Ok I was crusing up the interstate today to 70Mph and I started to pull a hill and the truck shifted as normal untill I got to the top and it shifted into 2nd and tach out at 5000 rpm (ouch ). It did it about 10 more times on the way home.
I had the crusie on the whole way.
Not sure weather its a transmission prob. or a Cruise control prob.
Any Ideas.

 

i didn't even think the truck would go 70 in 2nd gear. does it do it when off cruise control? if so then it's probably not it.

 

theyll hit 75 sometimes 80 in 2nd gear to 3rd.

i would suspect a trans problem more than cruise because it seems more likely, see if it happens without cruise and that'll probably tell you somethings amiss. the good thing is it could potentially be a solenoid (simple, cheap). remember, i said could lol.

 

There is nothing wrong with either one.... It's because your CC does not "know" it's going up a hill.... All it "knows" is that the speed is dropping and it needs to keep the set speed... So, it is essentially matting the pedal to get back to it's set speed as soon as it can..

Moving a #5000 brick up a hill takes a lot of power. The faster you want to go, the more power you need.. What drivetrain do you have? What was the grade of the hill?

Mitch

 

4.6, 3:73 rears, 4x4, with 315-70x17. I think it might be the size of the tires throughing them speedo off?

 

maybe my floor mats in the way but ive never had it downshift to 2nd at 70. sorry

 

Just a bit.... If you haven't adjusted your speedo for those size tires (~35") then your speedo is going to run SLOWER then your actual speed.. If you see 70 on the speedo, you will buzz around 77 mph on the cops radar.....

The other thing is you are really bogging down the motor with those tall meats and the 4.6 needs rpms to get into it's power band, so it's a combo of all of that IMO...

Your options... Recal your speedo. It's done in the computer, so you'll need a 'tuner' to do it.

Regear the axles. Get some 4.10's and it should bring you back to around stock gearing on the speedo and engine/trans. If you want a little more off the line oomph, go for some 4.56's.

Get a truck with a real motor! ha, ha!! I'm jk!! But, it's always fun to bust the ***** of someone running a 281 CI engine in a #5000 brick!

Seriously, you need to do one of the above.. Your trans not being synced up with the actual speed causes it to not shift right and you have no clue what your actaul speed or miles traveled are.. You will now have to report that your speedo/odo is off if you sell the truck.... On the gears, you are bogging that poor little 4.6 down and it can't get to the rpms it wants unless it drops to 2nd going 70....

JMO on it all, but that's how I see it..

Good luck! Got a pic of the truck? I like those big ol' 315/70/17's on a 4x4....

Mitch

 

Thanks for the help. I have an SCT but SCT does not have my Stratogy code so I am waiting for custom tunes from Troyer. Crystal said today about another 4 weeks. It's been 6 weeks now, but I heat it's worth the wait. As far as the pics. having problems with the camera I hope to resolve soon. My computer won't read it. True Duels next Thursday.