Considering Eaton Truetrac for 2002 Sequoia

[JBMcG]

Looking for a bit better traction in slippery conditions. Anybody have experience installing Eaton Detroit Truetracs? If the 2002 Sequoias have "A-Trac", it seems to be pretty primitive and not terribly effective.

 

[Jetboy]

I have owned them. For me - they are the only type of limited slip I would put in an offroad vehicle or truck. They work really well as far as limited slip diffs go. They are not really on par with a full locker for more challenging terrain, but are great in mud, snow, ice, etc. I haven't had them together, but I think they would play very well with ATRAC. For a differential that isn't selectable and if you don't need a full locker - I think it's an excellent option. In a rear application you'll never know it's there on the road and it'll be a big improvement offroad.

I've actually said a few times that MTS/ATRAC in my 5th gen 4Runner is very similar to a truetrac. They feel almost the same in a lot of cases.

Watch a few videos on light brake application and how much it helps with the helical limited slips. It works surprisingly well for that type of diff in some situations. IIRC all 1st gen Sequoias have ATRAC that is pretty mild and only engages in 4low under 2k rpms. Even a very mild ATRAC function would make a pair of truetracs function very close to having full lockers. I've thought a lot about adding them to my gen2 Tundra except that it has a front ADD diff, so they don't really work well with the way that the system is designed to freewheel one side of the diff spider gears in 2wd. May be a minor issue in a Sequoia when you run in 2hi - it would just spin the full diff all the time and not save as much fuel.

 

[JBMcG]

I have owned them. For me - they are the only type of limited slip I would put in an offroad vehicle or truck. They work really well as far as limited slip diffs go. They are not really on par with a full locker for more challenging terrain, but are great in mud, snow, ice, etc. I haven't had them together, but I think they would play very well with ATRAC. For a differential that isn't selectable and if you don't need a full locker - I think it's an excellent option. In a rear application you'll never know it's there on the road and it'll be a big improvement offroad.

I've actually said a few times that MTS/ATRAC in my 5th gen 4Runner is very similar to a truetrac. They feel almost the same in a lot of cases.

Watch a few videos on light brake application and how much it helps with the helical limited slips. It works surprisingly well for that type of diff in some situations. IIRC all 1st gen Sequoias have ATRAC that is pretty mild and only engages in 4low under 2k rpms. Even a very mild ATRAC function would make a pair of truetracs function very close to having full lockers. I've thought a lot about adding them to my gen2 Tundra except that it has a front ADD diff, so they don't really work well with the way that the system is designed to freewheel one side of the diff spider gears in 2wd. May be a minor issue in a Sequoia when you run in 2hi - it would just spin the full diff all the time and not save as much fuel.

Thanks for the thorough endorsement. Everything I've seen and read is pointing me in the direction of Truetracs, front and rear. I don't plan to do any rock crawling, mostly messing around in loose gravel, maybe some mud, and definitely snow and ice. I'd called a local 4x4 shop and he'd initially thought it'd be about $3k all in for both axles, but when he got back to me, he gave me an estimate of $5,700. Apparently he hadn't factored in the Yukon overhaul kits. I suppose it makes sense; if you're going to be in there, might as well replace the bearings, etc. At that price, however, may be shelving this project.

 

[Jetboy]

Thanks for the thorough endorsement. Everything I've seen and read is pointing me in the direction of Truetracs, front and rear. I don't plan to do any rock crawling, mostly messing around in loose gravel, maybe some mud, and definitely snow and ice. I'd called a local 4x4 shop and he'd initially thought it'd be about $3k all in for both axles, but when he got back to me, he gave me an estimate of $5,700. Apparently he hadn't factored in the Yukon overall kits. I suppose it makes sense; if you're going to be in there, might as well replace the bearings, etc. At that price, however, may be shelving this project.

FWIW - that seems exceptionally expensive. There's usually no need to replace bearings. Especially in the front diff. But a bearing kit is around $250 per axle, so it shouldn't add that much. Swapping the bearings is almost an afterthought if you're doing a re-gear. If you're not doing a re-gear I would personally not do the bearings unless you're already at like 300k or some very high mileage. There's really no reason to. They technically wear out eventually, but this isn't a typical wear issue and most would last 500k miles or more in normal use.

