700R4 Constant Pressure Valve Body-Noises?

[Dave427]

Just like the title says. is there anyone else out there running these valve body's that is running into any buzzing/vibrating noises at idle or just above?

Dave

[TCITech1]

It's likely that the noise is coming from the pressure regulator valve. Since the spring tension regulates the line pressure, low engine rpms can cause the valve to resonate, causing a buzzing sound. This can happen if your PR spring has low seat pressure. The reason that the TV cable position doesn't affect this noise is because the TV cable no longer controls the line pressure with the constant pressure valvebody. What valve and spring are you using?

[Dave427]

I am using my pressure regulator valve, the heavy gold spring (street & strip) with the aluminum plug that came supplied.

Dave

[Dave427]

The Aluminum plug eliminates the TV & Reverse Boost Valves.
So what you are saying my pump at idle is not producing enough pressure to hold the valve open?

Dave

[TCITech1]

The pump flowrate certainly affects this valve resonance. A low flowrate at idle can allow the valve to oscillate. What pump gear are you running? Is the pump in good shape? What is your idle speed? At what rpm does the noise abate?

[Dave427]

I am using a 10 Vane pump, and yes the pump looked in pretty nice shape.
The idle speed is around 900 rpms and the noise goes away around 1500 rpms or so.
Like I mentioned earlier the noise happens in all gears Park/Neutral or Drive/Reverse moving or sitting still.

Dave

[Dave427]

Do I stick with the gold spring or try the silver with or without the washer?

Dave

[TCITech1]

Dave,

If the transmission doesn't shift too firm for your taste at this point, then you can try the washer with the gold spring. This will increase the line pressure even more and result in an even firmer shift.

[astro355]

I have having the same problem with my trans. I am running the gold spring with the washer and it still makes the buzzing/rattling noise. The only thing is that it didn't do it originally, it just recently started. If I can get ahold of a pressure gauge, I'll have to see what the pressure looks like while its making that noise.

I'm going to do a trans filter change and take a look at it. Maybe the problem will be apparent once I have the pan off.

To add,

my noise isn't always constant. If the van is cold, there will not be any noise. Once the van warms up, it will sometimes buzz/rattle while in park (idle at 800 rpm). If it does, shifting into drive usually makes the noise go away (idle drops to 600 rpm). Sometimes it will buzz at a stop but once you hit the gas, it goes away.