Different Hood Issue (67 250 SL)

[scoot]

Hello -

We have a different hood issue.  Our hinges are not rusty, everything moves fine, but it is a little out of alignment.  In attempting to re-align the hood we discovered that one of the bolts won't come out.  It just spins around.   We've tried applying outward pressure on the washer while using a socket wrench to loosen the bolt, but it hasn't worked.   Here's a picture of the bolt that turns freely but doesn't tighten or loosen.  




Oh, and in the picture, there are also these two things that are on the torsion bar that holds up the hood.  They don't seem to be serving any function - they can move freely.  What are they?

Thanks
Scott

[waqas]

Originally posted by scoot

 In attempting to re-align the hood we discovered that one of the bolts won't come out. It just spins around.

The nut-fixture inside the hood cavity needs to be repaired or replaced. See hood hinge repair thread: http://www.sl113.org/forums/index.php?topic=7019.0

Originally posted by scoot

Oh, and in the picture, there are also these two things that are on the torsion bar that holds up the hood.  They don't seem to be serving any function - they can move freely.  What are they?

I believe these are rubber bumpers meant to prevent contact between the hood spring and the hood. They should be supple not hard, and they should be spread evenly across the span of the spring.

[scoot]

I had read thread 7019 and was hoping that it didn't apply to me since I don't have a torn hood or rusted hinges.  The thread doesn't answer all of my questions, or at least I'm not clear on the answers, so I'll ask them explicitly:

1.  Inside the hood, is there somethng that is basically the same as Gernold's captive nut kit in there?  Is that how MB did this?

2.  Is whatever is in there attached or free-floating in the space provided?

3.  If I install the Gernold kit, it looks like this means I need to cut a hole in the side of the hood.  What's the best way to do this?

4.  To seal up the hole, do I need to have it welded (or whatever one does with aluminum) or can it be epoxied?

5.  What's the approximate cost of the Gernold kit?

I was hoping for a less intrusive/less expensive fix for my car.  It's a driver, not a show car.  For now I can leave it as is and have the one good bolt do the work of two, but at some point I should fix this.

thaks
Scott

[waqas]

quote:Originally posted by scoot

1.  Inside the hood, is there somethng that is basically the same as Gernold's captive nut kit in there?  Is that how MB did this?

Pretty much. Unfortunately, the dealer parts manual does not show this explicitly (it is part of the hood).

quote:2.  Is whatever is in there attached or free-floating in the space provided?

The nuts are free to move laterally, but not allowed to turn. In your case, the cavity in which the nut is held captive has widened to such a degree that the nut is no longer prevented from rotating.

Hopefully someone else is better-equipped to answer your other questions.

[Surfer65sl]

Scott, I am less technical than many on the site but I ordered the kit from Gernold at SL-Tech (thanks to Aqas and others from site for recommending) They cost $42 a piece but he recommends doing both sides once the hood is removed...Mercedes apparently made a flimsy design in this area of hood.  Yes, you will have to make a small slit to get the rectangle bracket installed but a skilled welder can apparently seal this area back up.  

I would look up Gernold at Sl tech and he can go through this issue in detail.  

http://www.sltechw113.com

Good luck,

Matt

[graphic66]

I wonder if the corrosion is damage from electrolysis? Possibly caused by not having the little copper grounding strip attached to the hood hold down latch, or it not making proper contact. Also of course you should check your engine fore electrolysis. Here is one of many sites explaining the test. I also am curious if the kit you buy is aluminum plates or steel. I would give an uneducated guess that if those plates are not aluminum you may be in for more damage down the road as dissimilar metals can create problems in a situation like this. I am no metallurgist by any means, so please all you engineers chime in here. And everybody run out and see if you have the copper colored hood ground strip in place. Most pictures I see have it missing. My 250SL parts car also had a braided ground strap from the coil mount to the negative battery post, now on my 230SL. I have never seen that in any pics, but I assumed that it can't hurt. Also, the engine has a ground strap to the chassis that is many times missing.

[graphic66]

Oops forgot the link for the electrolysis test  http://www.4s.com/fourseasons/tech_tips/tech_tips_english/AB350_Electrolysis_02.pdf

[66andBlue]

A member of the German Pagoda group posted an article showing his way of fixing this problem. Although the text is in German the pictures are self explanatory.
Go to: http://www.pagodentreff.de/diskussionsforum/t5365-haltplatten-motorhaube.html
Scroll down to the second post by Bochy3699 and download the PDF file:
"Käfigmutter Haube ersetzten.pdf"