schnorr washer question, trailing arm bearing bolts - use lock washers? Options

[burlybryan]

I've refurbished my trailing arms/bearing and the schnorr washers are pretty worn and I don't think they should be reused. Any reason I can't use common lock washers here?

[Superhawk996]

Any reason I can't use common lock washers here?

Common split ring lock washers are less than useless for locking anything.

Well documented by NASA and the entire automotive industry.

https://ntrs.nasa.gov/api/citations/1990000...19900009424.pdf
See page 9 & 10

There is no Schnorr washer involved at the trailing arm pivot & bushing. The OEM trailing arm pivot shaft itself has hardened serrations on the shaft ends. On the outside it is just a flat washer that goes beneath the OEM lock nut.

If you’ve used the 914 rubber pivot shafts they used a star (toothed) lock washer instead of the OEM serrated shafts. Get another star washer if this is what you’re calling a Schnorr (which is yet another type of lock washer). With the 914 rubber shafts - you could substitute a Schnorr for the star washer but I would never substitute a split ring lock washer.

[burlybryan]

Sorry. I should have been more clear. This is for the 3 bolts that connect the trailing arm perch/mount at the body. I replaced the shafts with 914Rubber ones - and have the star washer, etc for those connections.

[Superhawk996]

Ah, I think those 3 were originally split ring lock washers on some early cars and later on were superseded by Schnorr. I’ve certainly disassembled cars with just a split ring washer there.

However, would stick with Schnorr’s. They will actually help prevent movement which a standard split ring lock washer will not. The Schnorr is a much better solution.

[burlybryan]

Ah, I think those 3 were originally split ring lock washers on some early cars and later on were superseded by Schnorr. I’ve certainly disassembled cars with just a split ring washer there.

However, would stick with Schnorr’s. They will actually help prevent movement which a standard split ring lock washer will not. The Schnorr is a much better solution.

I agree but they're impossible to find in a physical store. (IMG:style_emoticons/default/headbang.gif)

[Superhawk996]

Ah, I think those 3 were originally split ring lock washers on some early cars and later on were superseded by Schnorr. I’ve certainly disassembled cars with just a split ring washer there.

However, would stick with Schnorr’s. They will actually help prevent movement which a standard split ring lock washer will not. The Schnorr is a much better solution.

I agree but they're impossible to find in a physical store. (IMG:style_emoticons/default/headbang.gif)

Yeah. Belmetric is your friend. Local Granger or McMaster might have them in stock. Or local fastener supply if you have one but agree you won’t find at most hardware stores.

I order them in bulk and keep on hand. Piece price is cheap. I routinely ditch split rings for Schnorr anywhere that mild surface damage from the serrations isn’t an issue. Split rings literally do nothing and weigh more to boot. Utterly useless.

If you’re in a pinch to a deadline, I’d assemble with either a flat washer or split washer and then I’d go back after and replace one at a time with Schnorr. Retorque one at a time so nothing shifts.

[mepstein]

Correct, schnorr washers are one time only. Amazon, belmetric, etc.

[URY914]

https://www.amazon.com/s?k=schnorr+washers&...sl_8f85554jbo_e

[worn]

Correct, schnorr washers are one time only. Amazon, belmetric, etc.

Rare in part because everyone wants to buy something called a Schnorr washer, or anything else called Schnorr. Rolls off the tongue. Apologies and admiration to any members with the name.