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street

32 Posts

Posted - 06/09/2017 :  20:10:47  Show Profile  Reply with Quote
I'm sending my rear struts off for a rebuild to Martin. I'm pulling the struts myself and I don't have a lift. Where are the jack stand points in the rear? Thanks.

'77 Silver 6.9

Aaron H

USA
473 Posts

Posted - 06/10/2017 :  06:26:21  Show Profile  Reply with Quote
They're in the rocker panels just fore of the rear wheels if your using a factory jacks (recommended). If you're going to use a generic floor jack, then put a piece of wood about a foot long between the jack and directly underneath of the jack ports in the rocker panels, or do the same where the rear sub frame attaches to the chassis just inside of the rocker panels, but in addition use a rubber pad and/or a folded up towel for protection against scuffing/bending something. Do one side at a time.
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oversize

Australia
261 Posts

Posted - 06/23/2017 :  00:02:23  Show Profile  Reply with Quote
Jacking under the sills is a bad idea and will likely result in bent panels. I always use a trolley jack under the diff and the front cross member behind the sump. Position jack stands under the sub frame mounts. Also use these points when using a bottle jack or similar since these are the strongest points under the car.

The factory jacking points can rust out and will therefore collapse when subjected to the weight of the vehicle. However there's not many choices on a car with depressurised suspension.

Mark


W116: Last of the steel Mercedes

1979 6.9 #6301 (Blue Flame)
1979 6.9 #5541 (Red Bull)
1979 6.9 #5398 (Blue Mallard) - Parts
1979 6.9 #5318 (Silver Arrow)
1978 6.9 #4248 (Skye Blue) - Parts
1979 6.9 #3686 (Moby Dick)
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street

32 Posts

Posted - 01/10/2018 :  18:31:07  Show Profile  Reply with Quote
My jack ports are in perfect shape and got this idea from my local shop. Jack up on the diff, put bolts the same size as the trunk jack tongue and lower bolts inserted into jack ports onto jack stands.

Gotta try this. Too tempting to remove the struts myself and shop can't have a lift tied up for 10 days while Martin rebuilds the shock struts.

'77 Silver 6.9
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rumb

USA
109 Posts

Posted - 01/10/2018 :  19:12:43  Show Profile  Reply with Quote






rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550
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Aaron H

USA
473 Posts

Posted - 02/16/2018 :  00:11:46  Show Profile  Reply with Quote
quote:
Originally posted by oversize

Jacking under the sills is a bad idea and will likely result in bent panels. I always use a trolley jack under the diff and the front cross member behind the sump. Position jack stands under the sub frame mounts. Also use these points when using a bottle jack or similar since these are the strongest points under the car.

The factory jacking points can rust out and will therefore collapse when subjected to the weight of the vehicle. However there's not many choices on a car with depressurised suspension.

Mark


W116: Last of the steel Mercedes

1979 6.9 #6301 (Blue Flame)
1979 6.9 #5541 (Red Bull)
1979 6.9 #5398 (Blue Mallard) - Parts
1979 6.9 #5318 (Silver Arrow)
1978 6.9 #4248 (Skye Blue) - Parts
1979 6.9 #3686 (Moby Dick)



Mark, a lot of what you stated is incorrect. If one jacks the car up directly under where the factory jacking support is, then nothing will bend, especially if a piece of wood 8-12 inches long is used.

Jacking any W116 up in the front using the cross member behind the sump is a definite no no. That is not a strong enough piece to support a 6.9, and will bend. It may work for a 6 cylinder car, but even then it's still extremely risky.

If using the factory jacking ports is out of the question, then the front of the car must be lifted up by putting a piece of wood between the jack and the left and right frame rails. If the front bumper and lower valence are removed, then the area where the frame rails are welded to the front cross member can be used as jacking points, as well.

And using a trolly jack on the differential? Do you have any idea how risky that is? Numerous differential housings have cracked/broken doing that. Please be careful.
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rumb

USA
109 Posts

Posted - 02/16/2018 :  07:53:25  Show Profile  Reply with Quote
"If one jacks the car up directly under where the factory jacking support is, then nothing will bend,"

That all depends if your jack points are good in the first place. I'm currently currently replacing my sills and jack points and it is very typical of non-restored cars to have compromised jack points. They always rust out from the bottom up. If you jack points are bad, then there is nothing there to support lifting from the rocker seam either.

(trying to upload file, but keep getting error message)

https://1drv.ms/i/s!AgQ9-BbdVO39qhmYjOl8bHb8T5j1

rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550
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StianLode

Norway
43 Posts

Posted - 02/16/2018 :  09:08:00  Show Profile  Reply with Quote
quote:
Originally posted by rumb







rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550



Ohh scary. Will this not introduce a lot of bending moment into the jacking point?

The factory jack is shaped as a 7 to lift directly underneath the jacking point.

