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Saginaw P/S pump shimming for better feel.

Kern Dog

Life is full of turns. Build your car to handle.
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Have you tried it yet?
Most everyone that I know with power steering in their Mopars agree that our cars have a ridiculously overboosted feel with their cars. The steering is so easy, you feel as if the tires are on wet ice. Mopar Action magazine had an article on this subject. Rick Ehrenberg found that the V8 car P/S pumps generated nearly 1300 PSI of boost pressure while slant six pumps were near 900. It is believed that the slanty cars got less boost because the demands were lower in lighter cars. Physically, the pumps were identical aside from the mounting brackets. Rick delved a little deeper though...
Since the power steering boost is directly related to the steering feel, if you reduce the boost pressure, the effort needed to turn the wheel increases. The only internal differences Rick could find between the sl/6 and V8 pumps were the thickness of the shims in the pump. Pictures are necessary to fully explain, so log on to www.moparactionmagazine.com and click on "Pump it down" to get all the details.
My Charger has several steering mods but no P/S shims. I have a Firm Feel stage 3 steering chuck, an inline P/S oil cooler, fast ratio arms and a fully rebuilt front end with a performance alignment. My steering effort feels great as is, but for those on a tight budget, the "shim trick" is a cheap and effective way to get a better feel for pennies. The shims/washers are 3/8" inside diameter with a 17/32" OD. Elsewhere, I've read that the best "feel" is achieved with a stack of shims no thicker than .125, which is 1/8". Today at the junkyard, I checked several pumps to see what they had. MOST only had one thin shim, far too thin for me to measure with my cheap calipers. It may take 8-10 of them to add up to .125! My local hardware store had some copper washers that were slightly under 3/8" I.D, so I took a 3/8" drill bit and honed the center out. I'll have to mill down the outside diameter to fit back into the pump.
Thistopic may have been posted before, but I thought that I'd mention it anyway. I'd like to hear any comments you have on the subject, Greg
 
I also sure would like to have some first hand info on this also! :eusa_think:

The first person to chime in will get a bright new shiney nickel
 
I built up a stack of washers to put in my bro-in-laws 72 Duster pump. His car handles well but feels waay too easy to turn. The danger with the stock setup is that you may tend to "over-turn" the wheel in a cornering manuever and cause the car to tail spin. Granted, that isn't a likely scenario if you are familiar to the car, but it can happen. I prefer a wheel that gets a little harder to turn as you get to the end of each direction. This makes it so each turn of the wheel is a deliberate one. It sucks to have unintentional actions result in a collision or a spinout.
 
Yes I read the article. Oftimes I get Independant information with a personal view piont from the members here and I do value the FBBO opinions.
So if any FBBO members have done this or have something to add to this conversation, I would love to hear from You.

Thanks in advance
 
I tried this with my 66 coronet. It has a 78 motor home 440 in it with the motor home steering pump. I often felt there was an fix for the light feel of the steering wheel. I read the mopar action story and it does work. I measured .020 shim in my pump. I used a crimp style "eyelet", the yellow one, for additional shim. find a 3/8" eye, snip off the un needed part, install and file down the excess. The eyelet was .040 for a total of .060 inch. Im thinking of adding another eyelet and removing the original shim for a total of .080. I noticed a big improvement right away. I recommend using a suction gun or turkey baster to remove your steering fluid from the can before removing the line to save some money on fluid expense. Hope this helps.

Im still working out handling issues with my car, Im thinking i need adjustable upper control arms to get the caster that i need, and possibly adjustable strut rods.

Just a note of precaution, when breaking down the components of the valve, use a vise grip on the smaller diameter, un machined portion of the valve, not the larger machined area. Good luck
 
Saginaw PS Pump Shimming

Borgeson has recently offered a Pressure Adjusting Kit PN899001 for just that. It contains a clamping tool, six shims and installation instructions for lowering the bypass pressure of the Saginaw pump. This is also a big problem for street rodders using the Mustang II rack and pinions with Chevys with the Saginaw pump. There is an article in the new Street Rodder, Sept 2012. It would save having to machine your own shims. There are several nice color pictures in this article also. I have yet to try it also! I hate Chrysler's over assisted PS. Especially at high speeds.
 
Funny, I've always loved being able to steer with my pinky. I think that's one of the few things I would NOT change. lol
 
Love to have info on a similar mod to my Federal.
 
From what I gathered in the article, the gains are similar with the Federal pump. There is more disassembly to it though.
 
Steering pressure

I put a .065ish washer in sag pump and it feels a lot better however i think i might put more in it to firm it up even more. I am in the process of trying a federal or TRW pump for the 64 plymouth. the set up inside is different however i think i have figured it out, will be trying it this week.
 
Steering pressure

I put a .065ish washer in sag pump and it feels a lot better however i think i might put more in it to firm it up even more. I am in the process of trying a federal or TRW pump for the 64 plymouth. the set up inside is different however i think i have figured it out, will be trying it this week.
Whatever happened with this? I have a federal pump I would pressure down if I could
 
I have done it to my pump it's a piece of cake, pressure reduction didn't effect my hydro boster either still works great.
You may have a problem if you are running a hydro booster if you Idle a long time on brakes.
 
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