Saginaw 670 (Jeep) Steering Tuning

pmazza

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May 8, 2008
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40
Location
St Louis
I wanted to post this since a lot of people have made the Saginaw 670 (Jeep) steering box conversion. Hopefully it will be useful to someone. I have the Corvette Steering modified box and a TC pump with stock GM plastic integrated reservoir.

The car steered ok, but it is obvious that the parts are not engineered to work together real well. At higher RPMs the steering was very touchy and created a 'disconnected’ feel. At any speed it seemed ‘overboosted’. In addition, I would always end up with air in the system after longer driving sessions at operating temp despite good lines and no leaks.

I sent the pump and box to the best in the business at Lee Manufacturing to match up the components. They rebuild/blueprint the pump and box, flow check the units and match them up to what type of driving the vehicle is used for. Total cost for this service was @$210. On top of this, they were very nice to deal with and would answer all of my stupid questions. There is not much that they have not seen with steering systems in 40 years.

The result has been amazing - much better road feel and centering. A lot of the higher speed jitters are gone and once I get around to do a thorough realignment it will make it even better.

The cause of the air in the system was the stock GM integrated reservoir - no internal baffles and not enough capacity with the fast ratio box and hydroboost. Lee proved this through testing my pump and replaced the stock tank with one of their aluminum ones which is a 'race' type of part. KRC and many others make similar versions as well.

Picture below shows updated steering pump and reservoir.

22448aa2a16b5f7c

Phil
 

BBShark

Garage Monkey
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When they "matched them up" do you know what they did? I had my power steering bypass pressure reduced to 1100psi. I'm hoping that will fix any overboosted feeling.
 

Twin_Turbo

Der Maulwurf
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Mar 5, 2008
Messages
7,572
With the KRC pumps you can swap the flow valve.

KRC 25304 000
Aluminum Flow Valve, -6 Male, 1.05 GPM

KRC 25305 000
Aluminum Flow Valve, -6 Male, 1.32 GPM

KRC 25306 000
Aluminum Flow Valve, -6 Male, 1.58 GPM

KRC 25307 000
Aluminum Flow Valve, -6 Male, 1.84 GPM

KRC 25308 000
Aluminum Flow Valve, -6 Male, 2.11 GPM

KRC 25309 000
Aluminum Flow Valve, -6 Male, 2.37 GPM

KRC 25310 000
Aluminum Flow Valve, -6 Male, 2.64 GPM

KRC 25311 000
Aluminum Flow Valve, -6 Male, 2.90 GPM

KRC 25312 000
Aluminum Flow Valve, -6 Male, 3.17 GPM


Lee, aren't those the guys that sell the weld it yourself reservoirs?
 

pmazza

Active member
Joined
May 8, 2008
Messages
40
Location
St Louis
Based on my conversations with them and what the invoice listed, it appears that they work with the valving in the steering box itself more than the pump. I had a 'low flow' valve on the TC pump that they took off and sent back. It sounded to me that they viewed adjustment of the pump flow as only a small part of the equation if it even factored in at all.

I am not sure if they sell the weld up kits or not, but it would not surprise me. I found about him on Pro Touring boards and from what I have read and in talking to them Tom Lee is the man for performance steering. Lots of racing teams use them and he seems to have had a big part in the design of the 670 gear.

Phil
 

Kid Vette

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Mar 25, 2008
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Santa Cruz, CA
Good post. It could explain why some guys are having trouble with burning up their pumps.

Does Lee Manufacturing have a web site? I can't seem to find one.
 

Solid LT1

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Mar 24, 2008
Messages
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Location
Fremont, CA
Lee is a leading manufacturer or racing power steering systems and some Sprint Cup teams use their services. They have been in the business since the 1970's and know their business and Saginaw steering boxes.
 

pmazza

Active member
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May 8, 2008
Messages
40
Location
St Louis
No web site, don't think they have much use for one. Address and phone:

Lee Manufacturing
11661 Pendleton St.
Sun Valley , CA 91352
(818) 768-0371
 

turtlevette

The Turdle
Joined
Mar 24, 2008
Messages
1,492
Location
Marshfield, MA
With the KRC pumps you can swap the flow valve.

KRC 25304 000
Aluminum Flow Valve, -6 Male, 1.05 GPM

KRC 25305 000
Aluminum Flow Valve, -6 Male, 1.32 GPM

KRC 25306 000
Aluminum Flow Valve, -6 Male, 1.58 GPM

KRC 25307 000
Aluminum Flow Valve, -6 Male, 1.84 GPM

KRC 25308 000
Aluminum Flow Valve, -6 Male, 2.11 GPM

KRC 25309 000
Aluminum Flow Valve, -6 Male, 2.37 GPM

KRC 25310 000
Aluminum Flow Valve, -6 Male, 2.64 GPM

KRC 25311 000
Aluminum Flow Valve, -6 Male, 2.90 GPM

KRC 25312 000
Aluminum Flow Valve, -6 Male, 3.17 GPM


Lee, aren't those the guys that sell the weld it yourself reservoirs?

it seems to me reducing the flow is an incorrect method of achieving road feel. It will seem to work until you turn the wheel very quickly. You will then run up against the max flow rate and it will seem to lock up on you.

You need to take the box apart and adjust/replace the spring for the valving to do it correctly. Jimmy Shea has told us this many times.

The vendor selling the thing should have done that already.
 
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Yellow73SB

Well-known member
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Mar 24, 2008
Messages
1,201
That spring is still determining how much pressure it's getting, whats the difference if you do it before the box?
 

Yellow73SB

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Mar 24, 2008
Messages
1,201
I don't think it's restricting it enough to effect the power steering though

We'll never know until we try it
 
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turtlevette

The Turdle
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Mar 24, 2008
Messages
1,492
Location
Marshfield, MA
I don't think it's restricting it enough to effect the power steering though

We'll never know until we try it

What's the hold up? Have you driven it with the jeep box?

if you rely on a flow restrictor the feel will still be mushy when making small corrections such as when on the hwy because the restrictor does nothing to reduce the pressure when the flow is low. When making evasive manouvers the flow restrictor will make the pressure drop down and the wheel will get hard to turn.

Its the exact opposite of what you want. You want a more manual feel when making small wheel movements and more assist when quickly turning the wheel through large angles.
 
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