C3-Jeep Steering Gear Conversion

[mrvette]

I was all about doing this conversion and stuff got in the way. Then I found a rebuilt OEM steering box for super cheep. I am going ahead with the direct replacement. If anyone is interested in the pitman arm and the jeep steering box, let me know and shoot me an offer. Actual shipping cost. I am in the Miami, FL area.

IMO, that is a mistake, but best of luck with it.....

I would not sell the other stuff, until you sure you happy.....

:amazed:

 

[BBShark]

Make sure it's really "rebuilt". There are a lot of them being sold that are rebuilt by putting new seals and a paint job on them.

 

[stewdesignjts]

size of hole in chevelle pitman arm

I finished modifying my jeep box and have it mounted, and after receiving a pitman arm in the mail yesterday i tried to install and attach my c2 manual drag link.

The tapered hole in the 7814221 pitman arm is larger than the one in my old corvette pitman, and it doesn't look like it will tighten up completely.


Anyone else have this trouble? I believe my pitman was an unmolested original, and the tapered hole size is approx the same as the dimensions given for the speedway motors arm.
I'm also assuming that the stud diameter didn't change through the years?

I could make a tapered shim out of some shim stock to get it together.

thanks for the help in advance, jason

 

[BBShark]

The small hole in the 221 pitman arn should be about .450-.460*. I have done a few of these and never had any problem.

Just looked at Speedway, the arm they advertise is .580 it the top of the hole. That's not an A body arm. More like a Impala arm.

*EDIT: My measurement SHOULD have been .550-.560. Sorry for the confusion, my bad!

 

[stewdesignjts]

Thanks for the info

I bought it off of ebay (advertised as a chevelle arm from the vegas guy) and the taper hole measures .560 on the small side.

I will go back to them about this and get another, i guess.

Jason

 

[BBShark]

Does it have the 7814221 cast into it? All I have seen have this.

 

[stewdesignjts]

Yes, it does have that casting number.

 

[stewdesignjts]

well the guy on ebay says all of his 7814221 arms in stock have the .560 diameter (small side) tapered hole.

i guess my only option is to make a tapered sleeve to take up the slack - i did come across one guy on cf (has a silver midyear coupe) that had to do this on his pitman arm. but he didn't give a casting number for what he used.

at least this thread can give a warning to others to verify the tapered hole size before buying.



*** UPDATE: i was able to make a "cone" of .015" shim stock to fix my problem, so the tapered hole size wasn't that far off. maybe my problem was an over-tolerance issue from the factory? anyway, if the small hole on the taper of the 7812441 arm is more than about .535", you may run out of threads on the stud.

 

[fiberglass shell rider]

Coupler

Which universal coupler works best for this install? I have everything else figured out, but the coupler.

 

[BBShark]

The Borgeson Ujoint style is PN 114350 and the rag joint style is PN 055043. I think you can get both through Summit.

 

[fiberglass shell rider]

Thanks for the info. Are these bolt on parts or do they require any mods? Is one any better than the other?

 

[BBShark]

You have to collapse the steering shaft into the column for either one. Lots of people have used the u-joint style without issues. Also, it is smaller than the rag joint style so it might help if you have clearance issues with headers, etc.

 

[fiberglass shell rider]

I got everything together yesterday, and the gear box is setting about 1/2" too far over to the outside of the car. I was going to put a 1/2" plate in between the frame and the gear box unless there is a better way. Any ideas?

 

[BBShark]

Something is wrong there. The sterring input shaft of the Jeep box should be in line with the old box. Same with the pitman arm.

Seet the scales with the tape mark in the image with the Corvette box? I realize you are talking about the view from the top but the input shaft for both should be exactly in line.

 

[fiberglass shell rider]

Maybe I have the wrong gear box? It was for a 99 Jeep Grand Cherokee. I'll cross the Delphi # on the one in the pic you posted.

