Author Topic: upper control arm  (Read 14557 times)

bcjm

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upper control arm
« on: August 20, 2005, 09:41:22 »
I was greasing my upper control arm and noticed the nut was lose. I made it too tight and ended up sheared the bolt.  The bolt must be pretty rusty inside since I can't put any grease into the sleeve (kingpin?) through the grease nipple.  I can't turn it ofrom the other side either.  

I would like to replace it and here are my questions:
1. Does the control arm have to be in a certain position to remove this bolt?

2. Is the bolt threaded in or slide in?  Can I heat the part trying to break it lose?  Is there a easier way to remove it?

3. Do I need to watch out other parts like the spring or anything before I taking it apart?

Thanks
Bob

Download Attachment: upper_control_arm.JPG
66.58 KB

JimVillers

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Re: upper control arm
« Reply #1 on: August 20, 2005, 11:24:12 »
Bob .... It is hard to tell from the picture what you broke.  If you purchase #80, you will have everything that you will need to repair the trunion.

The bolt is part of the camber adjustment.  The bolt fits through two eccentrics that can be rotated to adjust the wheel camber.  If you broke the nut end of the bolt, you should first remove the clip, #77, and try to rotate the bolt and remove it.  If it will not come out, you should be able to drive it out with a punch.

Your grease problem is caused by #69 and the upper kingpin.  If you remove and replace #69, you will fix your greasing issue.

If you jack up the car from under the lower control arm, you should be able to replace these items without a spring compressor or much difficulty.  Just be very careful, when you remove the upper trunion, the bottom of the spring must be supported.  



Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
Jim Villers
190SL, 230SL 5-Speed, MGB 5-Speed, MGB GT V8 RHD (real MG), 2016 SLK

bcjm

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Re: upper control arm
« Reply #2 on: August 20, 2005, 12:16:28 »
Thank you for the perfect photo.  I broke #76 off with a threaded section of #70.  I did removed #77 but can't turn the bolt. I just want to make sure the bolt can be driven out and not threaded inside.  Hope I wouldn't ruin the kingpin or the control arm.

What does #80 called?  Trunion?  Do you know who carries it?

Thanks
Bob

ja17

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Re: upper control arm
« Reply #3 on: August 20, 2005, 13:58:49 »
Hello Bob,
The broken cross bolt is eccentric and merely slides through the  steel bushing which is threaded into the top of the king pin. It is probably rusted into place. Try removing the 10mm bolt and toothed lock plate on the other side then attempt to rotate the 17mm head of the broken eccentric bolt. If not stuck too bad everything should loosen up enough to slide the rest of the broken eccentric bolt out the end.

Clean everthing up and replace the "upper eccentric linkpin" .  You may find that you have more rust and wear in other areas. The treadded steel bushing and the upper threaded opening in the king pin may wear or be rust damaged.

This "upper link pin" assembly also called "upper trunion assembly" controls the caster and camber on the front wheel. The washer with the slotted outer surface is actually an adjuster wheel which is used to turn the threaded  steel bushing in the kingpin top, which changes caster.  The eccentric bolt that broke is used to adjust the camber (thanks ADalton). This is why it's head is toothed and  lock plate prevents it from turning after adjustment.

Joe Alexander
Blacklick, Ohio
« Last Edit: August 20, 2005, 15:45:27 by ja17 »
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

ja17

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Re: upper control arm
« Reply #4 on: August 20, 2005, 15:44:25 »
Thanks ADalton,
Yes, camber!!

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

bcjm

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Re: upper control arm
« Reply #5 on: August 20, 2005, 18:45:00 »
I have spended all my afternoon trying to take the eccentric bolt out.  #74 came off from the control arm so I can hammer it from that side.  It wouldn't move at all.  Using air impact wrench trying to turn it from the hex size did not work either.  I heated and shrinked the bolt couple of times already.  I don't know what else I can do.  Bigger hammer?  Cut the top kingpin open and replace the whole thing?

Bob

JimVillers

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Re: upper control arm
« Reply #6 on: August 20, 2005, 19:50:07 »
Bob .... Welcome to the world of old cars.  Replacing everything is always an option but the last one.  The expensive pieces are the control arm and the kingpin so try not to damage them.  I have found that "PB Blaster" (a penetrating oil available from most auto parts stores) is excellent.  Spray everything and let it sit, and then spray it again.  It works but may take a few days.  Heating also works but it is hard to get everything hot enough without an oxy/acy torch.  I prefer to spray it and then try to wiggle #79.  Eventually, it will move and then and then keep spraying and wiggling every few hours or days.  I prefer being patience to damaging expensive parts.   You can also try driving it from the #76 side but if you mushroom the shaft, it will not go through the hole.  You could also try drilling it out since you will be replacing everything except the control arm and the kingpin.

