Thoughts on switching to LSD
#11
Join Date: Nov 2008
Location: Malvern Pa - Canadensis Pa
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The 31-35" is tire size, than he is talking about gear size. Since you are running stock the gears in the rear you have now are fine. Some of us guys pushing big tires we have no low end. In order to get that low end back we need to gear/change out our ring and pinion. This is one of the things you should have a shop do unless you do it all the time. I don't think you want a total blow up rear end?
#12
Join Date: Jul 2007
Location: South Georgia/East Florida
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If'n it were me and I was going to the expense of a new ring and pinion, I'd go the extra and have a good aftermarket LSD in there at the same time.
My trusty old '98 1500 5.9 4x4 came with an open diff (WTF?) and I had an Auburn Gear LSD put in. GREAT UNIT. I know they say the Detroit TruTrac won't wear out over time, but I had 68,000 miles on my Auburn when I traded the truck in, and it worked same as on day one.
Was gonna try the TruTrac on my 3rd Gen when I lifted it, put on 35s and went to 4.56 gears, but Detroit was in the middle of being bought by Richmond, and the TruTrac was back-ordered nationally for about 6-8 weeks on the Chrysler 9.25" model. So, not wanting to wait to do the gears, I went back to the Auburn unit. I kinda would have liked to see the difference 'tween the two, but I don't regret having the Auburn for one minute.
You can't go wrong with either one.
As far as a locker goes, I'm not really a fan of a non-selectable one in a daily driver truck, and the ARBs are just so much money, especially when you have to do the compressor, etc...
My trusty old '98 1500 5.9 4x4 came with an open diff (WTF?) and I had an Auburn Gear LSD put in. GREAT UNIT. I know they say the Detroit TruTrac won't wear out over time, but I had 68,000 miles on my Auburn when I traded the truck in, and it worked same as on day one.
Was gonna try the TruTrac on my 3rd Gen when I lifted it, put on 35s and went to 4.56 gears, but Detroit was in the middle of being bought by Richmond, and the TruTrac was back-ordered nationally for about 6-8 weeks on the Chrysler 9.25" model. So, not wanting to wait to do the gears, I went back to the Auburn unit. I kinda would have liked to see the difference 'tween the two, but I don't regret having the Auburn for one minute.
You can't go wrong with either one.
As far as a locker goes, I'm not really a fan of a non-selectable one in a daily driver truck, and the ARBs are just so much money, especially when you have to do the compressor, etc...
#13
Then you have about a 30.5" tire. The 2xx by xx by 16 is a metric hybrid of sorts. the last number is always your rim diameter in inches, the rest is metric.
The truetrac replaces your entire carrier, which is the big bell shaped piece with the smaller spider gears in it.
The power trac is a decent unit, but I've heard multiple stories about them grenading so I decided to spend more and be safe. To be fair, most of the stories I've read about them failing are from guys that are using them for more than they were intended. If you aren't going to go 4 wheeling or running massive tires, you should be OK. Kind of depends on how heavy the stuff you're towing is too, should the rear end ever slip and put a load on the power trac.
Auburn makes an LSD that is kind of in the middle, price point wise and it's a really solid unit too.
Don't forget that the Auburn (and I believe the power trac, not sure) require a friction modifier in the gear oil for the clutch pack. That might be the reason your buddy's Cherokee stopped chattering, because the Royal Purple has a modifier already included.
Hammer, you type faster than me, LOL!!!!
The truetrac replaces your entire carrier, which is the big bell shaped piece with the smaller spider gears in it.
The power trac is a decent unit, but I've heard multiple stories about them grenading so I decided to spend more and be safe. To be fair, most of the stories I've read about them failing are from guys that are using them for more than they were intended. If you aren't going to go 4 wheeling or running massive tires, you should be OK. Kind of depends on how heavy the stuff you're towing is too, should the rear end ever slip and put a load on the power trac.
Auburn makes an LSD that is kind of in the middle, price point wise and it's a really solid unit too.
Don't forget that the Auburn (and I believe the power trac, not sure) require a friction modifier in the gear oil for the clutch pack. That might be the reason your buddy's Cherokee stopped chattering, because the Royal Purple has a modifier already included.
Hammer, you type faster than me, LOL!!!!
Last edited by aim4squirrels; 11-26-2009 at 10:46 AM. Reason: Hammer cheated.... :)
#14
#15
I used the term "locker" in my post. I just read some more about that and didn't fully understand that concept. I was using "locker" and LSD interchangeably.
All I am intersested in adding is some sort of LSD. I have now looked at Detroit True Track and Powertrax No Slip. Anybody have any experience with Powertrax? Kinda intrigued by Powertrax due to the cost and relative ease of installation. A True Track bolts to the existing ring gear, right?
Also, you guys are using "31" and "35" when referencing tire sizes. I guess you are talking about over tire diameter, right? i just run stock 245/70's (whatever size is recommended on the sticker on the inside of the door)
All I am intersested in adding is some sort of LSD. I have now looked at Detroit True Track and Powertrax No Slip. Anybody have any experience with Powertrax? Kinda intrigued by Powertrax due to the cost and relative ease of installation. A True Track bolts to the existing ring gear, right?
Also, you guys are using "31" and "35" when referencing tire sizes. I guess you are talking about over tire diameter, right? i just run stock 245/70's (whatever size is recommended on the sticker on the inside of the door)
The difference between the Powertrax and the True trac (or any limited slip) is what constitutes "limit".
A limited slip differential actually has two limits. The first limit is how much one tire spins before the clutches* (or helical gears in the true trac) engage and lock in the opposite axle. This is usually measured in ft/lbs.
But the second limit is as important. That is the "over torque" limit, where in the clutches will slip and leave you with one wheel spinning, just like an open rear end. As the clutches in most LSD's like the factory one wear out, both "limits" are increased and decreased respectively.
The True trac uses a helical gear mechanism that is claimed to never need rebuilding, which is good. But because it is a limited slip design, it still has an over torque limit, maybe higher than many, but again NOT like a locker.
The disadvantage, if any of a locker, is that as long as an engineered amount of torque is applied the locker remains mechanicaly bonded. Only releasing torque, by say letting off the gas, allows it to differentiate, Since is is a metal to metal lock, it can be noisy or possibly "violent" when it releases. Most of todays lockers are nowhere near as bad as thier early realitives.
The Powertrax design has been around since the early 50's. Trivia...The company's founder designed and built the orginal powertrax to go in his early DODGE powerwagon. Sweeeet!
I hope that helped...
* I left out the early 70's metal cone design, but it works the same way as a clutch pak, and same wear issues. The Auburn is also a metal cone design.
Last edited by dsertdog56; 11-26-2009 at 01:31 PM.
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hmm... well in that case its now 3.92s or 4.10s i dont need 4.56s as the biggest i plan on running currently is a 285/75...though once this thing is paid off im gonna get a 5 inch lift and run 37x13.50x16.5 militarys. and then is when ill go to the 4.56s. but for now a 3.93s or 4.10s with an LSD will do... i just need to determine what LSD i want to get.