Eaton/Detroit Trutrac LSD
- Thread starter IanB
- Start date
badattitude
Member
Just want to add... I have the trutrac and when I jack the rear axle (both tires) off the ground it does not act like an open diff. The wheels are locked. Of course, the truck is in park.
With an open diff, i could spin a tire and the other would spin in the opposite direction. With the trutrac neither tire will spin when off the ground. If I put it in neutral both tires spin in the same direction.
Perhaps people are lumping regular LSD's in the same group asa a Trutrac. They are all LSD's but the gear driven trutrac is differant than a clutch-based LSD. Also, IIRC, Trutrac changed the tourqe bias setting a few years ago to make them more robust. If I can find that info I will add it.
EDIT: if you're speaking about trail use I can't comment. I have never lifted a tire while offroad with the trutrac. Not a lot of hills here and when I do get a hill it's just up or down. not lifting any tires. on the trails here
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J-money$$$
New member
I would take his word for it. HE had one up front. It sucked and he ended up installing an arb.
And both tires spin the same direction because it doesnt have spider gears. But they need resistance on both tires to work. If one is in the air/on ice then all your power will go to that tire. I Have seen Maclean and my friend wheeling they lift a tire where the tru trac is and it opens right up. Out wheeling and on jack stands are way different stories. the helical gear LSD vs clutch pack LSD we will save for another day, but honestly they can have the same bias ratio. the gear version doesnt mean it works any better or worse.
And both tires spin the same direction because it doesnt have spider gears. But they need resistance on both tires to work. If one is in the air/on ice then all your power will go to that tire. I Have seen Maclean and my friend wheeling they lift a tire where the tru trac is and it opens right up. Out wheeling and on jack stands are way different stories. the helical gear LSD vs clutch pack LSD we will save for another day, but honestly they can have the same bias ratio. the gear version doesnt mean it works any better or worse.
brian2sun
Elite Member
It's funny, because people tend to pigeon hole us "rock jocks" into only seeing one way of off roading and only giving advice as it pertains to rock crawling at 3mph. I bolded some of my earlier post in which I gave almost the same advice as you. I admit I prefer rock crawling over bajaing, but I do feel like I try to give unbiased advice for whatever the poster asks.
IanB
New member
Agreed, your input was much appreciated!
maclean216
Member
LOL Jason. I love your hatred of the Trutrac.
I know this thread is kinda old, but figured I'd throw my thoughts up. I don't know if anyone is familiar with a place called Mabell in western Mass., but there's a rock face there called Committed. It is basically a loose dirt/gravel hill that leads up to a 40-50ft rock face at about a 45* pitch. We were wheeling there one day and after a few Jeeps with 35" tires locked at both ends tried for a long time unsuccessfully, my buddy took a run at it with his truck. Dodge Ram 1500 with D60s F/R, 4.56 gears and tru tracs. Took 3 or 4 attempts, but he made it up wide open throttle, smoking all 4 tires the whole way up. To say the least, it was impressive for limited slips. I understand that the tru trac is not a locker, but I wouldn't call it useless for street/trail/snow. Rock crawling may be a little different story.
maclean216
Member
I am guessing his wheelbase helped.
ChildrenOfBodom
Moderator
I bought a Detroit Truetrac rear end before my truck had 4WD. It was a great choice and I certainly don't regret making that choice.
That being said, I'm itching to get lockers.
In fact... It has always bothered me that they can't make locking LSD's. That would be one hell of a diff.
95% of my driving doesn't require lockers. I love hauling ass on loose dirt. I love jumping and sliding around loose gravel. I especially love on road use as this is my daily driver. I plan on a Total Chaos long travel front end someday... which really makes me want to keep the LSD. Freeway onramps, quick turns... there really is no match for a limited slip differential.
Just my luck that 5% of my driving wants to be up rocks now... and well, I was secretly very disappointed with the LSD's performance since 4WD happened. LIKE HELL do I want a stupid lame ass open diff... and with lockers, you've gotta deal with open diffs on road and when they're not engaged.
No complaints though... LSD's and lockers are two far different devices, both of which are excellent for their intention.
As far as whether or not I'm getting lockers... I'm a little more partial to my 95% of non-lockable use.
That being said, I'm itching to get lockers.
In fact... It has always bothered me that they can't make locking LSD's. That would be one hell of a diff.
95% of my driving doesn't require lockers. I love hauling ass on loose dirt. I love jumping and sliding around loose gravel. I especially love on road use as this is my daily driver. I plan on a Total Chaos long travel front end someday... which really makes me want to keep the LSD. Freeway onramps, quick turns... there really is no match for a limited slip differential.
Just my luck that 5% of my driving wants to be up rocks now... and well, I was secretly very disappointed with the LSD's performance since 4WD happened. LIKE HELL do I want a stupid lame ass open diff... and with lockers, you've gotta deal with open diffs on road and when they're not engaged.
