how many kickdowns should I be able to get?

[bigtendude]

I am curious, How many times should I be able to make my tranny kickdown. So far I can make it do only once, from approximately 35mph. after it kicks out at about 60mph. I cannot make it do it from then on. Am I expecting too much? 350c.u.i. Quadrajet Carb. 350THM, 3.73 gears, 107,000 miles on engine, unleaded regular gas. Carb looks brand new, but then again so does whole truck, extremely clean. C10 Big 10. Thanks in advance......Larry

[Pontiac1976]

Well it should do a few times , But has to do it at a higher & steady cruze speed & it will depend on the trans age has some to do with it.
if the trans has been tuned up, a bit it will be easyer to do.
If your vaccume to the tran is not good or leaking that will efect it .
I be leave if you go to the trans section some of this will be in there.
I sure bowtieguy or 19_ Chevelle _69 can tell you. much better.

[BowtieGuy]

Getting the tranny to kick down is not something any one can give you a specific answer on, there are alot of variables. The 3.73 gears are the main roll, rear tire size is also. At 60 mph with 3.73 gears and about 28 diameter tires, you are running about 3k rpm. If thats the case and you kick it down to 2nd gear then you can figure about 5k rpm and unless you got a well built motor you really dont need it to kick down. Trans ife and wear also comes into play here too. These are not exact figures but real close. With 3.73 gears and not knowing your tires size, I would say it probobly will not kick down after about 45 mph or so, that is just my educated guess so don't take it as exact figures.

[bigtendude]

I have P235/75R/15 Load range " D's " on it. Am not planning on hauling heavy loads with it. What is best tire size for all around city and freeway cruising, and also will be driven in the snow for its first time ever, this year, also, what load range should I be running? I don't like agressive noisy on the pavement type tires either.

[bigtendude]

I also do not have a Tach in my truck, but plan on getting something for it, I have one opening left for a gauge, I think a clock was supposed to go there. If I have to, I will set one on the dash or seat next to me.....lol.

[BowtieGuy]

I am currently running 275/60/15 on my truck not sure about the load rating without going to look. Never really paid much attention to that, since I don't haul any thing but ass lol. The tires you are running should be about the same diameter as mine though so the rpm should be about right. I have the 700r4 tranny in my truck but in 3rd gear it would be the same as a turbo 350 or 400. The O/D does make it nice with the steep gears.

[Pontiac1976]

C / D tires are used mostly for pulling heavy loads long tread life harder rubber ,Oh they take the road heat better for long road trips.
There Not considered a passanger tire more of a work tire.But it's really up to you . what you like or what your using the truck for.

[bigtendude]

I plan on using it for pleasure, Maybe drive to Upstate New York once in a great while. Not hauling anything over 300 pounds. Would a B or C grade be more comfortable or does that have to do with tread Diameter?

[Pontiac1976]

those would be better or more what you are looking for the Other thing will be Tread . If you go to a good tire shop get some info & tire sheet info card from a few brands compare the tires . The tires will have a load weight on them if you get 4 of them x the # bye 4 ( IE. 25lb that would be 100lb total ) that number should hold the weight of the truck + the a weight up to the biggest loads you will carry But still in the limits of the Suspension too. This should in clude the fuel tank full Try to pic out some tire that you like the tread patern & have good numbers you like tread life ( now truck tires do not all was give this # because of loads on the truck ) You will have to ask the tire guy & know he can be trused or know his tires.
The tires have to work with the shocks too.
Has a little bit to do with it the taller the tire softer the ride un less you have a reall hard heavy duty tire . Helps with the hard hits of the road. Try to see what your tires say on the side after you pick up a tire info cards for a few brands compare . you should start to see how the info works then it should help you pick some tires.

[bigtendude]

Update on downshift. I found all my downshift points, I just wasn't mashing down on accelerator hard enough....lol. Man, do I have a wicked power thrust, just wanted to know, because sometimes you have to get up to speed really quick on the entrance ramps around here to the freeways, as most people are traveling in excess of posted limits in the right hand merging lanes......ZOOOOOOOOOOOM! There are also a few instances where entrance ramps dump ya into left hand HIGH SPEED lanes.....YIKES! Because of the characteristics of the 3.73 rear gears, that aint gonna happen, unless you can hit that magical speed and make tranny downshift. I can make it downshift for last time at about 60mph. then it kicks out at about 75-80mph. But, I also know that all four barrels are open at the same time and can see fuel gauge being depleted, so I don't don't do this very often. Larry

[Pontiac1976]

Kool glad to hear that it working . Yes that the nice thing about the 3.73 . That the other think if you go to 3.08 you will not have the real snap kick down for the highway ramps. As I said before I think you would really like the 700R4 trans with a 3.42 or 3.55 with the 235/75/15 this way you get all the snap you want still but save on gas. or you can play with smaller tires to get some gear back if you go with the 3.08 gear 205/75.15 . I sure BowtieGuy or 19_Chevelle_69 can tell you what it like to have gears & try to pick the right set up if you want to try to get the best miles out of the gear and tire set up.
I sure there a few on here that can tell you about the 700R4 with the 3.73 how much better the fuel miles are over the 350TH & 3.73