Stuck Cross-Shafts

[mswyka]

Good morning.  We have about a half a dozen suspension arms with frozen cross-shafts.   In the past we would just replace the suspension arms with good ones.  Well, we are running out of good suspension arms.

I have read about freeing cross-shafts using acid or caustic and would like a little more information from people who have actually used these techniques.  I am specifically interested in specific product names and concentrations as well as whether there are any contraindications to watch for.

Thank you.

[gixxer6]

I tried soaking one in Lye.  I soaked it for 2 or 3 days.  It did absolutely nothing.  The only effective way I have found, is to use a RBFH...  Aka: really big f****** hammer...

[Lloyd (ljm)]

 A little heat sometimes helps. Too much heat distorts the shaft.

 I have seen some that the outer tube was cut, shaft removed and tube welded back together.

 I have heard of people throwing them in a fire and melting the aluminum out and replacing the shaft.

 They can be a real pain.

Lloyd

[Interceptor398]

I have chucked them up in the lathe and drilled them out.  If you pound on the end of the shaft it just makes them fit tighter.  Stand them up on end and keep adding a real light penatrating oil for several days and start tapping on the shaft.  Another option is to add a grease zert and try to get some lube in that way.  I've had then that did not like that too.  That's when they go in the lathe.

[kawhead]

anybody tried electrolysis

[greeno]

I use electrolysis on my M37 army truck all the time.  Google the instructions. 

The problem is it works 'line of sight' only.  SO, it won't eat rust that is covered by other parts. 

[jimvw57]

I have had a number of people mention using Muratic Acid (used in swimming pools to control the PH balance) it is fairly easy to get and I have been told it works great. Have not had a need to try it yet.

Heating does not work. Penetrating oil sometimes works, tapping on the outside of the tube has worked but not all the time. Once the shaft is out, a grease zerk is the best solution but you do need to add grease occasionally..

[JDmatt]

For aluminum shafts, I have used the Muratic Acid.   Home Depot here had two options, a "green" more environmentally friendly type, and the regular type.  The "green" doesn't work well enough for this, use the regular.  Carefully pour some in a plastic bin, and let the shaft soak in it.  It will bubble and smoke, and put out some nasty fumes, so don't do it in an enclosed area, or even near a wall where the fumes can take the paint off (got that tip from someone else who did that).  In one or two soaks, it will dissolve the aluminum shaft.  It will also strip the paint from the steel. 

[Metalman]

I have a couple of these I am messing with that are frozen. One I am adding a little Kroil to daily and the other I am trying the Acetone/Trans fluid mix.
 I am going to try this for a couple of weeks and see if I have any results.

[nickw]

On my invader I beat the crap out of one of the shafts with no luck moving it.  Then I heated it up and it slid right out.  The old grease was like glue holding that thing in. 

[mswyka]

For aluminum shafts, I have used the Muratic Acid.   Home Depot here had two options, a "green" more environmentally friendly type, and the regular type.  The "green" doesn't work well enough for this, use the regular.  Carefully pour some in a plastic bin, and let the shaft soak in it.  It will bubble and smoke, and put out some nasty fumes, so don't do it in an enclosed area, or even near a wall where the fumes can take the paint off (got that tip from someone else who did that).  In one or two soaks, it will dissolve the aluminum shaft.  It will also strip the paint from the steel.

Matt, Can the old shaft be reused after this treatment?  And, have you ever had some shafts that did not respond to this treatment?  When you say one or two soaks, how long is a soak?

[JDmatt]

Noooo, the shaft is literally gone.  The aluminum dissolves.  I replace them with steel shafts so I don't have the dis-similar metal seizing issue any more.  A day or so, until the acid loses it's potency and it stops working.  I've done it twice. 

[mswyka]

Noooo, the shaft is literally gone.  The aluminum dissolves.  I replace them with steel shafts so I don't have the dis-similar metal seizing issue any more.  A day or so, until the acid loses it's potency and it stops working.  I've done it twice.

Matt, where do you get steel shafts the correct length?

[JDmatt]

I just used spares I had laying around, but there are some aftermarket shafts available, or you can order shafts from McMaster-Carr and have a local machine shop cut and drill/tap them. 

[mswyka]

I just used spares I had laying around, but there are some aftermarket shafts available, or you can order shafts from McMaster-Carr and have a local machine shop cut and drill/tap them.

OK, thank you for the insight.  My current plan is to continue daily applications of PB Blaster and in a few weeks attempt the judicious application of a large hammer.  If that does not work we will go the acid route.