converter feed pressure???

[VIN7]

I trying my best to follow the fluid path diagram that I have...

I've had a long history with an EA stage II trans and a billet 9x11 not locking at wot (commanded through chip and using a manual switch doesn't matter) but locks fine at low tps, part throttle.

Had the converter checked out by Rusty, he said it looked fine but put new clutch assembly in anyway. Still doesn't lock at wot.

Looking at the fluid path it seems that during lock up, the billet housing side evacuates fluid through the input shaft, and converter clutch apply is still feed by the PR system.

Question 1: Is the converter feed from the PR system the same pressure as the pressure reading while in Park?

Question 2: Does the converter feed pressure rise depending on what gear the transmission is in?

Question 3: I have a whine coming from the transmission (I took off the assesory drive belt) that sounds like a power steering pump. It only happens in Park. Cold pressure readings in Park 50 psi, 1500 ( drops down to 30 psi at idle speed), full tv has no change in reading while in Park. I also get a buzz noise right at gear change (no pressure data yet, I'm heading out today to collect data).

The other pressures cold, Min TV, 1500 rpm

R - 220
N - 120
OD - 120
D - 120
2 - 275
1 - 275

Thanks,
Mike

 

[bison]

What solenoid are you using?

 

[VIN7]

Whatever Lonnie puts in his transmissions, I believe it is the 700r4 style because the mounting tabs of the solenoid do not fit flush, there is a "spacer" that pulls the plastic shaft out of the tcc valve bore.

Mike

 

[VIN7]

Also, what would be a possible cause for the Park psi to be different than Neutral psi???

Mike

 

[VIN7]

More data... , hot, 1500 rpm

Gear Min TV Max TV

P----50--------50
R----275------275
N----150------275
OD--150------275
3----150------275
2----250------260
1----250------260

Part throttle cruise 150psi

Part throttle 1-2 shift 150, buzz at gear change, psi fluctuates 5 psi
Part throttle 2-3, same as 1-2

WOT 1-2, 2-3 250 psi, fluctuates 10-15 pis (lower) at gear change.

 

[SSedan64]

Not all VB's boost in Park.
The 10 & 13 Vane Pumps were designed to get rid of Pump buzz, smooth Pump pulses but, have less Pump volume.

 

[VIN7]

What psi does the converter feed get?? (Does it rise to match whatever line pressures read on the gauge according to gear?)

Looking at the fluid diagram, converter feed is isolated from the line pressure path due to the top three lands, but I'm not sure if I'm looking at it correctly. (Does the long valve get forced down against the spring as line psi goes up or the other way around?)

I guess the question I have is does the low psi in P give any clues to why I can lock the tcc at part throttle but it doesn't hold at wot even though the clutch checked out fine by TCS.

Since the whine at idle goes away in neutral (or any other position other than park) as the psi jumps, what can I do to raise park psi??

Mike

 

[quickt]

What psi does the converter feed get?? (Does it rise to match whatever line pressures read on the gauge according to gear?)

Looking at the fluid diagram, converter feed is isolated from the line pressure path due to the top three lands, but I'm not sure if I'm looking at it correctly. (Does the long valve get forced down against the spring as line psi goes up or the other way around?)

I guess the question I have is does the low psi in P give any clues to why I can lock the tcc at part throttle but it doesn't hold at wot even though the clutch checked out fine by TCS.

Since the whine at idle goes away in neutral (or any other position other than park) as the psi jumps, what can I do to raise park psi??

Mike

Ok will do my best to explain lock up. The solenoid does nothing other that shuttle the valve in the pump. The brand I use is Fitzall Universal.

When the fluid path is in the NL mode fluid pressure behind the clutch keeps the lock up clutch dis-engaged. When lock up is commanded the fluid behind the clutch is exhausted back threw the pump allowing the converter clutch to seat against the cover. In effected lock up or direct drive. The apply of the clutch is simply the turbine oil in the converter forcing the clutch against the front cover.

Charge pressure has nothing to do with converter clutch apply but has a lot to do with wiping out the thrust in your engine. In the 2004R the is no way increase charge pressure other than grinding the second land off the PR valve.