No complaints though... LSD's and lockers are two far different devices, both of which are excellent for their intention.
As far as whether or not I'm getting lockers... I'm a little more partial to my 95% of non-lockable use.
J-money$$$
New member
Duhockey
Senior Member
Well, interesting that J-Money comes out this info now, would have been nice to have the info awhile ago, but either way... I did a ton of studying, and LINY4runner and FoneRunner both have the LSD in front with a locked rear and rave about it.
I put in my order for the Eaton Tru-Trac for my front diff yesterday...
I plan on locking the back when I get a chance, but the front I wont do anything but tru-trac.
My personal opinion from watching all my friends wheel here in CO and Moab is that Locking an IFS front diff is asking for more broken cvs, especially in an Automatic. Ill let you know how it goes, but I think that the little slip that they allow will save CVs.
I already think that having Manual has saved Me, Gerdo and Dylan from any broken CVs while Jeff and Glen are at what 20 combined for last year alone???
obviously, theres no scientific fact for it, but standing on the side watching CV after CV get replaced on my friends Automatic Locked front ends gave me lots of time to think about it.
I made the choice I felt was best for me. Ill let you guys know how it goes...
I put in my order for the Eaton Tru-Trac for my front diff yesterday...
I plan on locking the back when I get a chance, but the front I wont do anything but tru-trac.
My personal opinion from watching all my friends wheel here in CO and Moab is that Locking an IFS front diff is asking for more broken cvs, especially in an Automatic. Ill let you know how it goes, but I think that the little slip that they allow will save CVs.
I already think that having Manual has saved Me, Gerdo and Dylan from any broken CVs while Jeff and Glen are at what 20 combined for last year alone???
obviously, theres no scientific fact for it, but standing on the side watching CV after CV get replaced on my friends Automatic Locked front ends gave me lots of time to think about it.
I made the choice I felt was best for me. Ill let you guys know how it goes...
FoneRunner
New member
I've had my trutrac for a year now and done lots of wheeling, street driving, and highway driving with it in there in that time. I love that I don't have to think about whether or not I have a leak in an air line, whether or not the thing is engaged or not, whether I'm going to need to service it soon or not...etc....
When I've needed it, it's been there to pull me up and when working with my rear factory elocker I've been just about unstoppable(except for that one rock on the way up to Bill Moore Lake!! Thank God for a working winch!).
So, I guess you'd say I'm pretty happy with my purchase. Thanks for listening!
When I've needed it, it's been there to pull me up and when working with my rear factory elocker I've been just about unstoppable(except for that one rock on the way up to Bill Moore Lake!! Thank God for a working winch!).
So, I guess you'd say I'm pretty happy with my purchase. Thanks for listening!
J-money$$$
New member
This is an old thread my responses are about 3 months old. I dont like LSD's they are not for me but maybe you will like it. I wheeled moab with my front and rear locker and it was fine. I didnt do any thing too crazy since i had t drive it 800 miles home but I ran hells revenge and most of the optional stuff like hells gate. and i ran poison spider mesa with no problemos. and a quick little trip on fins.
Ran the rubicon and didnt break anything either. But i have had my fair share this season locally. We all wheel different stuff and have a different goal for out trucks. I was shooting for something i could run some of the hammers in and still be ifs.
I like the 5spd with f+r lockers.
Good luck with you new stuff
Duhockey
Senior Member
Eaton Tru Trac install flaws/experiences
So, heres some info I have about the Eaton Tru Trac...
the step by step isolation is on these two threads
Rocky Mountain 4x4, Where Wheeling Enthusiasts Are! • View topic - Actuator trouble??
and then
Rocky Mountain 4x4, Where Wheeling Enthusiasts Are! • View topic - Light at the end of the tunnel for Shon
I have most of the summary here
http://www.toyota-4runner.org/3rd-g...ys-build-thread-lots-pics-14.html#post1030806
Here is what I have learned about the TruTracs specifically,
#1 They have the worst customer service ever.
I called Eaton many times and 90% of the time I get an answering service that cant do anything but take a general message.
I finally got ahold of someone and got the direct # for the TruTrac support tec and he pretty much told me he didnt think the problem was even with the Tru Trac. More on that to come.
#2 They have some pretty big design flaws that have been pointed out to them several times by ECGS. They have ignored and blown him off.
Design Flaw#1 some of the Trutracs are machined off and the C clip will click in before the axle is fully seated (was happening with mine) others will go in all the way and not reach the C clip seat. Some of the people that have had the previous issue have also reported massive leaking since the axle housing doesnt seat against the diff properly.
Design Flaw #2 the stock driver side needle bearing has a gap in it that allows for diff fluid to flow into the area where the axle sits. The Trutrac sits flush and allows no lubrication in.
