Offroaders: recommendations of shop to help diagnose rear driveline vibrations?

[qmikep]

Hi guys, i just finished up a project I have been working on . Basic rundown is the truck is a 92 dodge w250 cummins 5 spd. Dana 60 front , I swapped a newer 14 bolt rear in woth an arb locker, 4.10 gears and 37” toyos .

Chevy 52” rear springa in front chevy 64” apringa in the rear and shackle flip.

Just got a couple of short droves on it and unfortunately i have a fairly decent rear drivetrain vibration above ~50 mph.

Driveshaft is in phase and u joints are good no play.

Im looking for a shop that has experiance in modified trucks, that is very good at differential installs and trouble shooting ,hopfully near the indianapolis area.

Been trying to trouble shoot this myself but i need help as I have to move cross country and this thing
Need to be drivable asap

Thanks for any advice.

 

[Butch627]

If we had some idea where you are located that might help with reasonable recommendations

 

[qmikep]

NE side Indianapolis

 

[Gary119]

Are you sure the vibration is in the rear?

Joint & Clutch....Kentucky Avenue does driveshafts (out of vehicles)

 

[halfmileharry]

Tight U-Joints can cause a vibration if they're not moving freely. Check the rear yoke nuts as well. Over 50mph I'd be looking at tires (aggressive I'm betting), lug nuts loose, wheel weights thrown off, etc.
Matching drive axles are a must. I've had issues with 4:10/4:11s before and it took all day long to figure it out.
You can mark the drive shafts and tires with crayons and slowly and methodically count revolutions to make sure you're matching correctly.
Lots of possibilities on project toys. Joint and Clutch have been around a long time.

 

[qmikep]

Are you sure the vibration is in the rear?

Joint & Clutch....Kentucky Avenue does driveshafts (out of vehicles)

Absolutely, joint and clutch just lengthened and balanced the rear shaft actually , so pretty sure its not the issue.

 

[qmikep]

Tires are aggresive however the vibration is only under load. If I get up to 55-60 and hit the clucth and coast at that speed it goes away.

 

[qmikep]

My guesses are either driveline angle is slightly off, maybe .5 degree (i am not confident in the either of the angle finders i have, but have tried 3 differnt ones and my angles look good).

Or ring and pinion isnt quit right ( more betting on this as the gear set was used and its my first time seting them up,then again my backlash is well within spec , an my pattern looks pretty darn good, (according to pirate4x4.)

 

[churchmouse]

I had a serious issue such as yours in my last lifted truck. The rear shaft from the transfer case was to steep an angle. I had Paterson put a Velocity joint in the shaft by the T-case and problem solved.

 

[blackenedman]

I had a serious issue such as yours in my last lifted truck. The rear shaft from the transfer case was to steep an angle. I had Paterson put a Velocity joint in the shaft by the T-case and problem solved.

Patterson, aka accurate driveline and machine, gets my vote. They are pros, will take good care of you.

 

[qmikep]

Cool will give them a call

 

[halfmileharry]

Cool will give them a call

Find the issue? Cure?

 

[easy]

I would bet your rear pinion angle is wrong. If so the 'fix' is the double cardion/CV joint plan.