Trust bearing !!!

[odell4o8]

trust bearings

Around here a lot of fast cars run power glides, and 400 . few are manual 5 spds. even a manual shift trans, with a strong pressure plate is hard on the trust bearing, last sat, nite at muncie dragway i walked around the pits asking car owners about trans, problems these were mostly big chevys, some glides, some 400 some said they had no problems with trust b, some said that they have had in the past,, i never saw fire or sparks coming from under any cars,that i could see that is,,,

 

[Alky V6]

Thats is exactly correct. Hence this the force that eats the thrust bearing.
Don I use a Setrab cooler. I saw variences in pressure non proportional to the main line pressure changes. IE: 40 psi increase in main line did not raise cooler out pressure 40 psi. It did however raise it say 20 psi.
What you see at idle or in gear for cooler out pressure or even with a raised rpm in park or in gear does not remain constant. The pressure will spike after transbrake release and some times near the finish line as well.

Have you checked the pressure drop across the Setrab cooler?

What range of cooler pressures are you seeing at what low line pressure setting and what are the spike values?

What range of cooler pressures are you seeing at what high line pressure setting and what are the spike values?

I don't understand the spike on release, unless there's a hydraulic leak in the high clutch circuit holding pressure down while applied. There is commonly, a 1/16" bleed hole drilled into the high drum on transbrake 400s. I wonder if that would cause your pressure spike on release of that circuit. But then for it to show up that easily on your cooler gauge.

That cooler gauge sounds interesting. I may have to install one and play with it.

Lazaris. I'm a little afraid to ask, but how many gauges do you have in your car?

 

[Alky V6]

Around here a lot of fast cars run power glides, and 400 . few are manual 5 spds. even a manual shift trans, with a strong pressure plate is hard on the trust bearing, last sat, nite at muncie dragway i walked around the pits asking car owners about trans, problems these were mostly big chevys, some glides, some 400 some said they had no problems with trust b, some said that they have had in the past,, i never saw fire or sparks coming from under any cars,that i could see that is,,,

Yep. If I build a PG for a customer and it's a racer, I even orifice them. Like was stated earlier. Better safe than sorry.

Like I said before. Not all 400s are crank killers. The mod is to safe guard against those that have the potential to be.

I will never suggest that other transmissions won't also kill cranks. People just need to be aware of what causes this and take the time to test for it.

I have a buddy that runs a comp eliminator dragster. He bought this pump and valve body from a well known company for his PG he built. He has been building his own for awhile now after some tutoring on my part. Now he builds them for all his comp buddies. Anyway, on start up he checked line pressure and this thing was at 280 psi. I told him, why the heck do you need that much line pressure?! He agreed with me and called the supplier. They said that's how they set it up. Good grief! Anyway, we brought the line down. This thread got me thinking. I haven't asked him yet if he made sure T/C feed was orificed. Imagine 280 psi line with a possible crank killer and no mod. I'm off to call him now to make sure he checked cooler line pressure on that thing.

 

[Dusty Bradford]

With the Reid case glide's it's not unusual to see 260-300# of main pressure behind these 2000+hp turbo cars. They need the pressure to keep high gear clutches in them. I had 180# and could burn high gear in less than 5 passes with 1600hp. I then swapped everything into a Reid case with 240# pressure and haven't hurt it in a whole season.

 

[Alky V6]

With the Reid case glide's it's not unusual to see 260-300# of main pressure behind these 2000+hp turbo cars. They need the pressure to keep high gear clutches in them. I had 180# and could burn high gear in less than 5 passes with 1600hp. I then swapped everything into a Reid case with 240# pressure and haven't hurt it in a whole season.

Yeah, I can understand that. But for a 900hp BBC in a comp E dragster (light car) ? Not necessary.

And my friend knew that from past history with the car.

 

[lazaris]

Have you checked the pressure drop across the Setrab cooler?

What range of cooler pressures are you seeing at what low line pressure setting and what are the spike values?

What range of cooler pressures are you seeing at what high line pressure setting and what are the spike values?

I don't understand the spike on release, unless there's a hydraulic leak in the high clutch circuit holding pressure down while applied. There is commonly, a 1/16" bleed hole drilled into the high drum on transbrake 400s. I wonder if that would cause your pressure spike on release of that circuit. But then for it to show up that easily on your cooler gauge.

That cooler gauge sounds interesting. I may have to install one and play with it.

Lazaris. I'm a little afraid to ask, but how many gauges do you have in your car?[/QUO

I dont have the gauge mounted in the car. I just T'd it in when I was testing the pressures. My cooler has a very low pressure drop 5psi diff if that. I dont have as many gauges as Norbs.

 

[S2V6RACER]

I'm seeing 3-4 psi rise after release of T-brake. I wouldn't call it a spike because it's a smooth transition. That is only for .300 of a second then it drops. It does spike in the shifts though for just a instant. Nothing of the PSI creep through the lights but I'm sure everybody is probably seeing something different.

 

[Alky V6]

I'm seeing 3-4 psi rise after release of T-brake. I wouldn't call it a spike because it's a smooth transition. That is only for .300 of a second then it drops. It does spike in the shifts though for just a instant. Nothing of the PSI creep through the lights but I'm sure everybody is probably seeing something different.

That would be nothing to worry about. If you were seeing 20+ psi spikes, that would interest me.

 

[Brad T]

Is this problem worse with some converters?

 

[Alky V6]

Is this problem worse with some converters?

The T/C can be a factor if the internal flow pattern into and out of the T/C is restrictive.