Jump to content

Crank pulley fail?

Recommended Posts

I recently swapped to a perrin crank pulley, 5lb to 1lb and same o.d. as factory, when I installed I used a fresh bolt, oiled it up and torqued to 94 foot pounds roughly and thought things were fine. Started the car and the pulley doesn't move but the bolt looks like it wobbles, took it to a few local shops and they were all dumbfounded, so I paniced and got another fresh bolt and replaced the oem crank pulley and same problem and the bolts don't appear to be out of round to cause an illusion. I'm stumped. 13 legacy fb25 engine has 60k on it.
Link to comment
Share on other sites

I believe there is a crank seal and a key'ed ring that can be removed or not mate up correctly on those FB motors (similar issue on the FAs). That could explain what you're seeing.


Should just remove everything, inspect the crank area with the pully removed, reinstall the stock pulley and see what happens.


LWCPs on Subaru motors is a mistake. Either OEM or Fluidmpr or similar, eveything else will just cause a lot of excess false PKC, FKC, FLKC and additional IAM instability.

Not to mention the n-order harmonics spikes acting on your internals.


Zero benefit to the LWCP unless the engine is installed in a dune buggy and about to tackle a desert race after which it will be rebuilt or scrapped.

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...

Important Information

Terms of Use