Honda K Series Manual Transmission Countershaft Thrust Shim

Honda K/J Series Manual Transmission Countershaft Thrust Shim

If you're tearing into your K or J series transmission for a rebuild and someone told you about countershaft shims but you have no idea which one you need? Here's the problem, you won't know until the trans is apart and you've measured the gap with a feeler gauge. These OEM countershaft thrust shims control the spacing between the countershaft ball bearing and the 35mm shim. They come in thicknesses from 0.87mm to 1.99mm with part numbers ranging from 22981-PPP-000 to 23995-PPP-000. Honda's spec says the gap needs to be between 0.04mm-0.10mm. If your gap's outside that range, you need one of these shims or your gears aren't going to mesh right and you're going to have problems.

Here's What Happens If You Skip This

The countershaft's the shaft that holds all your counter gears. It meshes with the mainshaft gears to give you different ratios. The shaft needs to spin freely but it can't be flopping around side to side. That side-to-side movement's called endplay. Too much endplay and the gears hit each other at the wrong angle. The gear teeth start wearing funny and eventually you're grinding gears or burning up synchros because nothing's lining up right. Not enough clearance and the bearings bind up. Now you've got friction and heat and the shaft's not spinning smoothly. The shim sets the endplay so the gears mesh properly and the bearings don't bind. It's a critical measurement that most people ignore until their rebuilt transmission starts eating itself.

You Definitely Need This With Aftermarket Parts

Stock rebuild with all OEM parts? You can probably reuse the shim that came out. But the second you start swapping in aftermarket synchros, new gear sets, or upgraded bearings, all bets are off. That aftermarket Synchrotech hub? It's not the exact same thickness as the OEM one. Those new bearings? The inner race height's slightly different. All those tiny differences stack up and throw your endplay out of spec. We've seen people rebuild transmissions with expensive aftermarket synchros and skip the shimming step. Three months later they're back with the trans apart because it's grinding or popping out of gear. K series transmissions aren't like swapping pistons where you just bolt stuff in. You have to measure and shim or it doesn't work right. That's just how they're built.

How to Figure Out Which Shim You Actually Need

You can't guess this. You can't use a chart. You have to measure. Here's how it works: get the countershaft assembled with the bearings and the 35mm shim on there. Grab a feeler gauge and check the gap between the ball bearing and that 35mm shim. Honda says it needs to be 0.04mm-0.10mm. Your gap's bigger than that? You need a thicker shim. Gap's too tight? You need a thinner one. You're picking the shim that gets your endplay into Honda's spec range. Most people doing serious transmission builds just buy a set of different thickness shims so they've got options when they measure. Trying to guess which one you need before you've got the trans apart is pointless. Measure first, order the right shim, then finish the build.

What You Get

• One Honda OEM countershaft thrust shim (part number varies by thickness)
• Available in thicknesses from 0.87mm to 1.99mm
• Controls countershaft endplay so gears mesh properly
• Goes on the countershaft between ball bearing and 35mm shim
• Required for proper gear alignment with aftermarket parts

Fits These Transmissions

• 2003 Acura CL Type S
• 2006-2011 Acura CSX Type S
• 2013-2015 Acura ILX
• 2024-2026 Acura Integra Type S
• 2002-2006 Acura RSX Base/Type S
• 2004-2014 Acura TL
• 2004-2014 Acura TSX
• 2003-2017 Honda Accord (K24/V6)
• 2018-2020 Honda Accord 2.0T Sport
• 2002-2015 Honda Civic Si
• 2017-2021 Honda Civic Type R
• 2023-2026 Honda Civic Type R
• 2002-2006 Honda CR-V
• 2003-2010 Honda Element
• 2016-2018 Honda HR-V (including R series)

Note: These shims are sold individually by thickness. You're ordering one shim. Before you order, measure your actual clearance with the trans apart. Don't guess and don't try to reuse your old measurement from a previous build. Every build's different. You can't return shims once you've opened them because they're precision parts. If you're rebuilding a trans with aftermarket synchros or gears, buy three or four different thicknesses. That way when you measure, you've got the right one sitting there instead of waiting for shipping while your trans is in pieces all over your garage. When you're measuring, make absolutely sure the countershaft bearing's fully pressed on and the 35mm shim's seated right. If the bearing's not seated all the way or the shim's crooked, your measurement's garbage and you're going to pick the wrong thickness. After you install the shim and put the countershaft back together, measure again. Check it with the feeler gauge. If it's not between 0.04mm-0.10mm, you've got the wrong shim. Pull it apart and try a different thickness. Don't skip this recheck. We've seen people install the shim, assume it's good, button everything up, and then realize the endplay's still wrong when the trans starts grinding. Now they're pulling the whole thing apart again. Wrong endplay kills synchros and gears fast. A $15 shim's cheap compared to replacing a $400 synchro kit because you didn't measure properly.