This is something you can DIY if you're handy. The front clamshell is a huge PITA to re-gear, but to do a carrier swap is pretty easy. You've got about $1500 for the two truetrac units. I think a rear diff swap should take about 3-4 hours. Front would take more like 5 because it takes more to R&R. The $3k sounds reasonable. The $5700 sounds really high to me. You're already swapping bearings on the carriers. The only other 2 bearings are the pinions, so the extra $1700 is for replacing 2 bearings on each diff that should take no more than maybe 30-45min or so in extra labor per axle. The pinion depth is already set by the factory. You can just measure it, re-shim to the same spec and you're good to go. No need to do a full pinion setup again.

 

[JBMcG]

FWIW - that seems exceptionally expensive. There's usually no need to replace bearings. Especially in the front diff. But a bearing kit is around $250 per axle, so it shouldn't add that much. Swapping the bearings is almost an afterthought if you're doing a re-gear. If you're not doing a re-gear I would personally not do the bearings unless you're already at like 300k or some very high mileage. There's really no reason to. They technically wear out eventually, but this isn't a typical wear issue and most would last 500k miles or more in normal use.

This is something you can DIY if you're handy. The front clamshell is a huge PITA to re-gear, but to do a carrier swap is pretty easy. You've got about $1500 for the two truetrac units. I think a rear diff swap should take about 3-4 hours. Front would take more like 5 because it takes more to R&R. The $3k sounds reasonable. The $5700 sounds really high to me. You're already swapping bearings on the carriers. The only other 2 bearings are the pinions, so the extra $1700 is for replacing 2 bearings on each diff that should take no more than maybe 30-45min or so in extra labor per axle. The pinion depth is already set by the factory. You can just measure it, re-shim to the same spec and you're good to go. No need to do a full pinion setup again.

I appreciate the unwarranted vote of confidence, and I wish I were handy enough to tackle a job like this, but I know my limits!

I talked to another shop and the guy sounded like he'd been doing working on differentials in his sleep for about the last 50 years. His take was to do the Truetrac in the rear, but up front would be a mistake because in the snow you're going to be fighting the front end wanting to ride up and over the crown of the road. His explanation was that since the wheels would be spinning at the same speed (and I guess torque), it would be hard to control (but maybe I misunderstood?). My understanding of the Truetrac helical style differential was the opposite, that it would transfer power to the tire with the best grip (provided the opposite tire had at least some grip). At any rate he quoted me a much more reasonable $1600 for the rear axle with new bearings, if needed, but he acted like it was malpractice to send me out there with an LSD on the front axle. He said if there was a decent selectable locker, he'd suggest LSD rear, and a selectable locker up front. He said the Eaton E-lockers were prone to solenoid failure, and the ARB air lockers are prone to hose failure.

So, now I'm just debating on getting another shop's opinion re: the Truetracs front and rear. Curious to hear your thoughts about adding Truetracs just to the rear. Maybe try it for a season? Maybe spend the money I'd save on some decent recovery boards and new tires.

 

[aztoyman]

I had Detroit Tru-Trac's in both axles on my 88 IFS pickup when I bought it from my buddy. He had them installed with 4.56 gears when he went to 31" tires. He set it up for hunting and scouting but it was his daily driver as well. It was perfect for sand washes here in AZ and also in snow up north. He had the truck for over 18 years and sold it to me in 2006 when he bought a Tacoma.

It wasn't distracting to drive on the street like an auto locker is. The front hubs were unlocked on the street so no affect from the front. If you did have issues on snow you could unlock the hubs, but I doubt you would need to. I had the truck in snow and sand and it didn't handle weird at all. The truck didn't have a winch at the time and I never got stuck in anything I wheeled in. Mostly deep sand washes. Snow once in a while during winter up in the mountains. I did notice more steering effort at times. The Tru-Trac's also don't have clutches to wear out like a limited slip. I've had those in cars and they do wear out.

I ended up turning the truck into more of a rock crawler and the Tru-Tracs did not work well whenever I lifted a wheel so I sold the diffs and built my own with auto lockers.

Edit, I guess you wouldn't be able to unlock front hubs in your application. I never actually had to. Just food for thought.

 

[Jetboy]

I appreciate the unwarranted vote of confidence, and I wish I were handy enough to tackle a job like this, but I know my limits!

