8N cam thrust washer/spring

[CRJ70]

Howdy,

Im rebuilding my 48 8N engine and have stopped due to a missing cam thrust spring PN 8N6276. It wasnt in there when I tore the engine apart and there is no evidence of it hitting the front cover but if it is supposed to be there then it should go back. Ive called Roberts and New Holland and neither have one. Anybody want to sell one? I thought about making one out of delrin but that just seems like a pain. On the same line wouldnt the front mount distributor keep the cam from walking forward?

 

[Den N Ms]

CRJ70, The camshaft thrust washer was not used in engines before SN#187030.Engines made before 8N187030 didn't have it. The cut of the gears drive the cam rearward most of the time, but in an off-throttle coast down, that force may momentarily be interrupted, causing the cam to jump forward slightly. The washer was to stop that. Cam gear cover and front mount keeps it from going far.

 

[CRJ70]

(quoted from post at 08:00:08 08/19/21) CRJ70, The camshaft thrust washer was not used in engines before SN#187030.Engines made before 8N187030 didn't have it. The cut of the gears drive the cam rearward most of the time, but in an off-throttle coast down, that force may momentarily be interrupted, causing the cam to jump forward slightly. The washer was to stop that. Cam gear cover and front mount keeps it from going far.

Ahhhhh thank you for the info.

 

[Dogdoc427]

So the thrust washer is considered
optional? I'm in the middle of a teardown
/ check over on a several times short
blocked 2N and found everything to be in
decent condition. Oil gap on bearings is
in spec, no wear on liners, mouse house
removed from intake manifold etc. I took
the timing cover apart to seal some old
leaks and found the oe cam thrust washer
burned and blued with corresponding
gouges in the timing cover. If it is not
a required item I'm golden!

 

[Den N Ms]

Dogdoc427,Washer not needed for a 2N.Some one must have added it at some point and if has turned blue and scored that should tell you that things are to tight in there with it installed.

 

[Dogdoc427]

I have no way of knowing where this engine originated, I'm sure it's not original, that one went back to the rebuilder around 1978 or so. There have been 1 or 2 since. There is very little end play in the cam
so I'll leave it out. Thanks for the reply!