Advanced Auto Ball Joint Press Tool - Page 6 - PeachParts Mercedes-Benz Forum

JEBalles · #76 12-23-2009, 01:51 PM

I was making the assumption that if anyone was going to know how to do it correctly, it'd be the MB dealership. Seems like plenty of people around here like to take MB's word as truth.

Of course I shouldn't be surprised. They were wrong about the fuel. kabam

Not that it really matters, though, I was gonna use the generic tool anyway.

whunter · #77 12-23-2009, 03:03 PM

Quote:

Originally Posted by funola

Thinking again about this method, with the knuckle not supported in a vise but resting on the ground, I wonder if there is any danger of bending the knuckle at the weakest point (near the UCA where it is thinner)? It is a long and curved piece. If it was straight, I'd have less worry. It is a pretty beefy piece but hit it hard enough without any give from the ball joint, could it bend? And how would you know if it did or did not bend? It would be hard to tell without a jig.

NO.
No human is strong enough to bend the knuckle, just knocking the ball joint out.

A 20+ ton press can, if setup wrong.

winmutt · #78 12-23-2009, 03:35 PM

Quote:

Originally Posted by JEBalles

I was making the assumption that if anyone was going to know how to do it correctly, it'd be the MB dealership. Seems like plenty of people around here like to take MB's word as truth.

Of course I shouldn't be surprised. They were wrong about the fuel. kabam

Not that it really matters, though, I was gonna use the generic tool anyway.

Well first off the MB dealership is just a franchise. I used to have high hopes for MB dealerships but so far I have found them to be less than perfect, like what I would expect from a Ford dealership in some cases.

Diesel911 · #79 12-23-2009, 03:55 PM

Unfortunately it seems to be choice of doing it yourself and risk screwing the job up or risk letting someone else screw the job up but having to pay for that!

I have managed to survive all of my screw ups both mechanically and financially. And, I think it has been worth it.

I wish those folks who take any of there Cars to a Dealership the best of luck.

funola · #80 12-23-2009, 04:49 PM

Quote:

Originally Posted by whunter

NO.
No human is strong enough to bend the knuckle, just knocking the ball joint out.

A 20+ ton press can, if setup wrong.

So you don't think the knuckle can bend supported on its end on solid ground absorbing the force from with a 10 lb sledge hammer swung from overhead in a splitting wood motion? Can someone calculate how much force is generated from such a hit? Add to that the moment arm of the bent knuckle. If it's ok supporting it on its end, why did Mercedes recommend supporting it in a vise by gripping it on the thickest part of the knuckle closest to the ball joint?

JEBalles · #81 12-23-2009, 05:12 PM

Quote:

Originally Posted by funola

So you don't think the knuckle can bend supported on its end on solid ground absorbing the force from with a 10 lb sledge hammer swung from overhead in a splitting wood motion? Can someone calculate how much force is generated from such a hit? Add to that the moment arm of the bent knuckle. If it's ok supporting it on its end, why did Mercedes recommend supporting it in a vise by gripping it on the thickest part of the knuckle closest to the ball joint?

Swinging a 10 lb sledge over the head in a splitting wood motion is more than enough force to get ball joint out, so the knuckle won't absorb the entire impact, so, not an issue.

It's funny that you bring up the MB recommendation. They're not infallible. T'is blasphemy. They don't want you to bend the knuckle, so they're going to take the safest course. Not to mention, putting it into a vice that can take it is probably easier.

Diesel911 · #82 12-23-2009, 07:56 PM

When new Ball Joints are installed does anyone use Never Seeze or just plain Grease so it is easier to remove if you had to at a later date.
Road Salt can rust thing resonably fast.

whunter · #83 12-23-2009, 08:36 PM

Quote:

Originally Posted by funola

So you don't think the knuckle can bend supported on its end on solid ground absorbing the force from with a 10 lb sledge hammer swung from overhead in a splitting wood motion?
Can someone calculate how much force is generated from such a hit?
Add to that the moment arm of the bent knuckle.
If it's OK supporting it on its end, why did Mercedes recommend supporting it in a vise by gripping it on the thickest part of the knuckle closest to the ball joint?

No human is strong enough to bend the knuckle, just knocking the ball joint out.

From Newton's second law, we know that force is equal to mass times acceleration (F=ma).

Calculating Force
http://www.physicsforums.com/showthread.php?t=160005

Press versus hammer, kinetic energy vs pressure
http://www.physicsforums.com/showthread.php?t=298040

Hammer problem: Newton's Laws
http://www.mathhelpforum.com/math-help/advanced-applied-math/17181-hammer-problem-newtons-laws.html

Mercedes does recommend supporting it in a vise by gripping it on the thickest part of the knuckle closest to the ball joint:
(my educated guess)
because of mechanic safety = when held in a vice by the narrow end the knuckle can/does move/jump out of the vice hurting people/cars/shop equipment/ the spindle threads...

I have tried to bend an MB knuckle making a special tool.
Result; sore arms/shoulders.
I was checking it with a jig and dial indicators..
In the end, I was forced to use an oxygen acetylene torch to "cherry" the metal + a 20 ton press.

tangofox007 · #84 12-23-2009, 09:10 PM

Quote:

Originally Posted by whunter

From Newton's second law, we know that force is equal to mass times acceleration (F=ma).

