Harmonic balancer installation, tool and thread size for crank bolt

**Lifespeed** · 06-22-2018

I need to install a new harmonic balancer after replacing the crank position sensor, water pump and supercharger isolator. I know the hack mechanic method of using the old crankshaft bolt (I have a new one also due to torque-to-yield) is verboten on nearly all engines as it can damage the crankshaft threads. Typically a harmonic balancer installation tool is used, which is basically a long stud and a thick nut used to pull the balancer onto the crank so as to not stress the crankshaft threads.

However, as I look for such a tool that fits the giant threads in the 3.8L SC (I measured 18.8mm, 3/4" (?) across the threads), and am having some difficulty finding the matching tool. Can anybody confirm the crank bolt thread diameter (obviously fine pitch), as well as a tool that might be available. Locally from Autozone or similar same-day would be great, but reality may force me to wait for shipment.

**Scottydoggs** · 06-22-2018

i used the old bolt and put my balancer on a good 5 - 6 times. and im using the old bolt to hold it all together. really aint a big deal. used a air gun too.

**Lifespeed** · 06-22-2018

Originally Posted by Scottydoggs

i used the old bolt and put my balancer on a good 5 - 6 times. and im using the old bolt to hold it all together. really aint a big deal. used a air gun too.

Yeah, I know. Just not the way I do things, with my luck the threads would strip.

**Scottydoggs** · 06-22-2018

if good ol billboost pops in, hes gonna tell ya the same, air gun, bap! done, next. im sure hes got over 20 crank sensors under his belt.

the only bolts you really cant reuse are head bolts, everything else 100% reusable.

**wstefan20** · 06-22-2018

I agree with Scotty on the air gun.

**Lifespeed** · 06-23-2018

I air gunned it. Oiled the old bolt, 3/4" fine thread is unusually strong for a balancer bolt. New balancer as well, rubber was starting to separate on the old one. Angle-torqued the new bolt per the service manual. Hope the CKP sensor was the culprit.