yeah, coincidence
short wavelength with high amplitude is usually something rotational under torque.. check your u-joints and center support bearing too
Help Needed Vibration in Brake Pedal
- Thread starter JRJ04
- Start date
yeah, coincidence
short wavelength with high amplitude is usually something rotational under torque.. check your u-joints and center support bearing too
JRJ04
Senior Member
Arite, well to be honest with you, i know what u joints are, but dont know exactly where they are.
Would you mind givng a little more detailed explanation of them as to where they are located and what the look like? also, what is the center support bearing and where is it located?
What am I looking for on them?
Thanks a bunch JL
On edit:
this really only happens between 45 and 55mph, 4wd or 2wd, hubs locked or unlocked, when im accelerating it almost sounds like its in 4wd. tranny still shifts smooth and everything runs fine...just the vibrating. does this point it in any direction?
Would you mind givng a little more detailed explanation of them as to where they are located and what the look like? also, what is the center support bearing and where is it located?
What am I looking for on them?
Thanks a bunch JL
On edit:
this really only happens between 45 and 55mph, 4wd or 2wd, hubs locked or unlocked, when im accelerating it almost sounds like its in 4wd. tranny still shifts smooth and everything runs fine...just the vibrating. does this point it in any direction?
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if it vibrates on accelleration too, I'd be guessing (I don't have the luxury of crawling underneath it) U-joints.
park the truck, shut it off, crawl under it and grab the driveshaft and try to twist it back & forth. If that reveals no play, I think I'd put the truck up on jackstands and remove the shaft, and check the joints for "tight" spots and you work the joints through their range.
put a chalk mark on the shaft segments if it's a two-piece driveshaft to make sure you get it back in phase when you re-assemble it.
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dpantazis
#12
j:
is this happening with tunes uploaded by the predator unit?
which one and when did you upload them?
iirc, the programs will modify the shift pressures and lockup. 45-55 is where a shift point should be. i am going by memory here.. so, if the programs mess with the tranny, then eliminate that variable to ease diagnosis.
put the stock program back and see what it does.
dp
is this happening with tunes uploaded by the predator unit?
which one and when did you upload them?
iirc, the programs will modify the shift pressures and lockup. 45-55 is where a shift point should be. i am going by memory here.. so, if the programs mess with the tranny, then eliminate that variable to ease diagnosis.
put the stock program back and see what it does.
dp
JRJ04
Senior Member
dp, im almost positive its not the predator because ive had it on there since january and it hasnt done this until now. i'll give it a try.
jl: I'll go and give that a try as far as seeing if there is any play in it. im takin it to my mechanic if it needs ujoints as i dont trust myself and totally trust him.
i'll post back up in a few and let you know.
jl: I'll go and give that a try as far as seeing if there is any play in it. im takin it to my mechanic if it needs ujoints as i dont trust myself and totally trust him.
i'll post back up in a few and let you know.
JRJ04
Senior Member
Ok i went out there and checked it out. if i can move my truck back and forth in park enough to slosh around diesel in the tank, would that be an indication that u joints are bad?
when its sitting on flat ground, i was able to turn the driveshaft if i slightly took the bind off of it from being at a slight slant. could bad u joints be the reason it sometimes seems like it takes forever to get into drive after getting out of the driveway?
and more importantly...would they be causing that feeling of feedback/vibration in the brakes? it just almost feels like the abs is kicking in or something, but then again who knows.
when its sitting on flat ground, i was able to turn the driveshaft if i slightly took the bind off of it from being at a slight slant. could bad u joints be the reason it sometimes seems like it takes forever to get into drive after getting out of the driveway?
and more importantly...would they be causing that feeling of feedback/vibration in the brakes? it just almost feels like the abs is kicking in or something, but then again who knows.
aw man..
now you've got me thinking there's multiple problems...
go see your friendly local tech and have him drive it...
and tell him about all these issues you just laid down...
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JRJ04
Senior Member
ohhhhhhhhhh boy.....not what i want to hear. what else are you thinking?
JRJ04
Senior Member
hey talked to my ford dealer...he seemed to think possibly the TC??? please tell me hes out of his mind!!! he said it could be u-joints....what are you thinking?
hey talked to my ford dealer...he seemed to think possibly the TC??? please tell me hes out of his mind!!! he said it could be u-joints....what are you thinking?
what am I thinking?
U-joints and something else..
U-joints by themselves are not going to account for the lack of drive..
it IS something transmission related..
what exaclty it is, I can't say without driving it.
TC would be a good guess, but without a "professional" checking it, it's just that. A guess.
