Shim the 7M Oil pump

How to shim your 7M-G(T)E oil pump

In stock form, the 7M oil pump isn’t known for putting out  high volumes of oil pressure. a lot of people increase the base pressure for peace of mind and you just found the tutorial on how to do so. Information on how to do this has been around for quite some time, however, a lot of good sites have gone down and Shoarmateam is known for making and/or having back-ups of a lot of old-skool information.

So here it is, a brand new how-to on the oil shimming process. Miss Fay Hadley was kind enough to let me use and share her video on this topic. In her video, she also discusses additional measures on how to improve the 7M oiling system. This article will be centered around the oil pump base pressure increase using some 10ct shims from a conventional hardware store. To find out more, go check out her youtube video.




Tools and parts needed for this mod:

  • A 22mm wrench
  • 5 or 6 stainless steel shims
  • Preferably a vice and something to protect the pump from damaging
  • Some assembly grease or fresh engine oil
  • An oi pump (duh!)

Using screenshots, I made a very short video covering just the bare minimum needed to do this upgrade for little to no money at all.


Step 1

Take out your oil pump, or even better, just order a new Aisin oil pump. Aisin is the OE supplier for these Toyota pumps. (Toyota original part nr. 15100-42020 or 15100-42021).



Step 2


We’re going to remove the big bolt that keeps the spring inside the oil pump.

This spring is 2-sided. So it doesn’t really matter what way you put it back in, so no need to worry about that. But please, make sure your pump is in a vice surrounded by nice fluffy cloths or carton board to keep it from damaging.

Step 3


Go on, grab a wrench and get that thing off. It may need some persuasion but you’ll get there eventually. Try not to drop the bolt or the spring but unscrew the last few rounds with your hand if possible and keep the spring from flying away.

Step 4


All done. It’s out.

Time to grab your gear and get that baby all shimmed up.

Step 5


Take out your digital caliper micrometer and keep adding shims until you get to about 5mm

Step 6


Make sure that the side of the shims is just large enough to make it fit snug inside the bolt you removed. The inner diameter must be large enough to not restrict oil flow.

Snug fit without restriction

Step 7

Everything is ready to back in. Before doing that, take the metal plunger out from where the spring should go and oil/grease it up so there is smooth movement. Make sure the plunger and spring are well oiled up and that they can move freely inside the pump

Step 8


When screwing the bolt back in, keep applying some pressure to the bolt to prevent possible damage to the threads. Wham! You’re all done.


Make sure it’s nice and tight before you place the pump back in your engine.


If you’re not into measuring with shims and want a one-fits-all solution, go over to and buy the custom uprated spring. for 12$ you can’t go wrong there.