Hello.

GM manual quiet on this item. My 85 305 crankshaft pulley needs to be replaced. There is one center bolt and 3 smaller bolts around the center's perimeter. The center bolt is a Grade 8 marked 'TR'; the 3 smaller bolts are Grade 5 wth no other markings.

It appears these bolts mount the pulley directly to the torsional damper. Torque per manual says 60 ft-lbs.

Does the TR stand for 'threads reversed'?? Is that center bolt on the pulley actually a reverse bolt??

Thanks for any help!!

Taj

Not sure maybe the "TR" means tighten right! he he he. Anyway, the bolt is right hand thread.

No you use that when setting the timing on a new cam and have to turn the direction of the engine rotation. So no it is not counter turned/reverse thread.

There is a puller to remove the damper. the three bolts hold the pully secure to the damper and the center holds the damper in place.

I think it means treated but I am only guessing now.

Thanks, folks!!

A non-reverse thread bolt it is!! (Maybe it should be!!)

Be well.

Taj