Author Topic: Upper control arm lube - trying to get flow  (Read 7266 times)

awolff280sl

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Upper control arm lube - trying to get flow
« on: May 05, 2009, 18:55:29 »
Fortunately, all of my lube zerks take grease, except for the one on the outer upper control arm, as in the picture.
The Zerk is new, and I am using a tool designed for freeing up the grease path. The tool consists of a cylinder that gets filled with PB Blaster, and then a plunger is inserted down the cylinder, and you hit the top of the plunger with a hammer to force the PB through the grease channel. Like a giant metallic pressurized syringe.
Despite heating and 3 days of patience, I still can't get the PB Blaster to flow.
I have also been trying to pass a thin guitar string down the Zerk hole and then around what should be the center groove in the threaed bushing, bit there doesn't feel like there is any gap there.
Also,I don't understand the design of this grease point. How does the grease get to the ends of the link pin? Is there a groove or channel in the threaed bushing that connects to the center groove?
The kingpin itself feels tight when I do the wheel test, so I don't want to mess with it , if possble.
Am I wasting my time or do I need more patience?
« Last Edit: May 05, 2009, 19:00:31 by awolff280sl »
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

mdsalemi

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Re: Upper control arm lube - trying to get flow
« Reply #1 on: May 05, 2009, 20:59:04 »
Andy,

I think I have the exact same issue.  When my car was in for some work in 2007, we greased all the zerks we can find and it was this zerk on the driver's side that would not take grease.  We did nothing about it.

Now the car is in again and we are cleaning up a laundry list of issue from 2007 and 2008, including this one.  I'll chat with the mechanic about it and see what he says--but my suspicion is first to remove the zerk and see if mine is passing grease.  If it is perhaps the assembly needs to be disassembled and cleaned and reassembled?  Perhaps some hardened grease is clogging something under the zerk.

OT: real funny.  The service facility, Motorwerks Group in Commerce Michigan, has my car "next up" after they finish some work on a Porsche.  So, since they don't leave my car outside, they put it in a showroom.  "Hey Mike, we got an offer of $5,000 for it...I told the guy no way, the owner wants $6,500!!" >:(
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2023 Ford Escape Hybrid
2024 Ford Mustang Mach Ex PEV

Allenh

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Re: Upper control arm lube - trying to get flow
« Reply #2 on: May 05, 2009, 21:55:10 »
Actually, I had all of my suspension apart for my restoration.  The grease passes through the upper housing of the kingpin and fills the cavity formed by the groove in the threaded pin.   Then as the suspension works, the grease moves onto the threads.  The moving surfaces here ARE the threads.  When you assemble from new or from  disassembly, it is important to prelube all of the parts. The cam bolt is only moved when adjusting the camber on the wheel.  Without prelubing this part, alignment might be very difficult at a later date.

You should disassemble, clean and reassemble the part.  If you intend to, you will need to reset the caster (plane of the wheel) and the caster.  You can do this at home, I have an easy way to get it perfect.  Let me know and I can explain.

 

awolff280sl

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Re: Upper control arm lube - trying to get flow
« Reply #3 on: May 05, 2009, 22:09:31 »
Allenh, if you can elaborate on the alignment that would be great.
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

Allenh

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Re: Upper control arm lube - trying to get flow
« Reply #4 on: May 06, 2009, 00:19:23 »
It is fairly easy, one must use care for accuracy.  This is how I did mine....

Level the front of the car- I measured the distance the brake rotor is off the floor and block the front wheels, at that height, tires off, on the rotors- EXACTLY level.  this would be your reference for the perpendicular, setting the camber.  Obtain an 11" digital level from Sears, about 30.00, it is accurate to 0.1 degree, magnetic and it will try to stick to the rotor.  Remove the camber locking plate from the cam bolt and you can turm the cam bolt to obtain the desired camber.  I didn't mention, hold the level firmly against the rotor in a vertical position for measurements.  It works.  Let me know if you have settings originally that are out of spec.  I can walk you through the toe-in.  I did my entire alignment myself, Very, very carefully and it drives srtaight and great.  Better than my spelling.

Changing the camber from the original setting will alter the toe-in.  If your car is currently in specification, before you disassemble the joint for service, use the level and record the angle.  just match it up and you are all set.  Setting caster is more difficult.  just be sure you position the threaded pin in correctly with the same amount of exposed threads, front and rear, as you started with and you will be fine. 

The difficulty level, 1-10, should be less than 3.   

awolff280sl

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Re: Upper control arm lube - trying to get flow
« Reply #5 on: May 06, 2009, 01:13:02 »
Thanks, I get the idea. The front of the car is on jack stands which are positioned where?
Andy   Sarasota, FL
'69 280SL 4speed
'06 Mitsubishi Evo

Allenh

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Re: Upper control arm lube - trying to get flow
« Reply #6 on: May 06, 2009, 09:26:33 »
Sorry I wasn't clear.  the car wants to sit on the brake rotor instead of the tire.  this provides working clearance and, very importantly, puts the front suspension under normal load.  I used 4X4's with suitable shims to set the height and make absolutely sure the axle is level.

glenn

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Re: Upper control arm lube - trying to get flow
« Reply #7 on: May 06, 2009, 15:23:25 »
Caster is adjusted by (per page 40-6/2 of the BBB Service Manual) 'The caster is adjusted by swiveling the front axle carrier by means of the cams(30) entering the two leave(sic) springs (31) for longitudinal support (Fig40-6/3).'    The section later says, 'Differences in caster between the left and right can be adjused within minor limits on upper steering knuckle bearing.' It also says don't turn the threaded screw in the upper knuckle(afore mentioned 'minor limits') more than 1 turn from center to balance-otherwise the rubber gasket is crushed and, voila,  corrosion!
   There you have it from the BBB.  Hope this helps.