Odd deceleration grind/noise
- Thread starter Azonic84
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since I have gotten rid of other noises, leaks, and new tires, I hear a similar noise if the windows are up and radio/etc is off. Reminds me of a set of gears meshing together or a chain/sprocket noise with a touch of whine/grind thrown in.
The u-joints are tight, and greasing them does not change it, recent knuckle rebuild and all good there with plenty of grease in the knuckle, properly tightened wheel bearings.
Seems to be more noticable with the winch in the front bumper now, and it mainly happens downhill. Perhaps there is some angle that is too low sort of like when you get an angle from a lift that requires a DC drive shaft??
I have an OME stock height lift/springs, with stickbug from the ARB bumper, winch, heavy battery up front.
The u-joints are tight, and greasing them does not change it, recent knuckle rebuild and all good there with plenty of grease in the knuckle, properly tightened wheel bearings.
Seems to be more noticable with the winch in the front bumper now, and it mainly happens downhill. Perhaps there is some angle that is too low sort of like when you get an angle from a lift that requires a DC drive shaft??
I have an OME stock height lift/springs, with stickbug from the ARB bumper, winch, heavy battery up front.
I def. just got used to the noise....but it took awhile for sure, along with a meaty pair of 35's to drown it out a bit. lol. I tend to obsess about stuff and that grinding was on my list for awhile until I changed the u joints, and searched on mud like a mad man. I wouldnt mind doing a DC driveshaft but damn are they expensive!
- Thread starter
- #24
Well, no change in noise yet, I am going to be installing a BIOR tube bumper with no winch (yet) in a few days. I will note any changes. Still freaks me out! 
It couldn’t be a torque converter could it? I haven’t noticed any slipping or anything though.
It couldn’t be a torque converter could it? I haven’t noticed any slipping or anything though.
- Thread starter
- #25
Well I may have solved the problem. It was a completely ridiculous thing too. My passenger side front tire had about 10psi more in it than the others and when I equalized them the noise has all but vanished.
Now I am afraid of the accelerated wear that noise has caused....
Now I am afraid of the accelerated wear that noise has caused....
Just installed an IronMan bumper and got my winch mounted only to be greeted with a wonderful grinding noise in the last couple weeks.
4" lift. Old Man Emu J-springs and L-Shocks
Thanks for the helpful post! I'll report back if I can make it go away.
4" lift. Old Man Emu J-springs and L-Shocks
Thanks for the helpful post! I'll report back if I can make it go away.
Funny, I've been dealing with a similar noise for the last few months. Started after I installed an ironman 2" lift, constant load rear springs and performance fronts. The noise didn't start immediately. It started after I installed some 2.5 degree caster plates. I installed the plates because the truck started wandering/following grooves/darting around. The problem started shortly after, sounds like a rattle/whirring sound upon deceleration or light throttle, usually at speeds over 50mph. I replaced the front u-joints. Noise persisted. I then rebuilt the front end, all new bearings. Noise was still there. If I remove the front drive shaft and lock the center it is dead quiet. A couple of people have told me that the front diff may be going out and that the noise is gear wine. It doesn't happen consistently, it's totally random. I got a replacement front 3rd and plan on swapping them out but it's been over 100 degrees for the last few weeks and I don't have any shade to work under.
Would a DC front drive shaft be needed for such a small lift? Would there be any problems with running a DC drive shaft on a 2" lift? (it actually lifted the truck around 3.5" due to the original sagging springs)
A mechanic that I trust told me to drive it until the noise gets real bad, that's the only way to really track it down. Otherwise I'll be searching like a madman for the source and will end up changing tons of stuff out trying to find it. He let me borrow his brand new chassis ear system, It's just been too hot to go out and mount the mics up and listen for it.
Would a DC front drive shaft be needed for such a small lift? Would there be any problems with running a DC drive shaft on a 2" lift? (it actually lifted the truck around 3.5" due to the original sagging springs)
A mechanic that I trust told me to drive it until the noise gets real bad, that's the only way to really track it down. Otherwise I'll be searching like a madman for the source and will end up changing tons of stuff out trying to find it. He let me borrow his brand new chassis ear system, It's just been too hot to go out and mount the mics up and listen for it.
