Can't party on the cruise control yet, it still can't hold speed on decent sized hills. I won't pull hard enough to down shift. Now I'm really lost on this. Is there a vacuum reservior anywhere on these?

I know how bad pulling one of these trannys is. Way worse pulling one of these trannys from a durango/dakota (this is from experience).There's a crap ton more room under the rams. But the dust shield is clean on the outside, its just right around the drain hole between the dust shield and tranny.

 

I don't believe So. I know the ductwork for Hvac is switch by vacuum bags on a series of tubes behind the dash, and obviously the cruise is regulated with it. It isn't like it has the old Vacuum operated Popup or rollover lights to keep closed when the engine is off.

Oh well okay then...definitely the Block main, or AT pump seal.
There is a myth that ATF stays red forever...as it ages it turns brown and like motor oil Black eventually.
I am guessing you have a notable oil level drop at changes or sooner to validate that it is Not the Tranny input seal then?

 

There IS a vacuum reservoir, but, the cruise control isn't plumbed into it. It gets its vacuum directly from the throttle body.

 

Is it possible that I have an electrical issue? Either Map or TPS related? I may run a new vacuum line to the servo just to make sure it isn't that. I put in a new servo already.

 

What kind of vacuum are you seeing at the servo? Can the servo pull the throttle all the way open?

Mine doesn't like to downshift when on cruise either. I always thought it was the PCM refusing to drop out of O/D, never considered the servo simply not pulling the throttle open enough.

 

No the servo can't even kick it to 3rd from O/D. I have had 2 durangos that both could do WOT, my uncles v10 and the v10 me and my brother have can do WOT using the cruise. Now I had to fix part of the vacuum line at the servo because before I bought it the battery exploded and made all that plastic brittle, one of the reasons I put in a new servo.I have an aftermarket display and it shows the cruise maxing out around 33%, right before kickdown because when it is at that point I pushed on the pedal and it kicked down.

HeyYou we may get your cruise figured out as well.

 

Is it because the servo just doesn't have enough travel?? Or is it simply not getting enough vacuum to pull the throttle open?

 

I'm going to look up the cable adjustment. When went to do my plenum I found out the PO had broke the throttle kick down cable for the transmission and glued it back on. Wouldn't surprise me if he did the same with the cruise but replaced it cause its easier to do. When I checked the cable routing and movement it seemed to have a bunch of slack.

 

Slack could definitely cause issues.... Not sure if there is a way to eliminate it, I haven't investigated that far. (I don't use my cruise very often anyway......)

 

Ok so I talked to the truck tech at work here. He said there is supposed to be some slack in that cruise cable. After describing my issue he told me it was most likely the TPS or it could be the governor pressure sensor in the trans. Apparently if the TPS is bad the computer will not unlock the converter and allow the cruise to kick to second. Apparently it is supposed to kick to second gear unless the vehicle is at a speed to high for second. Also if the cruise is acting weird it could need a relearn. To do this hold the throttle steady around 60mph and set the cruise. The important part is to let the pedal pull away from your foot. Do NOT let off the pedal and then set it (this is what throws them off). Let it cruise for a minute or so then turn the cruise off. Do this 5 times in a row.

For me a new TPS did the trick and my throttle response is way better. Now I just have to fix my plenum for the 2nd time in 6months. Not buying the cheapest gaskets I can find this time. Maybe time for a hughes intake...........