What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

wrong torque converter for wheelin?

K

k5blayzer

Registered Member
Joined
Sep 29, 2005
Posts
68
Reaction score
0
Location
oregon
i have a tbi 350 in my 89' k5. i just swapped a fresh th400 in and its holding gears ridiculously long.

it came with a b&m torque converter, but i am unsure of the stall speed.

it literally holds gears till like 5000 RPM's and this simply is not ok.

might this be an issue with the vacuum modulator?

i ran constant manifold vacuum with hardline to the modulator so i dont think that's the issue.
 
I would replace the modulator valve first. A stock convertor is somewhere around 1600-1800 stall speed and that's what you should be running in a wheeler.
 
i will try a new vacuum modulator valve and report back, i really am worried i may have some uuber high stall converter though.:doah:
 
It sounds to me like your kickdown solenoid could be stuck, or you supplied 12V to it fulltime? That wire on the side of the trans is only supposed to have 12V at WOT. That tranny is shifting like you are at WOT all the time. Those solenoids are easy to change to if that is bad, if you can change the filter, you can change the solenoid. It could be caused by the vacuum modulator or stuck valve in VB as well.

A high stall converter alone will not cause it to shift higher, but it will cause more slip and heat at lower engine speeds.
 
i am yet to install WOT switch, the lead going to the kick down solenoid is hooked up to nothing as of yet. but if its possibly just stuck im willing to give it a shot..
 
folkenheath said:
It sounds to me like your kickdown solenoid could be stuck, or you supplied 12V to it fulltime? That wire on the side of the trans is only supposed to have 12V at WOT. That tranny is shifting like you are at WOT all the time. Those solenoids are easy to change to if that is bad, if you can change the filter, you can change the solenoid. It could be caused by the vacuum modulator or stuck valve in VB as well.

A high stall converter alone will not cause it to shift higher, but it will cause more slip and heat at lower engine speeds.
Click to expand...


Yep high stall converter isnt going to have much if anything to do with your shifting.

5000rpm stall is like serious drag car lol.
 
It might be someone modified the govenor weights & springs too,that will hold it in gear longer before allowing an upshift...modulators are adjustible too,,most have a small screw inside the vacuum hose nipple,however,the adjustment only varies shift speeds about 5-10 mph or so..

The modulator should have its own isolated source of vacuum--be sure its manifold vacuum too,because if you hook the hose to a ported vacuum source the tranny will act as you described..
 
diesel4me said:
It might be someone modified the govenor weights & springs too,that will hold it in gear longer before allowing an upshift...modulators are adjustible too,,most have a small screw inside the vacuum hose nipple,however,the adjustment only varies shift speeds about 5-10 mph or so..

The modulator should have its own isolated source of vacuum--be sure its manifold vacuum too,because if you hook the hose to a ported vacuum source the tranny will act as you described..
Click to expand...


its on a dedicated full manifold vacuum, but what is definition of ported vacuum?
 
Stomis said:
Yep high stall converter isnt going to have much if anything to do with your shifting.

5000rpm stall is like serious drag car lol.
Click to expand...


if its that high, its probably a 9 inch convertor also.

The ported vacuum would be above the throttle blades.
 
Don't know the history of your trans but a very common builder error on the 400 is leaving the two bolts that hold the kickdown solenoid to the valve body plate loose. if these are left loose the upshifts will only come at the extreme rpm limit of the governor. If you have to pull the pan, this is the first place I would check once you have determined your vacuum source is good.
 
i know vacuum is good, but im not sure about the modulator, i need to through a new one at it to see..
 
Update!

replaced vacuum modulator and tried tweaking it a little with adjustment screw.. still not up-shifting correctly. i think i may be on to the governor, and if no luck there the shift solenoid for WOT... any suggestions, tips, or otherwise?
 
do i need to drain the oil out of trans before swapping governors? or is it dry in this area?
 
It won't hurt to drain it, you can check the fluid condition then too.

However, you may be fine if you just jack the back of the vehicle up and support it with jackstands, this will let most of the fluid flow to the front of the trans and not leak out. Have a drain pan ready just in case some does come out, and top it off before you drive it if it does.
 
k5blayzer said:
do i need to drain the oil out of trans before swapping governors? or is it dry in this area?
Click to expand...

There is very little fluid under the governor cap when you remove it, some will come out but it will only be a little.
 
folkenheath said:
It sounds to me like your kickdown solenoid could be stuck, or you supplied 12V to it fulltime? That wire on the side of the trans is only supposed to have 12V at WOT. That tranny is shifting like you are at WOT all the time. Those solenoids are easy to change to if that is bad, if you can change the filter, you can change the solenoid. It could be caused by the vacuum modulator or stuck valve in VB as well.

A high stall converter alone will not cause it to shift higher, but it will cause more slip and heat at lower engine speeds.
Click to expand...


noob queston... what is WOT?
 
You must log in or register to reply here.

Latest Posts

Top Bottom