Help diagnosing a rhythmic thumping noise when driving.

Doubeleive said:

have you tried jacking it up and putting it in gear to see if you can find the source?
it can be done within reason I just wouldn't try to rev it up much usually with wheels off the ground it will spin up to a slow speed like 10mph or so without even applying any pedal.
that might be enough to determine if it is transmission, transfer case, rear diff, etc
if you don't hear it then it might only be doing it under a load
if is awd then all 4 wheels need to be up
i have done it with wheel chocks and jack stands or just jack stands if all wheels need to be up
and these trucks are tricksters, the sound can carry might sound like it is coming from one place and actually be coming from another......

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fatmonk8 said:

Yes, I jacked up the back and put it in both neutral and in gear. In neutral I spun it myself.

Couldn't hear anything obvious.

As far as I am aware it's only 2wd as I never have it in 4wd, not even auto.

It's got to be something under load.

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fatmonk8 said:

Yes, I jacked up the back and put it in both neutral and in gear. In neutral I spun it myself.

Couldn't hear anything obvious.

As far as I am aware it's only 2wd as I never have it in 4wd, not even auto.

It's got to be something under load.

Click to expand...

Chassis Ears Automotive Electronic Stethoscope Engine Noise Finder 6Channel F1P1 | eBay

This Electrical Stethoscope is a high performance maintenance tool which is particularly suiable for use in machine noise detection. 1 Car Noise Finder Kit. Color: black. Material: ABS.

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Doubeleive said:

I see a kit on ebay for about $50

you attach it at various places, go drive then narrow it down based on the level detected

Chassis Ears Automotive Electronic Stethoscope Engine Noise Finder 6Channel F1P1 | eBay

This Electrical Stethoscope is a high performance maintenance tool which is particularly suiable for use in machine noise detection. 1 Car Noise Finder Kit. Color: black. Material: ABS.

www.ebay.com

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