Front coil springs

[Mark Haymond]

I replaced the front coil springs on my 1947 Plymouth Club Coupe. After installing a Mopar 318 V8 engine the extra weight on the 65 year old stock coils pushed the car down near the bottom control arm bumpers. The car would bottom out alarmingly on moderate road undulations and potholes. An friend of a friend gave me some mystery coils he was never going to use. I have no idea what car they were used in but they were NOS, in the box, and the numbers on the Mopar labels were 71765 and 52039056. The price was right so I tried them out. To my surprise they were the same diameter and height as the stock ones, but seemed stiffer that the old ones. After installing the new springs the car sits at least two inches higher and the ride is much improved.

I lost the low stance that I liked. I may go do some follow up work and cut a coil off both springs to get a little lower. I think the stiffness of the springs will prevent bottoming out even if I lower it a bit. I'll try posting photos.

[ntxcustoms]

Just bought me a set of Moog-cc840 springs from O'reilly. They are progressive rate and ride well, many guys use them on their shoeboxes but they are supposed to be a sure fit on Dodges and Plymouths. I plan to install mine tomorrow. I moved my spring plates to the bottom of the arms and with these springs it should bring the nose down a bunch. I'll post a pic of how it sits when they're in. Also running a 318...Tyler

[Andydodge]

As far as I know all Plymouth front springs 1939 up to 1956 are the same diameter although the 55/56 versions should be a little stiffer simply because of the V8 option............or maybe not......lol.........I have a pair of front springs supposedly from a 1956 Ford Customline that a mate had and I have had them in the 1940 Oz Dodge(US Plymouth chassis) for about 30 yrs.........work fine..........andyd.  

[fstfish66]

subscribed

[Mark Haymond]

Coil spring followup. The stiffer springs I installed gave the car a nose-in-the-air look. Front bumper was higher than stock height. The rear view mirror showed me what the pavement looked like behind the car but I could not see traffic very far back. Yesterday I cut one coil off the springs. It was one and a half inches of spring height measured on the work bench. It lowered the stance of the vehicle to a nice level look front to rear, and it does not bottom out. It took me four hours but part of that was a lunch break. It looks good now, does not bottom out, and I may just keep it this way.

[coletrain777]

Great thread... good solution for v8 guys for sure.  Thanks for the info!

[greg g]

I believe some one mentioned that Ford Aerostar springs are a good choice as they are a bit shorter and a bit firmer than stock springs.  Apparently still generally available and inexpensive also.   Also I think that it has been mentioned here before that the V8 engines and transmissions were actually marginally lighter that the flat head 6.

 

 

for example

 

http://www.thepartsbin.com/catalog/?N=9408&Nr=OR%28AND%28make:Ford,model:Aerostar,year:1990%29,AND%28universal:1%29%29&Vi=1616+10352+4294963736&y=1990&mk=Ford&md=Aerostar

[fstfish66]

I believe some one mentioned that Ford Aerostar springs are a good choice as they are a bit shorter and a bit firmer than stock springs.  Apparently still generally available and inexpensive also.   Also I think that it has been mentioned here before that the V8 engines and transmissions were actually marginally lighter that the flat head 6.

 

 

for example

 

http://www.thepartsbin.com/catalog/?N=9408&Nr=OR%28AND%28make:Ford,model:Aerostar,year:1990%29,AND%28universal:1%29%29&Vi=1616+10352+4294963736&y=1990&mk=Ford&md=Aerostar

ford aerostar springs sounds intresting,and certian year ?

[coletrain777]

It gets better... The same springs that greg g linked to on partsbin.com ($66.18) are only $42.79 (plus shipping) at rockauto.com.  I looked them up for a 1993 Aerostar with a 4.0 V6, they are the same Moog CC850. 

[Greg F]

Hey Mark,

Does that 318 v8 drop into our Plymouths without to many modifications? Just wondering..

