Front top support arms - thread length?

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Challenger2
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Front top support arms - thread length?

Unread post by Challenger2 » September 7th, 2018, 9:00 am

Hi Team G838,
I have just finished refurbishing the front suspension support arms with old bushings removed, blasted and repainted and new bushings pressed in their correct positions on my A2.
Prior to refitting to the subframe I test fitted the large gold outer retainers (washers) and slotted nuts to the ends of the upper arm shafts and found that on one shaft there was too much thread to allow the nut to be tensioned as the hole for the cotter pin is now too far away. At the other end there is not enough thread to expose the cotter pin hole!
The other arm shows almost equal amount of thread at each end to include the slotted nut and the cotter pin hole.
Now I see that the end of each shaft is slightly different. One has a more full 'shoulder' than the other and before reassembly I could not see any difference in thread length. Judging by my 'good' shaft it would appear the fuller shoulder should connect with the inner gold retainer and the 'long bushing' and this dictates how much thread will show at either end of the shaft.
There is no mention of this apparently key difference in TM 9-2320-218-34-1 9-12 and I have found an image of NOS upper and lower front suspension arms with bushings fitted apparently showing the same discrepancy (i.e. mismatched shaft ends with unequal threads showing on one arm).
So - where do I go from here? How much can I wind in (and possibly over torque the slotted nut and destroy the bushing) to expose one cotter pin hole?
How do I make up the difference between the slotted nut and the cotter pin hole on the other (use the smaller yellow washers supplied in the kit?).
Or do I have to remove the newly fitted bushings (aargh!) and swap the shaft round.
Is this something other members have come across - and I do appreciate that Stateside members often recommend buying new fully assembled arms. This is not an option for some of us in the UK and Europe. A set of new arms can cost around $850 compared to about $130 for new bushings (and some headaches fitting them :roll: ).
Your help with this will as usual be very much appreciated.
Steve
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rickf
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Re: Front top support arms - thread length?

Unread post by rickf » September 7th, 2018, 9:26 am

Without seeing pictures I am going by your description and it sounds like the arm is on backwards but unless you want to tear it all apart again I would just tighten things down as they should be ( with the vehicle weight on the suspension ) and then drill new holes for the pins where needed.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Challenger2
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Re: Front top support arms - thread length?

Unread post by Challenger2 » September 10th, 2018, 5:53 am

Thanks Rick - and Ken the Mutt Guru (via PM) for your input. All options are being explored.
Steve
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Re: Front top support arms - thread length?

Unread post by Cav Trooper » September 22nd, 2018, 2:33 am

I just finished replacing all of the the front upper and lower bushings and ball joints. I used the tm and finally figured out the long and short bushing placement and before I tore into the job, I removed on control are seat and used them as a model for the other side like one would do with a brake job. Turns out I had the same issue with the long and short ends of the shaft and found that the previous owner had installed the side I was using a reference backward. I saw the error too late and destroyed a set of new bushings removing them and correcting the problem. Good luck.

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Re: Front top support arms - thread length?

Unread post by Challenger2 » September 23rd, 2018, 10:24 am

Hi guys,
So - long story (or should that be bushing?) short!
I got the 'wrong' suspension arm on to the press and we managed to get it and the first bearing out without damaging either (or my lovingly applied gloss black paint.
Then we spun the shaft round, re-inserted the bushing and it all went back together - couldn't believe it!
What helped us was that the bushings had not been tightened (as per the advice here on G838 NOT to apply correct torque setting until the wheels are back on the ground). AND we used a stout steel bar to fit tight between the 'arms' of the arm close up to the bushing sleeves so it did not bend under the press.

I have re-checked all the bushings and we did have them in the right ends and re-reading the manual it does actually say when and where to fit the 'long shaft', but without making it clear that it means the end of the shaft with the longer thread!

Ken suggested the bushing sleeves (which according to the manual should be replaced and tack welded onto the arms) short and long might have been fitted incorrectly in service or by a previous owner. Again they appeared to be correct. Anyway the arms are now back and the front suspension now looking lovely with new fastenings, bushes, shocks, brake service etc.
Working on an M151 can be a pain and it can be a rewarding learning (or re-learning) curve thanks to the great advice found on this site.
Just don't get me on the non-NOS replacement lower ball-joints that needed the bolt holes re-drilled and the three 'toes' reduced in depth to fit the stock suspension arm!!! :roll:
Steve

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Re: Front top support arms - thread length?

Unread post by muttguru » September 23rd, 2018, 12:35 pm

Challenger2 wrote:Hi guys,
............I got the 'wrong' suspension arm on to the press and we managed to get it and the first bearing out without damaging either (or my lovingly applied gloss black paint.
Then we spun the shaft round, re-inserted the bushing and it all went back together - couldn't believe it!
What helped us was that the bushings had not been tightened (as per the advice here on G838 NOT to apply correct torque setting until the wheels are back on the ground). AND we used a stout steel bar to fit tight between the 'arms' of the arm close up to the bushing sleeves so it did not bend under the press.
Steve
Steve...a great result ! I hope you took some pictures for posterity (and for other members).
Ken
Kind regards....
Ken

Always wanted - Details and pictures of M416 Trailer data plates & M151 data plates & body-tags for my research. Thanks!

Contact address - - muttguru@aol.com

Note for 2023..... Ken..."Less Stress - More Exercise!"

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Re: Front top support arms - thread length?

Unread post by kwb » April 15th, 2021, 3:43 pm

I'm new at working on 151's but regardless of the vehicle, suspension can always be a challenge . I installed my rear bushings with a home made screw type press and it worked well but when i did the front a arm bushings i made a new press bed and split one side to remove the arm assembly when the bushings were pressed in. don't know if anyone else has done this but it works perfect for me and no chance of bending a control arm. just wanted to share this with anyone about the dreaded front bushing install. Ken
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Re: Front top support arms - thread length?

Unread post by rickf » April 15th, 2021, 5:22 pm

Good idea as far as making it easy to change the bushings but pretty much fubared the press bed! I don't know what size press it is but even if it is only 12 tons you will find that the bed will now bend down on that side, And at a full 12 ton and especially 20 ton load that one bolt is simply not enough.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: Front top support arms - thread length?

Unread post by kwb » April 15th, 2021, 9:51 pm

Hello rickf !That one bolt in the center only keeps the cut out section bed to the heavy angle iron. that section comes off with the angle iron when i remove the four bolts. no need to worry about the press bed. it's home made just for the a arms. the real one is unmolested. I'm sure the bed moves somewhat but i can't tell and the bushings push in without any damage to the control arms.

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Re: Front top support arms - thread length?

Unread post by rickf » April 16th, 2021, 10:19 am

Gotcha, I was just worried you were still using that bed for full on pressing and I could see that bolt breaking and punching right through you like a 20mm cannon round! I certainly would not want to be changing those press beds out very often! I have a 25 ton and the bed weighs about 350 lbs..
But the bushing press idea looks good.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Re: Front top support arms - thread length?

Unread post by kwb » April 16th, 2021, 2:34 pm

Hi rickf ! My press is only a 12 ton . I don't work on big stuff like some of you guys. don't you like it when pressing something apart and it goes bang and gets your attention real quick ? I still flinch even though ii know it's gona happen

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