K guys I know this has been mentioned before but couldn't really see a for sure answer in my search. As stated in the topic when I power brake the truck on wet pavement and in the messy stuff it will light both sides, but on dry pavement it does a one wheel peel. Can I get away with tryin to change out the diff. fluid or is it in need of a rebuild? And if it is due for the rebuild what kinda cost am I lookin at. I have a 02 CTD 4x4 Dually with 4.10 gears. Thanks in advance!!

Ken

 

Your truck is behaving normally.

I suspect you have a standard open differential (not limited slip). With a standard open differential, one wheel is allowed to spin faster than the other since while turning the outside wheel has to travel further. This works well in most situations, but works against you in other situations such as power braking on dry pavement and high centering in four wheel drive. The open differential allows all the power to go to the wheel without traction leaving the other "drive" wheel powerless. A limited slip (or better yet a locking) differential will allow power to go the wheel with traction.

Of course, if you do have limited slip, then you have a problem and will likely need a rebuild. I'm sure the problem wasn't caused by power braking a dually!

 

Well I know power braking didnt help the matter but it has done it since I bought the truck a couple months back. The window sticker says anti-spin, when I got the truck it only had 48,000mi. on it and it did it then. They told me at the dealership it was owned by a female and she used it to haul horses in a livestock trailer(gooseneck ball in bed). Well hasany of you guys had to rebuild one and any thoughts on why it took a **** so early?

Ken

 

I would research your "anti-spin" differential a little more. Limited slip differentials are not the same as having a locker in the diff. With a standard differential power follows the path of least resistance and only one wheel is "required" to spin. The other wheel will be feeling the the same amount of torque required to spin the wheel that is moving. For example, if you jack up one side of the truck and leave the other down, and try to drive, it may only take 10 ft-lbs of torque to spin the free wheel in the air. The tire on the ground is seeing he same force of 10 ft-lbs. If you stick one tire on ice, the other on pavement and block the front end of the truck from moving, it may take 150 ft-lbs to make the one wheel spin on the ice. The other wheel on pavement is seeing this same 150 ft-lbs force, but that force is not enough to overcome the static friction between the tire and the pavement, so it doesn't spin. Remember that just because it isn't spinning doesn't mean that it doesn't have forces acting on it.

Limited slip diffs decrease the difference allowed between the left and right wheels by making it harder for one wheel to spin freely. Think of it like this. In the previous example where one tire is on the ground, the other free in the air, with a limited slip differential, it may now take 100 ft-lbs to spin one tire freely. Now the tire on the ground is also seeing 100 ft-lbs, instead of 10 ft-lbs without the limited slip differential. But even with the limited slip diff, one tire is still allowed to spin without the other moving.

I would research "anti-spin". I have never heard it that way. You have a dually. It takes a lot of force to spin those wheels. Also, static coefficients of friction are generally much greater than dynamic coefficients of friction. This means that it takes more force to get the tiresspinning than to keep them spinning. So in my opinion, you probablydon't have a problem. But ifyou keep trying to roast your dually, you will have a problem eventually. Maybe your ok with that.

 

I've got an open end rear as well. Whenever I try a burnout only 1 wheel spins. Maybe someday I'll get a posi.

 

Thats the thing Mayfair, I dont have the open rear end. I have the Anti-Spin, but it does the one wheel peel on pavement. It spins both the back fine in the mud. I used my truck as a pull truck in our local county fair demo derby. I was pullin cars and combines around and both back tires where slingin the mud all over the place!! I guess the rear end is just gettin worn out.

 

put your emergency brake on a few clicks to get a little load on the brakes. . .this will cause the clutches to lock up and start to push power to the other side. . .when your in the mud both wheels are able to spin allowing the clutches to enagage properly. when your on pavement doing your peg legs everything is spinning to fast for the clutches to work properly.