Well I may have solved the problem. It was a completely ridiculous thing too. My passenger side front tire had about 10psi more in it than the others and when I equalized them the noise has all but vanished.
Now I am afraid of the accelerated wear that noise has caused....
ah man, if only. I have nearly constant pressure all the way around, and the noise is still there.
Thinking about trying heavier diff fliud.
while I don't have a real lift, I do have the OME stock height setup and a heavy front end.
About to go on a beach trip, so the back will be loaded down and it should sit level. Will see if the noise goes away or changes.
About to go on a beach trip, so the back will be loaded down and it should sit level. Will see if the noise goes away or changes.
I had a speed related noise & vibration that ultimately was the main shaft bearing in the front differential. It could be felt by grabbing the front drive shaft and jerking it up and down. Replacing the bearing and rebuilding the u-joints solved the problem.
I have the same issue, with a 3" lift.. Thanks for all the suggestions time to dive in and find out why.
Me too - 3" lift as well - chalking it up to change in angles - have had several good guys look at it and cannot pinpoint source for sure. Have to replace pinion seal, maybe even the bearing if it needs it - will know when I get in there. Maybe I will find something there ........ Let's all keep in touch and hopefully one of use will find a solution - even though it could be a different problem for any one of us 
I just got my new tires mounted and the shop threw my truck on the alignment rack to check it out. After the Iron Man 2" lift, that actually raised it 3.5" from where the sagging springs were, I installed 2.5 degree caster plates. My caster is now exactly 3 degrees, I don't know what it was prior to the lift though. The truck drives fantastic, except for the annoying noise. It's a good thing I got some noisy tires, I can hardly hear the whine now.
Noise still present for me as well.
I just tried adding a good bit of moly lube with the Slee spindle tool, easy to use and the knuckles are not low at all. Reset the wheel bearing preload while in there.
Noise still exists, maybe a little worse as time goes on.
Maybe the front wheel bearings, though they felt like new when doing the front axle rebuild about 7k miles ago. Maybe front driveshaft U joints, though they are properly greased and do not seem loose at all, and rotate around fine with everything in neutral.
Could be spindle bushing too, but those were looking perfect during the axle rebuild too, and got greased during re assembly. The bushings pull grease out through the spindle too, when I reset the bearings after about 1k miles post axle service, I left the area around the outer lock nut empty and it had filled up with moly grease when I took it apart this past weekend.
I just tried adding a good bit of moly lube with the Slee spindle tool, easy to use and the knuckles are not low at all. Reset the wheel bearing preload while in there.
Noise still exists, maybe a little worse as time goes on.
Maybe the front wheel bearings, though they felt like new when doing the front axle rebuild about 7k miles ago. Maybe front driveshaft U joints, though they are properly greased and do not seem loose at all, and rotate around fine with everything in neutral.
Could be spindle bushing too, but those were looking perfect during the axle rebuild too, and got greased during re assembly. The bushings pull grease out through the spindle too, when I reset the bearings after about 1k miles post axle service, I left the area around the outer lock nut empty and it had filled up with moly grease when I took it apart this past weekend.
There are a number of "Grrrr" threads you can search, all reporting the same symptoms. Seems most likely traced to the increased front driveline angle. Mine did not make the noise before lift, and makes the noise after lift, as many others reported. I doubt anything is "eating itself up"...it's more of a transient vibration, at a particular RPM range, which could be fixed with a DC joint in that location. I just grease mine at every oil change, and the U-joint still feels tight.
Perhaps I need to check the endplay of my front diff input shaft?
I got a spare set of drive shafts and had new u-joints installed and got them balanced. The noise is still there. The other day I checked my front diff oil and it was caramel colored and chunky, didn't even smell like 90wt anymore either. I changed the oil out to a different brand. After driving around for a while I checked the oil and it appears to be doing the same thing again. The oil looks like it was contaminated with water, but I've never driven through any. I'm pretty sure its a bad front diff. If it wasn't such a pain I'd have pulled my front axles and swapped the diff by now. When it cools off some more I'm gonna do it.
Same exact issue
When I am loaded with gear no grinding noise.. but when empty.. Its a grinding noice.. So I guess start wiht checking u-joints.. and go from there? 
When I am loaded with gear no grinding noise.. but when empty.. Its a grinding noice.. So I guess start wiht checking u-joints.. and go from there?