Follow-up to last night's post on the Control Arm spreader woes.
Last night I had mounted the spreader in the Shop Manual's photo position (in the "U-shape" cutout in the upper control arm). As I noted, the dimensions (after setting it to 0.015" over) were getting SMALLER down at the actual Bushing receivers (welded inside control arm). I kept going after multiple attempts to correct, and after torquing, had one VERY stiff king-pin.
OK, so I decided the "U-shape" stamped metal must either be continuing to bend/distort (making the opposite side where I was measuring get SMALLER), OR, the poor fit of the repro Spreader tool was causing it to move/settle with the pressure; SOMETHING was wrong.
OK, so today I modified the spreader by grinding off enough of the INSIDE "legs" so the would clear the kingpin if I used it right at the pin Bushing receivers (see photo). I carefully marked a location (blue tape and Sharpie) where I got good repeatability with my Vernier Caliper, and cranked it up, measured (had about 0.010), cranked a little bit more (still had only 0.010 !), cranked it some more, etc until I got to 0.015" over my initial reading at 'zero'. Figured maybe here too the tool had some slop taken up by the initial "pressure".
OK, screwed in the Bushings, and tightened them only to "as tight as I could with socket long-bar"; I checked the gap "just to make sure" before really cranking down to final torque. The gap was now about 0.050" greater than than where I had set it! Disgusted and not knowing what else to do with it, I loosened up the Bushings, re-measured, and the gap was still pretty much the same (about 0.050" + 0.015" more than the initial position). I removed the spreader, and the ears came back to close to the initial reading. So all I can figure is that the spreader is continuing to "spread" that slot in the control arm, even after you stop turning the screw. Or when I torque down the Bushings, it spreads the ears, but this was 'expected' and ignored, as the shop manual never has you check with a vernier, only SET the initial spread to 0.015" over.
So, do any of you use a Vernier? And check the control arm gap AGAIN, after torquing? (do your numbers change too?).
Maybe that is why they used a caliper-only (non-Vernier) and ONLY used it once, right after spreading?
Honestly, the gap seemed to CLOSE as I was spreading it (with bushings loose), and I probably spread it too wide initially, with the moving target (if you have 0.010 gap, turn the nut on the spreader and still have 0.010, something is moving; and I got GOOD measurements this time, very repeatable spot). And from that "supposed 0.015" over, it then got MUCH wider when I had tightened the Bushings. Pressure against the pin threads? Again, a Stude tech would never have watched or measured these things. So again, have any of you used a vernier caliper, and/or rechecked gaps when torqued but spreader still in place?
Sure seems the better position (more solid and positive) is what I did below, unless Studebaker INTENDED for those ears to move in (narrower gap) like I had last night.
If no-one has any better ideas, all I can think of is repeating what I have below, quickly spreading the gap to 0.015 and "not watching the vernier" or checking it anymore , just going with it as if it were the plain "hoop caliper" used in the Shop Manual.
Sorry to drag this out, I don't understand why things are moving around for me, with all NOS parts (arms, pins and Bushings). Bushings thread in nicely as threads are well-cut by now, so the NOS arms no longer are 'unthreaded" :-).
thanks!!!
Barry, walking away to fight another day
Last night I had mounted the spreader in the Shop Manual's photo position (in the "U-shape" cutout in the upper control arm). As I noted, the dimensions (after setting it to 0.015" over) were getting SMALLER down at the actual Bushing receivers (welded inside control arm). I kept going after multiple attempts to correct, and after torquing, had one VERY stiff king-pin.
OK, so I decided the "U-shape" stamped metal must either be continuing to bend/distort (making the opposite side where I was measuring get SMALLER), OR, the poor fit of the repro Spreader tool was causing it to move/settle with the pressure; SOMETHING was wrong.
OK, so today I modified the spreader by grinding off enough of the INSIDE "legs" so the would clear the kingpin if I used it right at the pin Bushing receivers (see photo). I carefully marked a location (blue tape and Sharpie) where I got good repeatability with my Vernier Caliper, and cranked it up, measured (had about 0.010), cranked a little bit more (still had only 0.010 !), cranked it some more, etc until I got to 0.015" over my initial reading at 'zero'. Figured maybe here too the tool had some slop taken up by the initial "pressure".
OK, screwed in the Bushings, and tightened them only to "as tight as I could with socket long-bar"; I checked the gap "just to make sure" before really cranking down to final torque. The gap was now about 0.050" greater than than where I had set it! Disgusted and not knowing what else to do with it, I loosened up the Bushings, re-measured, and the gap was still pretty much the same (about 0.050" + 0.015" more than the initial position). I removed the spreader, and the ears came back to close to the initial reading. So all I can figure is that the spreader is continuing to "spread" that slot in the control arm, even after you stop turning the screw. Or when I torque down the Bushings, it spreads the ears, but this was 'expected' and ignored, as the shop manual never has you check with a vernier, only SET the initial spread to 0.015" over.
So, do any of you use a Vernier? And check the control arm gap AGAIN, after torquing? (do your numbers change too?).
Maybe that is why they used a caliper-only (non-Vernier) and ONLY used it once, right after spreading?
Honestly, the gap seemed to CLOSE as I was spreading it (with bushings loose), and I probably spread it too wide initially, with the moving target (if you have 0.010 gap, turn the nut on the spreader and still have 0.010, something is moving; and I got GOOD measurements this time, very repeatable spot). And from that "supposed 0.015" over, it then got MUCH wider when I had tightened the Bushings. Pressure against the pin threads? Again, a Stude tech would never have watched or measured these things. So again, have any of you used a vernier caliper, and/or rechecked gaps when torqued but spreader still in place?
Sure seems the better position (more solid and positive) is what I did below, unless Studebaker INTENDED for those ears to move in (narrower gap) like I had last night.
If no-one has any better ideas, all I can think of is repeating what I have below, quickly spreading the gap to 0.015 and "not watching the vernier" or checking it anymore , just going with it as if it were the plain "hoop caliper" used in the Shop Manual.
Sorry to drag this out, I don't understand why things are moving around for me, with all NOS parts (arms, pins and Bushings). Bushings thread in nicely as threads are well-cut by now, so the NOS arms no longer are 'unthreaded" :-).
thanks!!!
Barry, walking away to fight another day
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