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Just curious as to how you all have addressed the driveline when you lifted your truck. I'm having a hell of a time with takeoff shudder and vibrations at 25mph and 45mph. It seems like I'm the only one, as more and more people lift their trucks.
A little background... I'm at 8" front Rize 4-link and around 6" rear lift, using "traction-blocks" from OUO. It's a block with an incorporated traction bar. No axle wrap. The carrier drop is also their unit. It is fully adjustable from almost stock height to around 8" down. I'm also running an '04 carrier bearing because of the stiffer rubber. Reading on other forums, the 08's have been a real b!itch to dial in because of driveline shudder even on stock trucks with 5th wheels & campers. I think I'm one of the "lucky" ones.
I'm wondering how many of you who have lifted and have shimmed the carrier actually MEASURED any angles for your drivelines. I'm trying to set this up with the "3 degree max ujoint angle" rule and it's not working out. Are you guys just dropping the carrier and not worrying about the tcase ujoint angle at all? My pinion sits at 12 degrees up, and tcase at 6 degrees down (according to gravity, my angle finder, and the driveway). That leaves a 6 degree difference to be compensated for. Ideally, 2, 2, 2, for the 3 joints (tcase, carrier, pinion) but it doesnt work that way in practice because of length differences in the 2 sections of the driveshafts. If I just drop the carrier, I can soften a lot of the 25mph and 45mph vibes, but at the expense of the tcase ujoint which will sit at 6 degrees, and almost zeroing out the carrier and axles joint angles. Nothing cures the take-off shudder though. I need a stock truck to measure for reference, but I'm almost certain that from the factory, the trucks are set up at the 3 degree maximum at the tcase end. So everyone shimming MUST be way over that.
So I guess the question is... are you guys just shimming to make the driveshaft as straight as possible and not measuring angles?
Dana literature (note PDF pages 12 for max angle and rpm, and 14 for 2-piece driveshaft setup):
http://www2.dana.com/pdf/J3311-1-HVTSS.PDF
Links:
One Up Offroad Traction Blocks
One Up Offroad Drive Line Drop
Pics:
A little background... I'm at 8" front Rize 4-link and around 6" rear lift, using "traction-blocks" from OUO. It's a block with an incorporated traction bar. No axle wrap. The carrier drop is also their unit. It is fully adjustable from almost stock height to around 8" down. I'm also running an '04 carrier bearing because of the stiffer rubber. Reading on other forums, the 08's have been a real b!itch to dial in because of driveline shudder even on stock trucks with 5th wheels & campers. I think I'm one of the "lucky" ones.
I'm wondering how many of you who have lifted and have shimmed the carrier actually MEASURED any angles for your drivelines. I'm trying to set this up with the "3 degree max ujoint angle" rule and it's not working out. Are you guys just dropping the carrier and not worrying about the tcase ujoint angle at all? My pinion sits at 12 degrees up, and tcase at 6 degrees down (according to gravity, my angle finder, and the driveway). That leaves a 6 degree difference to be compensated for. Ideally, 2, 2, 2, for the 3 joints (tcase, carrier, pinion) but it doesnt work that way in practice because of length differences in the 2 sections of the driveshafts. If I just drop the carrier, I can soften a lot of the 25mph and 45mph vibes, but at the expense of the tcase ujoint which will sit at 6 degrees, and almost zeroing out the carrier and axles joint angles. Nothing cures the take-off shudder though. I need a stock truck to measure for reference, but I'm almost certain that from the factory, the trucks are set up at the 3 degree maximum at the tcase end. So everyone shimming MUST be way over that.
So I guess the question is... are you guys just shimming to make the driveshaft as straight as possible and not measuring angles?
Dana literature (note PDF pages 12 for max angle and rpm, and 14 for 2-piece driveshaft setup):
http://www2.dana.com/pdf/J3311-1-HVTSS.PDF
Links:
One Up Offroad Traction Blocks
One Up Offroad Drive Line Drop
Pics:

