1989 chevy silverado k1500 autotrans

[SuperNova]

Re: 1989 chevy silverado k1500 autotrans

on my 1989 silverado k1500 350 automatic over drive transmission when on the interstate and in overdrive if i press the gas over like 1/4 throttle it slips it acts like it kicks down a gear but if i drop it out of overdrive the rpms come up a little bit more. would this be the torque converter unlocking for some reason or do i have bigger problems. i bought the truck with a blown head gasket and high millage but i had a rebuilt (well about 40,000 mile) 350 so i put that in there the trans had a sticker on it saying it was rebuilt and by what company and such on the bell housing and was pretty grease free unlike the old engine. i had never takin it on the interstate with the blown headgasket only around town enough to make sure that everything was functional on the truck. after the swap it took me a bit of messing around with the throttle valve cable to get it shifting like it used to. i mention that thinking maby my throttle valve cable still is not adjusted properly

1- The 1/4 throttle unlock of the torque converter sounds about right, although I am willing to bet you are underestimating how far you are actually pressing the pedal.

2- When you pull it out of O/D into drive it should gain more rpm because you are forcing the trans into 3rd gear instead of just a T/C unlock.

3-The main thing is the correct converter lock up speed, and it should actually lock around 42 mph in 3rd(drive) or 51 mph in 4th(o/d)

4- The throttle valve cable that runs from the throttle body down to the trans should be self adjusting. You lift the clip and allow the cable to retract all the way (it's spring loaded) and then just depress the throttle pedal all the way to the floor--the cable automatically sets itself.

5- If you decide to do a rebuild definitely install the shift improvement/repair kits from one of the reputable manufactures such as transgo, etc.
--
Stan

 

[Benny1963]

Re: 1989 chevy silverado k1500 autotrans

some of the older r4s have modulators . 4l6os do not
change your filter may have internal seal leaks causing low pressure prob and converter may be bad .its ashame that the rebuil cost is so high bench exchange in my area is 650$
but most shops cannot seam to make a r4 last
although ive seen gm r4s last 18000miles
good luck bennyb

 

[Ezrider_92356]

Re: 1989 chevy silverado k1500 autotrans

well i guess it looks like its gonna be a rebiuld or do a manual tranny swap, today i was driving it pulled into a parking lot and it wouldent back out of the space no reverse at all. so i push it back drive it home and i go to drive it to pickup my other truck and lost all forward gears on the way there

 

[Benny1963]

Re: 1989 chevy silverado k1500 autotrans

your having some some internal preesure probs the only way sometimes to get them right is to rebuid ive built several for my self but havent had much sucess longivity and they dont like hi horsepower unless upgraded
its hard to find a good trans guy to do these the most luck ive had is with factory remaned units but there high in price /i usually change to turbo 350s or 400s but there in vehicles that are up in horsepower/and gear so the over drive doesnt matter / but the overdrive does give the ability in these cars to run more gear and still be streetable
the turbo 350 is bullet proof / and rebuilds are cheap 200 plus converter
and parts 89$ are cheap thats what i build for right know and thse tranys with good clutch drums and bands and guality parts will stand up to 600hp
anyway it goes good luck

 

[Ezrider_92356]

Re: 1989 chevy silverado k1500 autotrans

the bad thing is i had a turbo 350 trans when i did the swap but opted to keep the 700r4 for the overdrive then i sold the 350 trans in the local paper for 150$ oh well i knew in the back of my mind that i should hold onto it but i was also wanting to make room and get rid of some ****