Rumble lid clearance to lower valance adjustment suggestions

[Str8-8-Dave]

Today I opened the rumble lid on my 31 8-66S coupe for the first time since I've had the car and it has a clearance issue I can't seem to get a handle on.  When the lid first starts to open, like when the top end is raised off the sills about 1-1.5" the bottom edge of the rumble lid comes into contact with the lower valance panel.  There is no adjustment feature on the hinge brackets, the wood screws are not installed and I've loosened the four 1/4" stud nuts that hold the lid to the hinges and pried on the lower edge trying to get the slightest adjustment and there is none observed.  The pivot screws are tight and the hinges are securely fastened to the body.  Any suggestions on how to get another 1/8" of clearance between the bottom lip of the lid and the top lip of the lower valance panel highly appreciated.  

 

Thanks in advance...

 

Dave

Edited August 24, 2019 by Str8-8-Dave
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[Terry Wiegand]

In looking at the third photo, the gap at the top of the lid looks cockeyed to me.  If it were me, I'd be looking for a good body person for some serious suggestions and/or help.

 

Terry Wiegand

South Hutchinson, Kansas

[Guest]

I wonder if chistech might offer a suggestion.  He has been restoring a cousin of your Buick, a '32 Oldsmobile.  Might be worth PMing him.

 

[chistech]

Funny that you linked me today as I just installed my rumble lid today. The pivot bolt screws into a floating captured nut. This nut has some movement when the pivot bolt is loosened. There should be a thick washer and a star washer in between the pivot point of the hinge and it is the combination of the two that prevents the floating nut from moving once the hinge bolt is tightened. Looking at your picture it appears your left hinge bolt is most likely low and back some. I would check it for tightness and I would assume it’s slightly loose. I would recommend you loosenthe bolt a little bit more then lift the lid up some then forward a bit. I find if the bolt is just snug enough, tapping on the bolt head with a hard rubber hammer works the best. It is much easier to adjust the lid with the seat back removed. There are two 1/4-20 screws at the bottom corners of the seat back that hold it to the lid. Plain and simple, they are a PITA to take out and put back in. You might be able to adjust the lid with the seat back in place, your choice. Hope this helps.

[Dave39MD]

Ted, My 31 Chevy rumble lid adjusts just as you describe but my 31 Buick has a different hinge. I have never had to adjust mine and hope I never do so I can't be much help to Dave. The Chevy has a metal lid while the Buick is wood framed.

 

Dave

[Hubert_25-25]

On a Ford model A rumble seat we had a similar situation.  We found it easier to remove the back seat cushions.  Loosen the hinge fasteners so that they can slide some with a little pressure.  Someone has to go in the trunk.  Use the light on their phone.   Push up  from the back side and move the trunk lid around.  The person on the outside helps verify the sight lines.  Hugh

[Str8-8-Dave]

Thanks to all for the advice.  The 31 Buick hinges I'm working with do not have the adjustable pivot, the boss is staked or welded to the side bracket.  The only adjustment feature I have found is the 4 bolted locations attaching the lid to the moving hinge are slotted.  Looks like the process was to move the lid around in the slotted adjustments, get it right, then install 4 1-1/2 by #12 wood screws into holes in each hinge.  The wood screws then lock the hinge into place on the wood frame of the lid as they are not slotted.  The left side of the lid is actually 1/4" or so higher than the adjacent quarter panel sheet metal so I need some way of correcting that issue to get the height corrected which may also correct the rub at the valance panel.  Wife and I hoisted the lid onto the body without the hinges and without the hinges it sits flat against the sheet metal gutters which are around the top, left and right sides of the opening.

 

Additionally I found a 1926-1931 Fisher Body manual copy I bought from Buick Historic Alliance and it talks about curing the rub by driving a series of thin wood wedges between the valance panel sheet metal and the "lower bar" which is the wood member that runs horizontally across the back side of the valance panel sheet metal.  The problem there is the previous owner/restorers thought it would be a good idea to bond the valance panel sheet metal to the lower bar so now unless I separate the bar and the valance sheet metal there is no way to install wedges.  They may have also put screws or nails through the sheet metal into the wood bar so separating the 2 could force fasteners back through paint and body filler wrecking the pretty paint job...

