Driveshaft vs. Skid plate
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JK Junkie
Joined: Dec 2008
Posts: 2,355
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From: San Diego
Driveshaft vs. Skid plate
So the other day I was at the dealership getting my free oil change and the mechanic called me in. It was up on the lift and showed me that my drive shaft was resting on my skid plate. I installed my lift about two weeks ago I am sure the two are related. It looks like I will just have to modify the skid plate by cutting out a 5" by 2" section. Before I start cutting into it I was wondering if anyone else has had this problem and/or what they have done.
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Very common, pretty much everyone with a lift and an automatic has run into it. The other contact point is the corner of the transmission, which will tear the boot.
An aftermarket (narrower) driveshaft is the fix.
And for those who may not have found the FAQ's yet:
An aftermarket (narrower) driveshaft is the fix.
And for those who may not have found the FAQ's yet:
Q: Are new driveshafts needed after installing a lift?
A: You really should consider installing a new rear double cardin U-joint style drive shaft if you have lifted your Jeep JK Wrangler 3" or more and have a 2-door. This is needed because the short rear drive shaft of the 2-doors will be at a steep enough angle that the CV boots will wear out prematurely. However, in order to do this, you will need to buy a set of rear adjustable upper control arms so that you can properly set your pinion angle. 4-Door Unlimited models do not have this problem as their rear drive shafts are very long and a lift will not effect the angle of it too much. As far as the front goes, if you have an automatic transmission, you will need to replace the drive shaft with a double cardin U-joint style unit as well as the diameter of aftermarket shafts will be considerably narrower and will not come into contact with the transmission and/or skid plate. Failure to do this will result in the tearing of the factory drive shaft boot as it makes contact with the transmission. Manual transmissions will not have this problem and keeping the factory front drive shaft will not be a problem.
A: You really should consider installing a new rear double cardin U-joint style drive shaft if you have lifted your Jeep JK Wrangler 3" or more and have a 2-door. This is needed because the short rear drive shaft of the 2-doors will be at a steep enough angle that the CV boots will wear out prematurely. However, in order to do this, you will need to buy a set of rear adjustable upper control arms so that you can properly set your pinion angle. 4-Door Unlimited models do not have this problem as their rear drive shafts are very long and a lift will not effect the angle of it too much. As far as the front goes, if you have an automatic transmission, you will need to replace the drive shaft with a double cardin U-joint style unit as well as the diameter of aftermarket shafts will be considerably narrower and will not come into contact with the transmission and/or skid plate. Failure to do this will result in the tearing of the factory drive shaft boot as it makes contact with the transmission. Manual transmissions will not have this problem and keeping the factory front drive shaft will not be a problem.
Last edited by nthinuf; Sep 19, 2009 at 04:29 PM.
Thread Starter
JK Junkie
Joined: Dec 2008
Posts: 2,355
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From: San Diego
I thought I would be good due to the fact I only installed a 2.5" lift. In fact I didn't want to mess with new driveshafts is the reason I went with the 2.5".
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Trim the skid, disconnect and go flex it. See just how close you are to the transmission. With only 2.5 inches you may be ok on the boot.
Also, what was your 'actual' lift height? 3 inches? 3.5?
With 4 inches of lift on my auto, I am contacting the skid, but have not noticed any marks or tearing on the boot. Yet. (I think I'm just lucky so far, and a new shaft is in my future)
Also, what was your 'actual' lift height? 3 inches? 3.5?
With 4 inches of lift on my auto, I am contacting the skid, but have not noticed any marks or tearing on the boot. Yet. (I think I'm just lucky so far, and a new shaft is in my future)
Last edited by nthinuf; Sep 19, 2009 at 04:39 PM.
JK Jedi Master
Joined: Aug 2007
Posts: 15,665
Likes: 4
From: Hammond Louisiana
Kupost, In order to save the boot on the front driveshaft, a few things- you gotta center your axle, you gotta trim and drop the skid, and very importantly you have to cut that metal band off that has the nub on it or it will hit the auto tranny pan and replace it with a ziptie. Most 2.5's don't have a provision for centering the front perfectly.
5in of susp lift
That being said, my stock ds has since given out, but at the top cv joint, I've never ripped the boot.
5in of susp lift
That being said, my stock ds has since given out, but at the top cv joint, I've never ripped the boot.
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
MKjeep, it looks like you have some scrape marks on the DS from the skid. Just wondering if those are from before the cut/drop, or if you are still contacting?
And did you have to get longer bolts to drop the skid, or are the stock ones long enough?
And did you have to get longer bolts to drop the skid, or are the stock ones long enough?
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JK Enthusiast
Joined: Apr 2009
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From: VEGAS
. I will get a new drive shaft next month. I am in the same boat as you. would have gone with a 3 inch lift if this was going to happen.O well, now with the new drive shaft, perhaps a 4 inch lift and 37s are next
JK Jedi Master
Joined: Aug 2007
Posts: 15,665
Likes: 4
From: Hammond Louisiana
Good eye, those were when I was testing it before dropping the skid and notching the crossmember a bit. Those are the stock bolts, plenty long enough.
JK Enthusiast
Joined: Mar 2009
Posts: 255
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From: Huntington Beach, CA
Just curious, when he showed you - your jeep was up in the air? Was it a drive on lift or a frame lift? I'm guessing it was a frame lift so all 4 tires we drooping at full flex. That might be the problem. I would think with a 2.5" lift, you wouldn't see the driveshaft rub like that. But, since you have the full weight of the axle pulling down, it made the axle come close to the skid plate. When you are "wheeling", I don't think this would be an issue. Unless you disconnect the sway bars, but even then I don't think it would rub.
What does everyone else think?
What does everyone else think?