Leaf Spring Installation: Washers or no washers?

[RayL]

Do you use washers on the U-bolts and front pivot bolt?

Finally getting around to installing new leaf springs on my '73. The old springs had washers on the U-bolts and front pivot bolt. But the Service manual doesn't show washers and the bolt kit I got from ESPO does not include them. And Laura @ ESPO says you shouldn't need washers in either place. Good enough for me.

But I'm curious to know if there is consensus to use or not to use washers in these two places.

In general, I like the idea of using washers to distribute the load and avoid marring the surface of the shock plate / spring perch. But it also adds another potential point of failure. One of the old washers had failed on the passenger side shock plate.

What do you think?

Further information - I'm installing +1 ESPO springs, all new rubber bushings, reusing the stock shock plates & shackles and installing Mancini Racing's leaf springs hanger kit at the stock ride position.

Thanks,
Ray

[headejm]

   No washer on the U-bolt nuts.

[Chryco Psycho]

All of the U bolts I have used included washers , front pivot no .

[headejm]

FWIW - Dave Wise's Fastener Reference Manual doesn't show washers on the U-bolts. My original 70 Challenger did not have them.

[MoparCarGuy]

U-Bolts = Nuts only, no flat or lock washers between nut and plate.
Front Spring Eye Bolts = Nuts only, no flat or lock washers between nut and spring hanger.

The factory U-Bolt Nuts are tall nuts with three dimples on the flats which creates an interference fit. Partsmix.com has the U-Bolts and Nuts. Diagram on their page, too.

The factory Spring Eye Bolt Nuts are Marsden nuts (interference fit) with six (6) slots cut in them. AMK has these listed (5/8-18 MARSDEN NUT 15/16 AF .44 TK PHOS. 2 pk) at the bottom of the page.

[RayL]

Thanks for the replies. I learned a few things from this post.

@MoparCarGuy - I never actually knew the proper name of the Marsden nut. And now I even know where to purchase them. Thanks!

@headejm - Also never knew of Dave Wise's Fastener Reference Manual. Great information.

@Chryco Psycho - With my limited experience with u-bolt installations, I'd say it has been about 50/50 on the use of washers. Reason I posted. Thanks for your feedback.

I'm going to go without washers, using the nuts & bolts provided from ESPO and Mancini.

[YellowThumper]

Great info on this thread.
My factory original does not have washers.