Subject: Packard Street Rod Springs
The following is a reprint of email correspondence between Wade Davis, who owns a 1937 Packard 120 convertible and William M Jones, Jr., who was rebuilding a wrecked 1941 Packard 110 convertible. If you would like to contribute information to this page, please email Wade Davis. See Contact Us on the home page.
Bill Jones wrote:
I noticed in the information about your car that you have a Fatman Fabrication subframe on your ’37. What springs did you use? Fatman sent me V8 springs and the rack and pinion arms that attach to the spindles make me think that I need six cylinder springs. In order for these arms to be parallel with the crossmember leads me to believe I need the weaker springs. Your car is a 120 and mine is a 110 model. My ’41 120 has a 127 inch wheel base where my 110 has a six inch shorter wheel base.
What is the wheel base of your ’37?
What springs do you use in the rear?
Wade Davis replied: Bill, I am not an expert on suspension and springs but I will give you the short answers to your questions based on my experience with my ’37. I would like to expand this conversation and put it on our website. This is exactly what I envision the PSRA being all about. My ’37 is a 120 series, which means it is 120 inch wheelbase. I don’t know if this carried over until 1941 or not, but the original series of 110, 115, 120, referred to wheelbase, with the 120 being 8 cylinder and 110 or 115 being the 6 cylinder.
Fatman Fabrication set up my car with his subframe, Mustang front suspension, motor mounts, transmission mounts, and 9 inch Ford rear end with the original leaf springs. Fatman used V-8 front springs and after I added the engine, transmission and all the weight I could pile on, the car was still too high. We changed the springs to 6 cylinder springs, which let the car sit lower and should give a softer ride.
Everything was great for a year or two. Then the weight of the car on the softer 6 cylinder springs began to sag. The arms were no longer parallel and the front was too low.
An Eaton-Detroit Spring representative looked at my car at the NSRA show in Richmond, Va. Knowing the final weight of the car, including the weight at each wheel, they sold me the correct spring for the car. I also changed to dropped spindles. The new springs ride a little too tall, but Eaton warned me that new springs will sag some, an inch or two in ride height. So you have got to install springs that are strong enough for the weight of your car, but too tall, to allow for sag over time. And you may still have to cut the spring to a shorter length to get the proper ride height. But remember that the length that you cut out of the spring will drop the car ride height about twice that amount. It’s all about geometry and Fatman will have to explain that.
Bill, if I were starting all over, I think I would install coil-over shocks and springs. These are more adjustable and easier to change than the coil springs. I have another street rod, a 1941 Chevrolet, that has a Chassis Engineering bolt-in front crossmember with Mustang suspension and adjusters on the top spring mount housing. This was really handy in getting the correct ride height without having to take out the springs and cut them.
The rear leaf springs is another story. Fatman did not change them, but I replaced the shackle bolts, and broke a spring eye. Ended up replacing the main leaf with new ones with new bushings. All of these parts were available from Eaton-Detroit Spring. I will dig through my old paper work and see if I can find additional information that may help explain some of this. Hope this helps. Good luck. Wade Davis, PSRA.
Willie Jones wrote:
Thanks for the info. Your 120 had the same wheel base as my 110. Don’t know when they went to the longer wheel base for the 120. It looks to me like I should leave the V8 springs in it for now and see what happens after they drop a little from age. I have a set of new six cylinder springs from Fatman but have been leary of putting them in for the same reason you had. They sag over time and I would have to change them.
From info you provided one would think I should consider doing what you did. I am also using the stock Packard rear springs, only 110. I ended up with another set of rear springs from my parts car. Both were 110 1941 cars. The set out of the parts car had less sag than the original springs from the convertible. I checked rear ride height of both chassis with no body and one set was about 2 to 2 1/2 inches higher than the other. I used the stronger ones. I am Also using a 9 inch Ford.
My 110 is six inches shorter from the firewall forward than my 120 car. The bodies are the same. The frame of the 110 is also six inches shorter than the frame of the 120. I almost tried to find a 120 frame and 120 sheet metal. The longer car is more majestic than the shorter one. Max Merritt told me 110 sheet metal was easier to find than 120 sheet metal. The 110 will be just fine as a street rod.
My LS engine is cast iron block with aluminum heads and aluminum intake. What heads do you have? I am trying to figure out if the engines weigh the same or not.
Fatman’s tie rod ends are longer than stock Mustang II by one inch. Changing these would bring the alignment within one inch of being parallel with the ground. Over time the V8 springs should settle about one inch putting everything where it should be.
I agree this type of dialogue between members should be posted on your website. Stay in touch. It is good to converse with other people who see the merit of a Packard street rod.