| When looking at skid protection for
the transmission, there aren't that many options available for the
Cherokee. Tomken is the only company I know that makes a
transmission(only) skidplate. I say only because Rusty's and Skid Row
offer a skidplate that covers both the transmission and oil pan.
Actually Tomken makes one of those as well. I didn't really want one of
these engine/tranny skids because of 4 reasons. 1) They engine
cost 3x as much as the transmission(only) skid. 2) There have
been some reports of fitting problems and even with a drain hole, I
think it'll still be a hassle to do oil changes. 3) I don't
think the oil pan is THAT vulnerable since with my 5"+ of lift it
is tucked up high behind the front axle. 4) Weight. I already
have more than enough weight on my rig!
So I decided to get the Tomken Transmission Skid. Unlike the Tomken gas tank skid, which I think is great, I am not all happy with this transmission skid due to its poor design. Read on for the details. |
photo
#1
|
Refer to photo #1
This is the Tomken skidplate. First things first - when you order it you
need to specify 10" or 14". This is roughly the measurement
from the front of the crossmember to the lower control arm bracket. Mine
measured about 14" so thats the one I ordered. The rear of the skid
fits onto the lip on the front of the crossmember and the 2 support arms
are "supposed" to connect to the framerails. The problems with
this skid's design are mostly in the support arms.
The biggest issue I have with the arms is it looked like I would only have 1/4" of downtravel in my driveshaft before it would hit the arm! Not good. This is mostlty because I have a low-pinion D30 (so do 2001 models) and my 5+" of lift makes clearance even less. So I don't recommend using this on a 00-01 XJ unless you are stock height or want to modify it like I did. Besides that, even though the arms are made of 1/4" steel, they are still pretty flimsy and I'm sure will bend. The skid itself is only 1/8" thick. The arms are supposed to mount to the framerail by a rectangular piece of metal that has a threaded hole in it. This rectangular "nut" is supposed to fit into the big hole thats on the framerail. The problem is how are you going to hold the nut so it doesn't spin around while you try to thread the bolt into it? VERY poor design. (more on this later) |
photo
#2
photo #3 
photo #4 
|
To address the issue of
the driveshaft hitting the arm, I decided I had to fab up a custom
support arm or send the whole thing back to Tomken and do without. This
also sucks because I don't know how to weld. But I can design it. So
thats what I did and had a friend weld it up for me for $20. See photo
#2. I used 1/4" thick steel that is 1.5" wide - a common
size of metal that also matches the Tomken arms (I am keeping the
passenger side arm). Photo #3 is just at a different angle but
shows the 4 holes I drilled into it. Photo #4 shows how it fits
to the skid and Tomken passenger side arm. As you can see, I designed it
to go up and over the driveshaft rather than under it so the driveshaft
has plent of room to move when I flex the suspension. Also, the way I'm
doing it doesn't require any modification to the skid itself, it simply
replaces the drivers side arm. After reading this article most of you
probably won't be doing this the way I am, but if you need the
measurements of my custom arm, I can send them to you upon request. If
you can weld, it might be better to custom design the entire skidplate
to your liking and you'd save some money along the way. I'm not done yet
though, I still have to show you how I fixed the mounting problem to the
framerail!
|
photo
#5
photo #6 
|
Here are my custom
nutserts! See photo #5. The black peice is the "nut"
that Tomken supplies. What I did is bought 2 metal braces from the
hardware store that are a tad wider than the Tomken nuts. I made one of
the holes in the brace bigger so the bolt can fit through it and thread
into the Tomken nut (the brace acts like a big washer). I cut the brace
shorter on one end so it would fit inside the framerail and could be
positioned in the right place. After drilling and cutting the braces, I
used "JB Weld" to secure the Tomken nut over the hole I
drilled. If you do this, you just have to be carefull not to get JB Weld
in the threads of the nut. By now some of you may be laughing at my
fabrication skills, but I'll have you know, these suckers worked like a
charm! The idea is when you start threading the bolt and the nut turns
inside the framerail, the long brace hits the side of the framerail and
stops turning, allowing you to thread the bolt in. By the way, the bolt
doesn't need to have 100 LBS of torque on it either - it just needs to
be tight enough to support the front of the skid and not become loose. I
tightened them very snug and could probably go a lot tighter before they
would break. Photo #6 is after everything was primered and
painted and test fitted. Ready to go on!
|
photo
#7
photo #8 
photo #9 
photo #10 
|
The design
and fabrication process was long and very involved. But the final
installation was a breeze. The actual attaching it to the jeep was
simple and was the easiest of any skidplate I have installed to date. I
used some antiseize on the bolts that go into the nutserts so I can pull
the skid off with ease in the future. Pushing up on the skid, I can tell
the support arm I designed is much stronger than the Tomken one. The
question is how strong is it? Hopefully the skid won't take any hits at
the front because that is directly beneath the support arms. The back
part of the skid is more likely to see some rocks but that doesn't
really concern me because the back is where its the strongest. Overall
its not the strongest skidplate ever made but it is better than nothing.
Actually I do see 2 very good benefits to having it. One is since it is
level with the Rusty's transfer case skid, hopefully it will help the
jeep slide over rocks that would otherwise get hung up on the
crossmember. See photos #7, 8, and 9 The other thing is it may
protect the front driveshaft. At least it protects it a lot better than
if nothing was there! See photo #10
So thats it. If the skid ever fails on me, I'll update this page and let you know. In the meantime I plan to use it, but I'm already eyeing the Rubicon Express control arm brackets. If I get them the skid's arms will be in the way and I'll have to take it off and design a whole new mounting arm : ( I really need to learn how to weld - then I could make all kinds of cool things! |
Back to Erics XJ