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View Full Version : Front drive shaft, should i have shop mod compression length or buy new?


4x4JeePmaNthINg
July 20th, 2017, 00:59
hey all

It appears after regearing a shop noticed my front drive shaft at full droop comes very close to maxing out its compressed ability. which could mean
bad juju for the TC if i really did something crazy to slam compression.

Any how im looking to the advice of:

should i have a shop mod the compression length by increasing its travel ( if do able), or

should i just buy a new shaft, BUT would a new shaft be any different if not custom made? thinking adams

looking for advice before calling shops/venders

Tim_MN
July 20th, 2017, 04:52
Any details about the suspension ? Any pictures with measurements ? Wondering what makes your suspension different than thousands of other lifted Cherokees ? Any idea if the regearing shop knowns anything about lifted Cherokee suspension or drive line geometry ?

themauler
July 20th, 2017, 05:24
I've never heard of anyone having to shorten their front driveshaft unless you swap drivetrain. But if it truly needs shortened then just have a driveshaft shop do the work. Most places only charge $50-$75 for that job.


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Vanimal
July 20th, 2017, 08:43
I've never heard of anyone having to shorten their front driveshaft unless you swap drivetrain. But if it truly needs shortened then just have a driveshaft shop do the work. Most places only charge $50-$75 for that job.


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they charge that just for balancing around here.




I'd fix your suspension issues before i wasted money on a driveshaft.
adjustable control arms, drop brackets, or longarms.... any of the three will probably fix your issue and it'll ride better.

trippled
July 20th, 2017, 09:56
I had that problem on short arms. When drooped the axle moved back enough to fully compress the shaft. I have adjustable arms now and since reclocking the t case up it's not an issue.

If you get upgraded splines they usually have more travel . The local shop told me $250 to respline an old shaft. Idjust go new.

VAhasnoWAVES
July 20th, 2017, 10:53
does it max out the shaft, or is it "very close"?

i run mine "very close" to full compression. but i am confident that my limit straps and bump stops will keep "very close" from becoming "too close."

4x4JeePmaNthINg
July 20th, 2017, 11:22
I had that problem on short arms. When drooped the axle moved back enough to fully compress the shaft. I have adjustable arms now and since reclocking the t case up it's not an issue.

If you get upgraded splines they usually have more travel . The local shop told me $250 to respline an old shaft. Idjust go new.

RE 3.5 lift, fixed UCA/LCA, stock DS f&r

well out of thousands apparently trippled is one that has seen my issue so it does happen. secondly the drive shaft does not need to be shortened. If a shop did the mod, the shaft would stay the same length, However the slip would need to increase in how far it can compress.

sounds like a new DS is a better cost effective option. adjustable UCA/LCA would be nice to stretch the axle forward a bit.
Trippled im unclear as to how re clocking the TC aided? i thought that only gives ground clearance.

4x4JeePmaNthINg
July 20th, 2017, 11:28
does it max out the shaft, or is it "very close"?

i run mine "very close" to full compression. but i am confident that my limit straps and bump stops will keep "very close" from becoming "too close."

i was told it was maxed out when at absolute full droop. This is a very well versed 4x4 shop, and they were simply pointing out the potential hazard for my awareness. It would be an extreme situation to cause a bad issue, but it is possible and i dont like the thought of destroying a TC in the mountains.

trippled
July 20th, 2017, 12:13
RE 3.5 lift, fixed UCA/LCA, stock DS f&r

well out of thousands apparently trippled is one that has seen my issue so it does happen. secondly the drive shaft does not need to be shortened. If a shop did the mod, the shaft would stay the same length, However the slip would need to increase in how far it can compress.

sounds like a new DS is a better cost effective option. adjustable UCA/LCA would be nice to stretch the axle forward a bit.
Trippled im unclear as to how re clocking the TC aided? i thought that only gives ground clearance.

Reclocking effectively raises the front output, making the distance between the yokes longer.

Vanimal
July 20th, 2017, 13:54
sounds like a new DS is a better cost effective option. adjustable UCA/LCA would be nice to stretch the axle forward a bit.

