Lower, outer control arm bolt siezed

[twistedtree]

I'm working on the front end of my 280 to replace the king pins and tie rod ends.  In taking apart the first (left) side, I've found that the bolt that attaches the lower knuckle to the control arm is seized.  I've removed the grease fitting and filled it with WD40 in hopes of freeing it up, but so far no go.  From the Haynes illustrations it looks like both the control arm AND the knuckle are threaded?

Is this common, and does anyone have any technique for freeing it up other that soaking?

Thanks

[Larry & Norma]

Hi, WD40 is not that good a release agent. Get proper release fluid it will work much better!

[ja17]

A good heavy duty air impact gun is the best tool for front end work. A torch is the next best thing for rusty bolts. Sometimes both are needed. If you do not have either, find a longer breaker bar, 1/2" or 3/4" drive with penetrant. Sliding a pipe on the breaker bar will give you a tremendous amount of leverage.
Yes both the a-arm and trunion are threaded.

[Benz Dr.]

I don't fool around with that stuff. If it won't mover I cut it out with a torch. You won't be saving anything excetp the main castiung with the spindle. Everything else is junk.

[twistedtree]

I don't fool around with that stuff. If it won't mover I cut it out with a torch. You won't be saving anything excetp the main castiung with the spindle. Everything else is junk.

I think this is the direction I'm going.  I've ordered the lower/outer repair kits, so I'll just cut off the bolt with a sawsall (I don't have a torch).  I've been pounding away at it with a 500 ft-lb impact wrench with no success.  In fact, the wrench blew up while doing it.

If WD40 isn't any good, what's better?  I use PB-Blaster as a lube.

[Benz Dr.]

Heat is about the best. Rust expands into any play between pars and swells to the point that nothing will move. Heat breaks this bond and helps to get things moving.

[glenn]

Hi, Done it a couple times in Boston at 617 947 6399.

[mylittlefintail]

I've got pictures from doing outer king pins from my w111. You don't need to remove the springs or the inner king pins. I learned after wresting around for two days with the springs on one side and then a mechanic told me the easy method. But I've replace both inner and out pins now. email mail me at moses.miu@serco.com and I'll forward you the pictures.

[twistedtree]

Inner king pin?  Isn't there only one king pin per side?

[mylittlefintail]

Sorry. Yes the I'm thinking of the upper and lower pins that hold the king pin in. I ended up going down the hacksaw route.

[twistedtree]

I ended up putting a cutting wheel on my little grinder and that cut through the bolts like butter - well, frozen butter.  It's all apart now.  I just need to get a new, un-pitted set of king pins then I'll be back in business.

[Iconic]

If WD40 isn't any good, what's better?  I use PB-Blaster as a lube.

It sounds like you solved the issue, but for future reference I've had excellent performance out of Deep Creep by Seafoam (usual disclaimer: I have no business association to Seafoam).