Power Steering & Steering Coupling issue, need some Help?

[longhorn70gmc]

Hey all,
I have a predicament. I have removed the Power Steering Box off of my 1970 ¾ GMC Longhorn. I have removed the Steering Coupling Assembly that attaches the Steering Column to the Power Steering Box. I have ordered and received two new Power Steering Boxes and both Splines measure out at 7/8.
The Original Steering Coupling Assembly measures out at ¾ of an inch and the new one I purchased measures out at ¾ of an inch as well. The new Steering Coupling Assembly is for 1969-1986 GM.
On the old Power Steering Box the spline measures out at ¾ of an inch and the old and new Steering Coupling Assembly slides on the old Power Steering Box no problem, but it will not go on the new ones.
To sum it up; I have ordered two new Power Steering Boxes and one Steering Coupling Assembly and have gotten together with a trusted local Auto Zone Representative and am just coming up short on getting solution for this replacement and install.
My question to you all is what else can I do here or try to fix this situation? Another question is do I have to have the new Steering Coupling pressed on? Please any and all assistance appreciated?
R/
Billy
Note: I am currently unable to post this thread in Suspension and Steering Section, so I apologize for not following protocol rules for posting threads and the intended titled sections.

[GMCMAX]

Billy,
The box that came with my conversion from a 70 blazer had the larger size.... I wound up with a coupler from a 64-65ish 60 series from the junkyard. I put a new rubber disc in the coupler from napa.
Max

[Rack Man]

Well there are several different couplers....two different sizes (3/4" & 13/16")....and with two different splines (30 & 36)....Not sure exactly which one you need.....Also, You should not have to press the coupler on.....should slip on fairly easy...

Here are the different ones available....(Scroll down a bit)
http://www.americanclassic.com/asp/d...ype=to&exyear=



RM

[longhorn70gmc]

Thanks Fellas, let me investigate your helpful info.
R/
Billy

[longhorn70gmc]

Hello Gentlman,
I am still looking into this and investigating it. I went to the web site you provided and matched everything up. I was able to confirm measurements of the spline and the Rag Joint. I have an appointment today with a local Mechanic to figure this out some more. I will bring what you guys sent me as back up. I will post the outcome and hopefully it puts me closer to solution. For some strange reason I think it will boil down to the power steering gearbox as the culprit.
R/
Billy

[longhorn70gmc]

Hello Gentleman,
Finally some resolve.
Recap!
I purchased a 1970 compatible steering box from autozone and tried to mate the original steering coupler. It would not go on because the spline was 13/16 on the new steering box, so I purchased a special order new coupler, 86-69, for the new box, still the same thing. The couplers were measuring out at 3/4 not 13/16. Next we ordered another new steering box and had the people on the other end measure it just in case and they stated to us it was 3/4 but when it came in it was 13/16. Now it was time for other measures, so we called the manufacturer. They stated the correct box needed was a 1977-1986 box with a 3/4 spline. What ya know the coupler fit the third box, so I am back in business.
Installed the coupler on the steering box; went to install new pitman arm I bought from board member and it doesn't fit, so I removed the old one and just went with it. Installed new box and mating up everything now. I hope to have it done today or tomorrow. This has been a screwy adventure, but well worth it. Not all parts are created equal contrary to what computer base lead auto parts places state. They really need to fix there data bases. I went to the other related auto parts stores here in town and they all were stumped as well. Napa figured out I needed a 1977-1986 box, but there boxes looked unprofessionally done. Good side is I have to do this one more time for the 1972. At least now I know what to order and what to look for.

For FAQ Purposes
Step one: Remove old Steering coupler, measure Steering coupler spline.
Step two: Remove old pitman arm, Measure Pitman arm spline.
Step three: Make sure parts are good or need replaced.
Step four: Order parts from a Auto Parts place, store or individual that you trust and will take care of you if the need arises.
Step five: Ensure all new and/or parts mate correctly for compatability.
Step six: Install both the Steering coupler and pitman arm back on. Make sure your turn radious matches up right with the arm, so you don't have install problems and later have steering issues.
Step seven: Install new Power Steering box, don't tighten mounting bolts until pitman arm is in intended linkage hole and Coupler is mated up correctly with steering column piece. Tighted all bolts and nuts associated with install once everything is alighned.
Step eight: Bleed system/perform functional check. Borrowed from fellow board member Storm91. Then there is a proper bleeding procedure you need to do:

(various service manuals for various years cars and trucks have some variation of this procedure)

The vehicle is supposed to be raised until the front wheels are off the ground, with the engine OFF, turn the steering wheel from stop to stop at least 30 cycles. This will force out the air bubbles into the reservoir. Be sure to check the level a few times. Then start the vehicle and repeat -- 30 times, stop to stop. If the pump is noisy or the fluid is very milky, shut it off and wait 10 minutes. Then repeat the process from the beginning until the fluid looks clear and the steering feels correct. Be sure to drive it carefully on the first test drive in case there are still some bubbles or something wrong with the box.

And there you go. 1969-1972 Power Steering Boxes/Steering Couplers, (AKA Rag Joints and Pitman Arm FAQ.