Thx Greg

[Mark Haymond]

Greg F, there are always modifications. The basics are cutting out the transmission cross member, welding new motor mounts, tranny mounts, cutting the fender wells for V8 clearance, off setting the motor to the passenger side maybe two inches to clear the steering tube, moving the radiator forward to clear the front of the engine. It is not a big engine, so I did not have to modify the firewall. I chose a floor shift for the 727 automatic to keep the shift linkage simple. Used the original steering tube and steering wheel, original gas pedal linkage, running original gauges. The gas gauge and horns work fine with 12 volts. I told my wife I would be done in six weeks. The project sat in the corner of the garage for a few years until I finished the job last May.

[greg g]

There are specs on the MOOG page for the springs, check the measurments and rates before ordering.  I was hoping the folks who did the original post would jump in for verification, so without that check check check.

 

Coil Spring Dimensions

End 1 Type End 2 Type Inside Diameter Bar Diameter Install Height Load Spring Rate Free Height Square Tangential 4.070 0.750 8.75 1825 605 11.65 MOOG-CC850 fitment:

Select your car from the list below to see other parts that fit your vehicle.

 

[bamfordsgarage]

Now, does anyone have a line on some cheap rear springs??

 

I could give you a helluva deal on these... (Full disclosure, the other side not as good)

Edited February 18, 2013 by bamfordsgarage

[pflaming]

Why do the car springs break, yet not so often the truck ones. I had a '50 plymouth and the rear springs broke on that and the car was only 8 years old at the time, my convertible project has a broken spirng also.

[TodFitch]

Why do the car springs break, yet not so often the truck ones. I had a '50 plymouth and the rear springs broke on that and the car was only 8 years old at the time, my convertible project has a broken spirng also.

 

It is my understanding that leaf springs break by being twisted. This can happen when one side of the axle bounces or rebounds more than the other.

[ptwothree]

I could give you a helluva deal on these... (Full disclosure, the other side not as good)

They look to be out of my price range...but let's see...Maybe.some JB Weld and some hose clamps.................I'll let cha know!!

[pflaming]

" . . . breaks by twisting". When the springs on my '50 Plymouth broke, one side went and them the other side, so the twisting makes sense. Could driving for some time with one bad shock be one cause?

[fstfish66]

It gets better... The same springs that greg g linked to on partsbin.com ($66.18) are only $42.79 (plus shipping) at rockauto.com.  I looked them up for a 1993 Aerostar with a 4.0 V6, they are the same Moog CC850. 

great info  thanks,,, do  you know  what the ride height would be compared to stok springs with the aero springs?

[50desotocoupe]

I put the Aerostar springs on my Desoto...it lowered it a few inches but rode on the bump stops.  I sent them back to the company and cut 1 1/2 coils. 

[plyroadking]

I put the Aerostar springs on my Desoto...it lowered it a few inches but rode on the bump stops.  I sent them back to the company and cut 1 1/2 coils. 

It lowered the car and rode on the bump stops? And then they cut 1.5 coils off? Wouldn't that lower it even more?

My '40 Ply has tired coils and im very interested in learning about returning to the stock height

[50desotocoupe]

Sorry, I meant that I took the Aerostar springs out and then cut 1 1/2 coils off the stock springs.  I haven't put it back on the ground yet.....it is a "while you are in there" project...new tie rods, shocks, etc...

[OldDad67]

What is the weight of a Mopar 318? I'm installing a Chev 327 which is a bunch lighter than the old Mopar 6. I did not have to move my radiator foward since the engine is shorter than the Mopar.

[Daliant.]

A 318 weighs in at about 525 lbs

[greg g]

here is a guy you can talk to about the Aerostar springs.

 

http://www.jalopyjournal.com/forum/showthread.php?t=806902

[James_Douglas]

Can you read the part number on the end of the Desoto Springs? (the last number is a series of chisel marks not a Latin number)

 

If so, would you tell me the free height, number of turns, and diameter (using a caliper) on the spring?

 

I am trying to deal with a 1949-1950 Desoto spring issue and I need to compare some coil springs.

 

Thanks, James

 

 

Sorry, I meant that I took the Aerostar springs out and then cut 1 1/2 coils off the stock springs.  I haven't put it back on the ground yet.....it is a "while you are in there" project...new tie rods, shocks, etc...