Hood (Bonnet) Hinge Bracket Plate Renew

[rutger kohler]

Hi all, I have removed my hood (bonnet down here) according to the excellent directions on this website.  Unfortunately, the 10mm threads in the backing plate that secure the bracket to the hood, are stripped (see photo).  

The backing plate is inside the strengthening rib which looks like it is sealed all the way around. I wonder if I remove the locating plate that holds the large rod spring (see also in photo), on this side, whether there would be a hole under this big enough to try to juggle the backing plate through? It would be easy to make a new plate. I could probably locate it again with a lot of patience.

I also suppose I could use helicoils if I could hold the plate in situ firmly enough, however as both threads are stripped, this could be difficult

[hauser]

Contact Gernold at SLTech in Arundel Me. 

http://www.sltechw113.com/

[Garry]

Rutger is a bit far away, like 20,000km but last I heard Gernold no longer had the repair kits available and that maybe Millers or Bud's may have.
http://www.sl113.org/forums/index.php?topic=13841.0

Either way it appears that there was some cut and welding needed with the kit.

Rutger

This Thread may give you some assistance and ideas
http://www.sl113.org/forums/index.php?topic=9769.0

[rutger kohler]

Hi Guys, thanks for that, it appears there is a repair kit however I can't see a pic of it yet.  I can easliy make a tapped back plate my self, the question is can I get the old one out without cutting?

[rutger kohler]

Have just had a look at the other side that is ok.  It seems that there are two separate nuts which might be square and run in beteen slider plates, rather than one long plate. They may actually be turning round rather than stripped. Time i went to bed down here, will look again in the morning.

cheers

Rutger K

[Garry]

Rutger,

Cannot answer re access, I think Naj in UK did a repair some time ago.

Try SLS at here for parts kit
http://www.sls-hh-shop.de/product_info.php/info/p14706_Set-4pcs-hood-hinges.html

[Naj ✝︎]

Hi, Rutger,

Yes, there are 2 caged nuts (on a plate riveted to the bonnet shell) to allow a bit of sliding adjustment of the hinge plate.
You may be able to repair the threads. I saw a body shop cut a slot on the side to remove the plate and replace the caged nuts.
If the thread is salvagable, you may want to consider changint to stud + nut arrangement (not for originality sticklers....)

[rb6667]

A "Shadetree Mechanic" fix is to cut a piece of an aluminum cotter pin, and place it in the hole while you slowly turn the bolt in.  The aluminum cotter pin allows the bolt to bite/thread into the cotter pin.   This only works 1 time. Once you take the bolt loose, you have to use a new cotter pin.

Worked for me several times.

RB6667

[George Des]

I had this same problem. I ended up cutting a small slot on the side to remove and replace the plate for the cage nuts where the hinge butts up against that area. This was the only feasible way I could see to make the repair. With the hinge in place, the slot is not even visible. I suppose for orginality sake the slot could be closed with a bit of aluminum tig welding if one is so inclined.

[ricrose]

George - this is exactly what a PO had done to mine - but they had replaced the two captured nuts with a solid plate, slipped in from the side, with two tapped holes. Works very well.

[George Des]

As I recall, I did use a plate that I drilled and tapped the holes in as well. MB used captive nuts in many places such as the hood. One other place where I had a problem and had to resort to a similar solution is on the bracket that holds the center bearing for the driveshaft. The captive nuts for this slide in a slot on the underside of the tunnel. The slots on mine had become mishapen and would not hold the original square nuts w/o them turning so I had to get some flat steel of suitable size that would 'ride" in the slot and then drilled and tapped with an appropriate size metric tap--it works fine

[rutger kohler]

I have made a successful repair after reading all the posts thanks and taken some photos. Looked at fitting a tapped backing plate but couldn't see how you could hold onto it when the two bolts were removed.  I decided to remove the old backing bracket by drilling a slot in the side as described by other posts. Haven taken some photos and will attach them but if they are too big let me know and i will try to reduce them somehow.  The quality is not as good as I would have hoped.

Hood 1 shows removing the damaged backing bracket out of the slot after drilling out the two retaining rivets. (Note to self, next time secure the backing bracket before drilling out the rivets, saves chasing the bracket around theinside of the hood  stiffener!)

