mine too.

 

I have a th400 in my Camaro that I'm just now starting to have a problem with. It has a rmvb made by BTE transmission with a transbrake.

I took the car to cruzin weekend in OC this weekend and noticed that if shift from 1-2 or 2-3 at redline, when I come to a stop, the transmission pushes about a table spoon of fluid out of the vent tube onto the exhaust and the ground.

It seems to only happen after a WOT run, after cruzin all day I only noticed it when I was beating on it a little bit. Today I drove it to the store when it was cool out to see if it was a Trans heat issue. The trip was about 3 miles and I onl accelerated hard once when coming off an on ramp. His time it did it when I shifted into park at the store.

The Trans was a low on fluid and I'm not sure if it is maybe cavitation causing his or not. Trans still shifts perfict and doesn't slip at all, it just wants to puke fluid on my exhaust and make me look like I'm on fire at stop lights.

Any ideas?

The main problem here is when pump faces are not flat.I proved this to myself a long time ago.

INSPECTION AND PREPERATION OF THE PUMP BODY AND COVER.​

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Inspect the bushing bore for any abnormal wear or evidence that the bushing has spun out in the bore. See Figure 2C-1. If during removal, the bushing was loose in the bore or the body shows signs of spin out, the body must be replaced. Inspect the pump body bushing bore for any damage or burrs present from bushing removal. If any burrs are present, remove them with a small file. Using a deburring tool, gently chamfer the bushing bore entrance. See Figure 2C-2.


FIGURE 2C-1

Carefully inspect the pump body face for any signs of damage or nicks that can result in hydraulic cross leaks between oil passages. See Figure. Inspect the 5 pump body threaded bolt holes for stripped or damaged threads and repair if necessary. See Figure






Inspect the pump body gear pockets. Careful inspection of this area should not be overlooked. Failure to identify wear will reduce pump efficiency. Inspect the side walls of the pocket for any signs of scoring or abnormal wear. There is a close fitting tolerance between the outer gear and the pocket. The pocket acts as a journal bearing that supports the outer gear on a fluid film during operation. If any wear can be felt with your fingernail, the body should be replaced. See Figure. Inspect the pump pocket face for any signs of scoring or abnormal wear. Excessive clearance between the pocket face and gear set face will result in leakage between the pumps inlet and outlet ports. If any wear can be felt with your fingernail, the body should be replaced. See Figure.



Inspect the ID of the crescent for any signs of scoring or abnormal wear. If any wear can be felt with your fingernail, the body should be replaced. See Figure. Inspect the OD of the crescent for any signs of scoring or abnormal wear. If any wear can be felt with your fingernail, the body should be replaced. See Figure






Using a deburring tool, gently chamfer the gear pocket entrance. See Figure. Using a whetstone and clean solvent, generate a nice cross hatch pattern on the face of pump body. See Figure.



Place a precision straight edge across the machined face of the pump body. Use the gages between the straight edge and the body to verify flatness. See Figure.





The face should be completely flat. If the face is out less than .002”, the following methods “MAY” be able to bring the face in flat without resurfacing or replacement. If the face is out by more than .002”, resurfacing or replacement will be necessary for the pump to maintain hydraulic integrity.
Tape some fine grit emery cloth to a precision surface plate. Rest the machined surface of the body onto the cloth .Using the weight of your hand, move the body in a figure eight pattern until the face has been trued up. As the surface becomes flat less resistance to attempted motion will be felt. Once again, use the whetstone and clean solvent to generate a nice cross hatch pattern on the face of body. Once again, use the straightedge to verify flatness. If the face is still not flat resurface or replace the body. See Chapter 2D.
A lapping plate may also be used to true the face of the body. Rest the machined surface of the body onto the plate. Using the weight of your hand, move the body in a figure eight pattern until the face has been trued up. As the surface becomes flat less resistance to attempted motion will be felt. After lapping, do not use the whetstone. Once again, use the straightedge to verify flatness. If the face is still not flat resurface or replace the body. If you have access to a lapping plate, use it. Even if the pump body was flat to begin with, it will produce a better sealing surface than the whetstone.






Carefully inspect the pump cover for any signs of damage or nicks that can result in hydraulic cross leaks between oil passages. See Figure. Using a whetstone and clean solvent, generate a nice cross hatch pattern on the face of pump body. Place a precision straight edge across the machined face of the pump body. Use the gages between the straight edge and the body to verify flatness. See Figure. The face should be completely flat. If the face is out by more than .002”, resurfacing or replacement will be necessary for the pump to maintain hydraulic integrity. See Chapter 2D.
















