Wheel compatability

[thebeebe5]

I'm of the understanding that a 16" wheel would have been original on my '37 P4.  Currently have a full 5 set of 15" wheels and mismatched tires.  Wheels have seen better days being rather rusty on the back side and with some definite bends (but not too bad!) on the inside only. Is it correct that these 15s are incorrect?   Wondering if bolt patterns or wheel design changed a great deal from 1937 to about 1950's or so in order that I might start to locate replacements.  I'm not in a panic about correct wheel size, but just want options for replacements.  If 16s came on it I ought to be able to go with either the 15s or 16s.  Basically, what are my options for swapping other rims onto my 37?

[Andydodge]

My understanding is that mopar went to 15" rims in the late 40's  and 16" started about 1935/36......as for the bolt pattern Frod started using the Mopar 4.5 in 5 stud bolt pattern in 1949 so that may help, also some Volvo and Toyota use the Mopar/Ford pattern......I assume you know Mopars used left/right threaded bolts into the brake drum and had a locating rivet or pin which will need to be removed if you decide to use non mopar rims.......not sure when mopar deleted the L/R hand thread and locating pin tho'.............no doubt others will chime in with this info..........my 41 Plymouth came with the stock 16"rims and I got a set of Wheel Vintique Chrome Smoothies with the Ford/Chev multi pattern, just had to remove the locating pin and even used the stock L/R bolts........but I'm a hotrodder so its o/k..........lol...............andyd    

[greg g]

I believe bobge Plymouth rims were the same as far as width, and back spacing until the 53 models came out. These were more closely designed like steel wheels we rember through to 70"s or so. The back space measurement is pretty critical on these cars as the rear leaf springs are mounted pretty far to the outside of the axle. Too much back space will allow the tire to rub on the spring. I also run 15 inch wheelvintique rims. These are 5 inches wide with a 4 inch back space. Your original tires were likely 6.00 x 16 with a diameter of 27.8 inches. Your selection of tires for the rear should closely align with that diameter to keep your speedo in the same neighborhood, speed wise. I am running 215 75.s but your rear fenders may dictate a different choice. I switched because it seemed the choice of 16 inchvtires available locally were either the tuner car rubber bands or trust tires. While on the subject of truck tires I did run into a fellow that has equipped his 39 Plymouth with tires from the rear of an early GM pickup with the dually rear set up. They are like a 205 90 16 so they retain the look of a borrower tire more in the period of the car.

[Plymouthy Adams]

International P'up truck and Volvo are also places to look for skinny rims if your in the market for them...also there are an abundance of late model 4.5 width  x 16 rims out there in the junkyards just waiting be to be picked up and bought..also 4.5 bolt pattern and alloy but that may not be for everyone..

 

as for measuring your rims...backset and offset deine the same thing only expressed differently...offset is based on rim bead width with neutral being the mounting surface as dead center of the rim's beads...positive offset sets this surface toward the outside of the rim allowing you to push the wheel further inward nearer the leaf springs if you will while the negative moves this mounting surface inboard allowing the wheel to be further toward the fender lip....the backset will be the distance of the rims inside wheel bead lip to that of the mounting surface of the wheel..most wheels are spec'ed in offset and usually in mm today...the mm number will have a +/- denoting relationship to centerline.  Modern wheels are largely positive offset and that is not much good to a stock axle in these cars

[TodFitch]

My understanding is that mopar went to 15" rims in the late 40's  and 16" started about 1935/36......

...I assume you know Mopars used left/right threaded bolts into the brake drum and had a locating rivet or pin which will need to be removed if you decide to use non mopar rims.......not sure when mopar deleted the L/R hand thread and locating pin tho'.......

16" "Air Wheels" were optional in 1933 for Plymouth (these were actually wood spoked wheels). Steel "artillery style" 16" wheels were standard on the '34 PE (DeLuxe) models. So the 16" wheels predate 1935.

 

Chrysler, in their infinite wisdom, went back and forth between using left hand threads a couple of times. Some of the early 4 cylinder cars used left hand studs and nuts while my '33 and later 1930s cars used right hand thread bolts all around. From the parts book it looks like the left hand bolts came in to use in 1940 so I think the OP's '37 P4 probably has right hand bolts all around.

