Diagnosing an Interesting Noise
11-14-2010, 03:59 PM
#1
JK Newbie
Thread Starter
Join Date: Oct 2007
Location: Albuquerque
Posts: 57
Likes: 0
Received 0 Likes
on
0 Posts
Diagnosing an Interesting Noise
So I have a new drivetrain related noise for all you detectives out there:
'07 Rubi Unilimited 6 spd - 37's, Tera 4", Tera steering stuff, JE-Reel 1350 Shafts - 50k miles with alot of hard wheeling.
The noise is metallic in nature - kind of like a slowly rotating glass jar of BB's.
Most evident at 55+ mph - no change with application or removal of throttle - still there when coasting in neutral.
Appears to be coming from the front of the console area, though it doesn't transmit through either shifter.
Does not vary with throttle application, it only changes with increases or decreases in absolute speed.
Things I've done:
Shifting into 4 Wheel High range completely eliminates the sound. Shifting back to 2 wheel drive and it comes right back.
Taking the front drive shaft off completely eliminates it.
The front u joint on the JE Reel shaft (with about 50k miles on it) had a rough spot when spinning one cap so I replaced it. The CV feels butter smooth through its range of motion. Greased all the ujoints and reinstalled - noise came back.
4Wheelparts threw it up on a rack and spun it up with the wheels in the air and they say its the front CV.
The front shaft slip joint has a fair amount of lateral play to it - its always seemed to be a little too extended at ride height for me.
My thoughts on the source:
Its seems to be either the CV in the front shaft (which I sort of doubt), the slip joint splined section, or the output section of the t-case (which doesn't seem to have any lateral play when the driveshaft was off). The noise "only" happens when the front shaft is spinning (because of rotation of the front tires) but not being driven with power (when I switch to 4 wheel drive).
What do you think?
I'm going to pull the shaft and send it up to JE Reel, but the CV rebuild is $175, so I may have them check the splines first on the slip joint. I'm thinking that passive rotation of the shaft from the front axle is allowing that slip joint play to rattle back and forth at speed (with no real power applied to it).
'07 Rubi Unilimited 6 spd - 37's, Tera 4", Tera steering stuff, JE-Reel 1350 Shafts - 50k miles with alot of hard wheeling.
The noise is metallic in nature - kind of like a slowly rotating glass jar of BB's.
Most evident at 55+ mph - no change with application or removal of throttle - still there when coasting in neutral.
Appears to be coming from the front of the console area, though it doesn't transmit through either shifter.
Does not vary with throttle application, it only changes with increases or decreases in absolute speed.
Things I've done:
Shifting into 4 Wheel High range completely eliminates the sound. Shifting back to 2 wheel drive and it comes right back.
Taking the front drive shaft off completely eliminates it.
The front u joint on the JE Reel shaft (with about 50k miles on it) had a rough spot when spinning one cap so I replaced it. The CV feels butter smooth through its range of motion. Greased all the ujoints and reinstalled - noise came back.
4Wheelparts threw it up on a rack and spun it up with the wheels in the air and they say its the front CV.
The front shaft slip joint has a fair amount of lateral play to it - its always seemed to be a little too extended at ride height for me.
My thoughts on the source:
Its seems to be either the CV in the front shaft (which I sort of doubt), the slip joint splined section, or the output section of the t-case (which doesn't seem to have any lateral play when the driveshaft was off). The noise "only" happens when the front shaft is spinning (because of rotation of the front tires) but not being driven with power (when I switch to 4 wheel drive).
What do you think?
I'm going to pull the shaft and send it up to JE Reel, but the CV rebuild is $175, so I may have them check the splines first on the slip joint. I'm thinking that passive rotation of the shaft from the front axle is allowing that slip joint play to rattle back and forth at speed (with no real power applied to it).
11-14-2010, 04:33 PM
#2
JK Super Freak
If you know someone that works at a Ford garage maybe you can get a free diag using their Chassi Ears. It is an electronic clip on sound amplifying system to isolate noises just like you have. From what you describe it sound like a t-case problem to me but would not commit to that without using what I described to you. You might be able to duplicate just by having the front axle off the ground and getting real close to the t-case and having someone sping the front tires.