Carefully inspect the gasket sealing face of the pump cover for any signs of damage or nicks that can result in hydraulic cross leaks between oil passages. See Figure. Using a whetstone and clean solvent, generate a nice flat sealing surface for the pump cover to case gasket (8). See Figure.


FIGURE

CHAPTER 2D​

RESURFACING OF THE PUMP BODY AND PUMP COVER​

If you are serious about pump performance, consider having the pump halves resurfaced. Typically a pump that passes the straight edge test will still suffer from pressure drops below 1000 rpms. on the dynamometer. A hand trued pump with a fixed line pressure that produces 210 p.s.i. @ 1000 rpms can drop to as low as 165 p.s.i. @ 650 rpms. A properly resurfaced pump will, in most cases, show no more than a 5 p.s.i. on the dynamometer between 650 and 1000 rpms. I will not build a high performance TH400 transmission without the use of a resurfaced pump. Extensive testing has proven to me the efficiency and performance benefits of performing this procedure. Our method for resurfacing the pump halves will be explained for those who wish to have a machine shop perform this operation
Using a manual lathe, the front end of the pump body is picked up on the inside diameter of the front pump bushing bore in precision machined soft jaws and indicated in. The pump face is then machined so that it is parallel and perpendicular to the bushing bore centerline. See Figure.





Typically this operation will remove .005” from the pump body face. Because we have removed this material, the pump pocket depth will be shallower and will require a gear set that matches the pocket depth. Gear sets are available in .721”, .723”, .725”, and .727” thicknesses. Gear sets can also be surface ground or lapped in on a lapping plate to the proper dimension for the application. A finished pump body is shown in Figure.
If the transmission will be fitted with a JW Ultra Bellhousing, the front face of the pump should be machined so that it is parallel with the rear face of the pump.This will provide a true mounting surface for the bellhousing. Typically the front face of the pump is .020” out.Without removing the pump, the facing tool is brought to the rear side of the pump cover and the gasket surface is resurfaced. This ensures parallelism between the front and rear faces, as well as the transmission case. See Figure.




























Resurfacing the pump cover requires a different lathe set up than the pump body. Both the front and rear bushings are removed from the pump stator tube. The rear end of the pump cover is picked up with precision soft jaws on the inside diameter of the stator tube and forward clutch sealing ring boss face. The front end of the stator tube is picked up with a precision plug and live center. The pump face is then machined so that it is parallel and perpendicular to the stator tube centerline. See Figure.

















Without removing the pump, the facing tool is brought to the rear side of the pump cover and the gasket surface is resurfaced. This ensures parallelism between the front and rear faces, as well as the transmission case. See Figure.

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CHAPTER 2E​

UNDERSTANDING AND PERFORMING MODIFICATIONS TO THE CONVERTER CHARGE CIRCUIT​

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When the desired pressure is reached, the pressure regulator valve moves down against the spring, opening a passage in the pump cover casting that after a short journey feeds fluid into the torque converter. This circuit is known as the “converter feed” or “converter charge” circuit. Converter charge pressure is directly fed from the line pressure port of the pressure regulator valve. If we are using a fixed line pressure system, converter charge pressure can become very close to line pressure. Because there is bleed off in the transmission lube circuit after converter charge oil leaves the converter and becomes lube oil the two pressures will never be equal. However they can get dangerously close. This excessive pressure acting on the inside diameter of the torque converter can result in the torque converter pushing out of the transmission. Lets look at this using “Pascal’s Law”. Pascal’s Law is a principle in fluid mechanics that states that pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio remains the same. This means that 100 psi. acting on a 1 “square surface will produce 100 pounds of force, and this same 100 psi. acting on a 10” square surface would produce 1000 pounds of force. This multiplication of force can be used to create motion. The same motion that thrusts the converter and crankshaft into the engines main thrust bearing. Let’s look at this principle using a typical 10 “converter, although the thrust force would be very similar regardless of converter diameter. The internal surface area of the torque converters front cover exposed to converter charge pressure is

 

They will puke oil if they are low on oil also.


Hutch

 

Nice! I just checked it and its low as shit. I'll topp it off and take it for a ride tomorrow. I'm headin to the track on Friday for a quest to reach the 11's. yea it's slow, but its a hell of alot of fun!

 

I hope its not damaged from low oil.


Hutch

 

Lets not talk about it lol. Hear no damage, speak no damage, see no damage.