JK Front and Rear Drive
Our JK-Jeep Drive Shafts
(front or rear)
There are many different ways to build a drive
shaft for the new JK. One method uses an adapter flange which bolts
directly to the original pinion flange. This is really not much more
than a round flat plate with bolt holes drilled into it and a
conventional drive shaft weld yoke welded into the center. This then
bolts to the stock pinion flanges. We just don't think this is as
“clean” of a modification as can be done. What if the weld yoke
portion breaks? You could have a tough time finding a new one or
repairing the old one. There is also a concern with maintaining the
accuracy of the part after welding. In addition to this, the center
of the universal joint gets pretty far away from the pinion bearing.
Excessive overhung load is not a good thing.
picture to the right, this shows the stock flange and adapter that
our competitors use on the left. Our version
is shown on the right.
With our version, we’ve elected to make a replacement flange for the
differential pinions. These flanges are machined from solid billet
steel. We do not believe this flange will
ever break. We designed this to accept standard "off the
shelf" mating flanges. If these flanges ever break, you at least
stand a chance of getting a replacement part from almost any drive
line shop. This also nets a longer drive shaft with the center of
the universal joint closer to the pinion bearing.
We can build either drive shaft in 1310 or 1350 series. Unless
you plan on beating the vehicle really hard, we believe the 1310
series front drive shaft would serve most people well. Likewise for
the rear drive shaft.
In a 1310 series the drive shaft is $489; a 1350 series price would
be $649. The price is the same for either front or rear. These
prices are for the complete package including required nuts, bolts,
and flanges/yokes. We can supply a good fit by application
information only but believe we can get the best fit if you will
supply a simple length measurement.
If you have a lift in the vehicle, you may need
something to pitch the differential for the CV type drive shaft.
This is typically done with adjustable control arms.
Installation is a simple bolt in. You should have
available for possible use; an impact wrench capable of delivering
180 LB/FT torque. Box end wrenches of the following sizes 1/2”,
7/16” & 18MM along with a 1-1/4” socket.
Need help deciding which drive shaft is right for you?
If your drive shaft is not properly sized for the tire diameter and differential gear ratio along with how & where you drive, you could experience problems with breaking the universal joints or other components in the drive shaft. We don’t want you to have problems.
The following is our suggestion, which requires a little math and for you to be honest with yourself about where and how you drive.
Use this formula; 20,168 divided by the tire diameter then multiply the result by the gear ratio of the differential. For example 20,168 / 37 = 2,234. If the number you come up with is near 2,500 and you do not beat the vehicle, you should be OK with a 1310 series drive shaft. If you drive it hard, we suggest the 1350 series. If your number happens to be less than 2,200, we strongly suggest the 1350 series.
If your number happens to be 2,500 and you do beat the
vehicle but want to save a little money, consider this
compromise. Run a 1350 on the rear and the 1310 series
on the front. Some compromise can be made on the front
drive shaft because when the vehicle is climbing a hill
where there is more load on your drive train, the weight
of the vehicle tends to transfer towards the rear and the front drive shaft is typically less loaded.
Four Wheeler's Sean Holman says about our JK drive shaft:
From: Holman, Sean
Subject: Four Wheeler's JK
We installed the shafts today. They went in without a hitch, perfect
fitment. If there was ever such a thing as a beautifully crafted
driveshaft, these are them. Gorgeously constructed, they look like
pieces of mechanical art and the guys at the shop were impressed. My
vibration at 70 is gone and they are baby butt smooth at least until
80mph or so. These are the smoothest, truest aftermarket shafts I
have ever installed. All of my future driveshafts needs will go
through you. Thank you for the support of Four Wheeler and thank you
for such a quality product - a rarity in these days of cost cutting.
Sean P. Holman
Tech Editor - FOUR WHEELER Magazine