37 Plymouth 4D Sedan Rear Shock Replacement

[cturboaddict]

I'm in the process of swapping an Explorer rear end into my 37 Plymouth project. While I was getting pinion angle set today and welding on the new axle pads, I figured I should probably grab some shocks seeing that the bushings are worn out on these old ones. I'll be making new U bolt pads and a shock mount in the same general location. 
Is there a factory shock available that is the proper length for the factory 37 Ply shocks? I'm sure the Autozone kid that asks me if my car is 4wheel drive or not for windshield wipers isn't going to have any clue. 

[Plymouthy Adams]

if you making the mounts, placing them in the same position...use stock application....you can probably get the shock number from the online Rock Auto, local big box and or cross your number on your present shock...if all else fails, the Monroe site will get you on the right track...

[cturboaddict]

32 minutes ago, Plymouthy Adams said:

if you making the mounts, placing them in the same position...use stock application....you can probably get the shock number from the online Rock Auto, local big box and or cross your number on your present shock...if all else fails, the Monroe site will get you on the right track...

I plan to place the shock mount in the same location. The diameter of the axle is larger on the Explorer rear, so I just need to spread the bolt holes out. I'll fab them the same as the originals, although I'll have to look at shoulder bolts. Hence, why I wanted to get new shocks now for the fab of the part. 

 

There's nothing on Rock Auto for suspension. 
Monroe's website only goes to 1939 P8 Deluxe, and only shows front shocks.

Advance Auto part, only goes to 1942.
Autozone shows no shocks at all.
Oreily's only goes to 1940 P10 Deluxe. (And doesn't list any parts)

No markings on shocks, or they're rusted over? 

 

It's a pretty standard looking shock. 

This was the only thing I found on Ebay.
https://www.ebay.com/itm/1937-1938-Plymouth-Dodge-Shock-Absorber-Set-Includes-All-Four-Shocks-/181931862234

 

[cturboaddict]

I guess I could always compress/extend the old one for shock travel and try and find a match? 

[Plymouthy Adams]

yes...the shocks are sold by compressed, extended and shock end mounting styles.....along with other build qualities....gas, air etc etc...again, the Monroe site should be of help....seems more and more parts suppliers are inching their way upward in parts covered instead of retain their old parts applications online...did not mean to mislead  you on this....

 

this I think has been on this forum before and I think a quick search should net a set of numbers that would be quite at home....else....maybe a brother in ownership can chime in...

Edited December 1, 2018 by Plymouthy Adams

[DJ194950]

I used the Monroe online catalog to find the Monroe of the length I needed for my 50 Plymouth (using the closest available) then shopped Ebay,Amazon ,web search for that shock number and ended with the ones I was looking for at $24 a pair shipped free!

Use the catalog unless somewhere on the forum has already done the looking for you.

 

Happy hunting!

 

DJ

[desoto1939]

I have an old delco shock catalog and did some looking and the rear shock is the same that was used on the Desoto, Chrys, Dodge and Plymouth from 37 and up.  so knowing this the same Monroe shock 3100 which is a rear shock will work for your car.

 

Rich Hartung

desoto1939@aol.com

[cturboaddict]

2 hours ago, desoto1939 said:

I have an old delco shock catalog and did some looking and the rear shock is the same that was used on the Desoto, Chrys, Dodge and Plymouth from 37 and up.  so knowing this the same Monroe shock 3100 which is a rear shock will work for your car.

 

Rich Hartung

desoto1939@aol.com

Gotcha, the monroe site had the 39 rear listed as the 3000. But mines a 37. 

I'll double check it with the length of the ones that are on the car before I order.

 

Correction, it says 31000 as well. My apologies. 

Edited December 2, 2018 by cturboaddict
correction

[greg g]

It has been noted here before that Mopar A body shocks are a good replacement if the originals are not available.

[cturboaddict]

So digging through this.... Just a little information for everyone.
Please keep in mind, that the rear shocks that are currently on my 1937 Plymouth P4 Sedan Deluxe may or MAY NOT be the original. 

I cleaned the shock off and did some measuring and made some discovery. 

Extended Length= 22.5"

Compressed Length= 13.625"

Travel Length= 8.875"

Approx width at eyelet top/bottom (including bushings, which are shot)= 1.5"

Approx inside diameter of eyelet= 11/16" (Mounting shaft is 5/8" diameter)

Mounting shaft smooth length (where its inside the shock bushing)= 1.25"

 

I did find some info on my shocks, after wire brushing the surface like an archaeologist looking for fossils. 

