XM757 steering

[alphadeltaromeo]

Perhaps you're right on the money. However, it could be that the joint is clean because of the friction of the movement recently. It could also be that there was no penetration of any water over the years. Or perhaps it's just a poor design to begin with. I'm sure you'll get it all figured out, you're a real sharp MVr

Have you thought of replacing the joint with a more modern design or do you want to stay original?

 

[BFR]

as long as the metal surface that contacts the delrin is not pitted/scarred I would leave them alone. Of course the only way you could check is to destroy the joint, that or become close friends with a radiologist who likes green iron.

 

[cranetruck]

Have you thought of replacing the joint with a more modern design or do you want to stay original?

A lot of (most?) modern designs are compromises, I think that a lot of 60's designs still are state of the art. Much was designed and built with money as no object.

I appreciate your feedback guys, that's how these problems are solved.

 

[Recovry4x4]

I'm assuming that the steel part may have some rust on it. Soaking it with Breakfree would lube it and protect it but does nothing to dissolve the rust. The GM heatvalve lube that I push so much has an acid in it to dissolve rust to a degree. I don't know how the delrin would react to it but I bet it would be a better product to be working in there to free them up. It's around $7.00 a can at the Generous Motors Dealership. I still refer to it as "The Spray from God"

 

[cranetruck]

I like the microscopic teflon dust in the CLP, it provides lubrication compatible with the Delrin.
If the "Heat Valve Lube" contains an acid, how is it neutralized in time? Wouldn't want it eating away at the ball once the rust is gone.
Vinegar is a good rust remover because it's a mild acid, but rinsing is required to stop the action.

 

[Recovry4x4]

Hmm, don't know about neutralization Bjorn, good point.

 

[cranetruck]

On the other hand, the acid approach may be a way to open the space between the ball and dry lube packing some....worth looking into, "the spray from God" huh.

 

[DDoyle]

I failed to finish my earlier thought - CRS setting in perhaps - to finish now - I'd consider trying to find a single NOS ball joint - and compare its "feel" to the feel of yours - strange as it may seem, your joints COULD be performing as intended.

Regards,
David

 

[cranetruck]

Tie rod end FSN 2530-045-1949. Okay David I'm considering finding an NOS one. Not a normally stocked item by most dealers, though.

EDIT: Since my manual is dated June 1969, the NSN for the tie rod end becomes NSN 2530-00-045-1949.

 

[cranetruck]

Got a can of "Heat Valve Lube" from a GM dealer in Mt Airy, NC, today.

The front tie rod is on a bench indoors at this time, an 1/8" hole in each ball joint cap. CLP squirted into one and Heat Valve Lube into the other.
The torque required to turn the CLP ball was 60 ft-lb and the Heat Valve Lube side needed 70 ft-lb. I'll test them again tomorrow.

 

[doghead]

Perhaps a bit of time lapse photography is in order here!
Seriously, this is very interesting When measuring the torque needed to break free (no pun intended) can you get a second reading to measure the drag needed to continue movement? I realize the "sticking" is the problem, but I am tyring to understand the cause of the effect. (does that make sense?) I am wondering if there will be a measurable difference for either lube / penetrant in either measurement.(force required to break free and force required to continue movement) Also ,the 1/8" holes i presume you drilled? Have you or can you blow into the hole to force air or lube into the joint and out the tapered stem end?

 

[cranetruck]

I'm going to let the penetrants work on their own. I will report back tomorrow.
The torque required to continue turning was insignificantly less (?), perhaps 5 ft-lb or so.

 

[DDoyle]

Contact Bob Anderson for the Ford parts - I believe you know him.

Best,
David

 

[cranetruck]

Thanks David, sent you an email.

Checked ball joints this morning. No change from yesterday. Added more penetrant.
This may take days....

Edit: After 24 hours, no change, added more penetrant.

 

[cranetruck]

After 48 hours:
CLP soak: required turning torque has dropped to 50 ft-lb
Heat Valve Lube soak: No change, still 70 ft-lb

 

[Recovry4x4]

The stuff is making a liar out of me.

 

[alphadeltaromeo]

Question though...the one that turned with just 50...was it one that you'd been pre-soaking prior for some time or ?

 

[WillWagner]

Bjorn, don't know what torque it takes to turn a new ball joint, but they are tuff to move. Maybe what you have is normal?

 

[cranetruck]

Will, as you know the purpose of the linkage is to transfer a motion, not to introduce resistance. Like a gear train/transmission, you'd want minimum resistance.

These ball joints were made with a hard plastic, Delrin to be able to keep very tight tolerances. No lube space required, normally needed when grease is used. I think the dry lubricant was there to primarily prevent corrosion of the ball and that's possibly why the "Heat Valve Lubricant" isn't having much effect, there may not be any rust on the ball to dissolve and remove. The dry lubricant and the packing has hardened "grabbing" the surface of the ball instead.
The CLP on the other hand is a penetrant/ lubricant and may actually help lubricate the ball once it gets in place (tiny Teflon particles).

IMHO the perfect ball joint should turn/swivel with zero resistance.

I'm letting this little experiment go on until there is a real change performance. No rush on this one.

 

[Elwenil]

There aren't any ball joints that I am aware of, or tie rod ends, etc. that turn with no resistance. I'd say they all have quite a bit really. Ball joints for car and light truck applications are almost impossible to turn by hand, tie rod ends are generally only slightly better. Why not pick up a tie rod end for something like a Ford F600 or similar for comparison?