American Expedition Vehicles 4.0L Universal Oilpan Skid Plate - Manual

Installation Instructions: Oil Pan Skid - Jeep 4.0L Engines
Nth30108 v2.1.doc page 1 of 3 download @ www.nthdegreemobility.com
Kit Part Numbers Nth24300 (Standard OPS – works with most factory original transmissions)
Nth24301 (42RLE 4-speed auto trans found in ’03-’06 TJ Wrangers)
Vehicle
Applications Any year and model Jeep vehicle equipped with a 4.0L engine - Models can
include YJ, TJ, XJ, ZJ, WJ, MJ
The transmission must be one that originally came behind a Jeep 4.0L engine:
Manuals: AX-15, NV3550, NSG370; Autos: 32RH (A999), 42RE (ZJ & WJ),
42RLE (‘03+ TJ 4-spd.), AW-4 (Aisin trans in XJs)
The exhaust does not cross directly below the front edge of the transmission
bellhousing (very unlikely since it would prevent draining the oil!) All known stock
exhaust systems will work with this skid if they are undamaged and in position..
Assumptions
Equipment that must
already be present
on your vehicle
Your engine block has two tapped holes just above the oil pan – one on each
side roughly halfway from front to back (all known 4.0L blocks will have these
holes.)
None beyond to common hand tools.
Required Tools
and Equipment
A floor jack is helpful if working alone.
Please take the time to read these instructions completely before beginning – they are long because we
want you to get the installation right the first time with no unnecessary delays.
Do not start or attempt this product installation if you are unsure of your abilities or do not have the
resources listed above. If applicable, be sure to have all welding done by a certified person, and
check/set all specified torques with a torque wrench…too tight is not just right!!
Step 1: Unpack boxes; Check contents against packing list; Verify parts are in good condition. Be
especially sure that you have the right parts for your application!
Step 2: Read all of the following instruction steps before beginning! Do not disassemble vehicle unless
all parts are present and all tools and facilities required are available.
Step 3a: Temporarily move Cooler Lines – Auto Trans only (not required for XJs w/ AW-4). In most
cases, the transmission cooler lines pass directly over the tapped hole on the driver’s side of the engine
block. The lines will not have to be permanently moved, but they will need to be out of the way to install
the bolt on that side. Unclip the lines from nearby retainers until you can get at least an inch of space
between the boss on the block and the lines. Once the skid is installed, don’t forget to re-clip the lines!
Step 3b: Temporarily remove knock sensor – ’87-’90 XJ’s only. If you have a pre-H.O. 4.0L XJ
Cherokee, your engine should have a knock sensor screwed into the larger hole on the driver’s side.
You will use this sensor to retain the oil pan skid at that location instead of the supplied M12x1.25 bolt.
There will be no change in the function of the sensor because it only senses vibration - so as long as it is
tight, it will work fine.
Step 4: Bolt front of Oil Pan Skid (OPS) to engine block. First remove the lower bolts on the
transmission bellhousing that correspond to two holes on the back of the oil pan skid. The oil pan skid is
designed to be placed in position without the need to loosen or remove the exhaust on any application,
but clearance is very tight where the exhaust wraps around the front of the oil pan (TJs) or driver’s-rear
corner (XJ, YJ, etc.). Lift the OPS into position so that the back edge is behind the drain plug (not under
it), then ‘wiggle’ the OPS around until you get past the exhaust pipe(s) and get the ‘ears’ at the front up
alongside the engine block.
Once the skid is in position, thread the correct bolt through hole in each tab of the OPS and into the
hole in the side of the engine block. In all applications and years, the passenger side bolt should fit the
gold 3/8” coarse thread hex-head bolt supplied, but the driver’s bolt depends on your application. For
’87-’90 XJ Cherokees, re-use the knock sensor that was removed in step 3b. For later model years, one
of two supplied bolts will be used:
-
’91-’99 Jeeps use the metric M12x1.25 socket-head cap screw (same size as knock sensor)