1931 Trunk lid prop question

Does anyone have a picture of a trunk lid prop used on a 1931 coupe?

My car is a 96 series and I haven't a clue as to what holds the trunk lid in an open position.

Any help is greatly appreciated.

Thank you, Mike

This photo is from a 1932 model 58 . I would expect the 31 90 series would be similar. There are 3 pieces. The lifting bar with a notch at the base and a step in the bar at the top. The base has a double wound torsion spring in it and the bar passes through the loop in the center of the spring and the notch in the bar rides on the spring loop. The top piece has a roller in it that the rod rides on and the step holds it open when the lid is raised.

I have been searching for these parts for over 10 years. The spring is broken on mine and spring mfgr's want over $250 to wind a new one. The rod is missing, but will be an easy piece to fabricate. The top roller assembly is salvageable . If you need individual photos of these pieces let me know.

Bob,

Thank you once again for coming to the rescue.

If it isn't too much trouble, individual pics would be very helpful.

Thank you,

Mike

I hope these photos help. I do not have an original lift bar. I made one by hand and have started a second one that will need fitting at assembly. The pin in the bar is there to hold the two ends of the broken spring. The assembly bolts to a wood crossmember under the top lip of thee trunk opening. Teh roller assembly mounts to the trunk lid. Let me know if you need any further clarification.

Bob Engle

Bob,

As always your help is greatly appreciated.

Seeing your pictures will allow me to fabricate the prop.

I will be asking you for a few critical measurements when I start, mainly the sliding bar.

I am guessing the torsion springs allow the bar to lock and then stow itself depending

on the position of the lid (open or closed). I assume the weight of the bar plays a large

part in the spring action.

Thank you

This description may get lengthy. I assume you have the two rackets, one with the spring intact and the other with the roller. You are only missing the bar. Since my car is a 50 series, you r 90 series may have a different size bar.

To make a bar, with the two brackets in place, prop the trunk lid fully open; measure from the pin through the spring bracket to the roller bracket. Add about one inch to this length, mine is 14”. You can trim the length later. Next measure the roller bracket space between the roller and the bracket top, mine measures .960”. Lastly, measure the width of the roller in the bracket, mine is .265”. I started with a piece of steel 14” X ¼” X 7/8”. Adjust your measurements to match your dimensions.

Mill a ¼” half round along the 14” length on both sides.

Measure the diameter of the pin in the spring bracket. Mine is .372”. Half of this with clearance would be .1875”. Measure in 3/16”plus 1/8” from one end and mill a 3/8” width slot in from the 7/8” width. Mill to a 5/8” depth. This will be the hook to locate the bar in the spring bracket.

Prop the trunk lid fully open. Slip the bar through the loop in the spring and hook the bar onto the pin in the spring bracket with the open side of the slot up. The spring will force the bar to its upper position. You may need to rig a way to pull the bar down away from the trunk lid. Remove the roller bracket and slide it onto the bar. Reattach the roller bracket. Decide how far open you want the trunk lid and mark the rounded edge of the bar for the roller detent.

Remove the bar and mill the half round to the detent mark. I don’t know how far or how deep this should be. You will need to cut and try until the lid is held open at your desired height and the step in the rounded edge is deep enough to hold without accidentally dropping out of the notch. You can trim the trunk lid end if it is too long, but don’t trim it so short that you can open the lid and have the rod clear the roller.

You will find that the weight of the bar is not critical as the spring force is quite high. While the spring will assist in opening the trunk lid, the lid is heavy enough to not spring open.

Bob Engle

Thank you for the in depth explanation. This will be a rewarding job. Between the pictures and with the measurements I can't wait to get started!

Thank you,

Mike

Be sure to let us know how it turns out. I am curious to see how close the 90 series is to the 50 series parts. I am still looking for the base with a good spring in it. I will get by with the broken one I have, but would prefer a ggod one.

Bob