[2003TjRubi]

Hi

I have a 1.75" spacer lift on my 2003 Rubicon and am experiencing slight vibrations at highway speeds and under hard acceleration. I have owned the jeep for 2 years and have always had them and just thought it was a jeep thing but have started to think otherwise. It is most noticeable on the highway doing abut 65 - 70mph. Its a slight pulsing vibration I can feel in the seat and center console. It seems to have gotten slightly worse since I replaced my worn out shocks with new Quadratec nitro 8.0s that ride awful BTW and will be replaced with Ranchos. I am skeptical it is drive line related however because I have read that even a 2" lift on a Rubicon should not cause any vibrations. I have checked the u joints and output yokes for play and everything's solid. I did however notice that on the transfer case side yoke there are rub marks that I believe is due to over flexing and binding while off roading. One other thing id like to note is whenever I've droped the transfer case skid I have had to spread the frame apart one way or another to get the bolt holes to lineup. I plan on doing a DPG OME 2" kit with adjustable control arms and a CV driveshaft in the future but would like to keep the spacer lift on for now. I do a lot of miles in the jeep and dont want to blow out a u joint let alone damage the rear axle/transfer case.

Any help would be appreciated
Thanks

 

[Mouse]

An easy way to determine if its a vibration from the front driveshaft is to simply remove it and go for a drive to see if anything changes.

What transfer case skid is on the jeep? What do you mean by "spread the frame apart?" That would probably require hydraulic assistance on my TJ.

 

[2003TjRubi]

So I removed the rear drive shaft and went for a long drive in 4hi and the pulsating vibes have gone away. I have the stock Rubicon skid plate. I do use a hydraulic ram to spread the frame to get the plate on. What I noticed when i pulled the rear drive shaft was that there is a bit of a gritty feel when I spin the caps of the U joint on the axle side, that might be the culprit so I am going to replace that one. What has me more concerned is that if I grab both ends of the driveshaft and twist there is rotational play at the slip joint in the middle of the shaft. No up and down movement though. Is that normal on a rear Rubicon shaft?

Thanks

 

[BobsLJ]

There should not be any significant lateral movement in the slip joint. Since you have it off take it apart and inspect it. Make sure you mark the phasing before you separate it.

 

[2003TjRubi]

Took it apart and id say theres about 1-2 mm of rotational play in the splines. I assume this is not normal and the shaft will have to be replaced. Has anyone else experienced vibes from a small BB on there Rubicon? Im worried if i just replace the whole shaft it will fail again. I m considering buying a stock shaft then removing my lift until I can afford to do it properly or maybe installing a Transfer case drop.

Thanks

 

[BobsLJ]

Have you considered a cv shaft as your replacement? Tom Woods, JE Reel or Adams? I think they are about $350 or so.

 

[2003TjRubi]

I have, researching that now. cant find if the upper control adjustable control arms are necessary with the amount of lift I have. Dont have the budget right now to do the cv shaft and the control arms. Would a cv shaft be a bolt in fix? I thought the pinion angle had to be adjusted.

Thanks

 

[BobsLJ]

My opinion only. Others need to give some input.
I would think with only having a 2" lift that you would be fine with a CV driveshaft and non adjustable control arms.
Really don't want to go with a transfer case drop, just throwing money away. If you plan on a lift at a later date you'll need the CV driveshaft and the control arms should come with the lift you get.
Again, this is my opinion only.

 

[Norminator]

I know two identical TJ‘s, an 04 and an 05, that have a BL, MML, and an AEV TT with stock control arms. Only the front shaft U joints were replaced for wear. The 04 under warranty which says a lot about the dealer accepting the geometry. The 05 was after 12 years. Both Jeeps are run hard, but carefully on the trail. At one time someone thought I was BSing on our setups, but truth is truth.

I have no advice.

 

[2003TjRubi]

I think I'm going to go ahead and call TW and order a cv shaft today. I'm assuming as long as my pinion angle seems pretty in line with the angle of the drive shaft I should be fine? If not can anyone recommend some decent budget upper adjustable CAs?

Thanks

 

[johncanfield]

I also think you will be okay with just the CV driveshaft based on your lift, etc. Don't have a clue about budget control arms, I use Rokmen and JKS. They are relative expensive but take a lot of abuse.

 

[Mouse]

I agree that a CV shaft should work just fine without adjustable control arms. I have no input on the control arms as I have never bought them, only built my own.

 

[2003TjRubi]

Ok Im going to go ahead and order a TW 1310 shaft. Does anyone have any input on if its bad for me to be driving the Jeep FWD in 4hi without the rear shaft for the time being?

Thanks for all the help!

 

[BobsLJ]

Shouldn’t be any issue.

 

[2003TjRubi]

Can the amount of weight on the back of the jeep change drive line angles? I used to have a hardtop and rear bumper with a swing out tire carrier and spare 32MTR but thats all gone. I dont remember the vibes being as bad back then. I will eventually be adding those back. Should I have taken a driveshaft measurement with a fully loaded jeep or am I overthinking this?

Thanks

 

[Norminator]

I would think you're fine taking measurements unloaded on the basis that people add tire carriers, winches, etc. to newly purchased Jeeps and we don't hear of driveline issues.

Weight could cause wear or accentuate issues, but I think you already know that.

 

[johncanfield]

Loaded ride height might make a tiny difference in pinion angle but like Norm said you should be fine.

 

[2003TjRubi]

perfect. Should have my new CV shaft in a little under a week. Ill let you guys know if it fixes the vibes.

Thanks for all the help!

 

[2003TjRubi]

So the CV shaft came in and the vibes are worse . Really think I need some adjustable control arms. Problem is Im sure that my track bar will hit the gas tank skid when I adjust out the pinion angle and I cant find a relocation bracket that I think would work with the small amount of lift I have. Im thinking im going to have to buy a stock shaft with a transfer case drop and put the CV away until I can afford to do the lift right.

 

[johncanfield]

I had a JKS rear trackbar with the offset bracket on the axle, maybe that would help. Once you start changing the suspension it never ends.