 

Keeping my fingers crossed on this one...   I know there is a solution. 

 

Thanks again and keep the cards and letters coming- I really appreciate your ideas and comments...

Dave

 

Slotted holes allow initial adjustment of top and bottom gaps.  Round screw holes are used to lock the final position of the hinge to the rumble lid's wood frame.

 

 

The back side of the hinge pivot bracket reveals the weld that holds the pivot in a fixed location.

 

 

Inboard side of the fixed hinge pivot shown with set screw to prevent the pivot bolt from backing out.  There is no adjustment to the hinge pivot location on the side bracket.

 

 

The 1926-1931 Fisher Body manual states that dragging of the bottom of the rumble lid is corrected by driving a series of thin wedges between the lower bar and the valance panel sheet metal.  this is impossible in this car because the previous restorer bonded and probably screwed or nailed the valance panel skin to the wood lower bar from outside the rumble compartment then filled the panel and finish painted it.  Separating the valance panel from the bar could result in forcing screws or nails back through the finished paint.  One idea I thought of was adding a second piece of ash lumber to the inside of the wood lower bar attaching it at the far left and right ends, then wedging between the added bar and the original lower bar to force the lip of the valance panel sheet metal out away from the rumble lid. 

 

Edited August 26, 2019 by Str8-8-Dave
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[chistech]

Okay, well, disregard everything I said and who said Buick had better ideas! Just joking but that sucks that there is not many options for adjusting. If you leave out the lock screws and only install the screws in the slots, can you get the lid right? On the lower deck rail, there is usually a piece of metal called a knife edge that the lower deck pan hangs on. That knife edge gets screwed into the lower deck rail wood. I carefully shimmed my knife edge with sheets of tarpaper to get the matching curve to the deck pan. I don’t know if you Buick is different along the bottom also because there would be no way to shim out my deck pan with a piece of wood like you said was recommended. Guess I have to spend more time on some Buick’s!

[Str8-8-Dave]

Hi Chris- thanks for that last post.  I bet you are right about the knife edge and I never knew it existed until you described it.  The lower deck pan is crimped over at the top and it is probably crimped over the knife edge.  If that is all correct the deck pan shims like you say should have been assembled between the knife edge and lower deck rail before it was screwed.  I've been working from the top of that rail, I wonder if I can wedge between the knife edge and the deck pan from below the wood bar?  I might try that. 

 

Dave

[Dave39MD]

You can see the knife edge in this picture

 

 

[Dave39MD]

I am not sure  Buick used the knife edge but they may have. The picture is a 32 Chevrolet Cabriolet taken in Ralph McEowen's shop by John Potter.

 

Dave 

Edited August 26, 2019 by Dave39MD (see edit history)

[Str8-8-Dave]

I can tell you they did on mine.  There is no clearance above the lower wood bar but if you reach under it there are 2 pieces of sheet metal with a good 1/2" gap between, one is the knife edge and the other is the painted valance panel.  The left side of my lid continues to be high.  I had it out of the car all day and did a minor cleanup of the wood where the left hinge attaches to the wood structure of the lid.  Not being able to adjust the hinge pivot bracket on the side bracket leaves me with little choice but to take more wood out from under the hinge.  I give up for tonight...

[Dave39MD]

Yes I should have said Fisher Body and it would make sense they carried the practice to all bodies. Hope you get yours straight it is not easy!

 

Dave

[chistech]

14 hours ago, Str8-8-Dave said:

Hi Chris- thanks for that last post.  I bet you are right about the knife edge and I never knew it existed until you described it.  The lower deck pan is crimped over at the top and it is probably crimped over the knife edge.  If that is all correct the deck pan shims like you say should have been assembled between the knife edge and lower deck rail before it was screwed.  I've been working from the top of that rail, I wonder if I can wedge between the knife edge and the deck pan from below the wood bar?  I might try that. 

