Hot Pursuit
1999 Dodge Durango SLT, 4WD, 5.9L, A/C Projects
~85,000 miles Auxillary Transmission Cooling System
Now that the Durango is being used for towing a trailer, I have installed an auxiliary tube and fin cooler in front of
the A/C condenser mounted on two pieces of aluminum bar stock. The plumbing for the cooler is all NPT threaded. The fluid
to the cooler first travels to a remote mounted oil filter, then through the first transmission oil temperature sensor, then
to a oil temperature bypass valve, then through the cooler, then through a second transmission oil temperature sensor, and finally
back to the pan. An Autometer electric gauge was surface mounted in the cab to the lower left of the steering column. It's
not easy to see here but I figured that it wouldn't get bumped there and would be the least obvious damage if we went to
sell the truck. Directly below the gauge is a toggle switch to select which of the two senders is displayed on the gauge.
If I had to do it all over again, I would have used a gauge that read to 300 degrees, instead of only 250. I have been told that
putting the remote oil cooler inline right after the oil exists the torque converter is ideal as it's best to filter hot oil.
During normal driving without a trailer, the transmission temperature was normally around 180-185 degrees F. When towing up hills
the temperature would climb to 230 degrees. Sometimes (Rocky Mountains), the temp would peg the gauge at 250, but I wouldn't let
it stay there for long. If it was there for more than 60 seconds, I would stop to let it cool. Even then, I thought the temperatures
were still too high. I considered installing a fan on the cooler (and water sprayers), but there isn't enough room because the Durango hood
includes the front grill. Anything mounted in that zone needs to clear opening and closing the hood.
~100,000 miles PCM Failure
While towing a trailer up a very steep, narrow, two lane road, the engine suddenly quit and could not be refired. Fortunately,
the road wasn't very busy, so the occasional car could easily drive around. The problem seemed electrical at the time. The coolant
temperature was also somewhat higher and this was a very hot day and the A/C was on. Subsequent attempts to refire the engine mostly failed.
After the engine cooled down, the Durango would again start and I could drive some more. I had certainly seen that sort of problem before
with magnetic sensors (crank and cam sensors) and suspected that the Durango had a crank sensor that was keeping the PCM from detecting
cylinder #1. I was mostly able to accomplish my mission that weekend, but ended up have the whole rig towed when it happened again and
letting it cool for 20 minutes didn't fix the problem. It got to the point that driving the vehicle for just a few minutes would cause
the failure. So to test a theory, I put a bunch of ice in a zip-lock bag and set it next to the PCM. Bingo! I could drive it as far as
I needed to as long as the PCM was kept cool.
The online Dodge forums seem to indicate that most 1998-1999 Durangos had PCM problems. I bought
an exchanged PCM from a place in Florida through eBay. The first one had security enabled, but since my D has no security features, it
wouldn't work. Apparently the security code is in the BCM on security enabled Durangos and the PCM needs to communicate with the BCM before
the vehicle will start. So I returned the first one and the second one has worked well. Interestingly, the lean mixture problem, seen as
pinging, went away with the new processor. The truck performed better than it had ever performed. It was like new.
~120,000 miles Transmission Failure
The transmission started to slip while towing a trailer. The slip was initially only detectable by increased transmission temperature. The temp would
rise very quickly on steep uphill sections of road. I pulled over several times to think about what could be happening. Finally, I got impatient
and drove it hot until the Dodge Transmission over-temp light went on. I can guess that the light doesn't come on until 280-300 degrees F! That's way too
late. I pulled over immediately and came to the conclusion that
the torque converter must be slipping and generating all of that heat.
Some interesting notes:
Dodge is doing their customers a great disservice in not triggering the over-temp light sooner.
Having a real temperature gauge is as important as I first suspected that it might be
Having two senders is worth the effort (the after cooler temps weren't that unusual, but the post TC temps were very high)
This time, I was able to drive the truck home, then fetch the trailer with a borrowed truck without having to pay for a double tow (truck and trailer).
Since the temps stayed normal during ordinary street driving, I thought all I would need is a new TC. So I took the Durango to a local transmission shop.
I had previously read online to never get the transmission flushed, and especially not when a problem was suspected, so I told the counter girl to just
drop the pan and replace the filter and gasket and check the pan from damaged parts. I didn't know what they did from that point, but when I got
the truck back, it wouldn't shift correctly any more. It was slipping right after leaving the parking lot. This was after the owner had told me that
it was a great shifting truck after the initial test drive. He denied all of this and refused to refund the money after basically junking my truck!
So, now I know where not to go to get a trans. I suppose that's something. So I looked on the internet for a builder with good reputation. I found one
in Martin Saine. I talked to him via email and we worked out what the best configuration would be for a tow-only Durango. I had to have the truck transported
to his shop, so I used a service called uBid.com to find a transporter. I was very happy with the transporter company uBid identified. In the end, doing it
this way cost me an extra $600.
~120,000 miles Solenoid Connector Failure
Click any image to see a higher resolution version
All of these images were shot through a mirror.
Below: Attempting to push the connector on with some help from safety wire and safety wire pliers
Below: The lower left corner of the connector is hitting the casting. The connector is just barely on the base, maybe 2 mm covered.
Below: The lower left corner or the harness connector tells the story - the corner has been worn away and the locking clip is broken.
Below: It's hard to tell from this image, but the hole was machined off center, so one side of the casting is too tight against the connector.
Below: The two black marks to the left and right and below the connector on the casting are from where the connector is rubbing on the casting.
They also show the total distance the connector was allowed to travel before stopping at the casting.
Below: After grinding the corner of the connector with a Dremmel tool, the connector slips down over the base.
Below: Another shot after the grinding.
Below: Park Rod E-Clip (In focus, center, background)
Last update: October 23rd, 2010
