You can type here any text you want

Loose Crankshaft Pulley

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!

daredevil95

Member
Joined
Oct 21, 2012
Messages
79
Hi, I have a 86 GN, I recently changed my waterpump, removed the intercooler and intercool small fan on crankshaft serpentine belt pulley. As i was reassembling and i went to install the intercooler small fan onto the crankshaft pulley, the fan connects to the serpentine belt pulley and I noticed this serpentine pulley was loose....I could slide it back and forth about an 1//8" to 1/4" of movement...i don't remember this movement being here in the past? I could be wrong? Motor was rebuilt about 2 years ago and a new harmonic balancer was installed so, Is the movement with the serpentine pulley normal? or should i replace or maybe tack weld in place?
Screenshot 2025-07-09 202951.png
 
You can see a bolt missing from the crankshaft pulley. Better check to make sure you have all of them in and tight. Also make sure the balancer bolt is tight. You'll have to remove the intercooler fan to check it.
 
^ as he said the pulley is held on the crankshaft hub with 6 bolts , three were from the fan and you removed them and as your pic shows at least two of the pulley bolts are missing maybe all three , replace the missing bolts (m8x125 x16mm) and forget the welding idea
 
and considering the bolts are missing and may have fallen out from improper torque and as you said your balancer was replaced , as has been posted by we2regal ..pull the fan and reach in and check the large crank bolt ( should be torqued to 225lb/ft) and while you're there check the 6 bolts (1/2" head 5/16-18 x 1.00) that hold the hub to the balancer
 
If it’s just the pulley that’s loose then just tighten it up.
More likely the balancer is loose. If so it’d be best to remove it and inspect it. Look for cracks in the key way. Inspect crank sensor and reluctor wheel.
 
Mannnn....I didn't notice the 3 missing bolts! Yes, they were there prior to engine rebuild., I looked up a pic I had from when I removed engine. Now that I'm looking at it, I'm not sure what those bolts do but, I will install them today. Thanks, The engine has a new harmonic balancer and engine builder installed that 200lb+ balancer bolt and I will check it out. Thanks for the feedback. I appreciate it.

The bolts were there!
Screenshot 2025-07-10 105844.png
 
If it’s just the pulley that’s loose then just tighten it up.
More likely the balancer is loose. If so it’d be best to remove it and inspect it. Look for cracks in the key way. Inspect crank sensor and reluctor wheel.
It is actually the Pulley itself is loose on the hub that connects to the crank. The bolts inside the hub connecting to the crank are tight. Although I'm missing bolts on pulley so, that may lock it down? IDK? I'm tryting to figure out how that works.
 
and considering the bolts are missing and may have fallen out from improper torque and as you said your balancer was replaced , as has been posted by we2regal ..pull the fan and reach in and check the large crank bolt ( should be torqued to 225lb/ft) and while you're there check the 6 bolts (1/2" head 5/16-18 x 1.00) that hold the hub to the balancer
Hi, do you know the size of the missing pulley bolts? I'm still google researching for size? Ill stop today and pick up new bolts vs digging through my bolt drawers for more time then I would like to spend sifting. lol
 
Back
Top