Question regarding expected issues with a 4.5 inch lift

[Don Bulee]

Do you have a TT? Swapping the DC driveshaft could help but the mml should help for sure. How’d you adjust the pinion angle?

The adjusment of the pinion angle was made by the mechanic... I didn't do it, he told me that it was almost 0 degrees but didn't ask from which section he made the measurements.. the lift was installed and after 10 days or so I added the upper adjustable control arms because of delay in shipping... so I was able to see how the jeep was handling without the upper adjustable control arms and the 4.5 RE lift (with 1.25BL) and damn... it rode like crap... I could hear all the metal suffering below my Rubi..

Yes, I would expect vibes with that much lift and the stock shaft.

So vibration will be there until I change the driveshaft? the MML won't help in the vibration issue? I can live with a small vibration but.... if the MML wont do a thing because the problem is the length instead of the angle.. then there is no point in the MML or is it???

 

[freedom_in_4low]

I have a Rubicon 06 with the 4.5 RE lift, I got the upper adustable control arms to correct the pinion angle and it still have a bit of vibration at 20-30 miles per hour... I haven't installed the DC driveshaft, would that be the reason for the vibration? would a MML could help with the vibration problem?

Yes, I would expect vibes with that much lift and the stock shaft.

The adjusment of the pinion angle was made by the mechanic... I didn't do it, he told me that it was almost 0 degrees but didn't ask from which section he made the measurements.. the lift was installed and after 10 days or so I added the upper adjustable control arms because of delay in shipping... so I was able to see how the jeep was handling without the upper adjustable control arms and the 4.5 RE lift (with 1.25BL) and damn... it rode like crap... I could hear all the metal suffering below my Rubi..

So vibration will be there until I change the driveshaft? the MML won't help in the vibration issue? I can live with a small vibration but.... if the MML wont do a thing because the problem is the length instead of the angle.. then there is no point in the MML or is it???

If by zero he meant straight in line with the driveshaft then it's set up for a DC shaft and a MML might even make things worse. If he meant it was zero degrees from horizontal then an MML might help but I still don't think it'll get you vibe free. 4.5 is just a lot of operating angle, period, even if things are lined up correctly.

 

[imahnu]

The adjusment of the pinion angle was made by the mechanic... I didn't do it, he told me that it was almost 0 degrees but didn't ask from which section he made the measurements.. the lift was installed and after 10 days or so I added the upper adjustable control arms because of delay in shipping... so I was able to see how the jeep was handling without the upper adjustable control arms and the 4.5 RE lift (with 1.25BL) and damn... it rode like crap... I could hear all the metal suffering below my Rubi..

So vibration will be there until I change the driveshaft? the MML won't help in the vibration issue? I can live with a small vibration but.... if the MML wont do a thing because the problem is the length instead of the angle.. then there is no point in the MML or is it???

Yeah if the pinion is at 0 degrees meaning flat with the ground then you’ll definitely have an issue and need to get that rolled up to point directly at the TC output. A MML lift will help with vibes once that happens.

 

[freedom_in_4low]

Yeah if the pinion is at 0 degrees meaning flat with the ground then you’ll definitely have an issue and need to get that rolled up to point directly at the TC output.

But not until he has a DC shaft. Before then, the pinion should be parallel to the t case output.

 

[NOTNSUV]

If you ordered RE's long-arm kit, I installed one years ago onto my last TJ and it was a bad decision. Plus their 4.5" is more like 5.5" in reality. Personally I'd put my $$$ into a different brand of lift.

Jerry is correct. OP RE 4.5" net 5.5". I'll be changing mine out for Currie if I ever stop spending every dime on other LJ "needs".

 

[NOTNSUV]

You have a SYE kit and DC driveshaft on your list right? A good source for those is Tom Wood's custom driveshafts at www.4xshaft.com

P.S. I ran their Monotube shocks and they were terrible with even more terrible offroad control. I had to slow WAY WAY down on bumpy desert roads that I could haul-ass on with my Rancho RS5000x shocks. Their Monotubes road well on the street but they were terrible offroad.

I'm likely mistaken but aren't RE shocks relabeled Bilstein?

 

[Jerry Bransford]

I'm likely mistaken but aren't RE shocks relabeled Bilstein?

I doubt it, my RE Monotube shocks were absolutely the WORST when offroad. They rode great on the highway but offroad they were horrific. No, they were even worse than horrific. A bunch of us would caravan together on bumpy washboard dirt roads heading to our wheeling areas and everyone but me would be doing 40-45 mph without problem. My TJ was out of control at 45 and I had to slow down to 5-10 mph to stay in control with the RE Monotube (their best) shocks. I remember several shocks being significantly better when offroad. My previous Rancho RS5000x shocks were amazing when offroad, I could run off and leave everyone in the dust at speeds that were faster than I liked offroad. It was just nice to be able to go faster than anyone else could with my RS5000x shocks if I wanted to. They made my RE Monotubes look like jokes so they aren't likely to be Bilsteins.