Edited by - StianLode on 02/16/2018 09:08:39
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rumb

USA
109 Posts

Posted - 02/16/2018 :  10:46:06  Show Profile  Reply with Quote
If I made some I would have them at the same angle as the ports.

rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550
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Aaron H

USA
473 Posts

Posted - 02/26/2018 :  15:56:24  Show Profile  Reply with Quote
quote:
Originally posted by rumb

"If one jacks the car up directly under where the factory jacking support is, then nothing will bend,"

That all depends if your jack points are good in the first place. I'm currently currently replacing my sills and jack points and it is very typical of non-restored cars to have compromised jack points. They always rust out from the bottom up. If you jack points are bad, then there is nothing there to support lifting from the rocker seam either.

(trying to upload file, but keep getting error message)

https://1drv.ms/i/s!AgQ9-BbdVO39qhmYjOl8bHb8T5j1

rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550




I wasn't taking into account there being rust. If there is no rust present, the rocker panel will not cave in if jacked up underneath of it with a piece of wood between the jack and the rocker.
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rumb

USA
109 Posts

Posted - 02/27/2018 :  08:40:10  Show Profile  Reply with Quote

[/quote]


I wasn't taking into account there being rust. If there is no rust present, the rocker panel will not cave in if jacked up underneath of it with a piece of wood between the jack and the rocker.

[/quote]

I agree, nothing I said discounts that. however I'm guessing there are more 6.9's with bad jack point than good ones.

rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550
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Aaron H

USA
473 Posts

Posted - 02/28/2018 :  08:23:00  Show Profile  Reply with Quote
I suppose it's merely good luck, but I've never seen or owned a W116 with rusty jack points.
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rumb

USA
109 Posts

Posted - 02/28/2018 :  09:05:44  Show Profile  Reply with Quote
both of mine, one New Mexico and one Colorado have nearly completely disintegrated jack points.

Maybe we need a poll?

rumb
68 250S, 77 450SEL 6.9, 91 300SE, 98 SL500, 14 CLS550
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benzman70

USA
200 Posts

Posted - 03/01/2018 :  07:19:50  Show Profile  Reply with Quote
I have a set of the factory jack point lifting adapters, part number
123 589 11 63 00, fits 107,114,115,116,123, by flipping over three flaps to configure the various model distances from jack point hole to rocker lower edge, will try to upload a photo. At one time or another have seen all the models with rusted jack points that i wouldn't attempt to use them on.I guess it may depend on what part of the country the car came from, where winter salt took it's toll on the metal. Gary
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wbrian63

USA
900 Posts

Posted - 03/01/2018 :  11:51:05  Show Profile  Reply with Quote
The problem with W116 chassis isn't the rust you see, but the rust you don't see.

On my 6.9, appeared that the jack points were OK, but when I cut the lower rocker outer sections away for replacement, the supporting frames for the front jack port "tube" were swiss cheese.





Obviously, a 6.9 is a very nose-heavy car, and it would be a real problem if someone were to assume the ports are OK and have the system fail with a lot of ripping and tearing and associated body damage (and not just to the body of the car - the potential for personal body injury is very high).

The ports are available from MB at an unbelievably high price, so I designed my own. The tube is made from a solid rod, so there's no path for water into the sill. The side gussets are formed from 3/16" plate with 1/8" angle iron for transition to the chassis.

Here are some pictures of the weldments:
The tube:





The side plate:


I used one of the more-or-less intact jack port assemblies to get the proper angle of the tube relative to the plate and hence to the body.


Lots of fitment testing:


Added angle iron for to attach the assembly to the chassis:


And more fitment testing:


The real test - will the tube poke through the hole in the new outer sills?


and will the outer washer fit?


"Yes" to both questions.

Final results - primed and ready to install, as compared to the original:


I'm quite sure that these jack ports don't 100% match the factory implementation, but it is my intention that they serve only as a way to lift the car in an emergency - i.e. flat tire out on the road.

When I spent the weeks necessary to pull all the dents out of the front subframes on the car, I created a jacking plate for each front corner to allow for easy lifting of the car with (in theory) zero damage to the body. You can see the assembly in the right-hand corner of this picture.


It's made up of 2 pieces of 2" x 3/8" flat bar:


The installation transfers the lifting loads to the vertical sections of the subframe and provides a gap so water, etc. shouldn't collect and the space can be kept clean:




My plan is to create something similar for the typical lifting points at the rear of the car around the rear subframe mount.


W. Brian Fogarty

'07 Lexus LS460L
'76 450SEL 6.9 Euro #521
'02 S55 AMG (W220) - sold
'92 300SE (W140) - sold
'76 450SEL 6.9 Euro #1164 - parted & gone

"Bond reflected that good Americans were fine people, and most of them seemed to come from Texas..." Casino Royale, Chapter VII
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benzman70

USA
200 Posts

Posted - 03/01/2018 :  12:30:19  Show Profile  Reply with Quote
Brian, That looks great!and a lot heavier duty than original, rust guard, painted and sealed will last forever. I agree, the rust you don't see is usually the main problem when you open it up.
Gary
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