Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks



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Shade Tree Mechanic
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I've been poking around on line for a good front shock conversion kit for my 37 coupe and have found lots of rear conversion kits but nothing for the front. Or should I say, what I HAVE found looks to be either a welded assembly OR what information that is given for these kits are so vague that I'm really reluctant to place an order.

But let me be clear. I'm looking for a bolt on application. From everything that I can see, it shouldn't be difficult at all to design an upper shock mount that bolts nicely into the existing knee action shock holes and equally mount the lower shock into the preexisting holes that the original strut mounts into. So why isn't anyone offering one?

I know I can (in desperation) design my own shock upgrade. I can do the research on applicable shocks and put a good working design together. I was just hoping not to have to.

Any input would be appreciated.

Last edited by Skidplate; 02/19/24 08:50 PM.
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I assume that you are talking about a Master with a straight axle and leaf springs.

It was been a few years since I bought the conversion kit for mine. Pete and Jake’s Hot Rod parts in Missouri bought the design of that kit when Chassis Engineering in West Branch, Iowa sold their business and closed shop.

I was lucky that Pete and Jake’s still had one lying around. I did need to have longer u-bolts made at a local spring shop.

They are still in business so I would give them a call.


Rusty

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Shade Tree Mechanic
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So what's the deal? It doesn't seem like the demand would be completely nonexistent. Rears are available but not fronts. Go figure.

Thanks for the reply.

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Typically the complete front end is replaced with an IFS sub-assembly with rack and pinion steering when one of these cars is converted into a hot rod. Very few hot-rodders want the poor ride and handling of a straight front axle.

The rear shock conversion will work with many different open drive shaft rear axles. So there is a lot more demand for the rear conversion.


Rusty

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Lou Offline
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. Here's a web page on Knee Action DuBonnet front suspension. <http://home.znet.com/r1937/Knees.htm> . If you fit tube shocks that clear the tire and tie rods, your turning radius is reduced. . Good luck, Lou .
. .
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I used 39 tube shock mounts to convert my 38. There is welding required because the provisions for the upper are not there on a 38 Master frame. The photos below are not on my car. These are the mounts I purchased and are on the 39 they were removed from. The seller sent these pictures to me.

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002.jpg 003.jpg 009.jpg 011.jpg shock brkt 001.jpg

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1938 HB Business Coupe
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Shade Tree Mechanic
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I looked around where the existing shock strut mounts to the axle. Not sure about the hole size but it seems a modern shock (with the straight threaded shaft) on the bottom would bolt right down into that hole. And there is bunches of room straight up from that hole for the shock and upper bracket to reside. Bolt it to the existing knee shock holes. Form it up to where you want the top of the shock to reside. Easy Peezy right?

I'm thinking the only real issue is to find one of the shock manufacturers that offers a shock with the lower end just a polished rod. This would allow for the clearance needed between the frame and the steering linkage right around where it bolts to the axle... as it is kinda tight right around there.

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I considered the approach that you described. Yes, the first challenge is finding a shock that is designed to work with the rod down.

The real challenge is finding one that has the compressed and extended length for that position.

While it is a minor point, getting one with the style and size of end connections you need can be tricky.

And don’t forget that it needs the proper damping rate for the weight of the car and the spring rates.

Last edited by Rusty 37 Master; 02/20/24 11:35 PM. Reason: More info

Rusty

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If I remember correctly operating length is the limitation with a shock mounted where he is considering.

The compressed length was a small number like 8” and extended it had to be 18” or some number like that.


Rusty

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Shade Tree Mechanic
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I just finished wiring in all new stop/blinker/marker lights and had a free day so I decided to kinda readdress the shocks that are on it now. The car's still up on stands so now's as good a time as any. And I can't really tell if they're leaking because of the earlier top off adventure. I'm really not sure yet bet they may actually be in reasonable working order. I had topped them all off when I first brought the car home but that was it and did nothing really extensive since. So today I pulled them all off and washed them out with cleaning solvent. Pumped them out and back in a few times then out really good. Even blew out the remaining moisture with air. Then I filled them all with clean motorcycle fork oil. Not sure if that was good or bad but I'm kind of a research and develop kind of guy anyway, so what the heck. Put them all back on and we'll see how they work.

We know the rears can be upgraded pretty easily. And the fronts also maybe NOT so easily. I'll run these first and see how it goes. We might be addressing this all again sooner or later. Guess we'll see.

Thanks everyone for the inputs. Cheers

Last edited by Skidplate; 02/21/24 08:12 PM.
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Hydraulic jack oil works well in shocks.


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Shade Tree Mechanic
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Oow. Good to know. Thanks

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. Here's a photo of the 37 Standard (GB) shock absorber. It is single action and only slows the rebound. After 80+ years, the bushings and pistons and valves inside wear out and oil leaks causing their demise. I haven't seen an ad for rebuilder for several years. .
. .
.

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And holding it in my hand I know that it indeed only dampens in one direction... on the best of days.

Last edited by Skidplate; 02/22/24 04:41 PM.
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It is a single acting shock by design. Check your shop manual.

The primary failure mode is that the seals get hard and wear a groove in the shaft. So adding new fluid works for a short while.

Apply Hydraulics in New York will rebuild them. The major cost is due to the fact that they need to spray weld the shaft and re-machine/polish it so a seal will work on it.


Rusty

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