Is my crank pulley on tight enough?

Reply Subscribe

Thread Tools

Search this Thread

Mar 3, 2006 | 03:40 PM

2blue

Thread Starter

Teching In

Joined: Jan 2006

Posts: 19

Likes: 0

Is my crank pulley on tight enough?

On initial re-assembly, I was tightening it with a 42" torque wrench, set at 250 ft.lbs., but I chickened out before it clicked. I just don't have any experience torquing 5/8" and 16mm bolts and couldn't think of a way to measure incremental degrees of bolt turn to the specified 140 deg. So, the crank pulley got loose and moved forward within .400" of the rack. Fortuneately I caught this in time. I fabricated a wrench out of 1/2" X 1" mild steel with a cut down 12 point socket welded to one end. I could feel the torquing effort go up when the pulley moved rearward about .230" until it hit the stop on the oil pump spline ring, gave a modest push with 18" of leverage and hoped this was 37 ft-lbs. Since I'm using a 12 point socket, I can make exact 30 deg. rotations when the lever bar hits the water pump pulley and I take off the socket to re-index. I figured I count four incremental twists and get to 120 deg., which should be safe. However, I could not get No. 3 all the way becasue the lever was springing, so I estimate I've only got 30 + 30 + 20 degrees of bolt rotation. Guys with similar experience, do you think the crank bolt will hold? I estimate I've been torquing the bolt with a 30" lever arm.

Mar 3, 2006 | 04:22 PM

2xLS1

TECH Senior Member

iTrader: (25)

Joined: Nov 2001

Posts: 5,649

Likes: 9

From: Warr Acres, OK

Quote:

Guys with similar experience, do you think the crank bolt will hold?

No. Do it right. Why use a tq wrench at all if you are not going to tighten it until it clicks? I don't know how many times this has to be posted, but here it goes again. Here is how to install a pulley using the correct tool.

1. Thread the stud into the end of the crankshaft until it bottoms out. Back the stud out 1 full turn. This will insure that all of the crank threads are supporting the load of pressing the pulley on, but will not bind up the stud in the end of the crank.

2. Position pulley on end of crank.

3. Install large washer, small washer, and nut in that order.

4. Use either a 15/16 or 24mm deep socket to turn nut and press the pulley onto the crank. I do not recommend using an impact gun for this as it will put extreme loads on the threads of the tool.

5. Once the pulley is installed, loosen nut and unscrew the stud from the end of the crank.

6. Install the old crank bolt and tighten to 250 FT/LBS of torque.

7. Install a new bolt and tighten to 37 FT/LBS of torque, then rotate the bolt an additional 140 degrees.

8. If you are using an aftermarket pulley, follow the manufacturer’s recommendations for final tightening.

Use a sharpie and mark the bolt at 12:00 and the pulley at ~4:30. Tighten the new bolt until the marks line up. IF YOU DON"T HAvE THE TOOLS TO TIGHTEN THE BOLT CORRECTLY, GO GET THEM.