light knock and jumping in fromt end

[97bignslow]

Long time no post-

I have recently had my truck overhauled due to a knock and bumping coming from the front of the truck. This is usually detected after the vehicle has warmed up and I am driving slow (going into a parking space). I replaced all of the front linkage, joints and half shafts and though this has stoppped some other annoying rattles, it has not helped the big problem. I am thinking it is a problem with the four wheel drive system and am interested if anyone else has had a similar problem. Has anyone had the fromt differential, gears, axel... go on their X. I have about 95000 miles on it now and other than this problem, it seems to be perfect.

Thanks

Eric

 

[97bignslow]

fyi

For those of you who may be interested, the knocking was coming from the front end due to a recent tire size change. I went for 30" to 31". The Control Trac was thinking the tires were abnormally spinning and it kept engaging and disengaging the four wheel drive system.
Ford had to reprogram the computer.

E-

 

[expl0der8]

Do you have the auto 4wd? If so, was it that causing the problem?

 

[97bignslow]

Yes, the Control Trac is the auto 4wd.

 

[expl0der8]

How much did it run you to get your computer reprogrammed?

Did you get it reprogrammed also for the new tires?

 

[97bignslow]

The whole reason I had a problem was because of the new tires.

Ford charges $100 bucks. About one hour of labor at their rate.

 

[expl0der8]

Well there's another $100 to add to my project price.

 

[Robert]

You are the first I have heard of having a problem after making such a minor change in tire size. I went from the factory 255 70R16 tires (30.1") to my current 265 75R16 (31.7") tires without any problems whatsoever. All it took was a change of my $7 VSS speedometer gear to on with one less tooth to correct the speedometer, odometer and transmission shift points. Countless others have made similar or even more drastic changes in tire size also without the problems you experienced. Rather than reprogramming your computer (if that is indeed what Ford really did) they probably could have fixed yours with a $7 gear as well. If not, then something else was already wrong. Your tires just exagerated it.

 

[97bignslow]

Robert,

It took me by suprise too. I have been subsribing to this site for years and have never heard of anyone having the same problem. Your probably right in saying there was a different problem. I never did change the speedo gear, but that should effect the trucks performance.

Eric

 

[Robert]

By not changing the speedometer gear, the only performance issue that would be noticed is it would shift at different speeds than normal. The week before I swapped out the gear, my speedometer said I was going 45 MPH I was only going about 41 MPH which caused it to lug a bit. Ford can correct it either way on '96 & '97 Explorers (new gear or reprogram computer). Starting in '98 the only way Ford can correct it is by reprogramming through the computer.

 

[canada74]

i went from 235/75r/15's to 31's and only found my speedo was off 10mph and my abs keep kicking in when not needed, im thinking of diconnecting the abs. i have a '96 so i still have to switch to control trac, will diconnecting hurt my control trac?

 

[Jason_25]

The ABS has nothing to do with control trac. You could save yourself the hassle though and just get a cheap speedo gear from Ford.

 

[canada74]

so i can "cut: my abs and not worry about it. im on my 3 rd car now and this i the first with abs and ont really like it, speed whise im not too worried