Cm870 Jake detent worn

[Hammerhead]

I have done this procedure a few times. As advised by Mr Hagg the first time I did mine, I advise everyone to also change Part # 3413129 Control Valve Assy Detent and Part # 2892986 Compression Spring in each Jake rocker arm. Shaft part #'s are 2882570 (front) & 2882571 (rear), do both while you're at it and be done. If one is worn out, the other is getting close and the downtime is just not worth the hassle.
The Control Valves are tapered, and wear round or ball shaped as the rocker shafts wear. Not replacing them means you will have a round contact area on a tapered surface. This coupled with Compression Springs which have been compressed over their lifespan & are weakened, will lead to prematurely wearing out your fancy new rocker shafts.
6 valves and 6 springs are less than 25% of the cost of one of the rocker shafts, making not changing them senseless. The only items required to do this part of the job is assembly lube (Vaseline or oil) & small snap ring pliers. This adds 1/2hr to the job and once completed, you will be absolutely amazed at how much your jakes have weakened over the years!
Oh yeah, and I second Rawze's advise, don't attempt to rotate the rocker shafts to locate the detent position. The new procedure with the new style shafts is to finger tighten the shaft bolts and torque the front bolt of each shaft FIRST to properly align the shafts, then torque the remaining shaft bolts. I also do not like the torque plus angle on these bolts, and torque to 95 ft/lbs.