Cold snap starts shift issues on 700R4

[89Suburban]

The first very cold morning of the season struck yesterday. Lows in the mid 30's highs low 50's. I went out around 3 PM to get lunch. Fired up Silvy and she revved up pretty high for the cold start. I waited about 30 seconds and shifted into drive. She slammed really hard into gear, like launching the truck. Freaked me the hell out. Then as I drove I would have to really rev it out high to get it to shift into the next gear and it would slam into the next gear. When I came to a stop it downshifts fine. As the truck warmed up it slowly got better but the rest of the day it still acted funny. It's not slipping at all just shifting really strange. I checked the trans cable was attached to the throttle and it was. I did not touch anything or do any work on the truck at all. Just been driving it and had 0 issues until now. Trans fluid level is fine. I also tried shifting through the years manually to see if it would clear up. In went back out again last night towing the boat, ran to the next town for supplies, hit the river then got dinner on the way home. No slamming gears but it still randomly shifts awkward. Not sure what I should be checking for these symptoms. One thing that I did not try was pushing the gas pedal all the way to the floor with the engine off, curious if for some reason the trans cable may be binding? Pedal feels like it always did. Whatever gremlin this is is a result of the cold snap waking it up. Ran flawless until this happened. I will report back how she does today. I have to change the motor oil and filter today so I will be under there.

 

[89Suburban]

And I don't beat on this truck, it is my baby and I drive it like a Paw Paw and take care of it.

 

[Jarhead79]

Try letting it warm up more, I had a Dodge Ram and a Dodge Challenger that when parked at an angle, during cold weather it would shift wierd sometimes right after tske off or around corners

 

[89Suburban]

Still doing the same thing today. Never did this before. It's like the TV cable is misadjusted but I have not touched anything. Revving out longer than needed before shifts. Something has to be hung up in the trans. I'll have to keep researching.

 

[Jarhead79]

I also had to replace the rubber vacuum hose that plugs into the back of the transmission modulator, mine wouldn't shift into passing gear and felt really soft when it would shift.

 

[PrairieDrifter]

Did you do any trans work over the summer or anything related to it? My Colorado has higher shift points and shifts harder than usual on a cold morning until it warms up enough, granted it is an 06.

 

[89Suburban]

Have not touched a thing involving the trans.

 

[yevgenievich]

Tv can get stuck on 700r4 causing harsh, high rpm shift. Went through that with my old suburban. When shifting harsh, pull over and leave it running. Then open the hood and pull the tv cable all the way out few times. If tv is sticking, it will likely unstick and shift ok untill next time it sticks. If it does not work, the other way to verify is with a pressure gauge or dropping the pan

 

[mistaake]

Did you do any trans work over the summer or anything related to it? My Colorado has higher shift points and shifts harder than usual on a cold morning until it warms up enough, granted it is an 06.

Wow... somebody else with a Colorado I have an 07. Do you dislike it as much as I dislike mine? On the top, mine does not do that, though.

 

[PrairieDrifter]

Wow... somebody else with a Colorado I have an 07. Do you dislike it as much as I dislike mine? On the top, mine does not do that, though.

I actually don't mind it. Its a boss off roading but its terrible on gas for a five banger. wish it had the v8...I would have sooo much fun. Other than the gas mileage sucking, I haven't had many repairs to do in the 100,000 ive put on it, just routine maintenance. Well except when I bent the front diff cover open...a new front end later... other than that its been good to me.

Im in ND so it gets pretty cold up here haha

 

[mistaake]

I actually don't mind it. Its a boss off roading but its terrible on gas for a five banger. wish it had the v8...I would have sooo much fun. Other than the gas mileage sucking, I haven't had many repairs to do in the 100,000 ive put on it, just routine maintenance. Well except when I bent the front diff cover open...a new front end later... other than that its been good to me.

Im in ND so it gets pretty cold up here haha

Yeah my gas mileage is garbage and I have the lame 2.9L four cylinder 2WD that is not only slow and underpowered but doesn't get nearly as much MPG as it should.

 

[PrairieDrifter]

Have not touched a thing involving the trans.

My vote is tv cable! if that's not the case then I would say a vacuum issue.

 

[PrairieDrifter]

Yeah my gas mileage is garbage and I have the lame 2.9L four cylinder 2WD that is not only slow and underpowered but doesn't get nearly as much MPG as it should.

The 3.5 has nice torque, if it was 2wd and a manual it would probably get a little better mileage...could probably get 20 with the 5.3 But its a heavy little bastard, its the z71 crew cab 4wd and weighs about 5500lbs. I like the idea of it having a big motor in it so I don't know if ill be able to get rid of it..i just want to do an engine swap if and when this motor dies

 

[mistaake]

The 3.5 has nice torque, if it was 2wd and a manual it would probably get a little better mileage...could probably get 20 with the 5.3 But its a heavy little bastard, its the z71 crew cab 4wd and weighs about 5500lbs. I like the idea of it having a big motor in it so I don't know if ill be able to get rid of it..i just want to do an engine swap if and when this motor dies

We better stop pooping in this guys transmission thread but in summarization it's funny that a V8 gets better fuel economy than a 4 or 5 cylinder... it makes it clear what GM has focused it's entire years of expertise on

 

[89Suburban]

Tv can get stuck on 700r4 causing harsh, high rpm shift. Went through that with my old suburban. When shifting harsh, pull over and leave it running. Then open the hood and pull the tv cable all the way out few times. If tv is sticking, it will likely unstick and shift ok untill next time it sticks. If it does not work, the other way to verify is with a pressure gauge or dropping the pan

Thanks for the input. I think that is exactly what is happening. TV cable or valve is sticking when it gets too cold out.