MTFCA Forum

What I am going to try to show you, surprised me. Apparently, the "rubbing" contact area between individual leafs in a spring occurs only near the end of the leaf.

The first photo shows seven of the eight leafs of the rear spring for my 1927 coupe. The next two photos are of the second and third leafs from the top.

The second photo shows the right ends of the pair. The third is a close-up. In the upper leaf, you can see the "rubbing" contact area. The yellow piece of tape shows the " length of the area" where the Ford script is located on the back side of the other leaf.

The fourth photo shows the back side. Note how close the script is to the "rubbing" area and that there is no indication of any "rubbing" over the script area. I looks like the "rubbing" occurred over about 2.5 inches. I knew that "rubbing" would occur near the leaf ends, but I thought there would be indications of "rubbing" at other areas along the leaf.

Someone told me that lubrication is only needed over the end 4 inches of each leaf. Maybe he had a point!

I followed Jim Patrick's recommendation to grind the bottom corners at the end of the leaf.

I will have some additional photos of another leaf and some comments in follow-up post.

Once bolted together, the entire spring save for a small % in the center, does indeed move (even if ever so slightly) and ought to be lubricated. Whoever believes only the ends move...well...

Additionally, the tops of the leaves, where the wear shows from each upper leaf, ought to have those worn indentations ground off and the bottom/end of each upper spring ought to have a small radius ground to facilitate sliding rather than digging. Those worn areas create a "captured" area for each leaf to rest in and when the spring sees movement beyond nominal "road vibration", those areas will make the ride a good deal harsher than if the ends were free to slide over the lower leaf.

The difference in a properly prepped leaf spring and an as-is spring is almost shocking in how one rides vs. the other. Most owners only know their own car, so if it runs crappy and has a harsh ride, well that's how they rode "back in the day". Actually, nothing could be further from the truth, but there is generally no convincing them otherwise.

A spring that is locked cannot flex. The leaves have to slide on one another. Dry, rusty springs will have a very high rate, and will force the frame to flex excessively when running over uneven roads. A stiff front spring will also give the radiator a beating.

Nothing new. Everyone who has dismantled their Model T springs has encountered this. The general remedy is to file the underside of the sharp ends of each leaf so that the ends will not dig into the top of the leafs. Jim Patrick

Jim, Thanks, I already ground the bottom edges of the end of the leaf per your earlier recommendations. How did you address the top of the leaf where the area was worn?

Since it is covered by the preceding leaf it won’t show, so just leave it as is. Jim Patrick

Like Scott said above. You grind the upper part of the leaf so the leaf above it can slide and not get caught. You want to try to get rid of that indentation without taking away too much of the leaf. Then make sure you lubricate that part of the leaf with SLIP plate or whatever lubricant you use.

I usually grind the step away as well as chamfering the bottom end of each leaf. You shouldn't have to worry about thinning the leaf with the step, since it's already been thinned by wear. All you really want to do is to blend-in the step.

Long ago it used to be common to see leaf springs wrapped with electrical tape in an effort to keep grease in the springs and dirt out.

Spring gaiters are the best solution.