Going with an Eaton truetrac on 327 ( 331 ) ?

[ian75c10]

Hey Guys I have a 331 in my 75 c10 and don't have the best torq. I have mild cam and headers, truck runs great, I have 4.10 in rear with a 30" back tires. I am thinking about adding the eaton truetrack limited slip. I am curious how this will affect my truck and driving. I would think that it would give some help in the torq department but am i right in thinking this? What are some other benefits and or non-benefits to adding the truetrac to my setup? thanks fellas

[SomeTexan]

A true track is just a posi. A better than stock posi, but it will not increase torque. Just send power to both rear wheels. If you get a one tire fire off the line, it will help.

[ian75c10]

Thanks Texan, could you tell me a bit more what you me by one tire fire? thanks

[LeftysRodandCustom]

I just finished my true trac a week or so ago and the first drive was yesterday. The thing is awesome. I cant begin to wrap my head around how it works because it doesnt act like any posi I've ever seen. On the jack stands if you rotate a wheel the other will spin opposite like an open rear end. If you spin the pinion both wheels go the same direction like and other posi, where it gets wierd is if you go back to spinning one wheel and the other goes the opposite direction, the pinion does not move at all. I understand that it uses a helical planetary gear but how that thing works is beyond me. I drove it around nice and easy to break it in and then let it cool. When I took it out again on a start from a stop sign i got a little wheel slippage from some sand and could feel it transfer power to the other wheel immediately and then back again when that one slipped a bit. Then when i stomped all over the throttle she locked up tight and spun em both like there was no tomorrow. I'm sold on the true trac for sure. It behaves nicely when cornering and does not whine or click at all. I'm running 4.11s behind a wild 355 and an M21 trans so the whole thing is a real blast.

[Captkaos]

By one tire fry he means you stop it and it just burns the passenger side tire off.  If you aren't spinning tires adding a limited slip isn't going to change anything.

[SomeTexan]

Captkaos has it right. One tire fire means when you hit it from a stop, an open diff will allow one tire to spin. Instead of going forward, all your power goes the the wheel that lost traction. A posi/limited slip tries to keep the wheels turning the same speed, but still lets you go around corners without slipping a tire like a spool would do. Locker's unlock under the right conditions, but usually surge or pop in turns. If you spend time on muddy roads or on the farm, a locker might be worth looking into. If its a near stock driver, an open diff won't hurt anything, and a posi won't gain you anything. Where I live, there are a lot of slick little roads. Even granny in a Honda is spinning tires leaving stop signs. A posi helps in that situation. I have neighbors that claim to have doubled tire life by adding a posi. Less spin, less tire wear.

[LeftysRodandCustom]

Agreed guys but the true trac isnt like any limited slip I've seen before. No clutches or srpings at all, just the planetaries. No popping or binding in the corner so far. Not even the clicking noise. A sweet piece if you decide to use one.

[SomeTexan]

They work well in moderate performance street and light off road applications, but still have limitations. I had one in the front of a street legal rock crawler. Ended up with an arb. Even locked in the rear, it didnt help enough until you really got the tires spinning. The best option if price is no concern is an e-locker. Limited slip normally, but turns into a spool with the flip of a switch.

[LeftysRodandCustom]

Agreed again. Mine is in a 79 2wd short box thats meant to be a street/strip truck so it works well. Take a look at his profile pic, I dont see any rock crawling of 4 wheelin in that trucks future.

[SomeTexan]

True, but I was using the refferance to a rock crawler to explain the limits of the true trac. To me it seems like it takes a lot of rpm difference between the wheels before it starts working. Although I used to do a lot of 4 wheeling, I also spend a lot of time on the strip. I use lockers and spools there as well. There are some places/situations where a posi just isn't enough. I don't know what the original poster's intentions are with his truck, so I listed most options and situations they help in. It's up to him to choose what he needs or wants.

[ian75c10]

Thanks so much for all the replies, this is definitely good stuff. I guess my original interest was in a simple assumption that if power was being applies to both wheels in a start and stop around town environment ( or even on the highway ) that maybe it would be correct to assume that the engine would have to work less on moving the weight of my truck. Hence possible longer engine life and maybe a bit better mileage.

[SomeTexan]

The only way a posi will help engine life is if you are reving it like crazy trying to get moving now because of traction issues. They are nice to have, if you need one. If you have performance upgrades planned, but need to rebuild your diff, that would be the time to add one.

My truck is a prostreet build, I'm currently looking at a late model z71 axle with an e-locker. I will have to narrow it, but with good axleshafts it will take some abuse. And it should be cheaper than building a 9" or dana 60 from the ground up.

[Captkaos]

That limited slip works rotational operation of the planetaries, simular to a gov-loc.  it has to have a lot of rotation force to engage the other wheel.

[SomeTexan]

Was that reply to me kaos? I could care less about the posi, the locked part is what I car about. I just don't like a spool on the street if I can avoid it. And 18" wide cheater slicks don't like it either. My goal is a strip monster that doesn't need a trailer, and a turbo'ed tall deck lsx with a massive stroke stroke should get me where I want to be.

[Captkaos]

No it was to the thread.  Someone said that it worked differently than any other limited slip, and although different, it still limits slips.  A "Posi-traction" the name GM called all of their limited slips.
A locker is the only thing that will lock both axles and still differentiate..