Pitman arm question

[tnljohnson]

I just upgraded my steering box to a borgeson. I have everything hooked back up however the pitman arm does not seem to stay engaged. I put it in place and wheels turn fine. Put the washer and nut on and it seems to drop a little. Anyone have any ideas of what I am doing wrong? Novice here so sure it is me, just looking for some ideas.

Thanks.

[Katfish]

Got a pic?
The shaft is tapered and its a forced fit, you gotta crank that mutha pretty good.
I'm guessing the Borg shaft doesn't have as tight specs as our originals
My pitman arm didn't go up as far as I would have liked, but it's not coming off.

[tnljohnson]

Sorry, meant to add those.

[Katfish]

 Wow! That's way up the shaft.
With my Borg box and Moog pitman arm, I have maybe 1 thread showing below the nut
I had to use a 3 foot cheater pipe on a 1/2 ratchet to get it seated that much.
And I've read others having same issue, you seem to have opposite problem.
You sure you don't have the larger pitman arm on a small pitman arm box?
Or maybe it's the pitman, what brand?

[tnljohnson]

So complete neophyte here. How does one determine if they have the larger pitman arm? I just assumed ( always gets me in trouble) that I had the smaller one since I have a small block 340.

[anlauto]

The spline size is determined by the year, I believe 70-71 were small and 73-74 were larger if I remember correctly

[Katfish]

Small is 1 1/8
Large is 1 1/4  (so 1/8" larger diameter)

No idea if you could push a large pitman arm on enough to make it work on a small shaft.
But in your situation, I'd pull that pitman arm down and measure everything.
Does it go on with force, or just slip on easily?  How much force does it take to get it back off?
Comparing to mine, yours is MUCH higher up on the box shaft.

Hopefully you still have the old box, measure the 2 steering shafts to compare.
Not uncommon to put a later model box (large spline) on and older car (small spline) over the years.

[moparroy]

The spline size is determined by the year, I believe 70-71 were small and 73-74 were larger if I remember correctly

My '74 was a small (manual steering) - though no way to be sure it was the original steering box - it was manual per original. Many parts listings show large - I was given a large by CTC some years ago (by the time I got to install it...)
I have actually listened to a vendor father and son (steering focused stuff) argue on the swap meet field at Carlisle on whether a '74 manual  was small or large. (Dad said large - son said seen many small - "lets go look")
I did a bunch of reading to see if I should replace the steering box, in the end I did not. The big challenge was to find the right seal for the output shaft size.
One story I recall reading is that e-bodies maybe used small shaft (on manual) to use up old stock when they switched.

[anlauto]

Yea I'm not sure about manual, that's a different story...

[tnljohnson]

Thanks everyone for your help on this....looks like I will be updating my pitman arm now. You guys are awesome.

[Katfish]

Thanks everyone for your help on this....looks like I will be updating my pitman arm now. You guys are awesome.

So what did you find?
If you need the small diameter pitman arm, unfortunately they are much higher cost.
1 of the reasons people upgrade to the larger shaft box when replacing.

[tnljohnson]

Old one was large diameter. I "assumed" all 71 340s used small and didn't check prior.