The Stovebolt Site Forums The Shop Area The HiPo Shop power rack & pinion steering turns to quick

I have a 57 1/2 ton.I put in Jim Meyer ifs with power rack & pinion.At highway speeds the steering is very quick to turn with slight movement of steering wheel.I have a 15" steering wheel,Ididit column,GM 74 camaro power steering pump.spindles are from 79 impala 12" rotors.any ideas on slowing the steering reaction down a bit.

Use a larger steering wheel

Attach the ends of the rack farther out from centerline on the spindles. May not be an option, but if it is it will surely help.
If you are not using the full available travel of the rack as is then this is a great idea, if it is possible.
If the steering is already using full travel of the rack then you would loose turning radius by moving the attachment points on the spindles, so probably not a good idea.

Other than that I think someone sells a gear box that goes in the steering shaft to either speed up the ratio or slow it down depending on which way you install it. May or may not be a good idea or legal?

Is there a different factory rack that interchanges and has a different ratio?

Grigg

who's rack are you using, and what is the rack ratio?

The in-line gear boxes are technically only legal for racing.

When you use a GM pump with a Mustang II rack the steering is too sensitive so Speedway Motors offers a replacement valve to lower the boost of the GM pump. If someone (not me) is sharp on the workings of a p/s pump maybe they would know if a spring that goes behind the piston is available that would drop the pressure. This would be an easy fix and it wouldn't harm any of the original parts so the process could be reversed.

Coilover,true on the reduced pressure valve. A GM pump puts out more pressure than an M2 rack can take ,and it will blow the seals out of the rack.Most M2 units use a rack out of an 1984 T Bird,which requires about a 7 to 8 PSI pump,whereas the GM pumps put out about 15 PSI.

I do have the T bird rack.so I will check on the pressure valve.thanks for the info on this.After all this work it was a little disappointing to drive on highway. only to get so tense not to make a slight movement of the steering wheel and possibly loose control.

This was discussed a while back and I've tried a search,without success.
The Speedway one AFAIK is an adjustable unit much like the brake balance valves you can buy.
If i'm not mistaken there is a fitting you can buy that reduces the actual pump itself and is at a fixed pressure.
I'm sure another 'bolter used this although I can't remember who.
I'm interested in this as I was going to ask the exact same question today!
Hopefully the 'bolter in question will see this thread and chime in.
Maybe I've looked at the wrong part,coilover,but if you know of such a thing do you have the link?
Thanks
Jock.

If you pull the output fitting out of the GM PS pump there will be a spring and a plunger behind it.
This spring sets the pump relief pressure, a softer and or shorter spring will give a lower pressure.
You could get a gauge and play with it yourself, or as suggested someone has probably already figured this out and offers a new softer spring, but I don't know who that would be.

Grigg

I did a bit more groundwork on this one, I was in fact looking at the wrong Speedway part!
For those that are interested,here's the part you need.
Pump flow reduction fitting

The good thing is..... it's cheap!
I believe Borgeson also do a shim kit that does the same job.
Thanks for the info too Grigg.

I bought a shim kit from Mullins ($19)years ago.I have a Pacer rack and was gonna use a GM pump. The dude from Mullins Said to start with two shims and that should give me the road feel that i want.
Since WebOld was Havin trouble blowing all the seals in his,and i have a new rack and dont want to take the chance. I decided to get a new AMC pump instead..even though i'm pretty sure they used a Saginaw rack..............dave

There's a ready made reduced pressure valve that sits in the saginaw power steering pump here:
http://www.sachserodshop.com/pdf/48.pdf
Does look like the standard valve with a thicker shim fitted though!

Stuart.

Hi Stuart...I'm confused again!(Easily done!)
The Speedway item i've been advised to use is shown fitting a Saginaw self contained unit.
Yet the self same item is shown in the Sachse link as the one for the GM type II stand alone pump.
What gives...do they use the same part? I've just ordered the Speedway one and i'll be pretty P'd off if it's the wrong one!(shipping costs!)
And BTW what's the difference with the RBS 1R600 Power steering valve?
What do I actually need to cure the problem? Is it a pressure or flow rate thing?
Thanks Jock

the RBS 1R600 valve replaces the standard valve in the integral resevoir pump and reduces the output pressure, it doesn't change the flow rate. M2 racks need a lower pressure than a Saginaw steering box setup.

You can do this modification on a Saginaw pump yourself if you want. If you remove the valve -it's behind the output union on the pump- and insert extra shims behind the bolt in the base of the valve body, it reduces the pressure on the internal spring that's behind the bolt, and therefore reduces the output pressure of the pump.

As well a s being a good mod for M2 racks, it's a good conversion to get some "road feel" out of the Saginaw P/S conversion for AD trucks; I have reduced the pressure by this method on my truck which has improved the road feel, and may reduce it again when I get the time.

HTH, Stuart.

What the other guys said....you can buy a shim kit for the GM Pump to reduce pressure output to the rack. With my Saginaw ( GM ) pump, I added ( 4 ) of the shims to slow down the reaction.
Easy to do - need to pull the pump out to install.

Stuart....so what you are basically saying is.....I've ordered the wrong part to reduce the output pressure of the pump?
Or do I still need this flow valve and the RBS 1R600 valve as well(or shim kit)?

Sorry starterman if I've hi-jacked your thread,but it's all relevant info.
I hope it's useful to you as well.

Thanks Stuart.

ordered flow valve from speedway and got it installed this weekend.now it drives great.thanks for the help on this to all who replied.going to its first show this next weekend.

Thanks Starterman

i had a pacer pump and one reducer from rb's obsolete and still blew three rack seals. now have the one from speedway and drove 1359 miles to kc and now problems so far. but before the 2nd one blew i put 3400 miles on it. i have my fingers crossed on this one. i do believe the one from rb's was not what it was supposed to be but i left in and used the speedway one on top. ron.

Huh?? How did you get one so quick? I ordered mine from Speedway last week and was told it was on backorder.
Starterman.....You must've beat me to the last one in stock just now!
Enjoy your show.......

Thanks for the info guys I just purchased one also but haven't received it yet.