American Expedition Vehicles Tummy Tucker – TJ Rubicon models - Manual (Page 13)

Installation Instructions: Tummy Tucker™ – TJ Rubicon models
Nth30116 v4.doc page 13 of 13 www.aev-conversions.com
present – check for crooked/misinstalled/bent brackets, bad motor mounts or motor mount spacing, etc.
If their appearance is okay, verify their height while they are supporting the powertrain with the engine
off. They should be about 1.0” to 1-1/16” tall from the surface of the TT to their tops (not counting any
shims above them).
Issue: Exhaust is too high over rear axle and at tailpipe and the hangers at muffler and tailpipe
are not ‘hanging’ and/or exhaust is touching heat shield over rear axle. Since the TT installation
does slightly elevate the center portion of the exhaust relative to the floor, the rear portion may require
adjustment to keep it in its proper place. If this did not happen ‘naturally’ via some ‘sag’ at the joint
between the catalytic converter and the muffler, you may need to make this adjustment deliberately.
Solution: On ‘03+ TJ’s there is a joint in the system made up of two large flanges that are held together
with two bolts - this connection is just ahead of the muffler. By loosening the two bolts, the exhaust
should drop back into place, then retighten the bolts. If the hanger at the back of the muffler is still not
fully ‘hanging’, bend the rod that is welded to the exhaust pipe slightly forward. The exhaust grows in
length when it warms up, so the hanger will swing into position during operation.
If your exhaust system is custom, you may or may not have a joint ahead of the muffler and it may be
necessary to visit a muffler shop to do a proper adjustment.
Issue: Engine Fan is touching fan shroud (static), or fan can be heard touching shroud while
driving over bumps, etc. Wrangler front-end sheetmetal is only supported by one body mount forward
of the firewall, consequently, there can be major variation (up to an inch!) in the position of the grille
along with the radiator and fan shroud. Normal TT installations tip the powertrain ‘flatter’ to the point
where the engine fan may touch the bottom lip of the fan shroud if the sheetmetal on your Jeep happens
to be ‘high’. You need at least ¼” clearance between the tips of the blades and the shroud, though more
is desirable - if you have less, you need to fix it.
Solution: The easiest solution is to lower the fan shroud. Remove the shroud from the radiator and slip
it over the fan (you may have to unbolt the fan to do this). Use a small round file or similar to ‘router’ the
mounting holes upward towards the top of the shroud. If you cannot gain enough clearance before the
holes are too close to the ribs in the shroud, you can also do the same to the radiator mounting flanges
where it bolts to the grille, but this is almost never necessary for drop TT installations. Not that if you are
using a body lift without a motor mount lift, you already had to make a fan shroud correction that may
have not been sufficient for use with the TT.
Issue: Manual transmission sometimes pops out of first gear. If you have a late production 2003
Wrangler or have had transmission work done, the dealer may have updated your shifter to the new
design described in step 18, and you will need to perform that step. If you have an ‘04+ Rubicon and did
not perform step 18, this problem confirms that you need to do it.