Heavy Duty

48040

Made in USA

OBA 

 

The Mopar A bodies used 2 different styles of rear shocks the Monroe 31131 and the Monroe 32073.
And the 39 Plymouth used the 31000

 

Neither the Monroe

31000= compressed length is shorter, extended length is shorter, travel length is shorter, and loop bushings are 5/8" ID. (Don't like a 5/8 shaft inside a 5/8 ID, probably wont fit)

31131= compressed length is longer, extended length is longer, travel length is longer, loop bushings seem to be correct.  

32073=  compressed length is correct, extended length is correct, travel length is correct, loop bushings top only is incorrect/small as it has a sleeve and a 12mm ID (.472")

 

So, I'm sort of torn here on what to do. 
Do I go with the 31131 and hope for the best? Or do I go with the 32073 and refab the upper mount. 
Pic below for the mounting bolts, Upper is the super long one as it bolts through the frame. Does anyone know where to find these? I've seen what looks alot like the lower shorter mount on universal shock mount kits like this one. 

https://www.amazon.com/JKS-OGS922-Weld-Universal-Shock/dp/B005TTZX9A/ref=sr_1_7?s=automotive&ie=UTF8&qid=1543771244&sr=1-7&keywords=Universal+rear+shock+mount

 

 

 

[cturboaddict]

Probably want to make a clarification on the 31000, the bushing ID is 5/8" which should fit a 5/8" shaft. If it's not sleeved, it should go right in with some minor persuasion. 

[cturboaddict]

And I found the lower mounts on Speedway. 
https://www.speedwaymotors.com/Speedway-Universal-Tube-Shock-Mount-Stud-Bolt,5485.html

[cturboaddict]

Using the Monroe Shock Chart PDF here.
http://www.monroe.com/downloads/install-instructions-guides/MonroeMountingLengthSpecifications.pdf

I found that the closest two my shocks would be the 

Monroe 33181 Closed 14", Extended 22.5", Travel 8.5" (Side note, this is the same shock for a Nissan Xterra 00-04)

Monroe 34802 Closed 14", Extended 22.75", Travel 8.75"

 

Both using the L1 style connector (Which is a 5/8" bushing type).
I found RockAuto had the best pricing next to Amazon. But I needed some other parts for the rear, so I went with Rock Auto. 
 

[38plymouth]

I went through this a year or 2 ago with my 38 4 door. I got mine from napa and used the original shock dimensions and found an almost perfect fit. They work great so far. I looked and cant find the thread I had on here with the part number. Maybe someone smarter than me can find the old thread, it seems like anything older than a year is gone.

 

Edit.....I found it, napa part # 94050, from a 1985 ram charger. I had to use the stock bushings and cut the new bushings out.

Edited December 2, 2018 by 38plymouth

[greg g]

Unless you are boogieing down a rough gravel road with a load of moon shine in the trunk with three people in the back seat it is pretty difficult to bottom out the rear of the car.  Using the car on smooth roads with the grand kids in the back seat surely isn't stressing the rear suspension. With that said an inch or so of travel at either end will probably never be an issue the way your car is being used today.

[cturboaddict]

Thanks guys. Appreciate the help! I'll try and salvage the upper bolts if possible. Unless someone knows where to get them? They look very similar to the lower bolts with just an extension to get through the frame....

[Robert Horne]

On ‎12‎/‎2‎/‎2018 at 3:52 PM, 38plymouth said:

I went through this a year or 2 ago with my 38 4 door. I got mine from napa and used the original shock dimensions and found an almost perfect fit. They work great so far. I looked and cant find the thread I had on here with the part number. Maybe someone smarter than me can find the old thread, it seems like anything older than a year is gone.

 

Edit.....I found it, napa part # 94050, from a 1985 ram charger. I had to use the stock bushings and cut the new bushings out.

 

On my 38 Coupe shocks, I used Monroes , mid 80s mid size dodge car.....

[Young Ed]

On 12/3/2018 at 6:39 AM, cturboaddict said:

Thanks guys. Appreciate the help! I'll try and salvage the upper bolts if possible. Unless someone knows where to get them? They look very similar to the lower bolts with just an extension to get through the frame....

The 39-47 trucks use a very similar looking rear upper mount. They are available new from DCM in michigan. I'd give them a call and see if they will measure for you.