Just replaced my GMB waterpump with a Gates off Amazon ($34). The new pump has forged gears instead of stamped, and the price was right. Thought I'd share because I am often leary of buying amazon/ebay parts, but this was legit.

Gates 42134
Complete with gaskets and o-ring

Old vs. New


Stay cool

 

It's cast, and also sold by pretty much every Miata-specific vendor.

 

Cast* yes it sold elsewhere but this is cheapest, and who can complain about 2 day free shipping?

FWIW, the stamped gmb pump was sold to me in a kit by a reputable vendor.

Just a quick fyi for those wanting to get cheap but quality parts. I wish we had a list of those things, maybe a shared Google doc that is updated as products are removed and added from ebay/amazon. Just to save us all time.

 

Rockauto also has the gates cast pump for a reasonable price.

 

If you can find them, Nissan Pump Co. makes a cast impeller pump and it's made in Japan instead of China like most others.

 

My gates cast water pump failed after about two years of use. The pulley bearing started squealing and threw out all it's grease. I had it replaced with another Gates waterpump. Don't knnow if it's a china pump...