I'm getting my truck (88 f350 in my sig) on the road soon and I have a question

It is my daily driver but it's also the occasional mud toy. I really want a rear locker because it would be helpful when I get into some mud. There has been more than one occasion where a locker would have really made a difference. I plan on leaving an open front diff. My question is, will this have any negative affect on pavement drivability? And will there be any downfalls besides a little tire scrub?

This is the locker I was considering http://www.summitracing.com/parts/dt...FZLm7Aod3jAASg

 

the type of locker you are looking at have better general road manners than those of say a lunchbox locker, however as with any locker it will change the road manners. the general idea out there though is that if you live in an area where there is alot of rainy or wet roads, or have snow and ice, a selectable locker is preferred, such as an e locker or air locker, as non selectable lockers will kick the rear end out in icy conditions, especially if its a patch of ice and you drive over it with only 1 tire. now i am not saying you cant learn and be ready for what a locker will do and feel like, as there are people with lockers in crappy conditions that daily drive them sucessfully, i am just telling you what friends have experienced with there lockers

 

I've driven with lockers in the rear for years and its not anything difficult. It does take a little getting used to, I drive pretty light footed with mine when its slick. Especially on corners. The trutrac is not a locker though, its a limited slip. It works well & has no clutches to wear out. Only down side is that it usually needs to be installed at a shop.

 

A truetrac will not change street driveability at all, you won't even know it's back there until you are in snow or off road where it shines.

 

As Big-Al said, a Detroit TrueTrac (usually just called a TrueTrac) is not a locker. It's a gear-type limited slip. It will always give 3.5 times as much torque to the tire with traction as the slipping tire receives. If the slipping tire gets absolutely no traction it takes zero torque to spin it and the other tire gets 3.5 times zero which is zero.

TrueTracs look to be great for on-road use, snow, ice, occassional slick but not deep mud. They don't wear themselves or tires as bad as a clutch-type limited slip (like Ford's TracLoc or Chevy's Positraction). They have less driveability issues as well. I've never had one, but I think it would be my first choice for an on-road driven truck. But most dedicated off-roaders wouldn't be happy with them.

A locker (like a Detroit NoSpin, usually just called a Detroit) will never let either wheel turn slower than the ring gear. Lockers are the gold standard for the off-road crowd. They do have the worst manners on-road, but I've had them in a Jeep CJ5, an F-150 SC short box and my early Bronco. I don't mind driving them on the street, although they are noticeable. The worst situations are on ice with a short wheelbase (the Jeep was pretty twitchy) and starting around corners, especially pulling a trailer. I wouldn't use an automatic locker in a truck primarily intended to tow trailers.

All traction aiding diffs will be less stable on ice. A TrueTac is probably best, a clutch-type limeted slip is next and an automatic locker is worst. All make it easier to spin out, but with a little care none of them are that bad.

And I should note that I'm only talking about the rear diffs here. Any traction aiding diff in the front is WAY more noticeable, even to the point of being downright dangerous in some conditions. I will NEVER again put anything but a selectable locker in a front diff (other than open obviously).