Swapping a Ford T-18 into your CJ may be the best alternative,
because in many cases it can be swapped in cheaper and easier than
any other transmission. The improvement in performance and durability
of your CJ will increase exponentially with this relatively simple
transmission swap. Ford T-18s are easy to find and inexpensive to buy
and the Ford T-18 is compatible to a large degree with '76-'86 CJs
because in most cases the originally bell housing can be retained.
A Jeeping buddy of mine, Steve Smith, asked me to help him swap
in a Ford T-18 in his '83 CJ-7 since I put one in my CJ-7 a couple
of years ago. I figured it would be an excellent opportunity to
document the swap, so I foolishly agreed. Just about everything
that could go wrong, went wrong during this swap, but the end results
were well worth it.
Steve's CJ-7 was originally equipped with a 258, T-176, and Dana 300,
but the previous owner "upgraded" to a T-5. Steve is mainly
interested in rock crawling and although the T-5 had served him
well so far, he knew it wouldn't last long. He wanted a heavy
duty transmission with a granny first and the Ford T-18 was the
least expensive option.
The Search
A local guy that does bench rebuilds in town recommended that Steve
find a good runner over a core even though the transmission would
need to be rebuilt. The thinking is that if any major parts are
damaged in a core, the cost of new parts will far exceed the cost
of a good runner. Steve purchased a running T-18, but the shift
lever was missing. It seems that the shift levers and the input
bearing retainers are some of the most commonly damaged parts on Ford
T-18s and this one was slightly canabilized.
Most Ford T-18 conversion kits I've seen replace the main shaft
and the tail housing of the transmission, so when you searching
for a Ford T-18 to swap into a CJ with a Dana 300, it is best to
get the 2WD version. The 2WD versions are generally cheaper than
the 4WD versions and the adapter kit bolts right on the 2WD version
where the 4WD version may need to have holes tapped in the case.
The Rebuild
Steve dropped off his Ford T-18 and a conversion kit from Advanced
Adapters at a for a bench rebuild. Bench rebuilds are fairly
inexpensive, normally $150-$200 plus parts. New bearings were
put in this transmission and a synchro was replaced. It is well
worth to replace any questionable parts at this time.
Clutch and Pilot Bushing
Advanced Adapters makes a special pilot bushing for the conversion
that is AMC on the outside and Ford on the inside. It is not part
of the Ford T-18 conversion kit, so you will need to order it
separtely. You can make you own pilot bushing by taking a stardard
Ford pilot bushing and turning down the outside to the size of the
outer large hole in the crank shaft. I've had one custom made at
a clutch shop local, but there was no cost savings over the
Advanced Adapters bushing.
A standard pressure plate can be used for the conversion, you may
want to keep your old one if it is fairly new. Since pulling
a transmission is very time consuming, a new pressure plate is
a good idea if you haven't put in a new one in a while.
The Jeep T-150, T-18, T-176, SR-4, T-4, and T-5 all use a 1 1/8"
10 spline input shaft and the Ford T-18 uses a 1 1/16" 10 spline
input shaft. Your old clutch disk will not fit snuggly on the
Ford input shaft, so you will need to purchase a new disk. The
disk can be a regular 10 1/2" Ford disk (or 11" if you have an
11" clutch). The Centerforce clutch disk #384180 is a 10 1/2"
clutch that will fit the Ford transmission.
Bell Housing
The bell housing bolt pattern for the Ford T-18 is exactly the same
as the T-150 and the T-176 transmissions. The Jeep T-18 has one
bolt hole different, the bolt near the clutch fork is higher on
the Jeep version. The SR-4, T-4, and T-5 use a different bolt
pattern.
Steve's Jeep had the bell housing that went with the T-5, so the
holes didn't line up quite right. If you drill carefully, a drill
press would help here, you can drill out the bolt pattern for the
Ford T-18 on one of these bell housings. The transmission can be
tilted a bit to the left or right, alignment on that plane is not
critical. We were trying to drill out the holes with a hand drill
and messed up one of the holes, so Steve purchased a used bell
housing for $30 with the proper bolt pattern. If you are going to
drill the holes, make sure you have the right size bit for the tap
you are going to use to thread them.
Skid Plate and Transmission Mount
Minor modifications are required to the skid plate to fit the larger
T-18. A notch needs to be cut in the leading edge of the skid plate
to allow room for the drain plug in the bottom of the T-18. The picture
on the left shows the modified skid plate with notch cut out. The
notch was cut with a regular circular hand saw with metal cutting
blade.
On the transmission mount, Advanced Adapters supplies a aluminum
spacer block to mate the bolt holes in the bottom of the transmission
to transfer case adapter to the transmission mount. This spacer block
forces the transmission very close to the tub and causes a minor drive
shaft vibration with a 2 1/2" spring lift. Dropping the skid plate
would resolve the problem, but at the cost of ground clearance.
