Driveshaft question on suspension installs

[ox4mag]

This will probably sound pretty generic but what problems could arise by not replacing the stock driveshaft after installing a 3.5" suspension lift? Obviously the geometry has been changed and consequently I would think the driveshaft should be changed as well. Just wanted to get your input as I've not swapped out my driveshaft yet and the install was done about six months ago.

Thanks!

 

[goodtimes]

Assuming you don't exceed the safe operating angle of the u-joints when your rear axle (I assume we are talking about the rear...) is at full droop (thus avoiding the u-joints from destroying themselves), the two concerns are vibration and overall length.

If you are able to run down the freeway without any vibrations caused by the operating angle of the u-joints, count yourself as one of the lucky ones. People seem to run into problems around 3" of lift. At 3.5", I was unable to run the stock driveshaft due to vibrations. Others have been OK.

Also, check the length at full droop. Be sure your slip-joint isn't on the ragged edge of coming apart...cause that would suck.

The actual problems would be the physical annoyance of vibrations + the increased wear on u-joints and tail shaft bearings. I have not seen a tailshaft bearing fail, but have heard of people complaining of it...take that for what it is worth (not much). If the driveshaft is to short, the result could be your driveshaft coming apart at the slip joint. If this happened at any sort of speed, it could result in the destruction of the driveshaft, possibly damage to the rear differential (when the back half digs into the pavement and delivers a huge shock load to the pinion), and possible transfer case damage (caused by having the front half of the driveshaft swinging around, uncontrolled, on the tailshaft).

Of course, this is assuming that you are using a fixed yolk (think: rubicon).

 

[Jeffb79]

What type of jeep do you have? If you've got a rubicon and a cv style shaft, it should be a little more forgiving on you. If you've got a non-rubicon lj, it will also be a bit more forgiving due to the extra length between the t-case and the axle. 3.5" is kind of the magic height. Some jeeps experience no problems what so ever, some get vibrations like crazy.

Assuming you don't have a cv shaft, and you're holding off on a sye and new drive shaft. Start with a t-case lowering kit... should be included in most generic lift kits that you would order. I drove my previous jeep for 2 years with no problems using a t-case drop w/ 3.5" of lift.
If you're still getting vibrations, start saving up for an sye and new drive shaft. Quite often you can find sye's for sale on craigslist... whether it's a new set up, or someone selling the whole t-case for pretty cheap.

If you're running a rubicon with a cv shaft, you might want to consider on getting a slightly longer one if you feel vibrations.
You can either get a driveline shop to lengthen your stock one and re-balance it. Will probably cost you $100. Or, you can call up a number of different driveline shops to have one built for you. This option will probably cost you $300 shipped. I know tom woods sells full greaseable shafts with a life time warranty. If you do upgrade, I'd recommend atleast getting something with greaseable joints/centering yoke.

 

[ox4mag]

What type of jeep do you have? If you've got a rubicon and a cv style shaft, it should be a little more forgiving on you. If you've got a non-rubicon lj, it will also be a bit more forgiving due to the extra length between the t-case and the axle. 3.5" is kind of the magic height. Some jeeps experience no problems what so ever, some get vibrations like crazy.

Assuming you don't have a cv shaft, and you're holding off on a sye and new drive shaft. Start with a t-case lowering kit... should be included in most generic lift kits that you would order. I drove my previous jeep for 2 years with no problems using a t-case drop w/ 3.5" of lift.
If you're still getting vibrations, start saving up for an sye and new drive shaft. Quite often you can find sye's for sale on craigslist... whether it's a new set up, or someone selling the whole t-case for pretty cheap.

If you're running a rubicon with a cv shaft, you might want to consider on getting a slightly longer one if you feel vibrations.
You can either get a driveline shop to lengthen your stock one and re-balance it. Will probably cost you $100. Or, you can call up a number of different driveline shops to have one built for you. This option will probably cost you $300 shipped. I know tom woods sells full greaseable shafts with a life time warranty. If you do upgrade, I'd recommend atleast getting something with greaseable joints/centering yoke.

I think I'll be okay (for now). I'm running a Rubicon with a cv shaft and have experienced no vibration or anything. My concern was really long-term and what I might see happen if I don't eventually replace the stock shaft with a slightly longer one. I should have probably mentioned that I've got a cv shaft on a Rubicon when I started this thread.

