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Does anyone one have any hints on freeing seized lower pivot arms in the rear carrier assemblies without totally destroying the a arms or splitting the uprights in the process ?

The  pivot shafts are locked /  rusted internally onto the outer sleeve and just will not move. The inner brass sleeves are also plainly heavily worn . They have  to be replaced.

Helpful directions like "gently tap out shaft " are not cutting it .

After having soaked them for days in WD40. I now have the carrier hub casting moving freely from the outer sleeve but  its on the outer sleeve, not the through shaft joint to the inner sleeve. That is acting like a single item.

I have had both LH and RH  assemblies  set up in a 12 T press and applied hammering on the press piston and prudent heat on the carrier sleeve while having some pretty good pressure on the jack. Nothing.

My current strategy is a full kero and oil submersion bath for a week, and down the road to use a 20T press. What could possibly go wrong ??

Any other smart ideas from the brains trust before I explode one of the most highly expensive pieces of scrap metal not yet sold to the government? 

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The lower pivot shaft is inside a hardened steel spacer which rotates in the bronze bushings. High carbon steel rusts more, and faster, than mild steel. There's no easy way to grease the bushings, shaft and spacer without disassembly, so no one does this. Thus condensation and rain cause the shaft & spacer to rust-weld themselves together over time. If you don't want to cut the ends off the steel a-arm, then reweld them, the solution is to cut the lower pivot shaft ends off just inside the a-arm ends. Cut right thru both of the upright's steel end caps without touching the forged steel upright.

This used to be so common that Hall Pantera once sold a 'repair kit' that consisted of a new lower shaft, two end caps, the thrust washers inside, a new spacer and a pair of new bronze bushings. Once the ends are cut off, the a-arm can be removed undamaged and the cut shaft can be knocked out of the hopefully undamaged upright. Once out, you'll be amazed how much force it will take to press the two ruined parts apart when you have full access and can apply heat where its needed. 12 tons of press force may not be enough....

Those are your two choices, unless you get very lucky with the press and soaking over days/weeks. Heat likely will do nothing since you cannot reach the trouble area.  After cutting the pivot shaft, if you own a metal lathe, you might consider making a custom inner spacer from 321 Stainless in place of the stock high carbon steel part, so condensation cannot ever again rust the parts in place. There are also various schemes in the archives to modify things to grease the insides without disassembly, but that does you no good now. Pantera specialty shops will fix this for you in exactly the way I described. It will not be cheap but you won't need to worry about wrecking your upright with a Sawzall, either. Good luck.

That is great advice. I think I have brought exactly that repair kit from halls.

My plan C was to carefully cut off both end cups to create a space between the a arm and the upright to allow  hacksaw blade width  and cut through the shaft. I could likely cut between the heavy end washer and the end cup which would also protect the a arm as there is a small space there where the o ring washer sits.

I am over pumping up the pressure waiting for the casting to burst!

I will get the 321 SS replacements made up as well.

Thanks so much Bosswrench - I will let you know how it goes.

I am pleased to say that I have managed to extract the shaft on the second upright. What an absolute pig. I cannot believe how difficult it was to press it out, the good news being the upright is still in one piece. The amount of pressure on the 12 t press was very substantial almost through to the end. It really hung on.  Judicious heat  and progressive pressure got there. You need some nerve as well. 

Thanks to everyone for their advice and comments.

What a great community of knowledge and encouragement when you are faced with these point of non-return decisions and activities.

Now I can start to put it back together !!!


A bit late to the party here.... but some rust disolving solutions now available....

WD-40 is not a rust dissolver.   It is a Water Displacement from the 40th mission of one of our space adventures back in the last century!  Used to keep ice off of the space craft.

That said, some dis-solvents that I like:

1) PB blaster. It works, but it may take some time........keep soaking what ever you are working on and testing it with a wrench etc...... I've had it work quickly and on other bits, perhaps a matter of weeks......(non-crucial project....)

2) Evap-O-Rust   Non toxic solution dissolves rust.   Not sure about it's penetrating qualities.....  Soaking for 24 hours usually cleans small stuff up.  I have used it to remove surface rust from small steel bits, nuts and bolts, bezels, brackets, before painting.  Doesn't seem to harm zinc or chrome coatings.  Will sometimes leave a blackish coating that you can wipe off or remove using a soft brass brush so as not to dork up the metal surface finish.    I find it much easier than chasing parts around the garage after the wire wheel flings them into the dark abyss....!

It does absorb moisture from the air, so use it in a closed container if possible......I keep a small collection of plastic "Costco" type containers from snack foods etc to do various size pieces.   Tougher with a set of lower arms, but me fears that I will need to do the same operation soon!  It's bugging me not knowing......

Once done with it, dump it into the toilet (probably not for septic systems!) or give your lawn some more iron..... won't hurt it.

Last edited by mangusta

Thanks for the great information. It will not go to waste as I am sure there will be more challenges involving rust in the front end.

Once I managed to press the shafts out I removed the shells. I was surprised the new ones are brass , the old ones were all steel. Except for the one in two pieces the others put up a bit of a fight before removal. I then scraped down the insides of the uprights and wire brushed the internal surfaces then covered them in grease. I checked out the cost of having 321 SS replacements for the liner shaft and it was more to have them done than the entire shaft repair kit. And I would have had to wait 2-3 weeks.

So that plan was shelved and I  pressed in the brass bushes - this was not so hard and can be done in a decent sized vice with lined jaws. Just be careful they stay straight otherwise you could wreak them. The inner shaft liner can be drifted in with a timber mallet once both bushes are in.

Just make sure the brass bushes and the inner shaft ends are flush both ends when your finished. It may need a touch in the press to finish them off.

They sure look a heck of a lot better now !


Images (2)
  • pivot shaft 1: New shafts and bushings
  • Pivot shaft 2

One of the dead give-aways for issues with the lower pivot shaft issues is the a arm having any movement at all on the lower upright. If it moves at all, one of the support shells are likely badly worn or broken . In my case there was two indicators - The wheel could move laterally a few millimeters on the lower shaft, and if the lower shaft bolts were removed neither shaft would rotate. One was locked inside the upright - the other was seized in the a arm pivot. There was no possible insertion or extraction possible on the shaft .All bad signs and indicators a repair is required and soon.

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