Long standing pulsating vibration issue that I need help solving

[Wes Harden]

Some time in the past it has rubbed, that can cuase the outer ring to move out of balance on inner hub

 

[tarussell]

I see rub mark on the dampner as well. When the engine mount sag they can rub on the cross member.

The ground bolt in 1st picture doesn't look tight enough to me. It may be bottomed out.

Damn good eye on catching the possible ground bolt issue !

All ex-wrench turners still look at everything and not just the main problem - I still can’t walk past a car in the parking lot and not notice the wear pattern on the tires.

 

[Ramba_ral]

Better shot of the balancer. Also found my water pump is wobbly

 

[imiceman44]

Better shot of the balancer. Also found my water pump is wobbly

View attachment 499516

That water pump wobble at 3k rpm definitely can shake the truck

 

[Ramba_ral]

welp replaced the pump and harmonic balancer. vibration is still there. guess the only thing left is the transmission

 

[dyeager535]

The transmission being the cause of a vibration, with no other symptoms, seems to me to be a very unlikely culprit.

I'm not a transmission guy, but no weird shifting or sounds, and a long-lasting vibration, doesn't seem likely to be an internal trans problem.

 

[kennyw]

The transmission being the cause of a vibration, with no other symptoms, seems to me to be a very unlikely culprit.

I'm not a transmission guy, but no weird shifting or sounds, and a long-lasting vibration, doesn't seem likely to be an internal trans problem.

A failing torque converter can cause these symptoms. Even a slightly out of spec one way clutch internal to the transmission can as well. Unfortunately, finding a minor problem inside a transmission requires major labor.

 

[Ramba_ral]

I thought i could be the torque converter as well so i had it replaced along with a new flexplate

I agree the transmission is unlikely but im running out of things to check

 

[eodcoduto]

LS swap, someone had to say it. But have you checked your axle? I had a bent axle shaft that caused all kinds of weird vibrations and the RPM was never consistent. I am replacing the other one this week because it runout too.

 

[imiceman44]

LS swap, someone had to say it. But have you checked your axle? I had a bent axle shaft that caused all kinds of weird vibrations and the RPM was never consistent. I am replacing the other one this week because it runout too.

I had that on my 97 suburban.
It drove me crazy, finally one day I decided to check if the wheel was the problem, I jacked it up and ran it and one wheel was wobbling, I swapped sides and it stayed the same.
Pulled the drum and sure enough the axle flange was wobbling.
Changed the whole axle.

 

[Ramba_ral]

LS swap, someone had to say it. But have you checked your axle? I had a bent axle shaft that caused all kinds of weird vibrations and the RPM was never consistent. I am replacing the other one this week because it runout too.

With how much money I spent on this rig i should of.

Both axles were replaced when rear was rebuilt

 

[MEMO43]

I know this is an old post,
but did you ever figure out what the cause was, I have a similar issue with my rig.

 

[Ramba_ral]

No not yet. I'm just now digging into pulling the transmission

i tried to push teh converter back and it wont budge at all so im thinking that its not installed right.

 

[Ramba_ral]

Pulled the transfer case and found a lot of micro cracks on the rear output

 

[imiceman44]

Pulled the transfer case and found a lot of micro cracks on the rear output

View attachment 511043

View attachment 511044

View attachment 511045

That is somewhat common and I have never had problems from it.
It's from the casting process, and it's untouched

 

[Ramba_ral]

Here's a video of the converter and flex plate

The converter is disconnected but won't move back into the transmission

View attachment 20250802_112629.mp4