Have a 2005 f150 and when I step on the gas it seems that the rear end is slipping and or goes into gear very hard. Is anyone else having this issue or is this normal? My neighbor has a 2003 f150 and said he has notice that his is doing the samething, but did he did not have this issue when it was new.

Thanks for any help with this.

 

...Welcome to Ford Truck Enthusiasts!
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!

…Enjoy FTE and The State Chapters are located at the bottom of the main forum page.
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.

 

Same problem here (2004 4x4 3.55)... I also have the rear axle whine... going in the garage Monday morning to work out the axle whine - I'll be asking about the rear end slipping too. Perhaps it's all related somehow.

 

I think it might be time for a class action suit or at least a complaint to the NTSB (or like governmental agency). I hope and pray that in another 6 months Ford will issue a recall with something more substantial than a different grade grease.

 

It's been a good six months since I pulled a rear end apart (9 inch ford) but refresh my memory, what part in a differential can 'slip'?
I sure can't think of anything myself.
I'm not refering to one side turning faster than the other, even with burned clutches, one side or the other gets the drive. I have seen a slipping rear end, but that was long ago on a Rambler Ambasador, one axle was stripped, and the 19 splines wouldn't bite. That's sorta obvious.

Or not, they had replaced the transmission before I looked at it, and were quite angry about it.

Now a little play in a splined shaft in the tailshaft of the transmission can cause clunk, usually only on new vehicles or very old ones, but slip inplies that one end is turning faster than the other, and to do that with a 3rd member or driveshaft would be something to see...
Chris

 

bought a brand new f150 stx 4x4 last year the first week i had it the rear end was slipping, brought it back to dealer, took them 10 min to adjust and tighten some things, no prob go back to dealer!

 

a rear end cant slip, if it did, you woulnt move, and it would be quite a racket, its more than like ly just the tranny.

 

Chrono4, I think what they are calling slipping is play in the front yoke. There are some that have had clunk and strange shifting from that. The cure seems to be thick grease, just like it the old days... Triumph Spitfires had a heck of a problem with that. It also sounds like a '10 minute' job.

This is not a Ford problem, it's a spline problem. For example, the secret fix for the 'bad steering rack' in a Cavalier. Thousands of these cars are sold by people every year because they 'need' a steering rack.
To fix it, the kit costs twelve bucks, takes ten minutes to grease the splines on the shaft, good for 50k miles. Same thing, just different part of the car, same spline shaft grease.

stx4x4, as to rear differentials needing to slip, nope not how they work. Look at a picture of one some time, look at the side gears. Then tell me about slip... One side or the other WILL get grab.
Pulling a differential down is a two hour job for a pro..

Now some of these rear ends on the LS have chatter and grab problems.

Been a problem with Posi types since the 50's. Usually cured by using the correct additives, or 'setting' the rear up, but the dealers are prone to yanking and replacing.
A guy that can set up a differential and the flag time to do it are usually not available.
Yanking the rear is a job for a helper, at a fraction what a gear man charges per hour.

Play in the front splines can cause clunk, or take up and often causes weird or wrong shifting.
Chris

 

Thanks for the wellcome Tim and everyone's feedback. After reading the responses, It sounds like I am having the clunking noise issue and that it is an easy fix. Once it's time to get my first free oil change at the dealer I will have it looked at.

Once again thanks for all your feed back and look forward to using this forums.