 

[BBShark]

99 Jeep Grand Cherokee is right. Here is a picture of one mounted on a frame. You can sorta see that the casting flash lines up with the inside of the frame rail. Is that how yours is?

 

[mrvette]

Loosen the bolts on column where it passes through firewall, center the column shaft up and then tighten them again.....

:smash:

 

[fiberglass shell rider]

I checked and it is the same Delphi part #. I loosened the column, and I think it will line up well enough. Thanks for all of the help. You guys have been very helpful.

 

[stewdesignjts]

Another question/problem related to the input shaft aligning with the firewall hole:

I just put my body on the frame after finishing up the steering box mounting a couple of months ago, and like fiberglass shell rider, the jeep box input shaft doesn't even point towards the hole in the firewall. I'm afraid that a c2 body/hole is going to be less forgiving than on a c3 to be fixed by loosening the steering column mount.

Looking down from the above the boxes, the original box's shaft is angled in towards the center of the car a significant amount and the jeep box is pointed straight rearward. I'm not sure i can easily get the jeep box rotated enough to copy this angle. If i could, then the centerlines would intersect and i could use a universal joint.

Anybody run into this issue on a c2 with the jeep box?

thanks, jason

 

[BBShark]

The original steering gear mounting ears are on a 3 degree angle towards the center of the car (birdseye view). The Jeep box is not but the offset is greater, from the input shaft to the frame. I have found that these centerlines intersect but I guess all cars are not the same.

You could put a shim plate between the frame and one side of the gear mounting to angle it I suppose.

 

[stewdesignjts]

I'll give it a shot - there's no turning back now. I'm going to assemble the pedals/column/brackets to see how far off it is.


On another topic, i found that i had to adjust the tie rods in a lot farther on the passenger side vs. the driver's side to get the wheels point straight with the chevelle arm and this box (in the center position). Did you experience this too?


Thanks for always taking the time to help.

 

[BBShark]

On another topic, i found that i had to adjust the tie rods in a lot farther on the passenger side vs. the driver's side to get the wheels point straight with the chevelle arm and this box (in the center position). Did you experience this too?

That does not sound right. I have fixtured the Corvette box with pitman and Jepp with Chevelle Pitman and found that the pitman hole lines up perfectly. The picture below shows the center of the Corvette pitman (circle with centerline) and the Jepp with Chevelle arm.

If you look at your Chevelle arm you will see 4 flats wher it mounts to the gear output shaft. Is the flat in the front lined up with the hole in the pitman?

Also, what is the diiference in tie rod length?

 

[stewdesignjts]

I've attached pictures of my misalignment problem - original box vs. the jeep box. My guess is that the c2 body isn't as forgiving with respect to moving the column over. The original box lined up in all viewing angles.

I'm going to make a plate that tapers from about 1/8" to 5/16" (at the bolt thru holes), because that worked well when i mocked it up. I'm also going to have to modify the two adapter brackets so that they can be at the same angle. That will be the not so much fun part.


On the tie rods, The difference in overall length is 3/4" (passenger side is longer). Rotating the box as described above will help this issue, but may not eliminate it. The 4 flats in the spline are lined up with the pitman stud hole.

Thanks, Jason

 

[BBShark]

For all looking for a correct pitman arm that will work with this conversion, I have contacted Speedway motors and verified that their pitman arm PN 91032555 is correct for this conversion. The picture below is a 74 Chevelle arn with the correct center to center, drop, spline and tapered stud hole. The Speedway arm is described as:

•5.5" center of eye to center of eye
•Splines are 1.190" outside diameter
•Bottom of tapered hole is 0.675"
•Top of tapered hole is .580"
•1.063" drop

The 1.063" drop spec is what concerned me but I sent these pictures to one of the techs at Speedway and got the following response:

Larry
It looks like the amount of drop is actually going to be .693" which look sto be very close to what you are showing in your picture from the surface it is sitting on the the bottom side of the arm where the tierod bolts on.


