members have ARB Air Lockers or Eaton/Harrop E-lockers.
The A-Trac and Crawl on these trucks is pretty dang effective for most uses, what is it that you are looking to gain from the Torsen?

 

[manofthewoods]

I've not seen a Torsen unit for the 200 series platform, but it may exist. A few members have ARB Air Lockers or Eaton/Harrop E-lockers.
The A-Trac and Crawl on these trucks is pretty dang effective for most uses, what is it that you are looking to gain from the Torsen?

Just last week I found a sandy hill to do some traction testing. Each day I took a different vehicle. '13 Taco OR (rear lockers) & ATRAC, '97 LX450 3xLocked, '19 LC stock (including tires!).
All vehicles got stuck w/o traction aids in 4lo. All vehicles made it past the top with traction aids. In the LC both crawl control and MTS set to Sand/Mud. Center differential set to lock or using it in TORSEN (default) mode.
Moral of the story for me, I can have confidence in my vehicles - if I use them to their advantage.
More isn't needed for me, but others might

 

[TimCFJ40]

Moral of the story for me, I can have confidence in my vehicles - if I use them to their advantage.
More isn't needed for me, but others might

On my last trip out, with my brother in law's Wrangler Rubicon Unlimited, we both made it through all of the obstacles, a few of which he used his lockers for. There was one place where I engaged Crawl control due to an off camber ledge on a narrow shelf of a trail, and it worked just as well as his lockers, albeit a bit noisier.

Coming from a past that included a fully locked buggy, I think A-Trac and Crawl are more than adequate for anything a stock to moderately built 200 series will ever see. I do miss the SILENT operation of a fully locked truck vs the cacophony of noise that CRAWL makes, but I will say that when needed CRAWL is impressively capable.

 

[TeCKis300]

I haven't heard much of them in the states, but I know Torsens exist for the 200-series and been discussed in Australian circles. Here's a couple

Torque Lock LSD Truetrac Alternative Bias for 200 Series Toyota Landcruiser - Torqueline Differential

Torque Lock LSD Truetrac Alternative Bias for 200 Series Toyota Landcruiser - Torqueline Differential

www.tuffcarparts.com.au

Toyota Landcruiser 200 Series Rear Differential (LSD) - Greenaway's Gearboxes & Differentials

Greenaway's Gearboxes and Differentials are located in Coffs Harbour, We have over 30 Years Experience in Reconditioning Drivetrains, We will not be beaten on price & ship Australia Wide.

www.diff.com.au

 

[bjowett]

This should also fit, but looks to be out of stock.

You are being redirected...

 

[rscoleman]

So this is good web site to explain differences in Torsen vs LSD diffs. Torsen vs. plated limited slip differential. – KMP Drivetrain Solutions - https://www.kmpdrivetrain.com/differentials/torsen-vs-plated-limited-slip-differential/

Question most common uses for Torsen or LSD diffs is track application in case of cars (my experience). You get both tires pushing when going in straight line and outside tire free turning in corner but both tires are still in contact with ground. Not sure I understand use case of either of these types of Diffs as it relates to off roading. Both will let tire that is in the air spin and loss of torque to tire with traction. The LSD will have marginal torque to tire with traction but not enough in my opinion to be useful in a 4low tires in air crawling situation. I probably don't understand your use case. Good Luck finding one.

 

[gluaisrothai]

This should also fit, but looks to be out of stock.

You are being redirected...

This unit from Summit looks very like the Nitro and claims fitment to the LC200. The Speedmaster Torque Worm (that's what SHE said).

The TorqueWorm is a torque biasing 6 pinion gear type limited-slip unit. This is a preloaded unit allowing for a faster-reacting unit. The use of 6 pinion gears means the stress on gears is spread over a greater surface area, reducing the load on all internal components. The internal components are made from EN36 Material as used in racing. The outer cases made from 8620 Chrome-Nickel-Moly steel and the case hardened for long life and improved strength.

Specs​

Brand:	Speedmaster
Part Number:	PCE204.1058
Part Type:	Differential Carriers
Aftermarket Carrier Style:	Limited slip
Cover Bolts:	10
Ring Gear Bolt:	12
Gear Ratio:	All Ratios
Axle Shaft Spline Quantity:	32
Manufacturer of Axle:	Toyota / Speedmaster
Carrier Material:	Steel
Quantity:	Sold individually.

Description​

Application:
1998 & Newer Toyota Land Cruiser 100, 105, 200 series, LX470, LX570
2007 & newer Tundra with 4.0, 4.6, or 4.7L
1999 & newer 70 Series Land cruiser with 5x150 lug pattern.

 

[bjowett]

I agree, probably the same manufacturer.

 

[gluaisrothai]

I agree, probably the same manufacturer.

Summit has it on sale for ~$700 plus tax. Going to snag one and figure out the install later.

 

[gluaisrothai]

Summit has it on sale for ~$700 plus tax. Going to snag one and figure out the install later.

Pulled the trigger...with all my research on here I might be the LC200 guinea pig for a Torsen rear. $800 shipped. I've done everything myself else on this truck but will probably try to have a local shop in Alameda or Oakland fit this for me...

