Why are torsion bars so vilified? And were Land Cruisers ever designed for recreational off-roading?

[jLB]

The consensus I've seen has been that ATRAC is great until you lift wheels, when it can become "confused" where the brute force of lockers will be better to get you through

Similar to a LSD. Brute force?

I could see ATRAC being better than lockers in some situations, like a slick shaly hill climb in which it could do whatever it oculd to find any traction, rather than lockers that might just spin all four wheels.

I personally don’t see how applying the brakes on one or more wheels, exceeds turning all 4 wheels at the same speed.

I'd also be concerned about the shock loads from ATRAC on the front diff.

Yes, but larger than that is unlimited wheel spin, with sudden traction.

Furthermore, how do we even know if it'd still be workinmg on a 2000 model, for instance? Does it go out or lose effectiveness over time like an LSD?

Please explain the “wear item” equivalent to LSD clutches? Brake pads?

 

[OwnerCS]

The consensus I've seen has been that ATRAC is great until you lift wheels, when it can become "confused" where the brute force of lockers will be better to get you through (see the video below).



I could see ATRAC being better than lockers in some situations, like a slick shaly hill climb in which it could do whatever it oculd to find any traction, rather than lockers that might just spin all four wheels.

I'd also be concerned about the shock loads from ATRAC on the front diff. Furthermore, how do we even know if it'd still be workinmg on a 2000 model, for instance? Does it go out or lose effectiveness over time like an LSD?

I can tell you from experience at Toyota Jamboree that the outer CV axle will shatter as the weakest link in the drivetrain.

 

[jLB]

I can tell you from experience at Toyota Jamboree that the outer CV axle will shatter as the weakest link in the drivetrain.

View attachment 3503914

I suspect, a certain somebody had a spare CV axle…

 

[SaturnAscends]

Similar to a LSD. Brute force?

I personally don’t see how applying the brakes on one or more wheels, exceeds turning all 4 wheels at the same speed.

Yes, but larger than that is unlimited wheel spin, with sudden traction.

Please explain the “wear item” equivalent to LSD clutches? Brake pads?

I was just wondering if the ATRAC ever went out on these, similar to the "Three Amigos" on a Disco 2.

I can tell you from experience at Toyota Jamboree that the outer CV axle will shatter as the weakest link in the drivetrain.

View attachment 3503914

Interesting. Maybe ATRAC puts more strain on the ring an pinion, vs sudden traction in a non-ATRAC 100 that shockloads the CVs?

 

[beatle_bayly]

I think people need to be careful with nomenclature/definitions.

While the 100s has torsion bars, the front suspension limitations rest squarely with the wishbone IFS design. The T-bars are simply springs, and in fact have some packaging and adjustability advantages over coils. But for a fair comparison, we'd be comparing a coil sprung IFS to a T-bar IFS, or a leaf sprung solid axle to a coil sprung solid axle (60 series Vs 80 series).

Saying the "torsion bar front end is crap" misses the point entirely. If the 100s had coils, there wouldn't be a lot of difference.

 

[87warrior]

That and the starter location are starting to make the oil leaks and head gasket issues on the 1FZ look less daunting by comparison.

Wait until you hear what a 3UR-FE starter replacement entails...

 

[Patassa]

There are a lot of us that spend a fair amount of time in the Ozarks enjoying our 100s. I think ATRAC is phenomenal, and I wouldn't trade it for lockers. I've been on many trails with others with locked 100s, and I fared the best in the lot. @OwnerCS lives in Conway and recently went to a 2002 from a locked 99, and has commented on how much better the 02 is.

Now mud can just suck (literally) and I prefer to avoid it if I can, but seldom do I turn around if its reasonable.

This seems a bit overstated. Not to mention you can have both. And if one has to go through mud, it's hard to beat all 4 wheels slinging and trying to grab anything they can.

 

[Patassa]

I was just wondering if the ATRAC ever went out on these, similar to the "Three Amigos" on a Disco 2.


Interesting. Maybe ATRAC puts more strain on the ring an pinion, vs sudden traction in a non-ATRAC 100 that shockloads the CVs?

Worst thing for any part of a drive train is to go from completely unloaded with lots of velocity to instantly fully loaded/instant max torque. Sure to break the weakest component.

 

[OwnerCS]

Just turn a screw to adjust ride height. I love the adjustability.

 

[Bisho]

This seems a bit overstated. Not to mention you can have both. And if one has to go through mud, it's hard to beat all 4 wheels slinging and trying to grab anything they can.

ATRAC will stop a wheel spinning faster than the rest in order to transfer power to the wheel with traction. If they are all spinning I don't think ATRAC will do anything unless a tire grabs. I can tell you when I was stuck in a mudhole all four tires were slinging mud and water. I'll admit I was thinking more about how am I going to get out of this and not have to go out a window than if my ATRAC light was flashing.

 

[Patassa]

This was more or less my sentiment. The only downside is that you have to worry about the front diff, though as long as you use the rear locker judiciously and don't drove like a maniac they likely hold up just fine.

I just think the exhaust manifold leaks and the starter location are unfortunate on the 100 - fixing those involve just about as much effort/expense as fixing the head gasket and common oil leaks on an 80 series.

TBF the starter job is a PITA, but I've had one starter change out in 390k miles and it happened around 300k. Not a reason to avoid the engine by any stretch.

 

[Patassa]

ATRAC will stop a wheel spinning faster than the rest in order to transfer power to the wheel with traction. If they are all spinning I don't think ATRAC will do anything unless a tire grabs. I can tell you when I was stuck in a mudhole all four tires were slinging mud and water. I'll admit I was thinking more about how am I going to get out of this and not have to go out a window than if my ATRAC light was flashing.

I spent alot of time in the south Louisiana mud in my youth and almost every 4wd with open diffs would at some point in a mud hole send power to the 2 wheels with absolutely nothing under them and the 1 or 2 that could actually grab traction even just for a moment got no power, frustrating for a bunch of kids who thought 4x4 actually meant all 4 would get power no matter what. I"m sure momentarily there are cases where all 4 wheels could be spinning at the same speed and a-trac wouldn't kick in but that's not the bulk of time in the mud in my experience. Either way, I don't think you can do any better than 4 locked wheels in the mud, the combination of high wheel spin to hopefully clean out the tread + grabbing any available traction no matter how brief is about as good as you can ask for. Jesus I can't type today.

 

[Patassa]

I'd also be concerned about the shock loads from ATRAC on the front diff. Furthermore, how do we even know if it'd still be workinmg on a 2000 model, for instance? Does it go out or lose effectiveness over time like an LSD?

Atrac should prevent shock loads because it's braking the wheel that otherwise would be spinning at high rpm, it can save the diff (in a perfect world). If the light is on and you can hear it, it's working. It doesn't wear out or lose effectiveness overtime, it's just the braking system.

 

[hoser]

All in all, it could be argued that the 100 series represents the best ever iteration of the Land Cruiser for the kind of use described above. It may have its downsides - cracking exhaust manifolds and less-than-ideal starter location on the 4.7 and relatively weak front diffs for the size of the vehicle - but it's arguably the most reliable version of the model Toyota has ever produced.

There has been hardly any mention of cracked manifolds in the past 10 years. It was a manufacturing defect. The part was updated in '03 or so. Most defective ones have been replaced by now. If not leaking by now, they are not defective.

I don't know of any Toyota V8 used in their SUV/Trucks that has a friendly starter location. (anybody?) The FZJ80 has a really convenient location but you'll only experience the joy of changing the starter every 100-150k.

 

[Devils Paw 80]

I have my eye on one, but I remember you saying in another thread they're not the best in mud (perhaps due to their weight)?, which I see a lot of when I do manage to get out to the trails these days.

Well that's part of what I was wondering, if a 100 with a rear locker or ATRAC would be better than a light, compact 4x4 with open diffs like my 96 Tacoma on slick rutted tracks, bogholes, etc...

Would you be getting rid of your old Tacoma if acquiring the 100? If it's an either/or question, IMO the most important consideration is what you do with the rig during the vast majority of time not going off road. Since these vehicles are so different it'd be an easy decision for me. As the only one for a family man, the 100 wins. For a single guy, the pickup. As a second vehicle, the pickup.

