The Jeep arm looks longer than de vet one so It must have a different turning radius than the idle arm.
Will that be a steering isue??

 

Pacha,
The Jeep pitman must be modified as the one on left. I've tried to scale my addition to Norval's photo as close as possible.

 

Nice job this is one of my next mods also,and as far as welding the pitman arm,i lengthened my idler arm and steering ram bracket to clear my oil pan with my stick welder also and trust it completely.Again nice job.

 

I don't have a comparison picture of my modified pitman arm but it ended up the same length as the stock arm and locates the ball stud in the steering center link in the stock location.

 

 

I am curious why install a Jeep steering box in place of the original? Cutting either the frame or the Pitman arm seems drastic and risky.

So far, no one has said what the significant advantage is to do this, especially in a seldom driven car like most of ours are.

 

For me it is simple. I want power steering and power brakes. The jeep steering box and a hydroboost are the cheapest, and in my opion, best way to get them. I purchased the Jeep box, a hydroboost that looks like new, and a power steering pump on Ebay for just a little over $200.00 including shipping.

 

Everyone seems to agree the stock corvette steering is junk, if not junk cluttered and leak prone.

Our stock system is a catch up system. You turn the wheel, that movement passes through a 30 year old box pushes on a control valve that then signal some controler to move oil to one side of a slave cylinder. The slave cylinder then turns the wheels.
The Jeep box is a 2000 design, actually came out I believe in 1999. It is a new design with the control valve right on the input. Turn the wheel and it is direct mechainical linkage to the control valve.
The jeep box isn't leak prone, really cleans up the lines, gone is the control valve and the slave cylinder.
It is neat and tidy and if you run hdro boost the lines are extremely short.
Gone is the dartiness, following grooves with wide tires.
I feel it is a far better setup then steroid type setups, alot cleaner installation and as far as modifying/welding a pitman arm if done with any skill is impossible to detect and will not cause a problem.
I have done 4 pitman arms so far, even welded spindles with out a problem and on fear of one.
If you feel strongly about modifying/welding parts then it isn't for you. To those that are it is a great modification.
Both steroid type and this jeep box were available to me extremely cheap so which I felt was best had nothing whatever to do with price. After posting, getting feedback from knowledgable people on the forum it was agreed unanimously by the steering group that the jeep box was the better way to go.
As for cutting the frame and inserting a plate it was a pleasure for me to actually do it. I am constantly looking for things to improve upon and cutting and gusseting the frame is one of those things I like to do.

 

Could someone tell me the difference in diameter of the pitman arm splined end? I understand the manual one is smaller than the Jeep, but what is the diameter of each?

If someone could measure those splined ends for me, I'd be very grateful.

 

Mustangsix, The small end of the spline on the Jeep box measures approx. 1.176 in. The Large end of the Vette spline measures approx. 1.115 in. Thus, the Vette pitman won't even start onto Jeep box spline.

 

Hey Gary, I have about 25000 miles with the jeep box and it is just like Norval said and more. The thing he left out is autocrossing improvement, it will cut seconds off your times, plus it is just plain fun to drive a c2-3 with one of these boxes.

I did this about 4 years ago and for you guys who can't weld steering parts, I found a pitman arm in the junk yard , Which I think was off a mid 70s cadillac or olds. All I had to do was build a small bushing were the drag link attatched.

Another alternative is Tom a Corvette steering is now resplining the pitman shaft so you can use your stock pitman arm. Anyway you get there If you like driving your old vette it is the best mod going.

SSS

 

SSS, did you do the adapter plate or the Novral route and modify the frame rail? If you did the adapter, how well did the shaft and box line up?

 

Hey Batman, I been busy for a couple days. I did it different than most about 4 years ago when I first found the jeep box. I used a 5/16 plate and drilled it to match the 4 holes in the jeep box. Then I counter sunk the holes and bolted the plate to the box with allen headed machine bolts. That gave me a flat plate to match to the factory holes in the frame. So I mounted the box to the steering column shaft and the pitman arm to the drag link and clamped it into place, getting the drag link level and in line with the idler arm. Then I marked the 3 original holes and drilled the plate, and bolted it on.

I have done some family members cars and we have probly 35000 miles and no problems. I have said this before, now that you can buy the complete deal from Tom at corvette steering for around 600 bucks, it is an easy decision to just buy the deal and bolt it on in a afternoon.

I have said it before, it is the best mod I have done to the car, and I have been trying to improve all aspects of the car for the last 35 years and over 200000 miles.

I have been wondering if Norval has driven his jeep box conversion yet and what his take is on it.

SSS

 

SSS, thanks for the info. I have a Jeep box and a manual steering drag link in hand, I'm just trying to figure out the best way to install it. It looks like your input shaft lined up nicely with the steering column.

 

Besides the simplicity, what are the other benefits? i.e. what is lock to lock turn ratio? How about speed? (I can't turn my steering wheel as fast as I'd like to) Why Jeep boxes? are they the only ones that fit?

 

As Jim Shea can explain in detail, the Jeep box is the closest in design to the original box. An archive search on "jeep box" will turn up a wealth of info.

 

Tonight is the night. My insurance started this morning, the weather is great so right after work I am heading out for a test run
I have started the car and taken a few test runs up and down the street but that is hardly a test. Nothing at speed. I was just settling the suspension, looking for leaks and making sure everything is ready.

 

Norval, You are going to love that box, especially after you have taken the bump steer out of your front end geometry. To be honest, it takes a very uneven road to throw my car off line, even with my 17 inch wheel and tire setup, and stock front end, other than a spreader bar.

Zman, the boxes I have used are 2.25 turns lock to lock and they have a great road feel and feed back. I have been told the reason they feel so good is they have rack and pinion torsion bar sensor in the power control valve.

The reason the jeep box is used, is because it is the first modern day power steering box designed that has a long pitman shaft so it can be mounted above the frame rail and still reach the drag link.

As far as speed, I autocross my car ever chance I get, and it reacts as quickly as any modern day sports car.

 

Hey Batman, here is a picture of my box mounting. I just keep and eye on it for movement and cracking. So far no change.

I have never heard a word from anyone not happy with this conversion. I spent 2 years trying to make rack work, never could get good road feel or flex out.

Hope this helps SSS

 

Really nice work SSS. The more I read the more I like this mod. I noticed you used the stock rag joint. Did that bolt right up to the Jeep box or did it have to be modified?