UberR32

I am reinstalling an OEM LS2 balancer with an ARP bolt, and I'm not sure if I need the POA friction washer or Diamond Embedded Washer if I'm using the ARP balancer bolt. I can't even find the part number at www.gmpartsdirect.com . . .

Wayne O

I'm no mechanical expert but with an OEM balancer I'd make sure it had the friction washer. The friction washer became a production part in the 2006 LS2 and LS7. Early 2005's without the DEW suffered problems. Short of pinning the crank I'd want the friction washer.

I don't know about ARP bolts but I believe the part number for the GM torque-to-yield bolt is #12557840. I vaguely recall they cost $5 or $6 and you need two when installing and setting the harmonic balancer.

UberR32

wayne, thanks for the reply. I read the TSB on the friction washer, and it mentioned that there was a misalignment in the torquing machine, and several crank bolts were not torqued properly. I also had the same impression that the later cars did get the washer from the factory, but I cannot find any data to support that. Thus, maybe the washers were used as a fix to the early cars only . . . Anyways, thanks for your post.

LeMans05C6

Can anyone comment on this. I am putting an in ASP underdrive pulley since the OEM Harmonic balancer is on "national Backorder". They can't get the diamond embedded washer since it only comes with the OEM piece, but any comment on if i need this washer to go with my aftermarket pulley would be great.

Someone please let me know.

LSCHLEM

When I installed My Powerbond UD Pulley I used a ARP Bolt and pinned the Crank. Arp bolts cost around $23.00 and are essentially reusable. When you torque the Balancer in you torque to a set value like 240 # as opposed to the oem bolt that you torque to 120# and then torque another amount in DEGREES using a Torque Angle Gauge. I used ARP Bolts on my Heads and they were so nice to work with and if I decide to change to a different thickness Head Gasket I can RE use the ARP Head
Bolts.

Eric D

The washer is used in all LS3, LS7, and LS9 engines currently being produced and reduces the risk of the damper spinning on the nose of the crankshaft. I would NOT put any damper on without it. The risk is having to replace the crankshaft that is damaged due to damper spin. If you don't use the washer you would be wise to pin the damper.

The LS7 also uses a diamond washer for the flywheel to crankshaft as well.

glenB

The washer is for production dampers. There was one on my 07 LS2, there's not anymore.

Apply a skim coat of Ultra Black starting about half way up the ARP bolt and a thin coat on the shoulder and torque to spec. The silicone is to seal against any unwanted leaks.

I have 7K miles on my ATI damper and ARP bolt, no GM washer.