Attaching front top-bow to windscreen on 29 Chrysler open cars

[Gasket]

Hi All,

What I have for attaching the front top bow to the windscreen on my 1929 Chrysler Series 65 touring is not very secure. I wonder if I am missing some of the hardware.

(For some reason the images of the left stanchion, posted below, came out sideways; my apologies for that.)

The top bow secures by means of a screw that bites the neck of the knob on the top of the stanchion.

The screw bites the knob from the back.  I am wondering if there should not also be some kind of plate that grips the neck of the knob from the front.  It looks like the two holes either side of bracket--see 3rd image--could be meant to secure such a plate. (Lots of guessing going on here.)

Thanks for any guidance

 

[viv w]

These are from a previous post on this group, hope this helps, A picture says it all. A lot of the Chrysler of this era were of the same design.

 Viv

 

 

 

 

 

 

[Gasket]

Hi Viv,

Thanks; these images help a lot....

So it's the bolt biting into the neck below the ball on top of the stanchion that does all the work.

The finishing plate is (mostly) decorative.

I don't want to second guess Chrysler engineering, but I do hope the whole thing stays secure at speed.

Just FYI; here's an image from a 1931 Chrysler showing a locking wing nut together with a wing bolt securing the top bow to the stanchion.

Cheers

[Gunsmoke]

Since the soffit board and top material extend rearward into cab area about 1/2"-3/4" beyond edge of roof clamp, a "locking wingnut" cannot be used as there would be no clearance to turn it. The clamping bolt I believe is 3/8" standard thread on mine and I believe was all that was used. Not sure there is any alternative to make it less likely to back out other than making sure it is good and tight. Some photos I've seen show a fairly long chromed wing bolt, necessary to clear the cloth soffit.

[1930 Kram66]

Here are some photos I took of a couple of 28/29 Chrysler's.

One has a single wing type bolt and the other's have a double type wing bolt. 

Note these are both Australian cars.

[Gunsmoke]

The 1930 Kram66 series of photos all are of tops where the inside "fabric over board" soffit has not been put in place during restoration, and thus the clamp looks a bit odd as it sits there with the holes for the chrome trim piece but no fabric or board. Ironically, today I just finished making a pair of stainless steel trim pieces for this very purpose, shaped as shown in viv w's picture. The piece is same shape as surface of clamp. viv W mentioned they were riveted to clamp. That seems a bit odd, as they would have to be riveted after fabric is in place? My clamps had been altered and these holes drilled larger for 1/4" bolts to secure to a board used as a bow. I brazed the holes full, then drilled them and tapped them for #12 pan head machine screws. Will be posting photos in next day of so on my CD8 diary.

[viv w]

The picture showing the 2 wingnut version of Gasket's is correct, both of my Chrysler 52's and the model 62 had this type. The "filler panel" above the windscreen goes back just far enough on the clamp to allow the finisher piece (made of aluminum) to be split rivetted thru the panel. It also allows the wing nuts to operate, wish I had taken more pictures of the cars when I owned them 20 years ago.

 The earlier cars such as the B70 did not have this cast type clamp, they had a bent metal stamping that went onto a threaded pin at the top of the windscreen post, this also had an aluminum finisher plate split riveted thru this filler panel.

 For Gasket's peace of mind, the locking bolt from the rear holds the top securely to the posts and does not come off as long as it is tightly screwed down. I used to sit at 40MPH and even with trucks passing the other way at 80MPH, it never came off. The only time I had it come loose and blow back was when I foolishly hired the car to a film company and they took the top down while filming, they then put it back up and they didn't tighten the locking bolts. It did some damage to the frames which I repaired. So just make sure it is tightly screwed down .

viv

 

[Gunsmoke]

Regardless of 1 nut or 2, those type clamps with the 2 extra holes were intended to be hidden by the soffit board and fabric and the decorative trim piece. I suppose those suppliers replacing these soft tops would find it easier to ignore the soffit, thus exposing the rather ugly clamps. Or perhaps not having an original top, they did not know how they went together. In that regard, just how did these tops go on. I always assumed the upholsterer made the top by creating the front fabric like a "sock" which he could pull tightly over front bow and secure to the bow board? Or was the soffit fabric was installed as a separate fit, then the roof material put on over it and stapled at front (or underside) of bow and hidden by hidem type strip?? Someone elsewhere inquired as to how these soft tops were assembled, I have no clues. Nothing was there when I bought my Chrysler CD8.

[Narve N]

 Initial posting (Gasket) displays regular machine bolts in the mounts. The bolts should rather be pointed to insert and grip tight below the windshield post top "head/bowl". On my Series 65 I initially used Ford Model A non-locking bolts (worked fine, same thread) and then replaced these by proper repro bolts with locking nut from Verdone as per Marty Lum's drawing from years back. Unfortunately neither Verdone nor Marty is active anymore.

[keiser31]

19 minutes ago, Narve N said:

 Initial posting (Gasket) displays regular machine bolts in the mounts. The bolts should rather be pointed to insert and grip tight below the windshield post top "head/bowl". On my Series 65 I initially used Ford Model A non-locking bolts (worked fine, same thread) and then replaced these by proper repro bolts with locking nut from Verdone as per Marty Lum's drawing from years back. Unfortunately neither Verdone nor Marty is active anymore.

I just happen to have the steel plate that goes into the top of a 1929 Chrysler Model 75 roadster if you need it....

Edited August 11, 2022 by keiser31 (see edit history)

[Gasket]

HI All,

Thanks, Viv, for those comforting words about the security of the the top attach design.  And to Narve for the useful images/drawings.

Just FYI:  I was pretty sure I would never be able to locate correct bolt hardware, so I simulated the look using reproduced Ford bits--see images (all tilted sideways) below.  Mac's Auto Parts has "Windshield Wing Nut - Chrome - Original Type - Ford Open Car" for $4.46 ea. SpeedwayMotors.com has "Standard Windshield Wingnut, Chrome" for $5.99 ea. Both are 3/8"-24 thread, chrome-plated brass. My top bow clamp wanted 5/16"-24, but a 5/16-24 helicoil can directly wind into a 3/8-24 nut--don't even need a tap.  I threaded and soldered the larger wingnut, from Mac's, onto the top of a sawed-off 5/16 bolt to make the wing bolt, and shaved the head off of the smaller wingnut, from Speedway, to make the locking wingnut.

I know that most viewers on this site have greater fabrication skills and higher standards that this, but it's a convenient stop-gap--in case all you have are hideous 'regular machine bolts' doing the job.

Cheers

 

[F&J]

There never was a solid "soffit board".     What was there is more identical top material on the underside to block the wind and rain.  It covered those sockets too.   That material is held to the top of the windshield frame with lift-the-dots.  Then the 2 hole oval thin aluminum plate protects that material from being torn when the top is lowered onto the posts.

 

And yes, they always had the locking wingnut.  Even then, they sometimes loosen as the body twists, and with normal wear on the posts and tip of the main wing bolt.