The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 47-59 Rear leaf spring swap issue

leegreen · 11-22-2022, 05:37 PM

it looks like you are measuring if your driveshaft is straight, not the relative angles on the transmission tailshaft and diff pinion shaft?

The yoke stick out does not look horrible.

My assumption: Your monoleaf spring was sold with the pin the right place to line up a modern axle in the fender. Your new OEM drop multileafs are sold with the pin in the right place for the original rear end to line up at the correct length for a torque tube on a factory trans.
Putting your modern rear end centered under the axle hole on the factory location pin will put it too far forward. Shifting the axle back to the other hole might work.

The measurements you reported earlier for front eye to pin seem to support this, the pin is further back on monoleaf

If you mount springs to frame front and back with the axle loose on both sides just sitting on the springs. With the yoke sticking out the same as it was before are the wheels where you want them in the fender? Where is the pin in the new leafs relative to axle tube and the two holes you have to choose from?

11-22-2022, 05:37 PM	#15
leegreen Registered User Join Date: Mar 2022 Location: Surrey BC Posts: 686	Re: Rear leaf spring swap issue it looks like you are measuring if your driveshaft is straight, not the relative angles on the transmission tailshaft and diff pinion shaft? The yoke stick out does not look horrible. My assumption: Your monoleaf spring was sold with the pin the right place to line up a modern axle in the fender. Your new OEM drop multileafs are sold with the pin in the right place for the original rear end to line up at the correct length for a torque tube on a factory trans. Putting your modern rear end centered under the axle hole on the factory location pin will put it too far forward. Shifting the axle back to the other hole might work. The measurements you reported earlier for front eye to pin seem to support this, the pin is further back on monoleaf If you mount springs to frame front and back with the axle loose on both sides just sitting on the springs. With the yoke sticking out the same as it was before are the wheels where you want them in the fender? Where is the pin in the new leafs relative to axle tube and the two holes you have to choose from?