Crankshaft Holding Tools used on my Miatas

Who needs this stuff?
These hold the crankshaft stationary to allow removal/install of the crankshaft bolt. Many people do this by putting the car in 5th gear and engaging the hand brake. So automatic transmission cars need them. While my cars are stick shifts, I prefer using a holding tool.

Do they give better accuracy?
This is a matter of disagreement. When I first took a wrench to my miata's crankbolt, I noticed that I could get 45 degrees of twist before the wrench torqued up the slack in the car's drivetrain. Most people say this doesn't matter. All the torque shown on my wrench eventually goes to the bolt. Well, I'll take their word on this, but if they're wrong, a holding tool can't hurt.

My buddy Tim Martin made this simple one for his 95 a few years ago because he said the parking brake method wouldn't hold the engine when he tried to torque the bolt. The only issue with it is that it only uses two bolts. The little bolts that would hold it may not be strong enough. I would use a separate set of bolts for that reason.

Here's it being used on my 94. It bolts to the pulley boss and holds the crankshaft. Works great.

Other tools, such as this one at http://www.birminghamauto.net/cams/techtool.html also exist.
Here's one I made from the above plans in use on a 1990 miata. It's more work to fabricate, as it has a double bend. I think Tim's design is easier to make. However, if you're doing the loctite fix on a miata 1.6 with a worn keyway, this design will not let the crank gear move, which is important since the gear is not constrained by the key.

Information on this website based on personal experience only and no claims made to its accuracy or reproducibility. Your results may vary.