why do some guys use a model t spring instead of a model a? i'm building an A with a quickchange. would the t be better? what are some dimensions?
I think it's just what you have or don't have. It's all going to depend on how you build the frame, you could even use a 39-46 front spring in the rear... or elipticals. take whatcha got and make it work!
The T spring will go in the same place as the A spring. The T spring IS NOT under pressure like an A spring. The T spring sits the car 2" lower than an A spring. The later front spring mentioned earlier WILL NOT allow the quickchange enough room to travel ...
When you install a model "A" spring, you need a spring spreader to spread out the spring to attach the shackles. On the '26~'27 "T" spring, The spring is made wide so all you do is install it right to the shackles.... Just like a front spring. I just went thru all this with the 2 different springs on My Daughters '27 "T" roadster pick up on an "A" frame. Did the "T" spring first, Truck was to low, So went with the "A" spring........ raised the back about 2 inches
A Model T spring should require either a spring spreader or blocks under the eyes to install it. It is "under pressure". You may not be able to read it in the scan, but it says, "A spring spreader can be used to facilitate entering perches through holes in flanges or two blocks can used as shown in Fig. 366."
Is the difference because the "T" spring is narrower or that it just doesn't have the stiffness of an "A" spring or is there less arch in the "T"? I know you always hear drop dimensions in swapping parts and I had heard 1 1/2" to 2 1/2" drop by swapping a "B"front axle for your "A" but on my RPU it dropped the front 1 3/4" with a stock spring. I'm asking because I want to drop the rear a little more than what I have with a reversed eye main leaf rear. I have a "T" spring laying out there somewhere.
The "T" spring has less arch than the "A" spring. The "T" spring i mounted in my car & the "T" spring i just removed from a 1926 "T" frame both went in & out WITHOUT a spring spreader or jack or anything. When you set the "T" spring next to an "A" spring you will notice the "T" spring is much wider when removed from the car. Hence, no need for a spring spreader .... I see what it says there in yer book, But i just did it and it needs no spreader, had perfect shackle angle & functioned fine. The '26~'27 "T" spring was good for 2 inch drop in the Roadster we are building. Used a stock "A" frame & cross member with a '26~'27 "T" spring on a '40 Ford axle
T spring will need a spreader. They also are really soft. Most of us running T springs here have tweaked the spring pack (added leaves)to get em stiffer.
If you are using the T spring where a narrower spring originally was, then sure you may not need a spreader. But that is the wrong spring to use in that application, unless you change to shorter shackles. The spring needs to be under tension.
On the ground, the T rear spring is about 4-5" lower than the A spring. However,when mounted, the A spring gets spread out more so its height changes quite a bit. There are two types of T springs-the 1926-27 version has a higher arch (and one more leaf). A T spring will make your car sit quite a bit lower than the standard A spring, and even a bit lower than an A spring with a reversed eye. All these facts become a little more confusing because there were a couple of different height A springs made (sedan, coupe, pickup, roadster, etc) and some As sit low because their springs are worn out, so when they are replaced with a new reversed eye A or good T rear spring, the stance doesn't change. Probably the best solution for getting an A lowered is an 8 leaf T spring (pre-1926) with a reversed eye and maybe a leaf or two removed-especially on a light car like a roadster. Heavier cars might not ride well with removed leafs. At the end of the day, it all become a trial and error approach!!!!!!!!!!!!!-GZ
The Model A rear spring perches are center eye to center eye 49.5". The Model T rear spring perches are center eye to center eye 48.5". Both have shackles that are in length 1.5" center to center but sized differently. So, whatever the at rest spring eye to eye measurement is, it must be spread to 46.5 for a Model A rear spring mount and 45.5" for a Model T rear spring mount. The only Model A spring that resembles the T springs is the Roadster rear spring which, back when, was the most desireable A spring ever. These days no one even knows what I'm talking about. When removing spring leaves, the rule of thumb is keep the main leaf(duh!) and second leaf and remove the odd-numbered leaves as required to achieve the ride quality you are seeking. A coupe or roadster will usually end up with 5-9 leaves out of the 12-15 you start with. The most desireable T rear springs are the very early 13-14 tapered leaf springs. The leaves are are actually tapered to a thin edge at the ends rather than just the ends being taper cut and unitform thickness throughout.
So, If I want to put a T spring in a Stock A coupe (to lower the back) will I have to make some sort of "shim" in the crossmemebr because the T spring is narrower, or once it's clamped with U-bolts should it stay put? Or does this just sound stupid
No, not stupid at all. It is actually a very good and pertinent question. I don't really know the answer, and look forward to hearing from others. I have always assumed that some sort of shim was necessary for safety, but have seen plenty of A's using T springs without any type of shim.
GZ, don't you have that backward? Don't the early springs have a higher arch? I've never compared side by side, but have thought that was the case since the 26/27 T was about 1 1/2 inches lower than the previous years. That was accomplished in the front by raising the spindles, and I thought that it was accomplished in the back by lowering the spring arch.
I'm hopeing to be doing this to my coupe soon....I had found a place (Pohl Spring works) that was gonna redo my spring, and lower it 3 1/2 inches. But useing a T spring might fill the bill. Now for my stupid, question...hopefully, not too stupid! When I lower my car, the rear trailing arm's come pretty close to the bottom of the frame. Here's my question.........can the rear trailing arm's be cut, and mount them to the outside of the frame.......like you do when you mount split wishbones up front? By the way..this is on a 31 Ford coupe.
Yup....thats the place. Frank is the spring man......very nice, and can do just about anything to a spring or make one. And great prices
I always thought the 26-7 spring had a lower arch too until I compared the different T springs. The 26-7 cars were lowered in the front by the spindles and lowered in the rear by a redesigned crossmember. The 26-7 springs were taller to fit the cross member and probably compressed down more because the 26-7s were much heavier cars. I think I have this figured out right......-GZ
My 1928 roadster uses an early T spring with the top leaf removed. No need for shims in the crossmember as the center bolt head (should have a tall, square head) keeps it centered in the frame. The difference is only 1/4" (1/8" on each side) so it isn't a big deal. Both the T and A spring and perch bushings are the same diameter, but the A bushing is, again, 1/4" longer. I used the A bushing in the T spring and let it stick out 1/8" on each end. Has been working well all summer!- GZ
Thanks GZ....I figured as much, just wanted some input. I also thought no shims would be required...I have a 1941 Ford car, and the facory rear crossmember is completly boxed, meaning that the springs just clamp to the underside of it, and have no "walls" on the sides. I figured if that car is equiped like that, then the same should go for a Model A...The u bolts will keep everything in line.
as said before a T spring will lower a stock model a about 2 inches( i have done it), also, you dont have to use a spreader because it is wider then an " A " spring, and third the t spring is softer, and in a hot rod that might way 1800 lbs thats a good thing. i believe a stock model a rear spring is rated at about 2200lbs by itself. thats a lot for such a light car. plus t springs look better in my opinion.
Anyone else done this swap.......or have knowledge on lowering a Model A coupe 'rear' with a T rear spring ?
I've installed a few T springs in A crossmembers, and have never used a spreader..I did however take the spring apart...and yes, there needs to be a blocks placed in the crossmember to allow the spring to sit in there properly... As said before, it will help the ride stiffness, and make the stance lower, and as Ken says, it looks sexy with a quick change
Do a search for "torque arm" & see what that turns up. There was a thread here a couple of years ago that went pages & pages on this subject. If you can't find it, the short answer was "no". JH
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