Thanks for all the input!

 

[JChatary]

Since having my 4" installed on my WJ...I've had to replace 2 front driveshafts on mine before having a new one measured up & made for me. Each of the stock shafts only lasted me a couple thousand miles before making this horrific grinding/rattling noise while I was driving. Being new to 4 wheeling then (not saying I'm an expert now by any means!) I had no idea my driveshaft would be affected the way it was!

 

[madizell]

Any lift change requires a measurement of the drive shaft length. Slip joints are intended to run with full compression of the suspension not quite collapsing the joint (a half inch of safety margin for example) so that the joint slip range is biased toward more spline engagement rather than less. If you lift the vehicle the drive shaft length increases no matter whose kit you use. If you do not normalize the slip joint operating range by increasing the drive shaft length, you risk running on minimal spline engagement at best and disengagement at worst. While you may get away with running the stock shaft on a lifted vehicle, that does not make it right, and the risk is yours. Sooner or later it will fail. Slip joints don't have a great range to start with unless you are using a custom built long slip joint, so I would never assume a stock shaft will work in a lifted vehicle, regardless of the amount of lift.

 

[f9k9]

..........I should have probably mentioned that I've got a cv shaft on a Rubicon when I started this thread. ........

Um, 03'-'06 Rubis don't come with a CV or Double Cardon style drive shaft. They just don't need a SYE or slip yoke eliminator.

You must have a newer one with the CV style

The top ds is a double cardon or CV shaft. The bottom one is the type that is on my Rubi.

I am running a 3.5" lift on my '03 swb rubi without vibes but, I have a 1" motor mount lift and adjustable control arms.

The newer JKs do have a true CV style shaft but, I would switch them out when time and money allows. The double cardon style would last longer and you can carry a couple ujoints on the trail and make repairs if, needed.

 

[madizell]

Double cardon joints are not trail repairable as a rule. They require proper tooling to disassemble without damage, and it is simply not an easy task. It requires a great deal of force carefully applied. On the other side of that, I have yet to see a double cardon joint fail in the field. I have seen them worn beyond safe use, and still not fail. Periodic inspection of the joints, especially prior to taking on a difficult trail, should be enough to guarantee that you don't have to fix one in the field.

 

[f9k9]

Double cardon joints are not trail repairable as a rule......

Agreed but, it has been done on numerous occasions. It is just a tail fix and should be redone when you get back to civilization. It's no worse than a blown front axle u-joint. You pull the inner axle, stuff a rag in the axle tube, reinstall the outer axle and limp home several hundred miles. The DS could be damaged with the typical hammer and socket trail repair but, you get out and back home. A $400 DS is cheaper than several nights in a motel while at the mercy of some local hack shop that you know nothing about. If, you have the room, then keep the oem ds, flanges and carry them as a spare.

 

[Jeffb79]

Or you upgrade to a double cardon and add your stock ds to the list of spares to throw in your rig so you don't have to worry about trying to fix the broken shaft. I've done drive and axle shaft repairs on the trail... not a fan of it. It's easier to just swap out and repair when you get home.

 

[UK4X4]

I ran a 3.5 rubon express on my TJ in the US, empty thats a good 4" lift

yes I added the adjustable front track bar, the rear came with an extension.

No increase in vibes from stock..oops forgot there's a 1 " lowering of the transfer skid plate.

Take a couple of uj's to the trail with you. a whole $ 22 investement in drive home..

or just disconnect the rear and drive home on the front in 4wd..

My budy however with the rubico ex 4.5 long arm broke stuff every outing and replaced drive shaft components on every trip....and he had the
sye ...

 

[madizell]

There are those who constantly break what they drive, and then there are those who seem never to break anything. I don't think this is always a case of what is driven and how it is modified.

 

[IXNAYXJ]

Frank, you should be fine. If you're not hearing any vibes on the street, you will likely not have issues. At some point, you will probably want to upgrade to an SYE and aftermarket shaft like a Tom Woods or JE Reel. I just picked up a JE Reel to replace my wasted Woods CV...but it lasted 80k miles of hard wheeling (you know how I roll), AND never failed, just made lots of noise for 2500 miles to and from Moab.

Here's my new shaft, a Cornay joint equipped JE Reel shaft...BLING!

-----Matt-----