Just recieved my superchips tuner. Installed the 89 octane tune in my 04 regular cab 4x4. Took it for a spin felt the shift points shifting harder, like everyone has said in the other threads. With a 1/4 tank left I put 93 octane in to a full tank. Took it for a spin felt a little more power and the shifts seemed sumwhat stronger. Pulled out of road from a dead stop to feel the full power and seemed to run good. Went through town, the truck stopped pulling. Looked underneath drive shaft spinning. Ford said rearend is shot. I have 7000 miles on truck, never had a problem and now rearend is out. I am worried about the tuner now. Just to let everyone know.

 

sorry to hear about your rear gear but it will take
a lot more than 20 more hp to break a ford rear end
hope its still covered

 

were you doin neutral drops from 5.000? if not i'm adjusting the shift pressure. do think its a little hard.

 

The dealer should cover it. If not, break out the whoop-***. There is no way a tuner caused your rear end failure.

 

Being a mechanic, I have to agree with dzervit. The rear end aready had a problem, but hadnt begun to show yet. The tuner did not cause the problem. It was just coincidence that it tore up after you installed it. Return it to the original program and let your dealer fix it under warranty.

 

From what I have read in other posts is that there was some problems with the assembly of the 9.3/4 rear end. Bet your F150 was one of those.

zman

 

That had nuttin whatsoever to do with the small bump of a tuner ! Adding an aftermarket supercharger and beating it mercilessly MAY do that.

 

I agree, there is no way the tuner was at all to blame. You would have to have some sick torque to bust that before it could transfer power to the wheels. It must have locked up or jammed and snaped. Regardless you just de-tune back to stock and let them fix it...tuner, whats a tuner, never heard of one of those...fix my truck meng!

 

Hey ZMAN…what trucks have the 9.3/4 rear end? Just 4X4’s? How do you know what rear end ya have by looking at it? Thanks!

 

Darn I thought I fixed that. But if you convert 3/4 to decimal that would be .75, add that to 9 and you get 9.75. Been working with to many fractions lately.

By the way the front is 8.4/5

 

Here is a link to rear end problems.