Shuddering - Bucking after settling of RE6200

So 1st off i wasnt sure about OEM tech forum or modified, but non of the parts involved [I think] are oem anymore.

So at highway speeds of 65-75mph i get crazy bucking and shuddering [I am not sure exactly how fast because i regeared to 4.88's and didnt change the speedo gear yet.] This is under throttle and some times gets bad enough that i wont even try to accel through it. Im at about 2500RPM when driving at .5 throttle on the Highway to keep speed. If i want to pass i can throttle up and the Rpms go to 3500 ish then will stay there if i want to keep that speed. but if i want to slow down abit then it will dump back into OD @ 2500 rpm. Not sure if thats normal with what else is going on.

The shuddering is clearly a backward and forward and a little bit of up and down too. i can see it because i have a Warn rockcrusher front bumper with grille guard that i can see it moving up and down.

I have just gone to a RE6200 hybrid with the lower springs and coils. I am using it with the Teraflex shackles in back and a ACOS's in front. The lift height is about 5.5" true. It has settled alot with the front bumper [Heavy as hell] and the rear tire carrier too.

The lift has dropped about 1" from its fresh from bieng installed state. i was shooting for around 5".

I have the T-case drop kit installed AND the AA SYE with a TW drive shaft here:
http://www.4x4groupbuy.com/store/advance-adapters-slip-yoke-eliminator-drive-shaft-p-115.html
I am also using shims with the leaf packs.

I am trying to throw that all out there mostly because i wasnt sure about the Drivetrain situation and useing the TCASE DROP and an SYE.

All my searching concluded that i dont need to or should not have both on there. But i didnt see that it would cause this problem. I thought that maybe since the ride hieght had changed it would change the behavior of the driveline...PHEW mouth full. and yeah im not a mechanic.


Also

Soooo things that i read when i searched this subject that where possibly related are [OEM techish]:

I have within 6-9 months old:
TPS
CPS 's
O2 sensors
Cat

Steering is Currie HD correctlink, and i have yet to Flip My TRE, tha angle isnt very good as is, but i thought that the TRE flip would only gain me droop/drop, not stop "other problems" like shuddering down the highway.


Finally if you made it through all that thanks.

Sorry for not having figured some of this out before guys..


:doh: :gag:

Thanks
Aaron

Def don't need to drop the TC with a fixted output. at 5"

thats what i thought.. thats the dumbassness. thanks

agreed, get rid of the TC drop - its putting more stress on your motor mounts (albeit, a small amount) but still...any unneccesary stress will cause problems.

Good luck, hope that fixes your problem!!! Keep us posted, would be good for reference in the future. Good job on posting ALL of your info like that...

Make sure your pinion angle is still set a little below your driveshaft. With shims and shackles your pinion could pointed right at your driveshaft or even be angled above. Under load, axle wrap would push your pinion higher and could be making things screwy. Not really sure if this would cause "death wobble" but I thought I would point it out since you have both the shims and the shackles.

Oh, and I agree on getting rid of the TC drop. Not needed at that height with an SYE.

Thanks guys.. will remove ASAP and post changes...

A