 

Likewise, not all Plymouth hubs had locating pins. Mine does not. I don't see any indication of what models had that or not in the parts book. That could be a later 1940s thing as well.

 

Edit: I see a "wheel hub pilot rivet" listed in the '36-48 parts book which I think is the locating pin. It shows that going back to '36 so there probably is a locating pin on the '37 P4.

[thebeebe5]

Okay, all great information. I'm looking for 4inch backspace (or thereabouts) 4.5"x5 pattern and dodge/plymouth wheels should accomodate the "bumps" or locating rivets I see on my brake drum/hubs. That was something I noticed last weekend, but it didn't occur to me that it was something to watch out for on replacements. I want to retain a stock look and keep my caps too.

Here's what I have now....

The top is the only wheel that was butchered around the center, but each if mine has something that was torched out in a single spot at the center oddly enough.... The 235/75/15 are right at 27 3/4" tall and speedo is spot-on with GPS.

Edited June 8, 2015 by thebeebe5

[pflaming]

Question: Wouldn't torching that circle weaken the rim?

[Plymouthy Adams]

that rim is no longer centric mounted is all...

Edited June 8, 2015 by Plymouthy Adams

[thebeebe5]

Question: Wouldn't torching that circle weaken the rim?

I don't believe so. It's still held on by five bolts. Like Mr. Adams said, it is no longer indexed to the hub by the center of the wheel. A non-issue once all the lug bolts are installed.

[james curl]

It is obvious that those wheels were made for a car with a smaller OD hub.  Now all of the weight and forces are on the lug bolts which probably not designed to carry loads that high by themselves.  I would be looking for the proper fit wheels even if I had to have them custom made.

[thebeebe5]

It is obvious that those wheels were made for a car with a smaller OD hub. Now all of the weight and forces are on the lug bolts which probably not designed to carry loads that high by themselves. I would be looking for the proper fit wheels even if I had to have them custom made.

It's just the one wheel that someone torched the center out of... And I'm looking, I'm looking! ;-) Edited June 8, 2015 by thebeebe5

[T120]

This is a photo of a stock 37 Chrysler 16 " rim

 

[thebeebe5]

Thanks Ralph. Do these wheels have date stamps on them anywhere...?

[TodFitch]

I don't believe so. It's still held on by five bolts. Like Mr. Adams said, it is no longer indexed to the hub by the center of the wheel. A non-issue once all the lug bolts are installed.

Looking at the wheel/hub interface on both my '33 Plymouth and 2004 Prius it seems that the vertical load from the wheel to the hub is through the relatively tight fit of the wheel center onto a seat on the hub. If they weren't worried about it, why would they make it such a close fit that they have to do extra machining?

 

The wheel lug bolts or lug nuts appear to be to clamp the wheel to the hub and to transfer rotational forces (acceleration/braking), not to actually support the weight of the vehicle.

[JD luxury liner]

AKH vintage wheels is located in WA  

a little expensive but their web site shows a lot of mopar wheels, sizes & styles. If nothing else good info on stock wheels. JD

[thebeebe5]

Looking at the wheel/hub interface on both my '33 Plymouth and 2004 Prius it seems that the vertical load from the wheel to the hub is through the relatively tight fit of the wheel center onto a seat on the hub. If they weren't worried about it, why would they make it such a close fit that they have to do extra machining?

 

The wheel lug bolts or lug nuts appear to be to clamp the wheel to the hub and to transfer rotational forces (acceleration/braking), not to actually support the weight of the vehicle.

Could be right, Tod.  At any rate I'm definitely looking for replacements.  Found some on another forum. Just need to get an appointment with the gentleman and plan a road trip. 

[T120]

Thanks Ralph. Do these wheels have date stamps on them anywhere...?

Nothing that I could see that is legible... You may choose to go with 15" rims. As well as the proper bolt pattern,you would probably also want the clips for the original hubcaps and holes for the locating pin on those rims.If possible buy as a set.