Hood 2 shows  dismantled bracket,  it was badly of shape.  The new square nuts (shown on side) came off some sort of shelving system and are contained in a cage which I removed.  They are substantially thicker than gutter bolts.

Hood 3  shows the nut cage being dressed back into shape and  being adjusted to make a snug fit on the new nuts.

Hood 4 four shows the assembled backing bracket being held in a vice and a new pop hole and pop rivet being fitted between the original ones.  This is to hold the backing bracket together whist it is fitted back into the hood.

I aren't allowed anymore attachments on this post will make another one.

[rutger kohler]

2nd part of refurbish for hood  backing bracket.

Hood 5 shows  the assembled backing bracket being slid back into the hood with a rare earth magnet on a stick

Hood 6 shows how I ran nuts up on the 6mm bolts, entered the bolts in the sliding square nuts and then tightened the nuts up against the hood to hold the backing bracket up snug against the hood whilst pop riveting in the original rivet holes (opened these out to 1/8" diameter.

Hood 7 shows the finished job with a holding coat of primer prior to preparation and painting.

I am confident that this will last.  In the end the problem was a combination of worn nuts turning, the backing bracket had deformed, and the threads on the nuts and the bolts were worn. A sightly different original design with longer slots would have allowed the LH hood hinge  bracket to slide right off the pin that holds it onto the car body without removing the hood bracket off the hood, after loosening the two 6mm bolts, but not removing them.

[zoegrlh]

Rutger, you should post this with your photos in our Technical Manual.  Would be good step by step to fix the problem.  Job well done.  Only one question, when you attach the hinge bracket, are you going to shim it because you can not flush up the hinge to the hood because of the two rivits.
Bob

[rutger kohler]

Hi Bob, thanks for your kind comments. I don't know how to enter up into the Technical Manual, if enough people thought it was ok I guess I could, bit diffident about it  though.  With regards to your pertinent comment regarding shimming the outer bracket because of the pop rivets, I peened the  heads down  fairly flush, and there was no remainder of the rod sticking out proud and after I had pulled the nuts up on the 6mm bolts prior to fitting the pop rivets it seemed to flatten things out under the outer bracket. Probably not precision engineering but I was happy with the result.  As an earlier post said the hinge tends to cover the slot I had to make on the side so at this point I have left it.

One thing I would reiterate, it is very important to tie the back bracket arrangment together before you drill the original rivets out,  or as ii found, you have to chase the bits around the inside of the hood/bonnet!

[ja17]

Hello,

Rutger's repair is good if one does not have access to an aluminum welder. I would opt for that solution as an alternative.

I recently fixed both sides of a hood which had been badly cobbled up from inadequate repairs. The inner nut cages had been distorted  and all bolts were spinning the special square nuts inside.  The sheetmetal (steel) nut-cages were originally riveted to the inside of the aluminum before the hood frame is attached to the outer skin of the hood. To make a undetectable repair and have the nut-cage working as designed, I had to cut the damaged flat area of the hood frame off all together. After it was removed I drilled out the aluminum rivets holding the sheet metal nut cages in place.  I thread chased and cleaned the  original special square metric nuts. I re-installed them in the repaired sheet metal nut-cages.  I then  re-attached the nut cage assemblies to a new piece of aluminum (same thickness as the original), with the correct aluminum flat head rivets.  I made the two slotted holes in the new aluminum as original.  I trimmed all damaged metal from the hood frame. I then fitted and trimmed the newly made assembly so it fit snugly, then I  aluminum welded it into place. After grinding and sanding smooth the weld no filler was needed and the whole area is correct as original.

The original function of the nut cage is to allow adjustment of the hood fore and aft. The slotted holes in the hood hing allow adjustment to left and right. Together they allow adjusment in any direction. When done correctly these adjustments are all restored.

I spent around two hours  on each side for these repairs. No paintwork was damaged on the exterior hood surface, but obviously the hood frame paint around the repaired area was damaged.

  I am sure Rutger's fix is much faster and often adequate in most cases.

[rutger kohler]

Hi Joe, I think your repair is superior, however I don't know of any aluminium welders I would trust near my hood/bonnet. If you do the repair welds yourself that is great repair job.
cheers
Rutger K

[ja17]

Hello Rutger,

I like your repair also. It is a good quality and economical alternative.  Now the readers have at least two good choices.