Thrust problems with two step in Stock

[GTX JOHN]

My son and I have both have lost thrusts on our Stocker
that run two steps.

Our SS cars have never lost the thrust. Many of our engines
have the same crankshaft builder.

Is there something about how the works on a brake petal
that is different than the way it effects the engine on a brake.

That does not make any sense to me, that there would be any difference
as both ways they operate under similar load.

It seems to happen about the 100 to 125 run point on the stockers.

Do I need to find a new crank man, I have been using the same guy
for last 30 to 40 years?

Does anyone else have this issue?

Appreciate any Feedback!

[1legjerry]

Have you checked your tranmission pump pressure?

[GTX JOHN]

We will check that.
Thanks!

All our transmissions for 30 years have been bought
from our friends at Pro Trans. (Waco, Texas). We seldom
(Maybe Never) have had and issue with them.

However, anything is possible.

[Tom Goldman]

Pump pressure is usually the number one culprit .
also check to make sure the converter pilot is not bottomed in the crank .
I've seen that problem on several SCAT small block Mopar cranks that caused thrust issues.

[GTX JOHN]

What should line pressure be?

110 PSI?

[Henrys Toy]

Originally Posted by GTX JOHN

What should line pressure be?

110 PSI?

Good morning John and to all,
Now what I'm about to say is not a recommendation for the line pressure in your transmission. In the past I ran 165 to 175 line pressure in my Glides and it didn't smear the frictions, and they lived a long life without thrust bearing problems. More recently I'm running 180 lbs. in my metrics, without smearing the frictions or any thrust bearing problems. I've known some racers to have less line pressure and a few to have more, what I'll say is - what line pressure works for you without destroying parts is best.
My past experience tells me that torque converters and/or front pump clearance's will more than likely be the root cause. If the thrust bearing is worn excessively on the converter side that would be my first clue as to where to look next. I'm going to say - if the gentleman that's been doing your cranks for you all these years without failure , and you've recently started having problems in that area , then he's not the problem.
Have a good day.

Respectfully,
Henry Kunz 1534 H/SA

[Steve Stasko]

Originally Posted by Henrys Toy

Good morning John and to all,
Now what I'm about to say is not a recommendation for the line pressure in your transmission. In the past I ran 165 to 175 line pressure in my Glides and it didn't smear the frictions, and they lived a long life without thrust bearing problems. More recently I'm running 180 lbs. in my metrics, without smearing the frictions or any thrust bearing problems. I've known some racers to have less line pressure and a few to have more, what I'll say is - what line pressure works for you without destroying parts is best.

While the info you provided is good, I don't know if a Torqueflite can be compared to a Glide or TH. I've never run more than 140 psi in a 'footbrake' 727. A transbrake 727 usually needs 150+ depending on who's brake is being used...then I've heard of people running as much as 200-220 with a brake. I was always under the belief that you should run as little line pressure as you can get away with.