Could you look at this (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7929470750&category=33589) for me. It is an ebay ad, the guy is claiming that the box he has for sale is the Jeep G.C. box but the application list is quite extensive. This same box cannot possibly fit all these applications. Is he full of .... or what?

Dennis,
I have a Jeep Grand Cherokee box sitting in my garage taking up space. I only have $25 in it. If you are interested I can ship it out to you.

Joe

It might fit all of those applications, but he is not claiming it's a true Jeep Grand Cherokee box. This is a very venerable steering box that can be installed in MANY vehicles. I would have a lot of doubts as to whether or not this is a true 12.7:1 quick ratio box. It is my feeling that it is just a standard box, nothing special.

In one word "YES", one gear could very well service a large number of vehicles. If the gear is as advertised, it definately is NOT a 12.7:1 gear. None of the vehicles listed would have had a 12.7:1 gear. If you want some of the reasoning, read on.

It is very possible that one Saginaw power steering gear can "fit" many, many applications.
The gear mounting pad dimensions and the mounting threads 7/16-14 UNC has remained the same for 40 years! So a typical Saginaw gear housing will bolt into literally thousands of models of passenger cars and trucks that were produced through the years.

The original car division ride and handling engineers may have specified a steering gear with ratios, valve efforts, travels, etc that exactly met their expectations for the car that they were developing for production. There were instances where a Buick R&H engineer would specify a power gear with efforts that actually overlapped a Chevrolet gear (all other things were identical!) but the Buick engineer would not release a lowly Chevrolet part for his BUICK. So during production there could be massive part proliferation of parts that are very similar to each other. An Oldsmobile engineer may want a power gear slightly different than the Chevrolet or the Buick gear. So now there were three gears CCCCCCC, BBBBBBB, & OOOOOOO.

All this changes for service (and particularly service for vehicles many model years old). Now the service engineers get together and decide what generic gear can service the most models. Many times they just notify AMC, Chevrolet, Buick, Oldsmobile, etc - "Saginaw Power Gears CCCCCCC, BBBBBBB, OOOOOOO are no longer available - Service Engineering has determined that Saginaw power gear XXXXXXX can be used in its place."

Since tires are now a lot different than original. Shocks have been changed. Body mounts and springs may have sagged, etc. There is literally no chance that a regular driver would ever notice (or care) that his 1980 vintage vehicle does not steer and handle exactly like the original with the replacement gear.

So rather than thousands of different power gears being available for service, only a limited number of generic gears are actually available.

One more thing! Unless a gear remanufacturer has a sophisticated valve testing machine, there is little chance that a remanufactured gear will have exactly the valve efforts that the original gear had. (I am not even sure that a gear remanufacturer would even have access to the Saginaw original valve effort specifications.)

I don't have data on any of the really old vehicles that are referenced in the eBay add. I did have information on a 1999 Jeep Cherokee. It had a 14:1 gear ratio, intermediate pitman shaft travel, and a nominal valve effort of 27 inch-lb. I assume that most of the other cars and trucks on that list had power gears when they were in production that had roughly those characteristics.

Hope this helps.
Jim

Joe, email on the way

Jim, so basically if somebody that really had a Jeep bought one of these boxes they would be very disappointed when it was installed. ebay is kinda like roulette-50/50 shot of losing. Thanks anyways, I figured he was full of cr@p.

The steering gear advertised is a Cherokee box not a Grand Cherokee box. The Grand Cherokee from 1992 1/2 through 1998 had a 12.7:1 gear box. The Cherokee had a 14:1 gear ratio during that time.