Stall Converters.....

[XplorerKid]

Ok heres the siutation the vehicle i bought has a stall converter in it, even though it is helping in no way, as far as i know, thats why i started this thread. The PO installed it when they rebuilt the tranny, but the engine is absolutely stock(short of me bout to install headers but that would not need a stall converter) Now in stock forum i know the stall was causing the truck to not shift at the right times, and in my eyes losing MPG.

I have since lifted the truck and put it on 37"s while retaining stock gearing. I know 37"s and stock gearing = ****ty milage, but in my head i was thinking the stall converter would help equal it out some, but i think its causing me the same problems, it not shifting at the correct RPMS and making even crappier gas mialge than it would be with a regular converter.

Now i do not know what stall the converter is and i do not know what RPMS my truck is running at or shifting at, as the vehicle does not have a tach. Will be picking one up tommorow and installing in the next few days. But i wanted the input from the Tranny Gurus, is the stall converter helping in any way, or just causing worst milage? I personally hate the stall cause takes for ever to shift, "i believe" its not hitting OD till high 60s which im almost 100% sure is way off, if i remember correctly isnt OD around 55?

Please give me yalls input.

Much appreciated!

-the Kid

 

[XplorerKid]

all these smart tranmission guys and no responses?

 

[Willard]

From what I've seen a converter with a higher stall than stock won't help you out on a stock motor. It's just over-revving the motor, which is useless because generally a stock motor makes most of the torque at a relatively low RPM. So basically you're kind of throwing power away.

On top of that, a higher stall means the converter will slip more initially, which means more heat, which we all know is bad for automatics. Also a high stall is very bad for off-roading, mostly because of the heat and because you would be uselessly revving the motor.

I would say you're best bet is to get a stock stall converter and gear it properly, and it should shift better.

Is this on the 1990 Blazer?

 

[IZwack]

I have since lifted the truck and put it on 37"s while retaining stock gearing. I know 37"s and stock gearing = ****ty milage,

Kinda confused, I thought you had 4.88s:

Drivetrain-
4.0L OHV
Auto Trans
4.88 Yukon gears

But shift points dont really have anyting to do with torque converter stall RPM. Vehicle speed is taken at the axles and it is this signal that is used for the shifts.

But also if gear ratio is the problem, why not get it reagered? You have a 2wd so its like half the cost off the bat! Slap on some 5.13s (if thats available)

 

[XplorerKid]

Kinda confused, I thought you had 4.88s:


But shift points dont really have anyting to do with torque converter stall RPM. Vehicle speed is taken at the axles and it is this signal that is used for the shifts.

But also if gear ratio is the problem, why not get it reagered? You have a 2wd so its like half the cost off the bat! Slap on some 5.13s (if thats available)

Iz this is on my 1990 Chevy Blazer, the explorer did have 4.88s, i didnt regear this vehicle yet cause i dont want to really regear both axles yet. Since im not sure what route im going to go, Id like to stuff a D60 under the front, and hoping i can find a set of 60/14ff already geared to save some money. I already put a 14ff in the rear that i got dirt cheap, and it matches my front 10bolt ratio. So what we are saying is toss the damn Stall converter out cause its doing nothing but hurting me.

Thanks for the help.

 

[CDW6212R]

Unless the stall is so high that it does get near the normal throttle shift rpm's, then the shifting issue will be unrelated. Look into the PCM control, and/or a valve body kit. That would help the shifting, but the TC still sounds like it is too high for you. Ask Jon here about his 3000rpm TC in his truck, it doesn't affect his normal shifting. I have a 2800rpm TC about to go in behind my stock 302 for now. It won't affect my normal shifting either.