harmonic balancer vibration damper bolt size

[faering]

Hey everyone,
2001 Cherokee Sport 4.0 I6. Can anyone confirm the bolt size for the 3 threaded holes on the harmonic balancer/vibration damper that the removal tool threads into? I bought the removal tool from Auto Zone, and none of the bolts in the kit fit. I thought it might be a M7 x 1.00, but I'm hearing 5/16 x 18 on the forum. Any input? Thanks

 

[xjtrailrider]

Im positive it is a standard thread. 5/16-18 or 5/16-24 most likely.

 

[2stix]

my renix (1989) uses the 5/16 - 18. if you are removing a dirty balancer you may need to chase the threads and clean them out. if you do not have a tap and die or thread chaser set, you can cut a groove in a same size bolt. it will clean the gunk out, but do not expect it to repair any damaged threads. it can sometimes, but do not expect it to.

 

[dj99xj]

Take the NEW balancer to the hardware store and test some bolts. Done and done.

I suggest stainless as they are very strong.

 

[Talyn]

Stainless is not very strong

 

[cruiser54]

5/16-18. Just checked the one on my freshly built stroker. Grade 5 will work fine. That's what came with my Snap-On puller set.

 

[dj99xj]

Stainless is not very strong

I stand corrected. I had a friend who always insisted on stainless for various projects it was stronger.

After reading, it is slightly stronger than Grade 2 but that's it. And not hardened due to the low carbon content....

It IS however great for bolting on fender flares and mudflaps!

Go with grade 5 or 8 then.

 

[Talyn]

Yes, its great for parts that see no stress.

 

[5-90]

I stand corrected. I had a friend who always insisted on stainless for various projects it was stronger.

After reading, it is slightly stronger than Grade 2 but that's it. And not hardened due to the low carbon content....

It IS however great for bolting on fender flares and mudflaps!

Go with grade 5 or 8 then.

300-series CRES is roughly comparable to about SAE5 or SAE6 - it's stronger than copper alloys, but definitely not SAE8.

For something like this, it can work. I wouldn't use it to press the pully onto the power steering pump tho - SAE8/ISO12.9 for that! (My HD puller kit doubles as a steering wheel puller, and all of the screws in it are CRES except for the ram screw.) No trouble here.

I have taken some SAE8 & ISO PC12.9 screws and ground longwise grooves across the threads, they're used for thread chasers. They'll clean the crud out of threads, and will usually reform a bruised thread, but will not cut a new thread (which takes care of potential for crossthreading!)

Screws are made from different materials, because different materials are useful. OEMs tend to stick with carbon steel because they don't want the expense if increased logistics and different materials. Just because that's the way the factory does it, doesn't mean it's the correct way to do it!