If you go ahead and order the parts, you can see how everything fits.


Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
« Last Edit: August 20, 2005, 19:55:52 by JimVillers »
Jim Villers
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ja17

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Re: upper control arm
« Reply #7 on: August 20, 2005, 19:54:26 »
Hello Bob,
You have a badly rust damaged upper link pin. You may try to cut the upper link pin under the rubber seal so that the suspension can be opened up. Then you can remove the 22mm nut on the bottom of the kingpin so the kingpin and whats left of the upper link pin can be removed to a vice to be worked on.

 As an alternative, remove the upper A arm along with the kingpin. A oxy /acet torch will help remove what's left of the pin. You may have to replace the king pin also if it is badly damaged or worn.

Joe Alexander
Blacklick, Ohio
« Last Edit: August 20, 2005, 19:56:03 by ja17 »
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

bcjm

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Re: upper control arm
« Reply #8 on: August 20, 2005, 20:10:23 »
Is the upper link pin (where the bolt passes throgh) and the kingpin one unit?  If I damage the upper link pin does it mean I have to replace the kingpin?

ja17

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Re: upper control arm
« Reply #9 on: August 20, 2005, 23:52:06 »
Hello Bob,
You can replace the eccentric link pin bolt and the threaded steel bushing. However if the threads in the top of the king pin are badly worn,  the kinpin should be replaced also.


Download Attachment: Kingpin and link pin.JPG
50.75 KB
Normall the outer suspension assembly part are ordered in kits as seen in Jim's diagram.

Joe Alexander
Blacklick, Ohio

« Last Edit: August 21, 2005, 00:06:40 by ja17 »
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

A Dalton

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Re: upper control arm
« Reply #10 on: August 21, 2005, 00:06:40 »
The car has not seen frequent grease.. you may want to take the grease nipple right off  and dig around in there and then fill the cavity/hole  with penetrant ... BP Blaster/overnight....
 Make sure you have the lock off when trying to turn the bolt back and forth after the penetrant gets in there...

mbzse

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Re: upper control arm
« Reply #11 on: August 21, 2005, 00:35:30 »
quote:
Originally posted by ja17

../.. replace the eccentric link pin bolt (70) and the threaded steel bushing (69).
Download Attachment: Kingpin and link pin.JPG


The design of the front wheel mount on our M-B's works quite well, particularily when all is greased according to schedule.
However, the interface between parts (69) and (70) is a weak spot, as there is no lubricant there (from factory). Rust will form and the parts sieze up. (see also the picture from the parts book that Jim V posted below)

A useful tip is to put a liberal amount of copper paste (or similar) in there when assembling the (new) parts, and it will then be a breeze to adjust camber on your car the coming 40 years... ;)

/Hans in Stockholm
/Hans S

glennard

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Re: upper control arm
« Reply #12 on: August 21, 2005, 03:50:12 »
Ah ya, The Mad Hatter said to Alice, 'Welcome to KINGPIN HELL.' Don't do this work in front of children!  Ball joints, anyone?

glennard

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Re: upper control arm
« Reply #13 on: August 21, 2005, 03:54:38 »
On a more serious note-  Is the whole assembly common(interchangeable) to any of the fintails(60s 190, 200, 220) or 111 bodies?  Drum brake complications??

ja17

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Re: upper control arm
« Reply #14 on: August 21, 2005, 05:42:24 »
Hello glennard,

Yes the parts  are shared with  Mercedes of the era with the king pin type suspensions.



Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

George Des

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Re: upper control arm
« Reply #15 on: August 21, 2005, 05:43:48 »
Bob,

A little war story on this part. Back in the early 80's when I was stationed in Germany, I had a 1970 280S. Loved that car--was a sheer pleasure to cruise down the autobahns and the engine could hardly be heard when I was stopped at a traffic light. It did have one problem though that took me a while to figure out. Every time I came to a stop , I would hear a thunk from the front end. I finally got under the car one day and took a good look at the kingpins--the source of the thunk was immediately obvious. I set about to fix the kingpins in my small backyard--having the car down for a while was no big problem since I had the current 230Sl as well. Ordered the top-end parts from the MB Torpedo Garage in Kaiserslautern and then started the disassembly and that's when my problems started. I didn't shear the bolt as you did, but try as I may, I could not remove that darn threaded pin. Years of lubricant neglect had literally "welded' that pin in. I tried a bolt remover, heat, a sledge hammer, a hacksaw, you name it! every day I went into work, I'd set about a new strategy to get that pin out. In utter frustration, I finally decided that my only recourse at that point was to do a complete remove and replace of the entire hub assembly. At that time the U.S.Air Force Base over in Sembach maintained a large Morale, Welfare and Recreation salvage yard of vehicles left behind by departing Serviceman who could not sell their cars-parts were there for the picking for next to nothing e.g. complete engines for less than $50.00 and the yard was loaded with 70's era MB sedans--wish that yard was still there--the base has been pretty much turned back over to the Germans as part of our drawdown and the yard is no longer there. I was able to get a part that appeared good readily and did the remove and replace. Next step was to get a front end alignment. Dropped it off and expected it would be ready the next day. When I went to pick it up the shop owner said he could not do the front end alignment because the kingpins on both sides were too worn! This front end wear was a common problem on all MB's of that era-- even the donor car had the problem. I only had a short time left in country and decided to just "live" with it. What I did learn from this experience is to make darn sure that the grease fittings on the kingpins on my 230SL are serviced regularly with a good quality grease. When it came time to do the front end on the 230SL as part of my restoration work, I had no problem doing either the dissaembly or the reassembly and all parts were still servicable!  Bottom line--keep these front ends well greased! Good luck with your work on this.