I talked to another shop and the guy sounded like he'd been doing working on differentials in his sleep for about the last 50 years. His take was to do the Truetrac in the rear, but up front would be a mistake because in the snow you're going to be fighting the front end wanting to ride up and over the crown of the road. His explanation was that since the wheels would be spinning at the same speed (and I guess torque), it would be hard to control (but maybe I misunderstood?). My understanding of the Truetrac helical style differential was the opposite, that it would transfer power to the tire with the best grip (provided the opposite tire had at least some grip). At any rate he quoted me a much more reasonable $1600 for the rear axle with new bearings, if needed, but he acted like it was malpractice to send me out there with an LSD on the front axle. He said if there was a decent selectable locker, he'd suggest LSD rear, and a selectable locker up front. He said the Eaton E-lockers were prone to solenoid failure, and the ARB air lockers are prone to hose failure.

So, now I'm just debating on getting another shop's opinion re: the Truetracs front and rear. Curious to hear your thoughts about adding Truetracs just to the rear. Maybe try it for a season? Maybe spend the money I'd save on some decent recovery boards and new tires.

I wonder if you could find one to test drive. I have only had truetracs in front diffs. Both were truetrac front and Detroit full lockers in the rear. That was a really good combo. I didn’t feel like the front was ever an issue. You couldn’t really tell it was there unless you were off-road. But that was on old solid axle Toyotas so it might be more noticeable on newer more refined vehicles.

In most cases the Detroit “soft locker” in the rear was also invisible. Very different from the lunchbox lockers that are really intrusive, noisy, and jerky.

I have had an arb front locker in my 15 4R. I took it out after about 6 months. It was really noisy in 2wd. It’s a bit complicated, but with the add front axle disconnect the spider gears free-spool in 2wd where the driver’s side axle is driven by the tire and the left side and driveshaft are uncoupled. Arb about 2018ish switched from cut gears to forged unmachined spider gears. They are stronger. But they’re also noisy. I’ll post a video.

ARB corporate was great. They replaced the locker twice on their dime including the labor at their gear shop also thinking it was something wrong but that’s just how the forged gears are. They took a few new ones apart and compared them and the new forged ones are just noisy. Heavy weight oil and/or manually polishing the gears could fix it I believe. But ATTAC/MTS on the newer ones is so good I just went back to open front with mts. For a dedicated trail vehicle I’d put the locker in. Or something with awd. It doesn’t spin the same in awd models so you’ll never have the issue.

I’m not sure if that helps. I think trying a test drive in a vehicle with one in front would really help know what it’s like.

 

[JBMcG]

I had Detroit Tru-Trac's in both axles on my 88 IFS pickup when I bought it from my buddy. He had them installed with 4.56 gears when he went to 31" tires. He set it up for hunting and scouting but it was his daily driver as well. It was perfect for sand washes here in AZ and also in snow up north. He had the truck for over 18 years and sold it to me in 2006 when he bought a Tacoma.

It wasn't distracting to drive on the street like an auto locker is. The front hubs were unlocked on the street so no affect from the front. If you did have issues on snow you could unlock the hubs, but I doubt you would need to. I had the truck in snow and sand and it didn't handle weird at all. The truck didn't have a winch at the time and I never got stuck in anything I wheeled in. Mostly deep sand washes. Snow once in a while during winter up in the mountains. I did notice more steering effort at times. The Tru-Trac's also don't have clutches to wear out like a limited slip. I've had those in cars and they do wear out.

I ended up turning the truck into more of a rock crawler and the Tru-Tracs did not work well whenever I lifted a wheel so I sold the diffs and built my own with auto lockers.

Edit, I guess you wouldn't be able to unlock front hubs in your application. I never actually had to. Just food for thought

I wonder if you could find one to test drive. I have only had truetracs in front diffs. Both were truetrac front and Detroit full lockers in the rear. That was a really good combo. I didn’t feel like the front was ever an issue. You couldn’t really tell it was there unless you were off-road. But that was on old solid axle Toyotas so it might be more noticeable on newer more refined vehicles.

In most cases the Detroit “soft locker” in the rear was also invisible. Very different from the lunchbox lockers that are really intrusive, noisy, and jerky.

I have had an arb front locker in my 15 4R. I took it out after about 6 months. It was really noisy in 2wd. It’s a bit complicated, but with the add front axle disconnect the spider gears free-spool in 2wd where the driver’s side axle is driven by the tire and the left side and driveshaft are uncoupled. Arb about 2018ish switched from cut gears to forged unmachined spider gears. They are stronger. But they’re also noisy. I’ll post a video.

