Product Advisory - SHS 14-tooth pistons

[Stealth]

It has come to our attention that the latest batch of SHS 14-tooth pistons have a design flaw and will cause excessive wear an/or premature gear/piston failure.

Reference the picture below.


On the left we have the NEW SHS 14-tooth pistons, and on the right we have the OLD SHS 14-tooth pistons.
Note the angle of engagement of the 3rd gear tooth on the 3rd piston tooth. The distance between the 1st and 3rd (or 2nd - depending on which way you want to count) is increased on the new pistons. The non-ideal interfacing angle of the teeth will cause excessive stress on that tooth.

So how do you tell if you have a new one or old one?
Easy. The new ones have a dark metal rack while the old ones are silver.

Just wanted to give y'all a headsup! Check with your retailer to make sure that you're getting the good stuff.

[HKGhost]

Most pistons that I've adjusted the AOE on required that second tooth to be filed down half way. Only on some rare occasion it wasn't required when adjusting the AOE.

[Stealth]

Agreed. I do that as well. But that's not the issue here.
Spacing between the 1st and the subsequent teeth increased by about 1-2mm on the new 14T pistons so even if you shaved that "2nd" tooth, you'd still be running into the same issue on the next.

[lurkingknight]

I think the shs 14 tooth comes without a 2nd tooth already, the issue is the rest of the teeth on the starting on what would be the 3rd piston on the rack are out of position on the new batch of pistons.

[m102404]

That's a solid head up, thank you.

[Spike]

Thanks for the heads up, I was just about to order a couple of these...

Is this just a lemon run, or will they be like this from now on do you know?

[Stealth]

SHS has been notified, but I would expect them to be on store shelves for the next few months at least as they try to clear out stock to less knowledgeable customers. Whether or not they'll re-tool back to their old molds, I don't know.

We have 3 of the old school ones left. Hell, I might keep them for myself.

[Spike]

Are the 15 tooth pistons still alright (after sanding the 2nd tooth off, obviously)?

[MaciekA]

First the bad bevel gear batch and now this. What a minefield..

[HKGhost]

After reading this I went and checked my stock of SHS pistons, and I have the lighter blue ones. I installed one and didn't notice anything thing wrong with the spacing. Maybe it's the sector gear you're using?

Ahhh, disregard what I said. I found some that had the issue. Crap!