I took the photos before tightening everything down. Everything is tight and torqued to spec. The photos were intended to show the double-double CV joint. I was going to take a pic of it on the ground but was too excited to put it on and drive vibration free. Wish it was loose because that would be an easy solve!
good to hear. With the drive shaft not bolted on tight it's hard to get a good idea of how aligned the pinion flange is to the t-case. If multiple drive shafts, some who have been proven to work, haven't worked on your truck it is likely a pinion angle alignment issue.
In my opinion, If you want to keep AWD and not have vibrations you have to settle for a lift height and solution that provides that. Otherwise part time the t-case and do what you want.
good to hear. With the drive shaft not bolted on tight it's hard to get a good idea of how aligned the pinion flange is to the t-case. If multiple drive shafts, some who have been proven to work, haven't worked on your truck it is likely a pinion angle alignment issue.
In my opinion, If you want to keep AWD and not have vibrations you have to settle for a lift height and solution that provides that. Otherwise part time the t-case and do what you want.
Thanks, appreciate the input and yes the the pinion angle could be the potential issue.
Having said that, there seem to be a ton of people who run this lift and have no issues.
I have a buddy who has the exact same truck, same lift, same bumper, etc - they are practically identical, and has no vibes whatsoever with running the single CV Landtank DS from Wits (ie yours). I tried his DS and had a ton of vibration. So it has to be something else other than the lift height/pinion angle?
Thanks, appreciate the input and yes the the pinion angle could be the potential issue.
Having said that, there seem to be a ton of people who run this lift and have no issues.
I have a buddy who has the exact same truck, same lift, same bumper, etc - they are practically identical, and has no vibes whatsoever with running the single CV Landtank DS from Wits (ie yours). I tried his DS and had a ton of vibration. So it has to be something else other than the lift height/pinion angle?
Also the same arms? If so I’d confirm that the hub to fender is the same and if so I’d have to believe it’s not a drive line issue as far as alignment.
I have a same 3 slinky lift on one of my with 37, single side dc, and caster plate. And i have no problem at all. Also check your transmission mount but again i have the same old mount on 220k truck.
What is the measurement from the center of the front hub to the underside of the fender? My 2.5" plates are expected to not vibrate with the stock shaft for lifts in the 2-3" range. And that is actual lift not what's on the manufacturer's label.
Took me a while to get to the science of a cardan shaft, I had the same problem for a long time, I do not have double-double CV as you do, I have CV just next to TC . double-double that can be your problem.
I can't see your angles, but the key is that your vibration cancelation point needs to be right on the double CV center (see image) if it is elsewhere it will vibrate. I re-did my caster 3 times till I got 90* in front.
Get a set of Chasis Ears and attach the mics to your transfer case and rear diff. You'll hear the vibration in the section having the issue right away. This is the quickest way to diagnose the problem and will save you a bunch of time and money. If I were to guess based on what you have said above, you might have too much play in the bearing in the nose of your transfer case. If so, you'll hear it with the chasis ears. Any reputable mechanic will have chasis ears. This is not uncommon when you lift a vehicle because it changes the angle that the bearing operates at with the drive shaft.
It sounds like you addressed the most common culprit, the front drive shaft that is typically eliminated with a DC shaft.
However, there is a possibility that the rear DS is causing what you are feeling
I chased a similar issue several years ago with a Slee 4” lift and finally brought both my drive shafts (Front DC and stock rear) to a very reputable driveline shop and had both phased and balanced and it disappeared.
You can search (yes I hate it when people tell me this) and there are probably the threads that put me in this direction.
Also, can you remove the rear DS (since you have the 7 pin mod and center diff switch) and drive to see if there is a difference, same as you tested the front Or swap your buddy’s Rear DS and even wheels/tires to further track down the source of the issue.
Any idea what the caster reading was before the new lift and after?
Good luck, I fought this for some time and agree, it can be very annoying.
OP: Did you try removing the rear DS, like mentioned above? I just went from Slinky intermediates to heavies in the rear and I'm not getting vibration when I didn't have it before. I'm betting it is rear DS u joints. When I get the u joints swapped in, I can update this thread to let you know if if makes a difference.
My bet is a bearing somewhere. Try some chassis ears as mentioned above to help narrow down your efforts.
My measurements on Dobinson’s 4”coils are 25.25” center hub to bottom of FENDER (I don’t have flares). Slee plates and DC shaft. My rear shaft has about 30 dents in it and everything is nice and smooth.
When I didn’t have the DC shaft my vibrations happened when I let off the gas at any speed or under steady cruising. It didn’t vibrate under acceleration. That doesn’t mean anything to you, but it’s a data point.
Tengo el mismo problema con las ruedas dobinson de 6 "y 37, no cambio los brazos, no sé mucho sobre mecánica, la solución del mecánico es bajar un poco la transmisión, espero que se resuelva
Took me a while to get to the science of a cardan shaft, I had the same problem for a long time, I do not have double-double CV as you do, I have CV just next to TC . double-double that can be your problem.
I can't see your angles, but the key is that your vibration cancelation point needs to be right on the double CV center (see image) if it is elsewhere it will vibrate. I re-did my caster 3 times till I got 90* in front. View attachment 2328212
OP: Did you try removing the rear DS, like mentioned above? I just went from Slinky intermediates to heavies in the rear and I'm not getting vibration when I didn't have it before. I'm betting it is rear DS u joints. When I get the u joints swapped in, I can update this thread to let you know if if makes a difference.
The rear DS has brand new u joints and hardware installed at the same time as the lift. Rebalanced also. But I am going to pull it this weekend and test. It has been a busy week, haven’t had any time to touch it.