ARB corporate was great. They replaced the locker twice on their dime including the labor at their gear shop also thinking it was something wrong but that’s just how the forged gears are. They took a few new ones apart and compared them and the new forged ones are just noisy. Heavy weight oil and/or manually polishing the gears could fix it I believe. But ATTAC/MTS on the newer ones is so good I just went back to open front with mts. For a dedicated trail vehicle I’d put the locker in. Or something with awd. It doesn’t spin the same in awd models so you’ll never have the issue.

I’m not sure if that helps. I think trying a test drive in a vehicle with one in front would really help know what it’s like.

Would love to test drive a front and rear axle Truetrac.

 

[JBMcG]

I had Detroit Tru-Trac's in both axles on my 88 IFS pickup when I bought it from my buddy. He had them installed with 4.56 gears when he went to 31" tires. He set it up for hunting and scouting but it was his daily driver as well. It was perfect for sand washes here in AZ and also in snow up north. He had the truck for over 18 years and sold it to me in 2006 when he bought a Tacoma.

It wasn't distracting to drive on the street like an auto locker is. The front hubs were unlocked on the street so no affect from the front. If you did have issues on snow you could unlock the hubs, but I doubt you would need to. I had the truck in snow and sand and it didn't handle weird at all. The truck didn't have a winch at the time and I never got stuck in anything I wheeled in. Mostly deep sand washes. Snow once in a while during winter up in the mountains. I did notice more steering effort at times. The Tru-Trac's also don't have clutches to wear out like a limited slip. I've had those in cars and they do wear out.

I ended up turning the truck into more of a rock crawler and the Tru-Tracs did not work well whenever I lifted a wheel so I sold the diffs and built my own with auto lockers.

Edit, I guess you wouldn't be able to unlock front hubs in your application. I never actually had to. Just food for thought.

I don't think I'll be doing any crawling. Mostly just want something that can get through a variety of "loss of traction" situations. Thanks for the feedback!

 

[Jetboy]

Okay - here's a video of what an ARB front differential sounds like when it freewheels like it would in 2hi on the highway. This has gear oil lightly coated on the gears - it was used in service and drained. I store my diffs in garbage bags in storage rack bins when I'm not using them. On my 4Runner I kept 2 complete sets. I actually still have one but sold the 4Runner. I re-geared a donor diff set to 4.56 with a front ARB locker and rear OEM E-locker, but it was a lot less stress for my daily driver to build the diffs separately and then just swap em over when it was ready to go rather than tear down the vehicle for a few days while I tried to do the work.

Anyway - imagine this only a lot higher rpm input and then attached to your frame. The noise was significant at highway speed. With mud tires and a bunch of offroad farkle bolted on making wind noise, maybe it would all blend in. But in my case with AT tires and usually no roof rack, it was really noticeable and intrusive for long highway trips.

At some point about 15 years ago Eaton made a truetrac type helical limited slip that had a cable actuated locking mechanism to fully lock it. I'm not sure whatever happened to it. I don't remember exactly how it worked, just thinking that it would be a really great differential for a daily driver that moonlights as a rock crawler.

One other thought is that I'm a bit OCD analytical. I kept track of failures over about a dozen offroad trips with larger groups and among all ARB air lockers the failure rate was around 10% on any given trip. That was some reason - compressor, air lines, or internal air seals, that kept the arb lockers from working. They're not very reliable in the field. They are VERY strong. And the actuation is super fast. Perfect for competition. And with the really aggressive ATRAC/MTS settings in a 5th gen 4Runner - a failure isn't such a big deal, the system is already 90% of the way there. I did the Rubicon twice without a front locker, so it's not totally necessary. But I would shy away from the ARB on something like a touring rig for long term reliability reasons. I don't have any good data on the eaton e-lockers. I've never seen a Toyota OEM locker fail to actuate on a trail. I know it happens. But I've been on a lot of trails with a lot of them and they're slow AF to engage and disengage, but as long as they worked when you started - they seem to work reliably throughout an offroad adventure. The failures I see are when they haven't been used in 10 years and the actuator had water get into it. So, not perfect either. The newer OEM lockers with eaton style actuation internally I have no experience with.