In order to set up the transmission mount with out losing ground
clearance, the transmission mount must be modified. It is easier
to take care of this before you install the transmission.
- Toss the spacer block in your scrap metal pile.
- Bolt the torque arm directly to the transmission to transfer
case adapter directly with the bolt hole on the drivers side
(fig. 1, item D) and the limiting donut to the drivers side.
-
Mark and drill the torque arm for the other hole (fig. 1, item B)
into the transmission to transfer case adapter. Bolt the torque
arm with both bolts to the transmission to transfer case adapter.
-
Drill and tap the transmission to transfer case adapter for the
hole in the torque arm that falls between the two holes (fig. 1,
item C) that bolt into the adapter. This hole should be either
for a 1/2" or 7/16" bolt. The transmission mount will bolt through
the torque arm into the transfer case adapter.
-
Cut a small notch out of the middle of the transmission mount
with a circular hand saw (fig 1, item E). The notch needs to
be large enough for the head of the bolt.
-
The passenget side bolt hole for the transmission mount remains
unchanged (fig. 1, item A).
Drive Shafts
If you are swapping in a Ford T-18 for a T-176 or T-150, the rear
drive shaft may need to be shortened and the front drive shaft
may need to be lengthed since the overall length of the Ford
T-18 and adapter is longer than the T-176. If you have an
SR-4, T-4, or T-5, no drive shaft modifications are required
for the swap if you use the Advanced Adapters kit.
Shift Lever
The shift lever for the Ford T-18 is in the same place as the shift
lever for the T-176 and T-150, but is several inches forward of the
shift lever for the T-5, T-4, and SR-4. For these transmissions, a
hole must be cut in the tunnel cover for the T-18 shift lever and
the old hole should be covered with sheet metal. If you have carpeting
over the tunnel, you'll end up with an extra hole in that as well. A
new boot is necessary, especially if you have the integrated
transmission and transfer case boot.
Depending on the source of you Ford T-18, you might need to
heat and bend the shift lever so it clears your console and
dash. The T-18 in Steve's Jeep is from a '83 Ford pickup and
it did not need any bending. My Ford T-18 is also out of an
'82 F-250 and the lever is snug on console. I've had my T-18
pop out of reverse a couple of times when there is a lot of
flex, but it normally doesn't happen.
Transfer Case Linkage
If you have a T-5, T-4, or SR-4, the position of the transfer
case is nearly unchanged. No modifications are necessary to
the transfer case linkage or the hole in the tunnel cover.
Modifications may be necessary to the tunnel cover when you
are swapping out a T-176 or T-150 because the transfer case
lever will be repositioned slightly.
Breather
Most Ford T-18s I've seen come with a little pop-up breather.
While the transmission on the floor, it would be a good time
to remove the pop-up breather, remove the transmission top
cover, and thread the hole with a tap. A short barbed fitting
can be installed to run a long breather hose somewhere high.
The hose can be tied into the transfer case breather if your
original transmission didn't have a breather hose.
Electrical
The easiest thing to do with the backup switch is cut the
other end of the plug out of the donor and splice it in.
There aren't many styles of backup switch, so your old plug
may work with the Ford T-18. The switch from you old transmission
might even work in the Ford T-18. None of those options worked
for me, so I spliced in a 2 wire plug and put soldered the
wires to the Ford T-18 switch. After soldering the wires on
the switch, I filled it with RTV to keep it water proof.
Weight
You'll find a significant difference between the weight of
the Ford T-18 and your originally tranmission. The transmissions
used in 80s Jeeps all have aluminum cases and weigh about 80
pounds or so. The Ford T-18 weighs closer to 150 pounds dry.
A good transmission jack will help a great deal for installation.
Converted Ford T-18
Conclusion
Most of the problems with Steve's Ford T-18 swap were not directly
related to the swap itself. One big problem we had was Steve didn't
have a shift lever right off. This wasn't really much of a problem,
but we hadn't run the transmission through the gears until we had
it completely installed. It turned out one of the dogs popped off
somewhere along the way and we had to pull the entire thing and
take it back to the transmission guy. Shift your transmission
through the gears before you install it! The other problem we had
was Steve chunked a rear bearing on the test drive, completely
unrelated, but it meant Steves Jeep sat in my garage for an
extra week or so.
The payoff in the end was big. The truck crawls much better and it
doesn't leak trans fluid on steep climbs like the T-5 tends to. Steves
crawl ratio went from 3.31*2.62*4.03 = 34.94:1 to 3.31*2.62*6.32 =
54.79:1. Reliability of the transmission is also greatly improved
with the heavy cast iron case and larger gears.
Contributors
Thanks to Jeepin Joe Heinrich for the 2WD Ford T-18 picture.
Thanks to Predator 4 Wheel Drive for allowing some of the converted
Ford T-18 pictures.
