Technical How to reverse a Model A Rear Spring

Just finished up rebuilding the banjo rear a couple weeks ago so it was time to get after refurbishing the rear spring.

Initial plan was to use the Model T rear spring I scored at a garage sale. After disassembly and cleaning I found a cracked spring.

My 13 year old son said we gotta check Ebay for another one.

Oh no son we are hot rodders and make/modify with parts we have on hand.

We have a decent 10 leaf rear spring and we can remove a couple leaves and reverse the main spring.

After scouring the Hamb for ideas and nothing else to do on the 4th we hit the garage.

Not sure how old the spring is but it must be a replacement, it came apart too easy and the metal is still blackened on the underside.

So armed with a 20 ton press, tape measure, grease pencil and straight edge we got to work.

We traced the main leaf out on the floor as a guide and marked the spring in 1 inch increments.



After a few pumps in the press we figured it takes 10 to 12 pumps to make things move. Started with the easy bends first and ends started to flatten out.





Ok time to start working out the main curve.



My right hand man working the press, after reworking the rear spring he should be able to do the front by himself. The spring is almost flat.



Ok it's flat enough time to start bending the other way.





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This is were I started getting excited and forgot to take pictures.

I first started bending the main curve and started at 4 inches and gave 15 pumps each side. This gave the basic shape. I followed up starting from the center and finished shaping the curve.

I forgot to mark center on the outline on the floor so I used the spring that sits on top of the main spring as a guide. Once I was satisfied with the main curve I moved to the bends on the legs.



After a few little tweaks here and there I layer it all out.



We started with 10 leaves and ended up with 7. We kept the top beveled spring, removed the next two small springs, kept the 4th then removed the 5th.

We still need to trim an inch or so from the spring that's on top of the main spring so it doesn't hit the eyes and bevel the edges.

I was out of cut off wheels and after I burnt up a Sawzall blade I called it quits for the day.

We should be able to wrap it up next weekend and maybe just maybe get the rear hung in the frame.

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Looks like a good job.

 

Nice job, Great way to spend time with your son too!

 

Thanks for sharing & for the pics!

 

nicely done

 

Nice

 

Nice work. I am glad to see your son helping! Cant wait to see how the car sits with the new spring pack.

 

That is how I did mine. Could have used a right hand man. I think mine took 3 hours.

 

Show some pics of the arbors in your press.

 

Good job, thanks for sharing!

 

Great Job, and u taught the next hot rodders how to do it. "Passing the Torch on the 4th"!!!

 

I just did a pair of leaf springs over the winter...You matched the arch but I guarantee if you put load on the leaf it will lose alot of its shape..Try it by placing on floor an compressing it; you only have to use your body weight..

 

great, glad it worked out for you. I did the same thing and broke mine, guess I went too fast.

 

Thanks folks, glad to share and super pleased it turned out so well.

Alchemy, I didn't use any special arbors and if I did I am sure it would have sped things up, once I made them that is I'll defenitely come up with some for the next time I do this.

I did use angle iron clamped to the bed when I flattened out the spring. For bending back in to shape I just rest the spring right on the bed.

 

BRAKING IS NORMAL, IF NOT DURING RE-BEND, AFTER INSTALLATION. IMO.

 

I have used a bunch of recurved springs in the past , no issues what so ever . I have went as far as cutting ,heating and recurving the loop on the ends . Just allowed to naturally cool and driving with it on my '32 today

 

Did some more work on the spring today with help from my Hot Rodder in training.

Trimmed and reshaped the spring that sits on top of the main. I used a Diablo cut off wheel in my angle grinder




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Trying to load pics and it's not working will try again tomorrow

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I would love this attachment for my hossfeld. Always wanted to try this

4 1/2" ×3/8 hot spring steel capacity. ..looks like fun

 

Now that the main leaf was reversed the leaf that sits on top needs to be shortened. Eyes have some wear but still have plenty of meat on them. Looks like it must have been rubbing an axle tube at one time. Also notice how the leavse dug into the leave below, we take care of that further down.


Diablo cut off wheel loaded in teh angle grinder makes quick work of cutting



Little more work with the cutoff wheel to reshape the end and some grinding to bevel the end of the spring so it glides on the spring below.



Time to put my helper to work, with 80 grit flap wheel to clean up the leaves.



Now time to tackle the gouges created from the leaves digging into the leaf below.
Before:


After some work with the grinding wheel followed up by the flap wheel the springs now have a smooth surface to ride on.



While I was grinding and smoothing the springs again I put my helper to work on installing the leaf spring bushings.



Couple clamps and a new center bolt and spring has been reassembled for mockup. Note spring is not under tension at this point so there is not much stress on the center bolt.



Again put "The Help" back to work hanging the spring. Couple blocks of wood under the eyes helps hold the spring up in the cross member.



All bolted up in the cross memeber. Other than needing grease between the leaves and needed to be painted it is done.

 

One last update to answer the "now that you reversed the eyes how did you spread the spring to install the rear" question.

I attached the left spring shackle first, then get a block of hardwood 2x4 not that cheap pine sheet as the spring will just dig in, load it up with grease, attach ratchet strap around frame rail and rear, pull it in place then compress suspension with another ratchet strap or as I did a BIG ASS ratchet clamp, insert shackle and viola!



And the finished project. Note I will need to do some paint touch up and need to swap out the rear spring clip bars for the 7-8 leaf spring style, my originals ar 10 leaf. Once the spring was spread it is no longer tight in the cross member.

 

this was exactly the advice i was looking for
thx a lot

 

Bingo...and thats how its done...mine done exactly the same way, been on my tudor over a year no problems.....another way to install after reversing is to just install the main leaf by itself, pretty flexable by itself....once main leaf is attached to shackles, stack the rest of the leafs and pull them all together with a long spring centerbolt, then cut excess bolt length off.....no muss no fuss, easy peasy" good job Tbone.

 

Thanks guys glad to give back after learning so much from everyone else.

Got a bunch of parts on order to get the spring properly bolted in, also picked up rear wide five brakes I'm cleaning up and fitting to the model a rear.

Hopefully have some updates after this coming weekend.

 

Nice job, thanks for sharing. On a side note, I have thought of trying this and giving the A spring the same shape or similar to a T spring.

 

The T spring is not so tall right? so the main leaf will be shorter, you may have to cut the ends and reform the "eye" on the ends.

 

The T and A main leaf are the same length albeit a 1/4 narrower.

 

This is exactly what I was wondering. I would think you could bend it to any shape. You would have to re-arch all of the springs though.

--louis

 

Thanks, did not know that.