Transmission Downshift Oddity

[chuzz]

Hey Guys, on my recent trip to Boaz, AL, I noticed a strange occurrence 3 times with my transmission. I had the cruise on and was running about 68 mph and was going down hill, when the transmission down shifted to 3rd gear. I thought, WTF is happening here? I put in into auto stick mode and up shifted to 4th and all was fine. It did it two more times while going down hill. Each time, after dropping to 3rd, I was able to correct it by going to the auto stick mode and bumping it up to 4th again. Any ideas what the hell could be causing this? There are no hills where I live in FL, and I've not experienced it since getting home. I have a new filter and fluid in it, so don't think the problem lies there. If was was a loose filter, I'm sure it wouldn't shift at all. I'm stumped. By the way, I averaged 23.98 mpg on the trip home and had the cruise set around 75 mph most of the time.

[Fk5]

Does it downshift for compression braking to keep the car at the specified speed?

I have a stick, but this car has the worst cruise control I have ever had on an EFI vehicle. My primary complaint is that stepping on the clutch does not cancel the cruise, so if you put the car in neutral it will bang the rev limiter to try to keep speed. Ugh. I had cars from 1984 and 1991 that had the feature. It's not so hard, there is a switch on the clutch.

[LionPT]

Originally Posted by Fk5

Does it downshift for compression braking to keep the car at the specified speed?

I have a stick, but this car has the worst cruise control I have ever had on an EFI vehicle. My primary complaint is that stepping on the clutch does not cancel the cruise, so if you put the car in neutral it will bang the rev limiter to try to keep speed. Ugh. I had cars from 1984 and 1991 that had the feature. It's not so hard, there is a switch on the clutch.

This is what I was thinking also.

[rckstein]

Didn't you recently replace the solenoid pack on the transmission with one from a u-pull-it? Could be related?

[chuzz]

Originally Posted by rckstein

Didn't you recently replace the solenoid pack on the transmission with one from a u-pull-it? Could be related?

I sure did, but I find it odd that it only did it 3 times. But each time was on a fairly steep hill. I've never had a Mopar do this before and I've owned a LOT of automatic Mopars over the past 45 years. Several were the Grand Caravans with the overdrives and NONE of them ever did such a thing. I may drain a pint of fluid out and put in a pint of Lucas transmission treatment. What do y'all think of that idea? I've never used it, but know a lot of people that love it.

[cruserdad1976]

my cruser down shifts all the time if I don't have it set way above 70 for some reason 65-70 is for sure not in the power band and mine will not stay in OD

[rckstein]

Originally Posted by chuzz

I sure did, but I find it odd that it only did it 3 times. But each time was on a fairly steep hill. I've never had a Mopar do this before and I've owned a LOT of automatic Mopars over the past 45 years. Several were the Grand Caravans with the overdrives and NONE of them ever did such a thing. I may drain a pint of fluid out and put in a pint of Lucas transmission treatment. What do y'all think of that idea? I've never used it, but know a lot of people that love it.

Did you drive those same roads before, with your old solenoid pack, and did not have a problem then, or is this maybe something new you are just noticing, but it may actually have always done that?

[chuzz]

No, I've never driven those roads in it before, man. BUT there were plenty of hills in TN that I drove it on that were steeper than these and it never down shifted on me. Cruiserdad, are you saying that this is normal for your car? If so, then I'm not going to lose any sleep on mine having done it 3 times. Keep in mind that this was almost a 1500 mile round trip for mine. I had two tool boxes in the hatch, as I really expected some sort of breakdown due to the age of the car. Lucky me, huh? I didn't even have to open a tool box for a week!

[podo2000]

Mine does that all the time. I live in a hilly area. If I am going downhill on cruise, once the speed exceeds the set cruise speed by 3 or 4 mph, it downshifts.

[Fk5]

Originally Posted by chuzz

No, I've never driven those roads in it before, man. BUT there were plenty of hills in TN that I drove it on that were steeper than these and it never down shifted on me. Cruiserdad, are you saying that this is normal for your car? If so, then I'm not going to lose any sleep on mine having done it 3 times. Keep in mind that this was almost a 1500 mile round trip for mine. I had two tool boxes in the hatch, as I really expected some sort of breakdown due to the age of the car. Lucky me, huh? I didn't even have to open a tool box for a week!

Again with the toolboxes! You don't have to open an old bucket of joint compound! Just pull the torn up old pocketbooks out - one compartment for sockets, another for wrenches. A separate old pocketbook for screwdrives, pliers, etc. What a bunch of fancy pants!

FWIW, you take the tools out and you have your car wash bucket.