Craig Hardman | Street Rod Tech

 

[Jupiter60]

Universal Joint

Can anyone verify the universal joint required for this conversion? I have heard 15.5 MM and 18 MM double D. Which is it? Earlier in the post someone mentions: 8DDx148. Does anyone who has actually completed this conversion have the part number for the universal joint along with the store they bought it from? Thank you

 

[BBShark]

The Jeep shaft is .73 diameter and .61 across the flats. According to Borgeson, their 18mm Ujoint measures .74 diameter and .635 across the flats. So you need a 18mm DD on one end and a 1"-48 spline on the other end. Summit sells them and you can look up the part number at the site.

 

[VetteV8]

I've attached pictures of my misalignment problem - original box vs. the jeep box. My guess is that the c2 body isn't as forgiving with respect to moving the column over. The original box lined up in all viewing angles.

I'm going to make a plate that tapers from about 1/8" to 5/16" (at the bolt thru holes), because that worked well when i mocked it up. I'm also going to have to modify the two adapter brackets so that they can be at the same angle. That will be the not so much fun part.


On the tie rods, The difference in overall length is 3/4" (passenger side is longer). Rotating the box as described above will help this issue, but may not eliminate it. The 4 flats in the spline are lined up with the pitman stud hole.

Thanks, Jason

Would this misalignment also occur on the C3?
I did not hear anyone about that.[Apart from the same comment in post 170 : http://www.vettemod.com/forum/showpost.php?p=82697&postcount=170 but no response , nor further comments about this by the poster].
The misalignment appears to be a little ove 1/2" since the steeringshaft is 1" thick.
Naturally, to put a taper in between is the best solution, but if you have the room [I have no headers, and willnever have them] then it would be easier to fit a 1/2" or 9/16"th spacerplate between the chassis and the housing.
Any experience with this on the C3?
The chassis are supposed to be the same, right?

I am not concerned about the angle of the ragjoint, because on my RV with a Chevy chassis, [P30], there is also an angle, never measured it, but perhaps 5 degrees or so; and that is still in perfect shape.

Cor

 

[VetteV8]

Here's the dimensions of the Jeep input shaft. Note that they are not symetrical.

Very interesting drawing part!
Would it be possible to publish the complete drawing here?
I am compiling my shoppinglist to get everything together across the water, (apart from the steel stock :wink
Thanks
Cor

 

[Jupiter60]

can anyone post some pictures or information on converting the control valve for this swap? I have the Speedway pitman arm and a Borgeson rag joint. I have removed the stock power steering components and am ready to start the conversion. Thank you

 

[VetteV8]

Well, I finally received all the parts I need from the States in good order, and began to remove from the car what's not needed.
No problems here.
When trying to move the new gear into position, it became clear that this required the removal of the alternator and vacuum hoses from the charcoal canister.
Moving the gear into position, it became obvious that this is not going to fit: the exhaust manifold is too much in the way and fouls the top flange of the steering gear, where the adjuster is located.
Question: has anyone done this mod on an '81, which has a stainless manifold?
This manifold is pretty wide, and of course I did remove the heat shields already.
It looks like I need to remove the manifold in order to dimple it.
Any comments or suggestions?


Secondly, I obtained the recommended pitman arm from Speedway.
I find that the ball joint taper is too thin, or the hole in the arm too large: the ball joint taper bottoms out on the ridge, and also the taper protrudes too far through the hole.
I have taken the sizes: the large size is 0.651" and the small end is 0.570"
The pin taper at the extreme end is 0.540" and where it 'should'stop, it is 0.618".
So, the difference between the two is about 30 thou [0.030"]
I would need a bushing with a wall of 15 thou to make it fit.
I have read on fora that such bushings would be available in the US, no idea if this would be for sale here.
Any idea about making a shim of 15 thou stainless steel, and form this to 'fill the gap' ??
A few pictures of the arm and balljoint are shown below.
The sizes I measured do agree near enough with the sizes advertised by Speedway, but my balljoint will not fit in there
Any comments or helpful observations are invited
Thanks,
Cor