 

Dave

Hi Dave,

if you try to put wedges in place now, all you will do is possibly put bumps or possibly worse, dents in the lower deck pan metal. The tar paper I installed went behind the knife edge before it was screwed to the lower deck cross bar. Thought I had a picture of the knife edge with the tar paper shims but can’t seem to locate it. Here are some other pictures similar to what Dave posted.

[Str8-8-Dave]

Chris- I absolutely agree.  If I do anything with the lower bar I will attach a cross beam in front of it screwed at the ends to the lower bar and either contour it to make it bow the lower bar out slightly or shim between it and the lower bar.  I identified the spot that needs to move out very slightly and it is just left of center of the valance panel. 

 

Another idea I am noodling rather than removing wood from the rumble lid frame under the left hinge is to make an eccentric hinge pivot bolt for the left side.   This would allow the pivot center to move down and forward in car and could be locked in position with the locking set screw on the threaded flange of the hinge bracket.  Doing something like that made from scrap bolts without modifying the original pivot screw would be reversible and therefore harmless. 

 

The area where the lid rubs the top edge of the valance panel is defined by the far left and right edges of the tape.  This was determined by propping the lid open t the point of contact and sliding a 3x5 card in along the gap between the lid and valance panel.

 

 

One idea to push the valance out slightly would be to add an ash stringer (poorly represented by the blue artwork, the red dots are supposed to be the attaching screws) across the interior of the lower bar attaching it at the far left and right ends.  It could be either tapered to bend the lower bar and push the valance out or it could be a straight piece attached at the ends and shimmed locally to push the bar and valance out.

 

 

Th left side of the lid is high and even with the hinge adjusted to the end of the elongated slots it is slightly rearward on the left top.

 

 

One way to correct the left side lid height would be to remove wood from the lid frame under the hinge mounting area to let the lid down, then file the adjustment slots to allow the lid to be moved forward.

 

 

A less destructive idea would be to fabricate an offset hinge pin bolt which could lower the lid and move it forward.  It could be locked into the final adjustment with the set screw on the hinge pin boss.   If nothing else my artwork was better in this picture...

 

Edited August 27, 2019 by Str8-8-Dave
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[chistech]

I really like the idea of the offset. Another idea would be to make a bushing with a offset threaded hole drilled in it and use a shoulder bolt through the hinge. Yes, the threaded section of the bolt would be smaller than the original but modern steel is very strong. The bushing could be threaded on the outside and thread into the hinge and the side of the hinge bolster could be drilled and tapped for a set screw to hold the bushing in its correct offset once adjusted.

 

Wanted to mention that my Olds had a area along top of the lower deck metal, similar to your Buick, that was too close to the bottom of the lid so I needed to shim the knife edge out. I made a wood pattern cut to the exact shape following the curve of the bottom edge of the deck lid. I laid this pattern on the top edge of the rear deck metal and kept shimming the knife edge until the deck metal matched the curve of my pattern exactly. When doing this, it is necessary to push the bottom of the deck metal into its correct (nail area) position along the rear cross sill. The reason for this is it flexes the metal and makes the top edge sit correctly on the knife edge. I suspect your car was not done quite right when it was restored as I see many cars that show rubbing in the center bottom area of the lid that just weren’t adjusted quite right.

Edited August 28, 2019 by chistech (see edit history)

[Str8-8-Dave]

So I win- I think.  I talked about doing a cross car beam and screwing it to the lower bar.  The idea was to force the center of the knife edge and the lower panel attached to it out by either tapering the cross car added beam creating a high spot in the center which would push of the lower bar or doing a series of shims between the added cross car beam and the lower bar.  I finally realized if I could lift the bottom of the lower bar it would rotate the knife edge and lower panel rearward.   I made some cardboard patterns and devised a couple of crutches that are a force fit to go between the lower wood sill and the lower rear bar.  I used my belt sander to ramp the crutches so they could be rotated into position and used them like sisters to the original upright posts the lower bar sits on.  Gorilla glue makes wonderful lubricant while still wet allowing me to easily rotate the crutches into position.

