Limited slip like the one you bought is always working no matter what ground you're on or how fast you're going

Edit don't forget to run friction modifier in your rear end now

 

I'll second that. Don't depend on the gear lubes that say they have that in it. Add your own.

 

Ill make sure i pick some up for this weekend!
Also from what i've been reading as long as i keep everything the same - i should be able to just swap carriers and not set the backlash or pinion.
I will check it, but can anyone verify that if i keep the shims same side the bearings all the same where they came of ect.

 

In theory, yes. Manufacturing tolerances can throw a wrench into it, though...
I'd want to check the pattern & backlash before the swap and again after.

 

I plan on checking it and crossing my fingers......who knows may be one of the 5% that have to reset everything or I'll get lucky and its all within spec

 

I got a set of used 4.10's for my dump truck and swapped them with the old shims and all was well.

 

While I know it's a redneck way, if you do not have a dial indicator with a magnet or visegrip base, you can still get it right if just swapping carriers. (not swapping gears or pinion bearings) The rule of thumb for backlash is to feel it, but not see it. It sounds crazy I know but grab the ring gear once it's all tight and rock it up and down. If you can feel the backlash but not see it, it's good.

Now before I get flamed, I know how to set up gears, have done it many times but many of the techs I worked with tested this theory many times and verified it with a dial indicator. It is always around .005-.007.

Ford spec is looser than this, but most shops shoot for .004-.009 or so.

 

Installed a Detroit Truetrac in my F250 this past fall. BIG IMPROVMENT!!!

I pull a medium weight trailer 4000 to 7000lb. No more slipping one tire on wet roads when taking off.

As for the the install. I checked the backlash of the original (.013") before removal. Swapped my ring gear to the new carrier. Installed with factory shims in original positions and checked backlash again (.012"). Worked out great!

Todd

 

While I agree that automatic lockers are poor to terrible for towing (and an incredibly terrible idea for towing heavy trailers with zero tongue weight), they do NOT lock "under power". They lock when one tire loses traction. Whether you are coasting or driving they will stay unlocked when turning unless you spin the inside tire (the only one being driven when it's unlocked).

And that's what makes them terrible with farm-type trailers that weigh a lot but have zero tongue weight. Heavy trailers take a lot of force to move, but with zero tongue weight they don't help the tires hook up to provide that extra force. So the inside tire essentially never has enough traction (even on pavement) so it spins, making the locker lock.


As noted above, automatic lockers (including the Aussie and other "lunchbox" lockers) aren't great for towing where a trailer adds to the force needed to move the load but doesn't add much weight to the drive tires to help you move it. Keep in mind that automatic lockers give you one-wheel drive when you go around a corner (until you spin that one tire and the locker locks, giving you two wheel drive from that axle, but scrubbing tires because it's locked). As has already been said, a limited slip is the only way to help traction at all times without significantly hurting traction when turning. And a TrueTrac is undoubtedly the best limited slip as long as both tires have some traction (they don't work at all with one tire in the air, although adding a couple of clicks of e-brake can trick them into working in that situation).

That said, I'd agree that a lunchbox locker is the second-cheapest way to address the original problem of not being able to start up on a slightly slippery surface (locking the hubs is far and away the best cheap solution). A lunchbox locker (or a Detroit for more money) will give you the most help in that situation (better than a TrueTrac and far better than most clutch-type limited slips), but they will result in you spinning the inside tire on almost all powered turns, pavement or not.

 

just noticed your updated signature, ironic 460, 4.10s 37s and a sig pic with the fuel nozzle shoved in the tank

 

Wrong

Detroit lockers are engaged when torque is applied to the differential ie hitting the gas

The only time they are unlocked is when you let off the gas pedal

The trutrac however will lock only when one tire starts spinning faster than the other the helical gears inside it slow down the faster spinning tire and apply torque to the slower or non spinning wheel

Clutch type ls only gives resistance to whichever tire is spinning to try and distribute torque to the other one imo not worth buying and wasting time putting them in

 

No, I'm right. Here's what the Eaton web site says about it(Detroit Locker is the link if you want to check it out):
No mention is made of "under power". They unlock "in turns and maneuvers" as I said.

Truetracs never lock. They do apply more torque to the slower or non-spinning tire as you say, but only up to some multiplier of the torque going to the spinning tire (I believe it's 3.5 times). That's why they don't work with a tire in the air (3.5 time zero is zero). But lightly applying the e.brake makes it take more torque to spin the tire that's in the air, so then you get 3.5 times a bigger number.

As I said above, that resistance is between the two sides of the axle. And although others do swear that they're useful and I won't say they're wrong, personally I agree with you and would never even bother rebuilding the one I have much less put one in.

 

I don't have to check out the link I have a Detroit locker in one of my trucks yes it will unlock going around corners but you MUST let off the gas

You'll get one of two things with a Detroit locker when cornering either tires chirping or a ratcheting sound all depends on how you use the skinny pedal

 

This is from the trutrac manual I don't see anything about 3.5 times

 

You're wrong though. If you get on the gas in a corner a Detroit is unlocked (because you are turning) so it only gives torque to the tire that's turning the slowest, which is the inside tire. Since that tire also tends to be unweighted by the inertia of the truck making it lean to the outside it's pretty easy to overpower the amount of traction that one tire has. In that case you will spin the inside tire and when it catches up to the outside tire the Detroit will lock and drive both tires. So if you get on it enough you will chirp it, but if you don't overpower the one wheel drive it will stay unlocked under power.