Extended Cab 4x4 Rangers used a two-piece rear
driveshaft through 1997. In stock form, the only problem with the 2-piece shaft is that
the rubber carrier bearing bushing can fall apart and need to be replaced. No biggie.
However, Lifting the rear more than 1-2" will cause vibration due to increased
U-joint angles. This will also lead to accelerated wear of the U-joints and carrier
bearing bushing.
Lowering the carrier bearing can correct the new vibration, but it's trickier
than it sounds. Because the carrier bearing is mounted on top of the crossmember, the
entire crossmember must be lowered. After all that, you can still have vibration problems
due to the design of the 2-piece shaft. The two U-joints at each end of the shaft (axle
and T-case) are not phased together, meaning the ears on the shaft are 90 degrees to each
other. If you lower the carrier bearing so that the two shaft sections are inline, you can
be guarranteed of vibration.
Instead of going through all that trouble of guessing and checking and maybe getting it
right, just ditch the two-piece shaft completely. 1998 and newer 4x4 Extended Cab Rangers
have a nice one-piece shaft that is a 90% bolt-in swap and will keep you free from
vibrations when you're riding high.
First, locate a one-piece shaft. Anything from a 98 or newer extended cab 4x4 Ranger or
Mazda B-Series will work. It doesn't matter if it's a manual or automatic transmission,
but the junkyard's computers will ask, so just pick either one. Some junkyards will also
ask for the distance weld-to-weld: It is 47". Some of these will be aluminum and some
steel. It's a matter of preferrence or availability which you get. Just make sure whatever
it is it's not dented or bent.
Set your parking brake and block the wheels. Without a driveshaft, having the tranny in
gear or in park is worthless. Mark the orientation of the ends of the driveshaft on the
axle and transfer case. If you ever go to put the original shaft back in it is good to
maintain the original orientation to avoid minor imbalances. Unbolt the carrier bearing
from the crossmember first. Then unbolt the ends of the shaft from the flanges with a
12-point 12mm socket (your 6-point sockets won't work here). A light tap may be necessary
to break the flanges apart.
Now is the easiest time to deal with a few clearance issues before you put
the new driveshaft in. The bracket that the carrier bearing was bolted to needs to go.
There are three rivets holding it to the crossmember that must be ground off and hammered
through. They'll be rusted in there well so use a heavy hammer and a 3/8" socket
extension as a punch once you've ground the heads off. There is a tab on the gas tank
skidplate that bolted to the carrier bearing bracket that needs to go also.
If you have a suspension lift taller than 4" installed, you will also need to either
move the entire crossmember forward some (drill new holes, reattach with bolts), or notch
the center of it for clearance. This is so the shaft doesn't contact it (and possibly get
dented) when the rear suspension is fully extended.
Complete removal is not recommended (it is a structural frame component).
The gas tank skidplate does not contact the driveshaft on level ground, but when the rear
suspension flexes a lot, it will hit towards the rear of the skidplate and make an awful
screeching sound that will make anything that isn't deaf wish it was. Remove the skid
plate to do this trimming. Throwing sparks around your gas tank isn't a great idea, and
you don't want to cut too deep and nick the tank either. There are four bolts holding the
skid plate on that will probably be tight and a pain to get out, but well worth not
sitting under the truck with a grinder and gas tank above your face. I took off a little
more than an inch for the rear 2/3 of the skid plate and have not had any contact since
trimming.


Bolt the skidplate back into place and then
install your new driveshaft with the slip-joint towards the transfer case. Torque the
driveshaft-to-flange bolts to 85 ft-lbs. There isn't a great demand for the two-piece
shafts, so I'm going to see if I can extend the long section of the old shaft for use as a
trail spare. Might work, might not. We'll see...~TRS
Editor's notes:
'98+ 2WD Supercab Rangers also were fitted with one-piece driveshafts from the factory.
This swap should be possible on these also. I cannot however comment on 2WD clearance
issues as I have not researched them. I've heard slight floorboard modification may be
needed.
All 98+ 2WD Supercab shafts will be the large aluminum units.
If you own a '83-'89 Supercab model, this swap can still be done, but the rear driveshaft
flange on the axle will be smaller. You will need to swap the larger rear U-joint
attachment with 3" bolt spacing with another forward one that has a 2.5" bolt
spacing.
It also was brought up just as this article was being finished that later Supercab 4x4s
fitted with aluminum shafts have a larger T-case flange (same as the larger rear flange
with 3" bolt spacing). These will require either swapping the forward U-joint piece
or swapping the t-case flange. --4x4junkie .