Design Flaw #3 The stock design uses a "needle bearing" on the driver side along with the spline "drive" to hold the axle and support it. The Trutrac eliminates the bearing and uses what Eaton refers to as a "race",
All of these combined lead to a situation where the axle is not fully supported the axle allowing it too much movement and friction leading to where the axle "cold welded" itself to the Trutrac "race". It took massive amounts of pressure and pounding and prying to get the axle free and out of the diff.
After talking to Eaton, they said they dont have a "bearing" in their design.
the fact is that I sent them a picture of the damage and its clear that it is part of the Trutrac.
Here is the open diff with trutrac
<table style="width:auto;"><tr><td><a href="https://picasaweb.google.com/lh/photo/DOsZosnLrHB7N0ohBfqOTtMTjNZETYmyPJy0liipFm0?feat=embedwebsite"><img src="https://lh3.googleusercontent.com/-NpRA9Glgctc/T39Xqhl10aI/AAAAAAAAEew/5UMoM5R1DcQ/s640/2012-04-06%252014.05.03.jpg" height="480" width="640" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="https://picasaweb.google.com/106779729868072622389/4runnerBuild?authuser=0&feat=embedwebsite">4runner Build</a></td></tr></table>
and the damage up close, apparently in the Trutrac
<table style="width:auto;"><tr><td><a href="https://picasaweb.google.com/lh/photo/6Yzxh0MuYp3jocyNnJ3fhdMTjNZETYmyPJy0liipFm0?feat=embedwebsite"><img src="https://lh3.googleusercontent.com/-oR0o1koJQTw/T39XaDprCyI/AAAAAAAAEeo/VVABb5BpJPQ/s640/2012-04-06%252014.05.43.jpg" height="480" width="640" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="https://picasaweb.google.com/106779729868072622389/4runnerBuild?authuser=0&feat=embedwebsite">4runner Build</a></td></tr></table>
After talking with Eaton, CVJ axle and several others, I happend to email then call Chase at ECGS, Chase read thru the posts and explained most of the above to me. He also has had so many customers come to him with issues stemming from these problems and problems with the Lockrights that he has fabbed up a solution for this problem. Apparently, this is an issue lots of Tru Tracs in other IFS vehicles as well. after weighing the options, I decided to send my Trutrac to Chase to have him take a stab at it.
<table style="width:auto;"><tr><td><a href="https://picasaweb.google.com/lh/photo/dLCQ6YBsPiKXavny1vUgdtMTjNZETYmyPJy0liipFm0?feat=embedwebsite"><img src="https://lh6.googleusercontent.com/-f-aX3cwZgS0/T3_l2IuiskI/AAAAAAAAEfE/AkbdPQokDm8/s640/2012-04-06%252016.51.19.jpg" height="480" width="640" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="https://picasaweb.google.com/106779729868072622389/4runnerBuild?authuser=0&feat=embedwebsite">4runner Build</a></td></tr></table>
It will be a few weeks before I get the TruTrac back, but I will let everyone know how things go from here. I will duplicate this post exactly as it is here in my build thread also.
EDIT: also read in the Trutrac owners manual that having tires of different sizes on the front will cause wheel speeds to be different and cause steering pull. I can confirm that about 1/8-1/4 diff in tread made me pull to the driver side hard. I replaced both front tires and the pull was eliminated. again, this also may have been accentuated by bad Lower control arm bushings.
*** notes: I am no expert on Diffs and/or gearing. The explanation above uses terms that I did my best to use the exact terminology of the people that explained them to me. You may have other terminology for the parts/issues Ive described.
So, heres some info I have about the Eaton Tru Trac...
the step by step isolation is on these two threads
Rocky Mountain 4x4, Where Wheeling Enthusiasts Are! • View topic - Actuator trouble??
and then
Rocky Mountain 4x4, Where Wheeling Enthusiasts Are! • View topic - Light at the end of the tunnel for Shon
I have most of the summary here
http://www.toyota-4runner.org/3rd-g...ys-build-thread-lots-pics-14.html#post1030806
Here is what I have learned about the TruTracs specifically,
#1 They have the worst customer service ever.
I called Eaton many times and 90% of the time I get an answering service that cant do anything but take a general message.
I finally got ahold of someone and got the direct # for the TruTrac support tec and he pretty much told me he didnt think the problem was even with the Tru Trac. More on that to come.
#2 They have some pretty big design flaws that have been pointed out to them several times by ECGS. They have ignored and blown him off.
Design Flaw#1 some of the Trutracs are machined off and the C clip will click in before the axle is fully seated (was happening with mine) others will go in all the way and not reach the C clip seat. Some of the people that have had the previous issue have also reported massive leaking since the axle housing doesnt seat against the diff properly.