Use case, as someone asked above. I like the idea of a torque biasing rear end helping traction control and having a mechanically backed traction aid as well. I also like the idea of maybe running with the TC off on higher speed dirt/gravel allowing a little controlled oversteer. But mostly I like modifying my vehicles for (mostly) better or worse

 

[gluaisrothai]

I have the new Speedmaster helical diff carrier from Summit. Just waiting for new bearings, bolts and gasket set from Toyota parts deal to do the job. Planning to take it to the rear end shop in Livermore CA, they have a great reputation around here. I do most things DIY (like literally everything else on my truck and airplane) but diffs are heavy and take some specialized setup.

 

[gluaisrothai]

Had the torqueworm diff carrier installed yesterday. Took just a few hours at the shop, some of which caused by fighting the KDSS (they didn’t know about opening the balance valves).

All good with the install…really you wouldn’t know it was in there, except all the spider gear clunks when shifting from drive to reverse are gone because of the internal carrier design. Will try to do a one-wheel-on-slippery-surface video (trac off) over the weekend. Will be putting 100 or so freeway miles on it today and re-checking for leaks etc.

 

[gluaisrothai]

Oil threads are always the best right? At the risk of WWIII, what is the collective wisdom on best diff oil for the LC200 with a helical limited slip carrier in the rear?

• Factory spec is 75W85
• Shop installed 85W140 which seems overweight for my use (I don't tow).
• Locally 75W85, 75W90, 75W140 are easy to find but all synthetic and most have LS additivie
• Speedmaster recommends single grade EL140 which seems like a very old timey oil; when I called they said 75W140 should work fine.

I'd like to keep my gas mileage no worse than where it is (awful) so I'm inclined to use 75W85 redline or similar.

Thanks...
Ken

 

[bloc]

Oil threads are always the best right? At the risk of WWIII, what is the collective wisdom on best diff oil for the LC200 with a helical limited slip carrier in the rear?

• Factory spec is 75W85
• Shop installed 85W140 which seems overweight for my use (I don't tow).
• Locally 75W85, 75W90, 75W140 are easy to find but all synthetic and most have LS additivie
• Speedmaster recommends single grade EL140 which seems like a very old timey oil; when I called they said 75W140 should work fine.

I'd like to keep my gas mileage no worse than where it is (awful) so I'm inclined to use 75W85 redline or similar.

Thanks...
Ken

Yeah, I'd verify the thicker oil isn't important for how the LSD itself functions, and if not, that redline product seems good. Clearly the factory gears don't need anything thicker than 75w-85 to have an obscenely long service life.

 

[gluaisrothai]

Yeah, I'd verify the thicker oil isn't important for how the LSD itself functions, and if not, that redline product seems good. Clearly the factory gears don't need anything thicker than 75w-85 to have an obscenely long service life.

I ordered 4qts of Redline 75w85. Will keep my gas mileage where it was and should help improve the diff bias.

Speaking of which…testing on some dirt today the truck hooked up posi quite nicely. Though it occurred to me that my crawl mode turn assist might be problematic now.

 

[skrypj]

Just found this thread while searching for a helical LSD. I had Detroit Truetracs front and rear on my Jeep Liberty CRD, which also had a full-time transfer case, and absolutely loved it for a daily driver/offroader. They where fantastic in all situations. The jeep did have the capability of going into 2wd though. Since the 200 series cannot do that i don't know that I would neccesarily recommend a front helical LSD since it tends to cause the steering wheel to want to center harder when turning and on the throttle. Its managable, but having it do that all the time in the 200 might get annoying. The jeep I could just drop it into 2wd if i was on dry pavement and still had that traction of a rear Truetrac.

How is it holding up so far? I think that a helical LSD should compliment CRAWL and ATRAC in a very positive way. When the truck uses the brakes to control wheel spin, the helical should help transfer the torque to the other tire more effectively. Not sure on turn assist. But I feel like it could maybe help there too.


On a different not, Eaton specifically says not to use full-synthetic gear oil with the Truetrac differentials, which are also helical.

https://www.eaton.com/us/en-us/products/differentials-traction-control/aftermarket-differentials/detroit-truetrac-faqs.html

 

[gluaisrothai]

Seems to be holding up well so far, though its operation is transparent so you don't really know it's doing anything. I do believe the torque bias helps crawl, I wonder if it might create enough torque to damage a half shaft with turn assist....but I have about 2000 miles on it so far, it's quiet and you really would not know it was there. I did get to turn all the electronics off and drift it a little on the level washes in Anzo Borrego!

 

[skrypj]

Seems to be holding up well so far, though its operation is transparent so you don't really know it's doing anything. I do believe the torque bias helps crawl, I wonder if it might create enough torque to damage a half shaft with turn assist....but I have about 2000 miles on it so far, it's quiet and you really would not know it was there. I did get to turn all the electronics off and drift it a little on the level washes in Anzo Borrego!

Thats what I loved about them. Very transparent, but always online and functioning. Lockers are cool and all, but their function is very limited whereas the helical LSD is always providing a benefit whether you are on dry pavement, snow, ice, mud, rocks, whatever. And I think with crawl/atrac they are probably 99% as good as a locker

For me it was extremely noticeable on snow, which I dont think you worry about too much. when I would have my Jeep in full-time 4wd powering both truetracs it was an absolute animal in the snow. Really predicable and controllable and had unreal traction. You could floor it and it would just claw in and go.

 

[CT3]

Following — this could be an interesting path to take on my next build. I’m inclined to agree that for the majority of use cases, this probably makes more sense than the all-or-nothing locker approach