I need some help. I have a 2006 Mega Cab and it has a vibration/shutter in the rear end. This only happen when you take off from a complete stop with the front wheels turned. Any ideas?

 

are you in 4wd?
do you have a LSD rear end? have you ever changed your rear diff fluid?

 

We covered the rear diff problem yesterday with a 1500 which was likely due to not enough or no Friction Modifier in the fluid of the rear diff.
The 2500/3500's which include the Megacab do not require any additives in the rear end. Now you could have old fluid as they need to be changed regularly.
few questions:
How many miles do you have?
Does this happen with the bed empty, loaded, towing?
4wd or 2wd?

I do know there was a few TSB's regarding driveline shudder in 2wd's due to the center support bearing and also from being loaded and towing near the GVWR.

 

good point, i fogot mega cabs have the 2 piece driveshaft. (never worked on one)
and yes we did cover the additives yesterday haha

 

truck is a 4wd. It happens with the bed empty, haven't towed with it yet.
checked the miles 42,000. Don't know if it has ever been changed.

 

I would first reccomend getting the gear oil changed first and then diagnose after if you have the same problem. Changing the fluid should be done anyways if you are unsure as it's due in relatively short intervals.

 

can someone link me to some more info about that TSB? or the center support bearing? i cant seem to find much on it.

 

what gear oil do you recommend? Do i need to change the oil in the transfer case also?

 

If you have these issue's, you should check your pinion angle as you can use shims to get back in spec if out. Maybe Weedahoe can look up the pinion angle specs?? But first order would be a fluid change.
If you have moisture in the diff fluid it will cause similar problems with the 2500/3500 helical LSD design. It's a tempermental carrier.

i double checked...I only have front/rear alignment specs. No pinion angle stuff.

 

Looking at Amsoil Sever Gear 75W-90, but can't find the capacities for the rear diff. or transfer case. Would it be ok to use 75W-90 in the transfer case?