Front Axle / Front Suspension: upper-outer a-arm install question

[Dan Ward]

Hello everyone!
I have read many of the threads about this subject and have a pretty good idea how this is suppose to work( thanks to everyone!).
I am doing my 57 Hawk off frame restoration. The frame is done and ready to start bolting front end parts on. I purchased new parts for almost everything(outer pins, hard bushings, seals & zirks), except I am trying to re-use the control arms because they are pretty expensive to buy. I realize these can only be used a few times because the hard bushings can "rethread" each time, and the control arm will eventually become un-usable because it will not hold the required torque. The problem is that it is a "judgement call" to decide if they will do the job "one more time". If I am reading my shop manual correctly, the required torque for the hardened bushing to the control arm is 170 ft lbs Minimum. That sounds like an awful lot to put on these upper a-arms. I am afraid they "will" strip out at that torque. I decided to give them a try, and the bushings tightened against the shoulder of the a-arm,and seem to be holding well at 110 ft lbs (no sign of stripping yet). I decide to stop there.
When I removed the spreader, everythings seems to operates well.

I know the book says 170 ft lbs, but do you think 110 ft lbs will be safe enough?? I would like to get everyones opinion on this one---As always ---Thanks to All!!------Regards Dan

[StudeRich]

quote:Originally posted by DWard

I know the book says 170 ft lbs, but do you think 110 ft lbs will be safe enough?? I would like to get everyones opinion on this one---As always ---Thanks to All!!------Regards Dan

Well I am not a mechanical engineer so I don't really know the correct answer, but I can tell you that last year when we did my '59 Lark we had to use a 6 foot pipe on a breaker bar just to make those suckers turn, on a car that was never rebuilt before! So I am thinking I would try for 140-150 Ft. Lbs. at least and if they strip, or not, then you will know the answer to your question.

On the other hand, if they turned very hard all the way to the "A" arm maybe you should call it good! [^]

[HammondA100]

I have a question relating to this thread - Hopefully someone could answer.

I am finished with this job but I ended up needing new upper control arms (they got stripped) so on the NOS replacements I did get 160 foot pounds at least - so satisfied there. Also the threaded pins do pivot or turn inside of the bushings although it's pretty tight and the grease has a hard time passing through.

Well I used the spreader properly but once you get past about 100 Ft lbs pressure the ears on the upper outers do start to fold in. There's no way to prevent that but any comments on that? I figure that's OK as the spreader does put just enough pressure that when it is finally removed the forces are shifted to the other side of the threads. But by no means will this OEM spreader hold the ears at that position especially with them positioned at the top of the fulcrum.

In summary with the spreader set to .015 over the free setting, then 160 approx ft lbs on the bushings, the measurement of the ears where the bushings are torqued - I measure about or at least 1/8" change bent in from the start point. Is that acceptable?

[Quentin]

[QUOTE=DWard;19491
the required torque for the hardened bushing to the control arm is 170 ft lbs Minimum. That sounds like an awful lot to put on these upper a-arms. I am afraid they "will" strip out at that torque. I decided to give them a try, and the bushings tightened against the shoulder of the a-arm,and seem to be holding well at 110 ft lbs (no sign of stripping yet). I decide to stop there.
I know the book says 170 ft lbs, but do you think 110 ft lbs will be safe enough?? I would like to get everyones opinion on this one---As always ---Thanks to All!!------Regards Dan[/QUOTE]

As above for me also- re-using lower A-arms due to lack of supply; there looked like enough thread for this time around, with no evidence of cross-threading, so on the evidence I am assuming this is the first pin changeover in the vehicles life (63 Hawk). I have the same concerns as the above quote however, having taken the left lower control arm pin up to 110 foot pounds( I am assuming the 170 foot pounds quoted in the manual is for new, factory spec control arms), and this seems to be pretty bloody tight- so much so that the pin "nut" is biting into the flat outer edge of the control arm, with slivers of metal being shaved off. I thought I would stop there and post this. J2044 tool is still in place for further tightening.....
So... legend has it that older A-arm threads used a couple of times can "let go" whilst tightening up - hence my caution, as they are not readily available in my part of the world. Is there any instances of this occurring with members vehicles, beyond the one case in this thread? (HammondA100 entry). Could the pin cap possibly be welded to the a-arm?
Secondly, I have tightened this pin working solo, one pin cap at a time. I am thinking that for further tightening I should "phone a friend" and tighten both caps simultaneously, duelling breaker bars at dawn, etc etc, so as to attain something approaching the 170.

[bezhawk]

I always tighten outer bushings progressively, that is a turn or two on each side so as to draw them in evenly. It seems to work for me.
On badly worn control arms I don't see anything wrong with putting a weld tack in place to hold things. (As long as you can get to it to cut it off later.)

[JoeHall]

I do not use a torque wrench, but estimate 80-90 foot pounds, and in waaay over 600,000 Studebaker miles, have never had one come loose. I also lightly grease the cap threads, and if they were gonna come loose, they'd a done so with grease on them. I have found V8 Studes need new upper rubber bushings every 75,000 miles or so, but most other components last at least 100,000 miles if greased every 5000 miles, and those caps & pins last indefinitely, even on 56Js.

Keep playing with the spreader till all caps take grease easily. When assembling, I also recommend packing the inner & outer threads with grease.

I have no idea why S-P called for 170 foot pounds, other than to sell more control arms when rebuild time came due.

[Skybolt]

I have no idea why S-P called for 170 foot pounds, other than to sell more control arms when rebuild time came due.

Maybe this was the spec for new arms with new caps/pins and as such the torque required to cut the new thread in said arms? Some of the procedures are not specified as being with new parts or the out of spec wear limits.

As you are aware cutting a thread requires more torque than afterwards installing a bolt.

Len