Design Flaw #2 the stock driver side needle bearing has a gap in it that allows for diff fluid to flow into the area where the axle sits. The Trutrac sits flush and allows no lubrication in.
Design Flaw #3 The stock design uses a "needle bearing" on the driver side along with the spline "drive" to hold the axle and support it. The Trutrac eliminates the bearing and uses what Eaton refers to as a "race",
All of these combined lead to a situation where the axle is not fully supported the axle allowing it too much movement and friction leading to where the axle "cold welded" itself to the Trutrac "race". It took massive amounts of pressure and pounding and prying to get the axle free and out of the diff.
After talking to Eaton, they said they dont have a "bearing" in their design.
the fact is that I sent them a picture of the damage and its clear that it is part of the Trutrac.
Here is the open diff with trutrac
<table style="width:auto;"><tr><td><a href="https://picasaweb.google.com/lh/photo/DOsZosnLrHB7N0ohBfqOTtMTjNZETYmyPJy0liipFm0?feat=embedwebsite"><img src="https://lh3.googleusercontent.com/-NpRA9Glgctc/T39Xqhl10aI/AAAAAAAAEew/5UMoM5R1DcQ/s640/2012-04-06%252014.05.03.jpg" height="480" width="640" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="https://picasaweb.google.com/106779729868072622389/4runnerBuild?authuser=0&feat=embedwebsite">4runner Build</a></td></tr></table>
and the damage up close, apparently in the Trutrac
<table style="width:auto;"><tr><td><a href="https://picasaweb.google.com/lh/photo/6Yzxh0MuYp3jocyNnJ3fhdMTjNZETYmyPJy0liipFm0?feat=embedwebsite"><img src="https://lh3.googleusercontent.com/-oR0o1koJQTw/T39XaDprCyI/AAAAAAAAEeo/VVABb5BpJPQ/s640/2012-04-06%252014.05.43.jpg" height="480" width="640" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="https://picasaweb.google.com/106779729868072622389/4runnerBuild?authuser=0&feat=embedwebsite">4runner Build</a></td></tr></table>
After talking with Eaton, CVJ axle and several others, I happend to email then call Chase at ECGS, Chase read thru the posts and explained most of the above to me. He also has had so many customers come to him with issues stemming from these problems and problems with the Lockrights that he has fabbed up a solution for this problem. Apparently, this is an issue lots of Tru Tracs in other IFS vehicles as well. after weighing the options, I decided to send my Trutrac to Chase to have him take a stab at it.
<table style="width:auto;"><tr><td><a href="https://picasaweb.google.com/lh/photo/dLCQ6YBsPiKXavny1vUgdtMTjNZETYmyPJy0liipFm0?feat=embedwebsite"><img src="https://lh6.googleusercontent.com/-f-aX3cwZgS0/T3_l2IuiskI/AAAAAAAAEfE/AkbdPQokDm8/s640/2012-04-06%252016.51.19.jpg" height="480" width="640" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="https://picasaweb.google.com/106779729868072622389/4runnerBuild?authuser=0&feat=embedwebsite">4runner Build</a></td></tr></table>
It will be a few weeks before I get the TruTrac back, but I will let everyone know how things go from here. I will duplicate this post exactly as it is here in my build thread also.
EDIT: also read in the Trutrac owners manual that having tires of different sizes on the front will cause wheel speeds to be different and cause steering pull. I can confirm that about 1/8-1/4 diff in tread made me pull to the driver side hard. I replaced both front tires and the pull was eliminated. again, this also may have been accentuated by bad Lower control arm bushings.
*** notes: I am no expert on Diffs and/or gearing. The explanation above uses terms that I did my best to use the exact terminology of the people that explained them to me. You may have other terminology for the parts/issues Ive described.
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KidVermicious
New member
I've got a TrueTrac in my front diff. No problems yet, but I'm interested to see what you find out.
Duhockey
Senior Member
Yeah, LINY4runner and FoneRunner have also had no problems with theirs
Mine didnt fully seat before the c clip engaged,
also, how tall are you sitting in front? Just suspension, not incl body.
LINY is at 3 or just under, and FoneRunner is also about 3",
I am at 4" and also had bad Lower Control arm bushings which contributed to the problem Im sure. The more extreme angles mean more pressure on the outside of the Trutrac "race" especially with an axle not fully seated inside
Edit: I also added a little section about tire size to the post above... another thing I learned from experience.
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KidVermicious
New member
Just the balljoint spacers, so about 1.5 plus or minus. I've also got a different IFS diff than you guys though, no c-clip.
KidVermicious
New member
If you're willing to go away from a Toyota axle, you can have a locking LSD. Take a peek at the Auburn ECTED. I don't think they make them for our 8 inch diffs, though, something about their design not being compatible with the removable 3rd.