 

[JBMcG]

Okay - here's a video of what an ARB front differential sounds like when it freewheels like it would in 2hi on the highway. This has gear oil lightly coated on the gears - it was used in service and drained. I store my diffs in garbage bags in storage rack bins when I'm not using them. On my 4Runner I kept 2 complete sets. I actually still have one but sold the 4Runner. I re-geared a donor diff set to 4.56 with a front ARB locker and rear OEM E-locker, but it was a lot less stress for my daily driver to build the diffs separately and then just swap em over when it was ready to go rather than tear down the vehicle for a few days while I tried to do the work.

Anyway - imagine this only a lot higher rpm input and then attached to your frame. The noise was significant at highway speed. With mud tires and a bunch of offroad farkle bolted on making wind noise, maybe it would all blend in. But in my case with AT tires and usually no roof rack, it was really noticeable and intrusive for long highway trips.

At some point about 15 years ago Eaton made a truetrac type helical limited slip that had a cable actuated locking mechanism to fully lock it. I'm not sure whatever happened to it. I don't remember exactly how it worked, just thinking that it would be a really great differential for a daily driver that moonlights as a rock crawler.

One other thought is that I'm a bit OCD analytical. I kept track of failures over about a dozen offroad trips with larger groups and among all ARB air lockers the failure rate was around 10% on any given trip. That was some reason - compressor, air lines, or internal air seals, that kept the arb lockers from working. They're not very reliable in the field. They are VERY strong. And the actuation is super fast. Perfect for competition. And with the really aggressive ATRAC/MTS settings in a 5th gen 4Runner - a failure isn't such a big deal, the system is already 90% of the way there. I did the Rubicon twice without a front locker, so it's not totally necessary. But I would shy away from the ARB on something like a touring rig for long term reliability reasons. I don't have any good data on the eaton e-lockers. I've never seen a Toyota OEM locker fail to actuate on a trail. I know it happens. But I've been on a lot of trails with a lot of them and they're slow AF to engage and disengage, but as long as they worked when you started - they seem to work reliably throughout an offroad adventure. The failures I see are when they haven't been used in 10 years and the actuator had water get into it. So, not perfect either. The newer OEM lockers with eaton style actuation internally I have no experience with.

That's noisy enough I could envision becoming annoyed by that pretty easily, at speed. I think for now I'll look at getting the Trutrac installed on the rear and do more research to decide on the front end.

Actually just did 100+ more miles of the Washington BDR in the last couple days, and besides breaking an exhaust bracket on a high spot ($40 repair had me back on trail) my bone stock Gen one did really great. I think for what I do, just having a little extra would be handy, particularly in winter.

Really appreciate your input!

 

[Jetboy]

That's noisy enough I could envision becoming annoyed by that pretty easily, at speed. I think for now I'll look at getting the Trutrac installed on the rear and do more research to decide on the front end.

Actually just did 100+ more miles of the Washington BDR in the last couple days, and besides breaking an exhaust bracket on a high spot ($40 repair had me back on trail) my bone stock Gen one did really great. I think for what I do, just having a little extra would be handy, particularly in winter.

Really appreciate your input!

I think you're on a pretty good track to getting setup for what you're wanting to do. At $5 or $6k for just traction aids - pretty soon you're going to be better off to just sell the Sequoia and buy something else. I know it's smaller, but an early 5th gen 4Runner Trail edition can be found in the $12-15K range and already has a rear locker and very aggressive ATRAC system. Even the base SR5 model ATRAC is really aggressive compared to the older software system and you could find one of those for probably under $10k. Vs spending $6k on just a pair of limited slip diffs - I'd be looking pretty hard at just buying another SUV for the weekends that already has most of what you want.

This is how good the ATRAC is even in a base SR5 4Runner. It's crazy to me how bad it is in my 2016 Tundra in comparison. It's barely useful in the Tundra. And in a 4Runner it's like 90% of the way to full lockers.



Also - holy inflation batman. I bought an ARB with the compressor and the full install kit for $899 IIRC in about 2019. Now that same set is almost $1800. More than double the retail price in 8ish years.

One other thought. If you don't already have a winch - I'd add a winch before a front locker. Super handy tool for offroad exploring. And you could add one with just a front hitch - $200, hitch winch plate $100, and a budget winch $300-350, Anderson connector kit $75. All in would be around $750-800. Or a hidden winch mount is more like $350 and all you need after that is the winch - no connector kit or extra mount plate and it's a bit cheaper, but more involved to install depending on your access to tools and workspace. Much less cost than a front locker and IMO a lot more useful.