What's the formula for determining the force required?

JEBalles · #85 12-23-2009, 10:26 PM

Quote:

Originally Posted by tangofox007

What's the formula for determining the force required?

You'd probably have to determine that experimentally, which whunter appears to have already done: 20+ tons of force after weakening of the steel.

Billybob · #86 12-23-2009, 11:03 PM

Quote:

Originally Posted by JEBalles

You'd probably have to determine that experimentally, which whunter appears to have already done: 20+ tons of force after weakening of the steel.

Quote:

Originally Posted by whunter

A 20+ ton press can, if setup wrong.

Quote:

Originally Posted by whunter

I have tried to bend an MB knuckle making a special tool.
Result; sore arms/shoulders.
I was checking it with a jig and dial indicators..
In the end, I was forced to use an oxygen acetylene torch to "cherry" the metal + a 20 ton press.

Well the first explanation was “a 20+ ton press can, if setup wrong” and the subsequent explanation was “In the end, I was forced to use an oxygen acetylene torch to "cherry" the metal + a 20 ton press” while some may have faith in those explanations, the methodology behind arriving at them is at the very least suspect.

So it’s pretty clear that no one has or is able to answer “Tango’s” prescient question!

The FSM procedure makes a point of not applying; the force necessary to remove a ball joint, to the thin upper end of the spindle. The FSM also outlines an inspection tool (116 589 05 23 00), a procedure for inspection of steering knuckle/spindle(FSM 123 Chassis and Body Vol. 1, 33-410), and specifications of ‘permissible deformation “.

Without question deformation of a steering knuckle geometry is possible, no one has yet provided the specification or relevant equation to determine the amount of force that would be required to cause deformation beyond the permissible limits, and no one has yet provided the specification or the equation to determine the amount of force required to remove any ball joint from every steering knuckle. Any information provided thus far is anecdotal opinion.

It’s your spindle and your ball joint so you can do whatever you’re comfortable with, but don’t confuse those options with knowing what you are actually doing.

whunter · #87 12-24-2009, 01:50 AM

Quote:

Originally Posted by Billybob

Well the first explanation was “a 20+ ton press can, if setup wrong” and the subsequent explanation was “In the end, I was forced to use an oxygen acetylene torch to "cherry" the metal + a 20 ton press” while some may have faith in those explanations, the methodology behind arriving at them is at the very least suspect.

So it’s pretty clear that no one has or is able to answer “Tango’s” prescient question!

The FSM procedure makes a point of not applying; the force necessary to remove a ball joint, to the thin upper end of the spindle. The FSM also outlines an inspection tool (116 589 05 23 00), a procedure for inspection of steering knuckle/spindle(FSM 123 Chassis and Body Vol. 1, 33-410), and specifications of ‘permissible deformation “.

Without question deformation of a steering knuckle geometry is possible, no one has yet provided the specification or relevant equation to determine the amount of force that would be required to cause deformation beyond the permissible limits, and no one has yet provided the specification or the equation to determine the amount of force required to remove any ball joint from every steering knuckle. Any information provided thus far is anecdotal opinion.

It’s your spindle and your ball joint so you can do whatever you’re comfortable with, but don’t confuse those options with knowing what you are actually doing.

I was checking it with a jig and dial indicators, the same procedure used in automotive R&D around the world until the 1990's..

Without question deformation of steering knuckle geometry is possible.
Major trauma = impact with a curb, pot hole, auto accident, etc, are common.
This is why a wheel alignment is needed, a bad knuckle will not align.

Mercedes Benz will not provide the specification and relevant equations to determine the amount of force required to cause deformation beyond permissible limits, it is proprietary (secret data) directly related to litigation that cost them tens of millions to develop.

My best guess as to why the FSM procedure makes a point of not applying; the force necessary to remove a ball joint, to the thin upper end of the spindle is that in R&D, mechanics where using a fixture to hold it bottom up in a forty ton electric hydraulic press = pretzel time, and the engineering management did not want to see this in the field, (special tool time)..

Please note: MB makes big money selling special tools around the world...

funola · #88 12-24-2009, 08:16 AM

Quote:

Originally Posted by Diesel911

When new Ball Joints are installed does anyone use Never Seeze or just plain Grease so it is easier to remove if you had to at a later date.
Road Salt can rust thing resonably fast.

Probably not a good idea. You want the ball joint to stay put. Adding lube may not allow that. Besides, the FSM does not say to lube it. After the BJ is in, I'd clean the area around the mating surface, degrease and run a bead of crazy glue around it.That should keep moisture from getting in.

JEBalles · #89 12-25-2009, 03:51 PM

I pressed the joint in today. I used a 1/2 in. drive socket with a pvc pipe and another metal pipe as cheaters and it went in alright. It wasn't too messy. Anyway, it's probably better than what I had and it wasn't very hard or expensive to do, so if it does last, good, if it doesn't, oh well, do it again the right way. I'll let everyone know if it doesn't work out.

Paulc66t · #90 12-26-2009, 06:28 AM

Good job. I have been wondering if you attempted it yet. When I did mine I got a used spindle from a junk yard and installed the new BJ before disaasmbling inorder to save down time. Now I have a spare if I ever need to do that side again.