Transmission - There is no mechanical function in the transmission that sends pressure to the converter for lock-up. The only mechanical function is in the pump itself. The TCC valve (when shuttled) exhaust fluid and reroutes cooling and lube oil. The TCC solenoid when closed shuttles the converter valve. The force that holds the clutch is internal in the torque converter.

Why will the converter not lock at WOT? Can be any or all of the following.

1) Converter clutch capacity is exceeded
2) Pressure plate clearance in converter allowing fluid to bypass. Vortex pressure bypassing to front of converter clutch not allowing full engagement of clutch. Enough leakage to exceed exhaust circuit of pump.
3) Fluid in front of clutch not exhausting completely

Precision made a vacuum tube to help remove fluid from behind the converter. This does 2 things. Exhaust oil under vacuum and Gets the lock up clutch on quicker. Also helps to remove Vortex leakage oil from in front of converter so you have full clamping force. If the problem is capacity nothing you can do other than add clutches.

Solution - Add a precision lock-up tube used for a multi disk. If this does not fix your problem then you have internal clearance in the converter allowing excessive leakage or you are over the capacity of the clutch.

 

[VIN7]

When the fluid path is in the NL mode fluid pressure behind the clutch keeps the lock up clutch dis-engaged. When lock up is commanded the fluid behind the clutch is exhausted back threw the pump allowing the converter clutch to seat against the cover. In effected lock up or direct drive. The apply of the clutch is simply the turbine oil in the converter forcing the clutch against the front cover.

Charge pressure has nothing to do with converter clutch apply but has a lot to do with wiping out the thrust in your engine. In the 2004R the is no way increase charge pressure other than grinding the second land off the PR valve.
QUOTE]

Lonnie,

What do you mean by "charge pressure"? Is this the converter feed in the PR circuit?

If I grind the second land off of the PR valve I can see where this would allow line pressure to enter the converter feed circuit.

But with the second land intact, and based on my pressure readings above is my converter feed pressure 50 psi? If not what regulates the converter feed pressure?



Thanks,
Mike

 

[quickt]

When the fluid path is in the NL mode fluid pressure behind the clutch keeps the lock up clutch dis-engaged. When lock up is commanded the fluid behind the clutch is exhausted back threw the pump allowing the converter clutch to seat against the cover. In effected lock up or direct drive. The apply of the clutch is simply the turbine oil in the converter forcing the clutch against the front cover.

Charge pressure has nothing to do with converter clutch apply but has a lot to do with wiping out the thrust in your engine. In the 2004R the is no way increase charge pressure other than grinding the second land off the PR valve.
QUOTE]

Lonnie,

What do you mean by "charge pressure"? Is this the converter feed in the PR circuit?

If I grind the second land off of the PR valve I can see where this would allow line pressure to enter the converter feed circuit.

But with the second land intact, and based on my pressure readings above is my converter feed pressure 50 psi? If not what regulates the converter feed pressure?



Thanks,
Mike

There is no set mechanical regulation system for the charge. As in charge pressure regulates at 50lb. It does not. Its a hit or miss system. When the PR valve moves the charge land moves from the charge opening allowing oil in charge circuit. Really no rime or reason for regulation.

By removing the land you allow a constant flow of oil into the charge circuit. The lube circuit now comes into play. The lube circuit is the dump so to speak. To much oil in charge or more than the lube circuit can relieve then charge pressure goes threw the roof. No way to regulate it or slow the supply when you remove the land. I NEVER REMOVE THIS LAND. There are too many negative affects by doing so. It was a modification discovered to remove the land to stop the pump from buzzing with no thought of the negative affects of removing it. It does work to stop buzz but I dont recommend it.

If you are getting confused you are thinking there is a relief for the PR valve. There is not. The vane pump is controlled by volume. When the pressure of the PR system is reached the PR valve sends oil to the pump slide to reduce volume to bring the pressure down. There is no PR relief in the 200 pump.

 

[quickt]

I forgot to add. Charge pressure is the fluid pressure in side the converter. This pressure is different than line pressure. Line can have some affect on the charge but very little if the PR valve is not modified.