Do I need adjustable control arms for an aftermarket driveshaft on the Mopar lift?

[Spank]

My rear OEM driveshaft is slowly dying after beating it to death and forcing it to push 37s. I've got an Adam's replacement on order, but I'm curious if I need to replace the upper control arms for the pinion angle. I'm running the Mopar 2" lift kit, but I've had it for almost 3 years, so it's definitely settled. Eyeballing it, the rear diff and the OEM driveshaft look good and in line together, but eyeballs don't always cut it.

Sponsored

 

[Sheepjeep]

the rear pinion should be pointing straight at the output of the tcase, you do not need to be super accurate but it doe help to be close

the front ideally would be the same as the rear (pinion pointing at tcase output) but caster angle wins the order of importance so you should adjust the front for proper caster than getting the u joint straight. If you still have a working FAD then the front really does not matter as the front shaft will not spin in 2wd

that being said do the driveshafts first see how it all sits then get control arms to fine tune if need be

 

[Spank]

Yeah, I know the front will definitely need adjustable LCAs when I replace that DS, but it's surprisingly in decent shape so I'm not jumping on it at the moment. The rear is toast, though. I'm just wondering if anyone else has replaced their DS while running the Mopar lift and needed to swap out anything else.

 

[JRINGO77]

To me that lift should've come with either new adjustable track bars or relocation brackets to get the axles centered again. Not sure why you think you need new LCA because the DS is shot? Or why do you think the DS is shot? They really don't have anything to do with each other. Front DS tends to be the one with the harsh angle at the T case especially lifted rear would tend to be pretty mild angles if any as was already suggested.

 

[Spank]

To me that lift should've come with either new adjustable track bars or relocation brackets to get the axles centered again. Not sure why you think you need new LCA because the DS is shot? Or why do you think the DS is shot? They really don't have anything to do with each other. Front DS tends to be the one with the harsh angle at the T case especially lifted rear would tend to be pretty mild angles if any as was already suggested.

I'm replacing the rear because my OEM DS is dying a slow and painful death. I managed to tear the boot sometime earlier this year. I'm not concerned with axle centering as I've already got adjustable trackbars and I'm not focused on the front DS or LCAs at this time.

 

[JRINGO77]

Gotcha...I'd say you don't need new rear LCAs I don't think this had anything to do with DS going out unless you just think they're worn out. An upgrade to a DS with U joints instead of those CV style joints would probably be a worthwhile upgrade and sounds like you already have one on the way so you're probably good to go.

 

[Spank]

Gotcha...I'd say you don't need new rear LCAs I don't think this had anything to do with DS going out unless you just think they're worn out. An upgrade to a DS with U joints instead of those CV style joints would probably be a worthwhile upgrade and sounds like you already have one on the way so you're probably good to go.

I think you might have misread the conversation. I'm not looking to replace the LCAs in the rear; replacement LCAs would be a consideration for the front, but my front DS seems to be fine for now. If I need to tweak the pinion angle for the rear, I'd replace the UCAs. That's what I'm asking: if anyone running the Mopar lift who has replaced their rear DS needed to do so.

 

[Roky]

Yeah, I know the front will definitely need adjustable LCAs when I replace that DS, but it's surprisingly in decent shape so I'm not jumping on it at the moment. The rear is toast, though. I'm just wondering if anyone else has replaced their DS while running the Mopar lift and needed to swap out anything else.

Rear DS should be plug and play.

 

[Spank]

Rear DS should be plug and play.

I thought so, too, considering the pinion angle is virtually the same between the DS and rear diff, but I have a feeling it isn't anymore.

I've been running the DS for roughly a month now and have developed a light vibration I feel on both pedals and the steering wheel. It's consistent regardless of speed or RPM and I can't find any issues with the front end (ball joints, drag link, etc.) that would cause this.

 

[Roky]

I thought so, too, considering the pinion angle is virtually the same between the DS and rear diff, but I have a feeling it isn't anymore.

I've been running the DS for roughly a month now and have developed a light vibration I feel on both pedals and the steering wheel. It's consistent regardless of speed or RPM and I can't find any issues with the front end (ball joints, drag link, etc.) that would cause this.

Do you have a new aftermarket rear drive shaft?

 

[Spank]

Do you have a new aftermarket rear drive shaft?

Yup. It's an Adam's. I'm gonna get adjustable upper control arms. Was just hoping I could get away with not having to.

 

[Roky]

Yup. It's an Adam's. I'm gonna get adjustable upper control arms. Was just hoping I could get away with not having to.

I have Adams front, and haven’t had any issues with it, but moto 21 had a bunch of trouble with his being out of balance. Something to check out. You wouldn’t think twice about that kinda thing before last year, but we live in a different world now . Quality control seems to be a thing of the past.

 

[Spank]

I have Adams front, and haven’t had any issues with it, but moto 21 had a bunch of trouble with his being out of balance. Something to check out. You wouldn’t think twice about that kinda thing before last year, but we live in a different world now . Quality control seems to be a thing of the past.

This isn't the front DS, it's the rear. But yeah, I know what you mean about quality control.

 

[Roky]

This isn't the front DS, it's the rear. But yeah, I know what you mean about quality control.

Yeah, I realize it’s the rear, I was just speaking to the potential problem in the company. Did you get the 1310 or 1350? And do you have pic of rear pinion ? Also can you put the old one back in to confirm we’re barking up the right tree, lol.

 

[Spank]

Yeah, I realize it’s the rear, I was just speaking to the potential problem in the company. Did you get the 1310 or 1350? And do you have pic of rear pinion ?

I got the 1350. Other than the pinion nut on the diff being damn near impossible to get off, the install was easy. Everything bolted on nicely and this thing drove nice and smooth for a good solid month. I figured any driveline issues with regards to balance or pinion angles would've shown up a lot sooner.

Yeah. Here is the rear pinion as well as the angles on both the DS and the rear diff.

Honestly, I don't even know what I would adjust the control arms to.

Sponsored