 

[NOTNSUV]

I doubt it, my RE Monotube shocks were absolutely the WORST when offroad. They rode great on the highway but offroad they were horrific. No, they were even worse than horrific. A bunch of us would caravan together on bumpy washboard dirt roads heading to our wheeling areas and everyone but me would be doing 40-45 mph without problem. My TJ was out of control at 45 and I had to slow down to 5-10 mph to stay in control with the RE Monotube (their best) shocks. I remember several shocks being significantly better when offroad. My previous Rancho RS5000x shocks were amazing when offroad, I could run off and leave everyone in the dust at speeds that were faster than I liked offroad. It was just nice to be able to go faster than anyone else could with my RS5000x shocks if I wanted to. They made my RE Monotubes look like jokes so they aren't likely to be Bilsteins.

I visualize your bitter beer face when you're trailing far behind..lol. I've yet to have my 5000x at any significant speed on such roads.

 

[imahnu]

But not until he has a DC shaft. Before then, the pinion should be parallel to the t case output.

Doesn’t he have a rubicon? I could be mistaken but wouldn’t he already have a DC driveshaft and he just needs to swap in the longer one? I could be mistaken though.

 

[freedom_in_4low]

Doesn’t he have a rubicon? I could be mistaken but wouldn’t he already have a DC driveshaft and he just needs to swap in the longer one? I could be mistaken though.

My understanding is that Rubicon has a fixed flange output instead of a slip yoke but it still came stock with a single cardan shaft. So they still need the DC shaft, they just don't need a slip yoke eliminator.

 

[imahnu]

My understanding is that Rubicon has a fixed flange output instead of a slip yoke but it still came stock with a single cardan shaft. So they still need the DC shaft, they just don't need a slip yoke eliminator.

You’re correct! I was able to find a stock rubicon shaft and it has a single joint on each end.

In that case, @Don Bulee you need you need to get the DC installed and get the pinion readjusted afterwards

 

[Don Bulee]

You’re correct! I was able to find a stock rubicon shaft and it has a single joint on each end.

In that case, @Don Bulee you need you need to get the DC installed and get the pinion readjusted afterwards

Thank you all!!! sorry for hijack the thread... you guys are amazing.. according to what I've read the Tom Woods DC would be the best bang for buck right?

 

[freedom_in_4low]

Thank you all!!! sorry for hijack the thread... you guys are amazing.. according to what I've read the Tom Woods DC would be the best bang for buck right?

I've got two of them and I like them. Shawn Wood actually posts here on occasion, he's helped me with stuff over the phone before, earned a lifetime customer from me.

 

[Don Bulee]

I've got two of them and I like them. Shawn Wood actually posts here on occasion, he's helped me with stuff over the phone before, earned a lifetime customer from me.

One last quick question.... if I'm not in the possibility to spend 500 bucks plus installation for the CV drive shaft right now.. I could only add some washers to the transfer case to reduce the vibration right? and if that's so... I would to need to realign the pinion angle after the washers added?

 

[freedom_in_4low]

One last quick question.... if I'm not in the possibility to spend 500 bucks plus installation for the CV drive shaft right now.. I could only add some washers to the transfer case to reduce the vibration right? and if that's so... I would to need to realign the pinion angle after the washers added?

To save money I would encourage you to do the work yourself. It's just wrenching, nothing particularly technical. If you don't have the tools, you could buy what you need for less than you'll pay for labor.

I needed 1" of transfer case drop AND a MML on my '99 TJ to get rid of vibes with only 2.5-3" of lift...and it took 3+ rounds of pinion angle adjustments and test drives to find exactly where it was happy. I did have a non-Rubicon so I had a slip yoke and the driveshaft angle would have been higher than if I'd had a Rubicon...but I definitely would not expect to have vibrations to an acceptable level at 4.5" of lift with a single cardan shaft. And it's not just an annoyance...the forces applied by the driveshaft are large and can destroy seals and bearings that are more expensive and technical to replace than the driveshaft.

 

[Don Bulee]

To save money I would encourage you to do the work yourself. It's just wrenching, nothing particularly technical. If you don't have the tools, you could buy what you need for less than you'll pay for labor.

I needed 1" of transfer case drop AND a MML on my '99 TJ to get rid of vibes with only 2.5-3" of lift...and it took 3+ rounds of pinion angle adjustments and test drives to find exactly where it was happy. I did have a non-Rubicon so I had a slip yoke and the driveshaft angle would have been higher than if I'd had a Rubicon...but I definitely would not expect to have vibrations to an acceptable level at 4.5" of lift with a single cardan shaft. And it's not just an annoyance...the forces applied by the driveshaft are large and can destroy seals and bearings that are more expensive and technical to replace than the driveshaft.

Thank you my man..!!