Transfer Case Shifter Linkage TSB
or thumping on the floor when accelerating)
About half a year
after I bought my TJ, I started to notice a funny knocking under the
driver side floor when accelerating or when going over a bump. It
was a kind of a low "thump, thump, thump" in rapid succession
and then it'd go away. Well, since I was still under warranty, I decided
to take my Jeep in to have it looked at. Well, six visits later, at
two different dealerships (once to see a DC specialist) and a lot
of anguish, I was told that nothing was wrong and that the noise I
was hearing was completely normal... "all Jeeps are noisy."
Pissed off, I started to do some research on-line and on the bulletin
boards and found out that a lot of people had this exact same problem.
Enough so that the NTHSA issued a TSB to have it fixed. So, with a
TSB number in hand, I went back to my dealer and what did they say?
"Oh yes, there is in fact a TSB for this, what do you know?"
An hour later my Jeep was fixed and the knocking was gone.
What I found Out
I don't know who
or why anyone would design a T-case shifter linkage as complicated
as this or why it is mounted to the tub but this is where the knocking
is coming from. What happens is that the bronze bushing/retainer holding
the torque shaft wears out and/or the rubber gasket tears on the end.
This allows the torque shaft to travel back and forth too much causing
one of the links to tap on the bracket on the tub. This problem can
also occur if you install a 1" body lift without installing the
T-case shifter drop bracket supplied with many kits.
How to Fix It
If you are still
under warranty, take the TSB (Technical Service Bulletin) number below
to your dealer and have them deal with it. If you are over warranty,
you can by the TSB kit from your dealer for about $19.
TSB 21-09-98 JUL 98
Transfer Case Shifter - Creaking/Thumping Noise
05014148-AA Torque SH 21-105-001
Although the kit comes with new bushing for every link end, the only
ones I needed was the bronze bushing/retainer and gasket. To install
it, you will need to remove the body bracket from the tub. In order
to do this, you will find the 4-bolts holding it in place underneath
your driver side carpeting. The rest can be accessed from under your
Jeep and you do not need to jack anything up or remove your T-case
Photos by: Tony's
1. First peel back the carpet on the drivers side
floor to get access to the four nuts holding the 'Body Bracket' in
2. Once those are removed, get a hammer and the same
socket wrench that you used to get the nuts out of the floor. Once
under the Jeep you'll have to wrestle the 'Body Bracket' loose from
the tub. It will still have a strong hold on the Jeep, so take the
hammer and give a few gentle whacks to break the seal. Now remove
the two screws (wont need these anymore) holding the 'Bronze Bushing/Retainer'
to the 'Body Bracket'with the socket wrench. When the screws are removed,
just wrestle the 'Body Bracket' off of the 'Torque Shaft'.
This part is why I was confused/cautious. I looked at the
new parts, looked at the area that the new parts would go, and didnt
see a resemblance. So the whole time, I'm thinking to myself "Am
I in the right place?" It turns out that my 'Boot' was gone,
and that the 'Gasket' tip was completely gone. So, remove what ever
remainders you have on the 'Torque Shaft'. Then, place the new 'Boot'
on the 'Torque Shaft'.
4. Now, put the 'Bronze Bushing/Retainer' on the
'Torque Shaft' with the flat end facing the drivers side. Slide
the 'Boot' over the lip of the 'Bronze/Bushing Retainer'.
5. Grab the 'Body Bracket' that you took off earlier
and place the 'Gasket' in the hole.
6. Now, wrestle the 'Body Bracket' with the newly
installed 'Gasket' back onto the 'Torque Shaft'. Align the 'Body
Bracket' with the holes on the tub. Go back to the interior of the
Jeep and tighten down the four screws you removed earlier. Now the
'Body Bracket' should be firmly tightened against the tub. Go back
under the Jeep and with the two screws provided tighten down the
'Bronze Bushing/Retainer' to the 'Body Bracket'.
Take it for a spin and you shouldnt hear the thud anymore. Now,
have a beer!
Please let me know if you have any questions.