Disagree... if you can't find a decent set of used adjustable short arms on the cheap, then you aren't looking lol

here's a set for less than a new drive shaft, and these are brand new. https://www.core4x4.com/products/product/tier-1-adjustable-front-control-arm-set-w-rubber.php?_vsrefdom=adwords&gclid=CjwKCAjwqcHLBRAqEiwA-j4AyOg-9IVdcq-xH9r-Ygdk4kxalERT3sL7wt_iRGTCWZqDiw8aAigo1hoCrsYQAvD_Bw E

Jim Malcolm
July 20th, 2017, 15:18
I'd suspect you'd have to have shocks sticking out of your hood to fit ones with enough travel to allow the suspension to droop far enough to fully compress the driveshaft... I have aftermarket fixed LCAs, adjustable UCAs and I had to get a longer driveshaft as mine was darn near fully extended at ride height with 4" lift. I think they were just trying to sell you something...

Kittrell
July 20th, 2017, 15:44
I'm going to say non issue here.

TRCM
July 20th, 2017, 19:49
I tried to answer this on the other site, and it happens far more than people realize, cuz very few realize the driveshaft does actually compress on droop for a front axle.

It happens on my jeep, and it happened on my ramcharger.

Usually, it isn't enough to truly bottom the shaft out tho, but it can get real close.

VAhasnoWAVES
July 20th, 2017, 21:52
RE 3.5 lift, fixed UCA/LCA, stock DS f&r

well out of thousands apparently trippled is one that has seen my issue so it does happen. secondly the drive shaft does not need to be shortened. If a shop did the mod, the shaft would stay the same length, However the slip would need to increase in how far it can compress.

sounds like a new DS is a better cost effective option. adjustable UCA/LCA would be nice to stretch the axle forward a bit.
Trippled im unclear as to how re clocking the TC aided? i thought that only gives ground clearance.

i chuckled a this one. you arent thinking about it correctly.

the slip shaft has a fixed amount of travel. fully compressed is fully compressed. there is no way to increase the compression stroke of the slip shaft. you have to physically shorten the drive shaft so that the slip shaft does not reach full compression.


im also going to vote none issue. tons of people run your lift. ive personally installed them as well. the shaft nearing full compression isnt a problem. if it reaches full compression and puts pressure on the case, thats when you have a problem. i see 3 options if you still are concerned... option 1, depending on what your castor is at you can possibly afford to dial in a little more. moving the castor adjuster will push the axle forward slightly, and point the pinion down, away from the case making the shaft extend. again, slightly. option 2 is to buy a new shaft, as you seem to want to do. which is perfectly fine. option 3 assumes you have an automoatic. the manual equipped XJs has a slightly shorter shaft due to the shorter trans. thats a cheaper JY option.

4x4JeePmaNthINg
July 20th, 2017, 21:59
I've been running my lift for years, and now to hear this from the shop, I just didn't want to pay for being ignorant to the drive shaft setupt.. I'm on 33s now so hopefully that's a little buffer for the DS Not needing to droop/ reach down as much.

I'm curious after tripples clocking the TC. I have a TC drop which should in turn grant some extra leeway for the DS because it's angled up right? If I eliminate the drop, would I really be pushing the tolerances?
Not sure if I can get the body high enough to fully drop the axle and check. Maybe the shop will let me check it out when I go back for gear break in check up.

Green XJ Jeep
July 21st, 2017, 07:43
If you think that it might be an issue under full compression the use a longer bump stop.

themauler
July 21st, 2017, 08:05
If you think that it might be an issue under full compression the use a longer bump stop.



Compressed conditions in this case will extend a driveshaft.

OP needs to stop making grand assumptions and get out some jack stands and drop the drivers side as far as it will possibly go to see for himself. Unbolt the driveshaft from the axle and compress it by hand and see how far it will compress. Use a light hammer if necessary, mark it's location, then bolt it back up and see if it hits that mark.

If the shop technician saw this while the XJ was on a lift, I am willing to bet those droop conditions will never be seen on four tires....or he is just trying to make a sale like most shops try


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trippled
July 21st, 2017, 08:38
I would say the t case drop if it does anything is negligible. Removing it would actually move the yoke farther away but may or may not be enough. I've seen this problem on more than one Jeep. Mine was so tight I could not remove the shaft if I had it on the lift at work. The usual combination seems to be factory uppers and (insert brand here) fixed lowers.

josh9mile
July 23rd, 2017, 01:07
I have a RE 4.5 short arm lift and noticed the shaft would compress when at full droop and extend when suspension was compressed. CAD brackets fixed that issue.