WHat year did Chevy ps steering gears switch to quick ratio?

[ubtripn]

Just another ps conversion question. thx

[67Slider]

Ttt

[gcburdic]

anyone?

[Longhorn Man]

there was no quick ratio. They went to a variable ratio in 73.

[ubtripn]

Cool, thanks.

[ubtripn]

Vaariable meaning that it assists more the slower you are moving right.

[ubtripn]

The following article is what confused me:


Conventional power steering gearboxes were originally manufactured with a wide ratio. Depending on the manufacturer, most were in the range of 16:1 to 24:1, requiring four to six full turns of the steering wheel from stopping point to stopping point (wheels locked from the extreme right to the extreme left, commonly referred to as "lock to lock"). Many of these units were also designed to have slow steering response around the center point, with improved response as you approached the ends of their maximum range; these were termed variable-ratio. Quick-ratio gearboxes will reduce the steering wheel lock-to-lock range to as low as 2½ turns.

The most popular gearbox used in the 1960s and '70s was the Saginaw model 800. Four bolts hold the Pitman shaft cover on the model 800; finding those four bolts is the easiest way to identify this type of gearbox. Aside from mounting-bolt patterns (some are four-bolt mount and there are two different three-bolt mounts), the pre-1977 model 800 units are all interchangeable; even 1977 and newer metric gearboxes can be adapted to earlier applications using metric-to-standard threaded adapters. Although mostly used on General Motors vehicles, AMC also used the Saginaw 800 box from 1967-'76; Jeep used the Saginaw 800 on some models from 1965-'79.

GM began using Saginaw 800 quick-ratio steering boxes as a sport option on Chevelle, Nova and Camaro models in the middle to late Sixties. Because the differences between a conventional 16:1 power steering box and a quick-ratio unit all are internal, it may be difficult to determine if a used box is, in fact, a quick-ratio unit. Purchasing an aftermarket unit or having your original box converted are sure ways to know the ratio is correct and that the internal stops, if any, installed in the unit will allow your steering and suspension to function properly.

So they used quick-ratio on the sports cars and they used variable on the trucks?

[Longhorn Man]

on many cars they used quick ratio boxes. And most, if not all, won't work on our trucks due to mounting locations. Our trucks are mounted outside the frame, while cars are mounted inside the frame rail

[68gmsee]

fyi:

I'm doing some research on this on the engine and drivetrain forum and have determined this:

My 68 GMC has a saginaw 800 series late 70's gearbox with a 3/4" input shaft and flared hose ends. IIRC it came off a dodge truck but not positive. It is a 2.5 to 3 turn lock to lock with variable steering. I was told that the 2.5-3 lock to lock is a quick ratio box.

I have another unit that came off my 69 and it has a 3.5 to 4 lock to lock.

I'm trying to determine which is a better unit for highway and some city.

[Longhorn Man]

very interesting info.

[ubtripn]

definitly

[VA72C10]

I purchased a box off of a 81 pickup and installed it on my 70. It bolted up and the thing that amazed me was even with no pump even hooked up, with the engine and all in the truck, I could turn the wheels lock to lock with ease. On my 72 super I have a rebuilt factory box and it's almost impossible to turn when on the blacktop (without an engine even in it so less weight)


It was amazing how much the newer box helped in the ease of moving the truck...I wouldn't have thought it would have w/out the pump to provide the pressure....

[wwotr]

Originally Posted by ubtripn

Just another ps conversion question. thx

Just my .02 cents worth, but my 72 GMC's turning is effortless!
(I'm Just Sayin......)

[68gmsee]

In the last week I've found out that there were numerous configurations on these boxes and used by different companies including Ford, Dodge, Jeep and possibly others. They can easily be converted from non quick ratio to quick ratio with variable steering since a lot of the parts are interchangeable. There's no telling which ones are rebuilt units on these 40 year old trucks.

I guess the only way to find out is to test them.