71roadster

Hey Jim
what is the ratio of the steering box in my car (71 of course). A while back I posted on an alternative to rack and pinion (I am leary of the linkage setup) and I just found this, which is exactly what I was refering to...
http://corvettesteering.com/55-57%20chevy.htm

It is 12:1 ratio and would utilize the manual steering relay rod. It would eliminate the ram and the control valve and perhaps the needle beering arrangement offers some advantages as well. A bit cheaper than the r&p too...


Chris

Jim Shea

The Corvette steering gear has a 16:1 ratio. The gear shown at corvettesteering .com is a Jeep Grand Cherokee power steering gear with a 12.7:1 ratio. I don't quite understand how they are going to bolt it onto a Corvette frame. The Corvette mounting has three bolts. The Jeep has four. The bolt holes don't line up. Some of the bolt holes are close. The picture seems to show four bolts and a plate on the gear.

I have overlaid the two mounting patterns and can eMail them to anyone that is interested.

One other problem is that the mounting face (three bolt pattern) on the Corvette gear is not exactly in line with the input shaft. The Corvette input centerline is skewed by about 1 1/2 degrees from the plane of the three bolt mounting face. The four mounting faces on the Jeep gear are in the same plane and are parallel with the input shaft centerline.

71roadster

Thanks for the good info Jim, as always. What years of jeep is that off of? The plate you see is part of a braket that they make. The box is bolted to the plate (taking care of the offset you mention) and the plate is bolted to the frame. I imagine for the corvette app (I'm sure the pic is for the tri-5 app)they just drill the correct pattern in the plate. I shot em off an email with a bunch of questions and hopefully they will get back soon. This looks like it could be just the thing for a steering upgrade!

Do you know if the pitman arm off of the vette will fit the pitman shaft of the stock jeep box (diameter, spline count)? It may be time to hit the junkyards!

Chris

tworottiedogs

Looks pretty good. I would like to get some more info also so, if they reply to your emails, please forward the info on to me..... Mine needs lots of steering work and I would rather upgrade than just repair.

Thanks,

Jim Shea

The gear is from a 1999 - 2002 Jeep Grand Cherokee. I have the pitman shaft serration data for the Jeep gear. I just don't have the same information for the Corvette gear right now. I'll try to get it so we can compare the two.

The input shafts are not the same either. The Corvette input shaft has serrations and a flat, the Jeep gear input shaft is round with two flats.

ddecart

That is rather interesting. I'd like to see a pic of the installation in a car.

Jim,
I'll have to pull out those drawings I have and see what sense I can make out of doing that retrofit we talked about.

Dave

71roadster

Drawings? What drawings?

I don't think the input shaft differences are a big deal as it is just a matter of a custom rag joint. Corvettesteering seems to indicate that there is a custom pitman arm. That is one of the questions I asked them in my email. Still waiting on a response.

Chris

tworottiedogs

I received a response from corvettesteering.com:

Corvette ratios 63-62 All are 16 to 1
we offer a totaly diferent steering box (Integeral)
you can see it at corvettesteering.com
then 55-57 Chevy.. Haven't had a chance to put them on the corvette page
yet.. call me with questions Tom Reina CV Steering 864-287-9990


If it fits, I am all over it. I'd like to see an installed picture. I already have zero clearance between the steering box and the header. With an extra adapter flange thrown in, it can't be better (unless the physical dimensions of the Jeep steering box are smaller).