 

I also talked about making an eccentric pivot bolt for the left hinge but I don't have a lathe or any welding equipment.  I still think that is a valid idea but it's a machine shop job.  For now I settled on the crutches and removing some wood on the rumble lid's wooden frame under the left side hinge.  The goal was to get the left side of the lid to sit down a little lower when closed. 

 

The results were I now have a lid that closes without rubbing and the left side of the lid does sit a bit lower but I didn't take much wood off and similarly the lid still sits a little high on the left.  Eventually I may explore the cam screw  arrangement.

 

I also got the latch and deck lid handle along with the strike installed and they all work.  I discovered the triangular corner braces and adjustable lid bumpers are missing from the top corners of the opening so will have to figure out what those consisted of and either find or make a set.

 

Thanks for all the input on this...

Dave

 

I dreamt up these nifty crutches to force the lower bar up and the lip of the lower panel rearward in car.

  

 

The crutches are a force fit between the lower sill and the lower bar.

 

 

I removed some wood from the lid frame where the hinge mounts to try to resolve the high lid.  It helped, the left side of the lid does sit lower,  but I didn't take much wood off.

 

 

I installed a reproduction latch and deck lid handle and got the original striker for the latch installed.  Conspicuous by their absence are the 2 corner braces the rumble lid bumpers are installed on. 

 

 

 

 

 

 

 

Edited August 28, 2019 by Str8-8-Dave
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[chistech]

Great job, that looks much better. So in essence, with your wedges, you rolled the top edge of the rear metal out and now it clears right? I’m amazed at how different your hinges and lid/construction are from my 32’ Olds. 

[Str8-8-Dave]

Hi Chris- Yes, that was the approach for the dragging lid.  The hinge wood removal was  to try to level the lid.  Every time I do a project on the car I discover parts that are missing.  This time it is the triangular corner irons and the lid bumpers that attach to the irons.  Dave39MD sent pictures of his original parts so I know what they look like.  The iron plates are easy to make but the bumpers are not so easy.  I'll figure it out.  Thanks for your input to this thread, your suggestion about the knife edge helped me understand the construction and figure out a fix.

 

Dave

[chistech]

Those bumpers are available from Gary Wallace @Early Chevy Parts. 5/8” with threaded shafts. The triangle corner is spot welded to the drip channel. I used a Harbor Freight 230v unit and it worked perfectly. I turned a threaded collar on the lathe and made a thin flange on the end that I peened over like the original. I believe you could also use the modern version called a nut set tool which installs a threaded collar much like a rivet tool would. Here is some pictures of the one corner I had to replace as it was also missing. I took a piece of 16g steel, bent the edge over, drilled it for the threaded bushing, installed the bushing and flared over the skirt to secure it to the piece, then spot welded it in place. The steel on these old cars is thick so it requires a lot of heat and time to get a secure spot weld. The corner in primer is the original and the one in raw steel is the new one I made.

Edited August 30, 2019 by chistech (see edit history)

[Str8-8-Dave]

Hi Chris- Great pictures, description and tip on sources for the bumpers.  The pictures here are of another Chevy  Dave 39MD sent.  Note they are different in that they used sheet metal with a folded rib with short pieces of 1/4" bar stock welded under the triangles which were then drilled and  threaded  for the bumper studs. While it looks like in these pictures the triangles are spot welded, my Buick triangles hang from bolts in the upper back rails at 3 points.  Chevrolet was a leader at GM for improved mfg. processes which probably explains the differences...

 

Thanks again Chris

 

Dave

 

 

 

 

 

 

Edited September 3, 2019 by Str8-8-Dave (see edit history)