In the
following pages, I will try and explain how I took an AW-4 transmission from a
Jeep Cherokee, and installed it into my 2001 Jeep Wrangler TJ. I’ll attempt to be as accurate as possible. But please do not blame me if you take on
this swap and all hell fails. This
information may or may not be the best way to perform this swap. I am not a professional mechanic. I’m simply, a jeeper
who likes to help out fellow jeepers.
That being
said… let’s move on to why I took this project on in the first place.
I bought my
TJ used a couple years ago. I had been
looking for a selection of options that I wanted, but none of the jeeps I
looked at had everything. If they did,
they were expensive or someone had beat the crap out
of them.
So a couple
months into the search, this patriot blue TJ shows up at the Saturn dealer up
the street from work. When I went and
looked at it, I knew I had to have it!
It was in perfect shape, loaded with options, low miles, and a good
price. The only options it didn’t have was the Dana44 and cruise control. But it was an automatic transmission. Well I grew up on sticks and that’s what I
really wanted. But for the price, I
decided to give the auto a try. On the
way home from the dealer in my new TJ, I found out how high the tachometer
actually runs at 70 mph, going with the flow of traffic. Something had to be done!
The last
couple of years, my attitude has changed.
First off, I’ve really taken to wheelin’! Even though I had been off road many times
before, I didn’t realize how much more fun it is to drive a Jeep. Second, I’ve grown to absolutely LOVE my
automatic transmission! Off-road, it’s
so much better than a manual. It’s even
better during stop and go traffic every morning on the way to work. The problem with the Jeep TJ automatic
transmission is that it didn’t have an overdrive gear (this changed in
2003). So, for a dual-purpose jeep like
mine, you’re forced to keep a (numerically) lower gear ratio in order to
maintain proper highway speeds. This is
not such a great thing off-road. But you
learn to live with it.
Now I do a
lot of research on jeeps, whether it’s something that pertains to my jeep or
not… Jeeps just interest me. So I read
all kinds of magazines and web pages talking about the different modifications
that people have done to their jeeps. I
stumbled upon Stu Olson’s web site one day and saw an
article about someone swapping an AW-4 Cherokee 4 speed transmission into their
TJ. What an awesome idea! But, my tranny was
still in like-new condition, with only 30 or 40,000 miles on it. Oh well…
It’s still a great idea.
A year
later, it happened! I had been wheelin’ pretty hard all summer, doing trails all
over. The last planned event for
At home, I
tried everything to get this tranny to start
shifting. The electric connectors were
cleaned, cables lubed, fluid and filter were replaced… just about everything I
could think of to do, but all I got was 2nd gear out of all that
work. I discussed this problem with
fellow automatic owners and quite a few have had problems like this
before. In many of the cases, the
problem just disappeared after driving it around for a while in second. So I did that, but to no avail. Then decided it was beyond my league… I
better take it to Aamco. The good news, it MAY be a valve body and a
couple hundred dollars to fix. The bad
news, the transmission could need a rebuild.
The next
day, I found out it would be $1800 to rebuild my transmission. “Screw that!
For that money, I could put in a brand new transmission myself!”
Ut-oh… brain starting to smoke on the way out the door…
“I could
probably upgrade for $1800!!! I better
do some research before telling the wife my brilliant idea”.
The next
day I went through all of my options, and called around to the junkyards to see
what was available. The options were:
The TF999
would still be a 3 speed, but would definitely be the easiest to do, and probably the cheapest as well.
I didn’t
really want a manual transmission. I’ve
grown to really love the automatics.
The 700r4 would
be really nice, but would require a pant-load of extra adapters. Those cost a good chunk of money and also
extend the driveline even further rearward.
Jeeps already have short rear drive shafts. The wife would kill me for spending that much
cash, over the price of the TF999 swap.
AW-4’s have
come in Cherokees for years. They are
already mated to a 4.0L from the factory, so no adapters are needed. They have a good reputation for reliability. The swap has been done before. And the guy at the junkyard just happened to
have one on the shelf from a ’99 Cherokee that had 38,000 miles on it, for
$200. SOLD!
Now if you know me, I like things to be a little out-of-the-norm. But I don’t just jump into things that are impossible to do. I had to find out as much as possible about this swap before jumping in with both feet.
This is where Stu Olson and Scott Kruize came in. Stu and Scott have done this same swap on Scott’s TJ. The only difference is, Scott’s TJ started life as a manual transmission version, whereas mine was an automatic. The best part was that Scott has the greatest write-up about it posted on Stu’s website. Scott goes into great detail about how he did it. He even has the wiring part all figured out! I strongly suggest you go take a look at this write-up before even considering this project.
Another website by Bob Basset was also very helpful to read prior to this swap. Apparently, Bob was the first one I know of to take this project on. He was the guinea pig. It helped to know what potential problems I would be facing and how much work this would actually take.
I already had the factory service manual for my TJ. Do not take on this project without one! You WILL need it. You will also need the FSM for the donor Cherokee (whatever year that may be… I’ll get into that later). By the end of this project, you will have become very intimate with section 8W!
If you don’t have the FSM in paper form, you can go to alldatadiy.com. They do charge a fee (it’s less if you get FSM’s for multiple vehicles). This is money well-spent. All of the files are in the .pdf format. This makes things nice because you can just print out the stuff you need.
There is also a transmission manual out there for the AW4. I looked at it, but it is mostly a manual on how to tear down the AW4 and rebuild it. It doesn’t tell you much else. In the future, it may come in handy. But it’s not needed for this swap. Just good study info.
The internet is your friend! Go to the discussion boards (forums), post topics, watch what others have to say. Most of these boards are loaded with good people that are willing to help you. Maybe someone out there has advice, or even parts that you need to complete the swap. Get familiar with the people on the boards. After a while, you’ll be able to tell who knows what they are talking about, and who’s full of it. This is a free resource that is very advantageous (It’s even a great place to find new wheelin’ buddys!).
My personal favorites are:
SIJA.org
Midwestjeepthing.com
Jeepinrocks.com
Rockcrawler.com
Jeepsunlimitted.com