 

[SaturnAscends]

Would you be getting rid of your old Tacoma if acquiring the 100? If it's an either/or question, IMO the most important consideration is what you do with the rig during the vast majority of time not going off road. Since these vehicles are so different it'd be an easy decision for me. As the only one for a family man, the 100 wins. For a single guy, the pickup. As a second vehicle, the pickup.

Yea I couldn't afford both, unfortunately. I don't really drive that much these days since I can walk or bike to work, but that may change fairly soon. I do get tired of the cramped quarters in the Tacoma - the dog is relegated tp the jump seats when I go out with my gf. But I love the narrow body for trails, and enjpy driving the 5 speed.

 

[SaturnAscends]

Atrac should prevent shock loads because it's braking the wheel that otherwise would be spinning at high rpm, it can save the diff (in a perfect world). If the light is on and you can hear it, it's working. It doesn't wear out or lose effectiveness overtime, it's just the braking system.

I'd think so too, but there are some anecdotal reports of it possibly contributing to front diff failure, mostly when "sending it." This reminds me of how a front locker in an IFS vehicle like a Tacoma should in theory prevent stuff breaking up front by maintaining constant wheel speed and preventing shockloads, it usually ends up contributing to a much higher rate of CV and diff breakage anyway, by most accounts.

Re: ATRAC - see the discussion linked below starting at post 104. I think Toyota engineered the system with careful throttle application in mind, and the old redneck method of 2nd gear and smashing the throttle doesn't always work out so well on these sophisticated 5500 lb SUVs. That's my theory anyway.

100 Series vs 80 Series

forum.ih8mud.com

 

[Patassa]

I'd think so too, but there are some anecdotal reports of it possibly contributing to front diff failure, mostly when "sending it." This reminds me of how a front locker in an IFS vehicle like a Tacoma should in theory prevent stuff breaking up front by maintaining constant wheel speed and preventing shockloads, it usually ends up contributing to a much higher rate of CV and diff breakage anyway, by most accounts.

Re: ATRAC - see the discussion linked below starting at post 104. I think Toyota engineered the system with careful throttle application in mind, and the old redneck method of 2nd gear and smashing the throttle doesn't always work out so well on these sophisticated 5500 lb SUVs. That's my theory anyway.

100 Series vs 80 Series

forum.ih8mud.com

What interesting about that failure case is though it's possible the application of the braking/a-trac is causing the problem (I can't prove it's not), it could also be the other wheel that's spinning on ice all of a sudden getting traction, similar to a tire lift scenario. There was a guy here who was spinning out aggressively in the mud on the side of the highway and when one of the wheels caught traction he grenaded a diff. I'll have to go find that post now.

 

[OwnerCS]

Yea I couldn't afford both, unfortunately. I don't really drive that much these days since I can walk or bike to work, but that may change fairly soon. I do get tired of the cramped quarters in the Tacoma - the dog is relegated tp the jump seats when I go out with my gf. But I love the narrow body for trails, and enjpy driving the 5 speed.

Through the years, I've driven most all of the technical trails in the Ozarks. Not once did I wish I had a SAS.

On the ride home I was thankful I had a comfortable IFS ride.

I would go test drive at least three 100 series to get a feel for the platform. They all drive a little different, so don't judge the entire series by one experience. Note that I hang up on the rear 3rd member way more than the diff drop.

 

[krice118]

I have my eye on one, but I remember you saying in another thread they're not the best in mud (perhaps due to their weight)?, which I see a lot of when I do manage to get out to the trails these days.

Well that's part of what I was wondering, if a 100 with a rear locker or ATRAC would be better than a light, compact 4x4 with open diffs like my 96 Tacoma on slick rutted tracks, bogholes, etc. So much of the discourse around vehicle capability and so forth revolves around California and Utah where traction is plentiful, unlike the backwoods trails of the eastern US. I keep meaning to go out with some 100 series owners here locally to test this.

That seems like a self-defeating project to me. If you really need long travel and 37s, you might as well SAS or just build a tube buggy.

I feel an 80 or GX might serve you better.

Honestly throw a rear locker in the Tacoma and sand bags and you’ll do better in mud than a 100….