I just bought a 1999 4x4 Sport 360. It has 72 000 miles on it.

I noticed a slight vibration at highway speeds and thought it might be a tire out of balence. But after cominng across this forum and reading about the tranny problems, I decided to take it in.
The check engine light wasn't on but there was a PO740 code stored. (No rpm drop at lockup). I had them flush the tranny and change the filter.

Has anyone had this code before?? I see a lot of P1740 converter codes but not this.
It has been about -30C here in ontario so I wasn't sure if its from the cold or not.

Great forum by the way, and good to see someone got a hold of the service manual download!!


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no one??
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You never said if it fixed your problem.

 

I still notice a vibration.. but it could be in the driveline.
it only happens at certain speeds

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THATS STRANGE MY 97 2WD THROWS THE SAME CODE PO740 BUT MY CHECK ENGINE LIGHT COMES ON AND I CLEAR IT WITH MY HYPERTECH PROGRAMMER

MY FLUID HAS BEEN CHANGED A FEW TIMES WITHIN THE LAST 10000 MILES

 

It may be a cold weather problem since in your description you noted that it had been -30C.
In my '96 Factory Service Manual, it says code PO740 is "Torq Conv Clu, No RPM Drop At Lockup" (Relationship between engine speed and vehicle speed indicates no torque converter clutch engagement).

When I lived in a cold climate (MT) had a JGC,V8, with a trailer towing option that didn't shift correctly in cold temps. The problem was corrected with a TSB that bypassed the tranny cooler @ cold temps.

I've seen several cold weather TSBs having to do with Dodge transmissions at the following: http://dodgeram.info/tsb/group_21.htm

When you find the solution, it would be of interest to me if you would pass it on. I have a '96, 46RE, with a relative large after market tranny cooler and live in asemi cold climate (ID). Forunately, have not had a problem.

 

I have this problem on my 99 dodge ram 1500, i was told to just do a full flush, cause its most likely your transmisson senors is gotten dirtty and is giving bad reading this sensor is one of the sensor most requires to run a vehicle aswell. I have done research and this problem comes up a lot in the the highway vibrations, and odd transmission shifting. Some expert so call say to replace the transmission torque converter clutch but i dont think you should go that far try for a flush with some cheap brand stuff, and then see if u need to do the clutch cause it not like most of you have ever end change your trans fluid before so it will be good for the trans even if it doesnt fix it. Plus a flush is a hell of a lot cheaper then removing the trans and changing out the torque converter clutch.

 

Just a suggestion, and it wouldn't have anything to do with your CEL code, but it will cause a slight vibration in the drivetrain. Do a quick check on the u-joints to make sure none of them are worn out. I was feeling a slight vibration after I got my gears replaced and I thought it was just the new ones breaking in. Turns out it was a worn u-joint at the rear axle. It was worn just enough to wobble when I tried shaking the driveshaft, but not enough to clank loud enough to hear when accelerating / decelerating. That's why I originally didn't even think of it being a possible cause for the vibration. It has been replaced and no more vibration.