George Des

bcjm

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Re: upper control arm
« Reply #16 on: August 21, 2005, 05:46:26 »
I am going to give the penetrating oil a try but I never had luck with it before.  Maybe the "PB Blaster" is different.

Is it physically possilbe to rotate the bolt off the kingpin with the steel bushing together?  If the answer is yes, then I will try to heat the top of the kingpin to break the interface bwetten the bushing and kingpin.   Heat/shrink the bolt did not work.

glennard

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Re: upper control arm
« Reply #17 on: August 21, 2005, 07:36:56 »
Amen to George's 'keep the kingpins(all fittings!) greased'.

JimVillers

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Re: upper control arm
« Reply #18 on: August 21, 2005, 09:19:03 »
Bob ... "PB Blaster" is different.  Take the suggestion of removing the grease fitting and filling the cavity with Blaster.  It is necessary to let it sit and "work" a while.

I once had an MG B engine that was frozen up after 10 years of sitting.  It took a week of PB Blaster in the cylinders before I was able to turn the engine.  Good Stuff.

Jim Villers
190SL, 230SL 5-Speed, 190E 2.3-16 Kompressor
Jim Villers
190SL, 230SL 5-Speed, MGB 5-Speed, MGB GT V8 RHD (real MG), 2016 SLK

Benz Dr.

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Re: upper control arm
« Reply #19 on: August 21, 2005, 10:07:24 »
If this stuff is junk I cut it all out and only save the upper and lower control arms along with the spindle assembly. Eveything else you will replace anyway so pounding, heating and using penatrating oil is a complete watse of time.
Time is money for me - I don't fool around with stuff like this nor am I gentle about it.  Just make sure you have plenty of water around to put out small fires.

Dan Caron's
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waltklatt

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Re: upper control arm
« Reply #20 on: August 22, 2005, 07:55:37 »
The kingpin is not salvageable anymore.  I had the exact same problem.  I resolved it by removing the entire kingpin assembly and installing a new one from a donor W108 sedan.  When doing this, please be careful with the spring, which is under compression.  Place carefully a block and jack underneath and take up the tension on the kingpin and then you can remove.  One end of the bolt was sheared off and then I simply squeezed a wedge in between the kingpin head and upper arm and used a small grinder to grind the bolt shaft out so I could remove the kingpin.  Mind you dont grind the upper arm.
It was a mess and now it's all free again with the new one and filled with grease.
Walter
1967 230SL-diesel
1963 230SL-for sale

bcjm

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Re: upper control arm
« Reply #21 on: August 22, 2005, 21:40:04 »
I have stripped everything except the steering knuckle and the control arm bushings.  I don’t think I have any choice other than cut the top link bolt.  The lower control arm bushing bolt is still very tight.  I can rotate the bolt but can't slide it out easily. This makes me suspect that the control arm is still under load.  I have a floor jack under the spring.  No matter how I adjusted the height it made no difference.  Am I doing something wrong?   Is it safe to knock the lower control arm bolt out as long as I have a jack under the sprint?

Download Attachment: kingpin.JPG
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ja17

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Re: upper control arm
« Reply #22 on: August 22, 2005, 22:22:54 »
Bob,
Raising the lower control A-arm will relive the  pressure on king pin and bolt. You will see the top A-arm move off its stops. When unhooked carefully lower the jack to relax the coil spring.

Another way to open up the suspension is to place the jack under the lower a-arm to relieve the pressure on the king pin. Loosen the big 22mm nut at the bottom of the kingpin (it has a sheetmetal lock plate). Do NOT remove the nut just loosen it. lower the jack. If the lower trunion does not pop loose stike it with a large hammer and drift. It should pop loose. Next raise the jack to relieve the pressure and unscrew the 22mm nut. Now lower the jack and the suspension should open up.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback