NEED a diagnosis from the experts at MUD: Front DS vibration/noise... (1 Viewer)

[RayW]

I need help diagnosing a strange noise/vibration on low speed uphill acceleration!

Here are the facts:
2006 LC - 78000 miles
AHC set in stock position
Slee diff drop, 33" Michelins, stock rims
Slee skid plate, Slee rear bumper with tire mounted

When I am at a stopped position and begin accelerating WHILE ON AN UPHILL INCLINE I get a serious vibrating sound from the DS front wheel area that sounds somewhat like the vibration of a tire rubbing on a fender. It happens even moreso when I have a load on the hitch and people in the back seat. This occurs in the 8-20 mph range. The sound only occurs on acceleration.

This dose not happen when starting on a level road with no load, nor does it occur when I am turning such as the "clicking" that occurs with a CV joint failing.

It has something to do with the raising of the front of the vehicle(pitch of the vehicle), and the rotation of a part in or around the DS front tire area. The vibration seems to be caused by something rotating.

Anyone else out there heard this issue before? I know the sound of a CV joint going outl and this just doesnt seem to fit. I had the AHC set at the highest point and the sound occurred more often, but I have now set it back to normal and it still occurs.

I have looked around in the wheel well area and nothing seems amiss. Im baffled...

Thoughts? Thanks in advance.

 

[jcrandall]

OP, I have a similar issue, so let me try to resurrect your thread. No responses from anyone. Did you ever determine the cause of this?

 

[RayW]

Take a look at your front drive shaft. Look for any shiny area that may be an indication its rubbing on any other part.

I had a torn bushing which allowed the diff assembly to drop down, causing the front drive shaft to rub when the truck was at a certain angle. Drove me crazy because it sounded like it was always coming from the drivers side front wheel.

PM me and I can send you pics tomorrow night. It was a simple fix for me.

 

[2000UZJ]

Check the end of the CV shafts for the C-Clip and also insect the inner and outer bell housing of the CV by snipping the clamps and slide the boot back. It will require new clamps and grease but it will allow you to take a look inside of the CV's. Does it do it on a lift rotating by hand? Check all mounts and drive shaft areas too. The front diff can develop a lot of play at higher mileage

 

[jcrandall]

Check the end of the CV shafts for the C-Clip and also insect the inner and outer bell housing of the CV by snipping the clamps and slide the boot back. It will require new clamps and grease but it will allow you to take a look inside of the CV's. Does it do it on a lift rotating by hand? Check all mounts and drive shaft areas too. The front diff can develop a lot of play at higher mileage

I have recently replaced aftermarket cv's with oem cv's. No change in this particular sound, but solved some other issues I was having. (C clips are present and sized correctly)
There is relatively new rubber on most mounts and bushings, relatively new upper and lower ball joints, front wheel bearings,tie rod ends, and steering rack.
Homemade body lift kit (1"), with verified tight mounting bolts.
No play in front wheels when jacked up and pulling at 12-6 and 9-3.

My best hack theory is that I have a driveshaft issue like the OP, or a diff issue as you suspect. Any thoughts on how to identify and narrow it down? I lack the experience to tell whether a lot of things are normal by looking.

I haven't been able to replicate the sound with tires in the air (don't have access to a lift, but I have jackstands).

How do you identify slack in the driveline? If the truck is in park, all wheels in the air, and you turn the front driver side wheel by hand, what should happen? Same question in Neutral, etc.

Anyone nice enough to read this, if there's a thread already with these answers I would appreciate a link.

 

[RayW]

SORRY JCR for my delay. I didnt get an alert when you sent me the convo request.

Below is an edited pic of my FRONT driveshaft. A torn rubber bushing caused my front driveline to drop down. When I put the 100 into certain low speed turns at an uphill angle, it allowed the driveshaft to contact the front sway bar causing a rub that sounded like a bump/knock. You can see where I marked the worn area with an arrow...these are the areas that rubbed. The balancing lug on the driveshaft caught most of the wear as you can see from the shiny wear surface.

This drove me crazy for a few months. Once you know where to look, it will be immediately apparent. None of these marked areas on the driveshaft should be shiny or have any wear. If you have this, check the rubber bushings that support the front driveline.

 

[jcrandall]

SORRY JCR for my delay. I didnt get an alert when you sent me the convo request.

Below is an edited pic of my FRONT driveshaft. A torn rubber bushing caused my front driveline to drop down. When I put the 100 into certain low speed turns at an uphill angle, it allowed the driveshaft to contact the front sway bar causing a rub that sounded like a bump/knock. You can see where I marked the worn area with an arrow...these are the areas that rubbed. The balancing lug on the driveshaft caught most of the wear as you can see from the shiny wear surface.

This drove me crazy for a few months. Once you know where to look, it will be immediately apparent. None of these marked areas on the driveshaft should be shiny or have any wear. If you have this, check the rubber bushings that support the front driveline.



View attachment 1266245

Thanks for the pictures, greatly appreciated.

 

[BamaCruzer]

SORRY JCR for my delay. I didnt get an alert when you sent me the convo request.

Below is an edited pic of my FRONT driveshaft. A torn rubber bushing caused my front driveline to drop down. When I put the 100 into certain low speed turns at an uphill angle, it allowed the driveshaft to contact the front sway bar causing a rub that sounded like a bump/knock. You can see where I marked the worn area with an arrow...these are the areas that rubbed. The balancing lug on the driveshaft caught most of the wear as you can see from the shiny wear surface.

This drove me crazy for a few months. Once you know where to look, it will be immediately apparent. None of these marked areas on the driveshaft should be shiny or have any wear. If you have this, check the rubber bushings that support the front driveline.



View attachment 1266245

I had the exact same thing a couple months ago. Thought it was a cv going. Dealer identified a worn bushing and replaced it, noise went away...until yesterday. Same noise of grinding or rubbing on driveshaft has returned. Back I go to the dealer.