Shock lower bolt washer size

[sbay]

Anyone know what size washer to use for the bottom bolt for installation of rear shocks?

They come already included on factory shocks but not on PSS10s, which I’m going to install. Don’t want to install without the washer and risk a blown bushing.

So far I have found using a 5/8 washer, but just want to confirm before install.

Thank you!

*Included a screenshot from a YouTube video, the washer between the bolt and bushing.*

[K-Dawg]

It's a M12 bolt.

A 1/2" washer would also probably work..

[sbay]

It's a M12 bolt.

A 1/2" washer would also probably work..

1/2” worked perfectly. Thank you!

[toy4to]

M12, 13mm ID, 37mm OD. That's what I used when I installed my KW's.

[SaoGregy]

I had a similar situation and used a 1/2" washer for it. I also was afraid it won't fit the construction I had, but it was actually the necessary item. However I suggest you be careful with choosing the washer, steel and smooth ones are the best. I purchased another washer, which had uneven structure but I thought it didn't matter. However when I installed it I noticed that it doesn't fit perfectly, though it still can do the work. I was afraid I would have to check this too often, and decided to buy a better quality washer. So, don't follow my mistakes and find the smoothest washer you can. More abuout it here https://intact360.com/products/fasteners/washers/ . Good luck!

[FBloggs]

Make sure it is thick (circa 1.5-2mm), good quality steel.
It is a secondary safety to retain the damper in the event of failure of the damper bushing.

[bigjae46]

An M12 washer is incorrect. You have to match the grade specification to the bolt. The correct fastener would probably be a class 8.8 or 10.9 M12 washer, should be stamped on the bolt head.

If you use the normal grade 2 washer from home depot, the hole will gall and the washer will no longer function properly.

[Tbonem3]

It's funny, real OEM doesn't even show a washer existing. The part # for the bolt is all that is listed (07119900402).

[bigjae46]

It's funny, real OEM doesn't even show a washer existing. The part # for the bolt is all that is listed (07119900402).

I think the OE rear shock has a metal plate on the end to keep the lower bushing from sliding off.

[Tbonem3]

I can't remember if Konis/Bilsteins come with a new washer then.

[heinzboehmer]

Konis have the metal plate on the shock, but also include the washer.

No washer used in this pic I found online (the yellow bit that the bolt head is clamping against is the metal plate that bigjae is talking about), but it is included in the kit. Never gave it too much thought, but I guess I don't need to use the washer.