TRW power Steering

[sputnik 440]

Setting on metering pin on TRW power Steering Pump

I have read all the threads on power steering. Very informative, but did not solve my problem. I have a TRW power steering unit in my '67 Sport Satellite. The engine is a 440 that is street/race (560+ HP). I have a 3.73 rear end which has the rpms a little higher than a 440 with a 3.23 or 3.55. I had a leak at the reservoir and took the unit off to replace the O ring. That is not my problem. I decided that while it was off, to check the flow control piston, metering pin and spring. I quickly noticed that the metering pin was not screwed into the flow control plug. The manual says if you remove the components DO NOT try to change this pin relationship to the plug. I couldn't leave it like it was, so I pulled out a Federal pump (very close to the TRW) and looked at the position of the pin in it and then screwed in the pin to the matching setting. I put it back together, put in new fluid and checked the fluid a couple of times while the engine was heated up.
I took the car for a drive and quickly noticed that the car would "dart" to the left on a left turn and to the right on a right turn. Not all the time. As the engine got warmer, the darting was more frequent. I did not have this problem prior to correcting the metering pin placement.
a) is my setting of the pin causing my problem?
b) Is the TRW pump correct for the engine and rpms it runs at with the 373?
c) What alternative pump should I buy if I need one? A TRW rebuilt pump is next to impossible to find. Some Federals are out there. What about switching over to a Saginaw?
I know I will need new brackets if I do this.
Thanks ahead of time. I am a newbee on this forum. I appreciate your help and hope to be able to help others in the future.
Capt jim

 

[SublimeSixpack]

Sorry, I can't address the "darting" problem you're experiencing, but it's my understanding the Saginaw pump is a better pump then the TRW or Federal (based on what I've read). If you have access to a Saginaw and the brackets I'd probably make the swap.
Having said that, if it were mine I'd be tempted to open the TRW pump and back out the pin you mentioned a bit, slap it back together and see if that made a difference then go from there.

 

[miller]

For what it's worth...since I had to rebuild my TRW pump.

Like you said, that valve sets the pressure for the pump, and book tells you to replace it as an assembly. Guessing those valves are adjusted on a test mule, to set the correct pressure. I robbed a valve off of a 'like' pump, leaving it alone. Might work okay, if you re-swap the old valve back to your pump.

There are two, or three, various pump sizes, the way I understand it, for SB/BB. For BB, the end of the pulley shaft has a hex reset, SB plain, or flat.

 

[sputnik 440]

If I wanted to try and set the pressure lower via the "tuned" metering pin, would you screw it in so that it opens the flow through the control valve and get more flow thru the line to the steering, or would you go the opposite way, thereby increasing pressure on the control valve and reducing flow to the line? I can't believe a person cannot find the sweet spot as set by the factory. Maybe it is too much trial and error, and maybe in doing so would cause harm to the steering. I almost wish I would have left it unscrewed. Have you looked into other pumps? Saginaw? I cannot find anything that tells me that I can make this conversion and with which pump and bracket to go with.

 

[Cmmopar]

Properly rebuild TRW pumps are available from Steer and Gear. Spendy but done right.

http://www.steerandgear.com/#!chrysler-online-catalog/snt9t

 

[kiltedrunner]

I went through some issues with a TRW pump last summer. I thought it was the o-ring that was leaking - but it turns out someone I trusted to replace the o-ring took it upon themselves to pull the whole pump apart including the pressure relief valve. After I reinstalled everything my steering box ended up cracking under the high oil pressure which was puking fluid all over the place. I found some original pump instructions online and found out that this pressure relief valve needs to be adjusted with the use of a special pressure testing machine.

Long story short, don't mess with the pressure relief valve, just replace it with one off another pump.

 

[miller]

Right! That 'special pressure testing machine' is what I was calling a test mule. Even in the service manual, showing the relief valve, all fairly high pressure, needing to be set right to make the steering right.

Don't think it's a good idea to try to adjust it. Either go with the old 'working' valve, or hunt down a replacement valve that's already adjusted.

 

[sputnik 440]

Thanks guys! I went ahead and swapped valves and metering pin with the Federal spare I have. Sure hope the settings of the metering pin is the same for both pumps. Will test drive it later today. Thanks for the experience sharing. What do you think about buying a new pump? Will a Saginaw pump work ok on this HP motor with a 3.73 rear end? Will the higher rpms dictate a different pump? The Federal is built just like the TRW, but, it has a larger outlet, meaning a larger dia hose and different inlet on the column side. These tells me the pressure and volume going to the column would be quite different.

 

[sputnik 440]

Called Steer and Gear. Very helpful and very expensive. 2 week turn around and $275 for rebuild. Thanks for the recommendation, Cmmopar. Guess I will send it in since they keep the pulley and reservoir on it. It would upset me if I used the pump I put together with the Federal parts and I cracked my case. I'd be pissed for not following the advice and experience of kiltedrunner. The other option would be to buy a power steering pump pressure gauge with valve and hoses and set the pump to specs. (900 - 1100psi) myself. Cost on that is about $180. Anyone know of where I can get the setup cheaper?