Clutch Pilot Bush: NOS vs Aftermarket

[AUSMHLY]

Hello, I need to replace the pilot bush in my 3000 Mk III engine.
I've found some NOS clutch pilot bushes.
Moss has reproduction ones.
Any reason to buy one over the other?

 

[Keoke]

HI TH, NOS hardware will probably fit,
sometimes replicas can give U a fit.

 

[red57]

I agree, I always prefer NOS where available. I suggest you read this Oilite technical bulletin and correctly re-oil (2nd page) before installing because you don't know how long they have been sitting. Oilite Bushings
Dave

 

[Bob_Spidell]

Another maintenance item I'm sure we're all doing religiously: "The oil should be replenished after 1000 hours of use or annually."

 

[AUSMHLY]

I"m glad I asked the question. I assumed it would be a simple buy it, install it. Not so.

The oil should be replenished after 1000 hours of use or annually.
Being in the location it is, no one does that.

Wash in oil if storage conditions suspect, if they have been held in stock for more than a year or stored in contact with an absorbent material.
Buying anything that's over 60 years old, storage conditions are suspect. I'll need to do that.

Always use a steady pressure to insert the bearing. Never use a hammer.
I use a metal socket on an extension and dead blow hammer. How does one install without using a hammer?

STORAGE: OILITE bearings can be stored for considerable periods at room temperature without deterioration or loss of oil if kept in a metal or other non-absorbent container.
How long is considerable periods, (that's like saying it's small. What size is small?) I'll assume it was stored over 60 years, in the plastic bag in the ad.

Re-OIlING: after machining of the bearing, or following oil loss during storage, immerse in high quality mineral oil conforming to ISO VG 60 or ISO VG 150 (SAE30 or SAE40) at 80°C to 100°C for 10 to 15 minutes and then cool in cold oil.
That's a lot of work for a $5 part that's available from Moss, no oiling needed....I'll assume.

How many people here, per what's required above, would use NOS?

 

[DrEntropy]

Re-OIlING: after machining of the bearing, or following oil loss during storage, immerse in high quality mineral oil conforming to ISO VG 60 or ISO VG 150 (SAE30 or SAE40) at 80°C to 100°C for 10 to 15 minutes and then cool in cold oil.
That's a lot of work for a $5 part that's available from Moss, no oiling needed....I'll assume.

IMHO, I would go with NOS and do the hot oil, cold oil "quench" routine. And check for fit with the gearbox input shaft BEFORE final assembly. The NOS one is sintered bronze, retains an amount of oil. The aftermarket bushings likely are not. And once in service for a while it's hard to access...

Schedule 40 PVC makes a better drift than a socket, BTW. Any burr or deformation will make fitting the input shaft a "challenge" IYSWIM.

 

[John Turney]

When the bush is flush with end of the crankshaft, don't push any more.

 

[WHT]

Always use a steady pressure to insert the bearing. Never use a hammer.
AUSMHLY: I use a metal socket on an extension and dead blow hammer. How does one install without using a hammer?

I always use a gear or pulley puller to install pilot bushings. As with a hammer, a socket or bushing driver can be used with the puller to gently press the pilot bushing without stressing the crankshaft by pounding on the bushing. It works very well.

Regards, Bill

EDIT: BTW, Hot Rodders used to put a thick felt pad saturated with oil behind the Oilite bushing to keep it from drying. And, use a bushing with no or low iron content to prevent damage to the input shaft.

 

[WHT]

Hi AUSMHLY.

Just a followup picture with my spigot bushing installed. It looks a little different than your because I am using a different diameter input shaft. And, as you know, make sure the inner diameter has not closed during installation. Spigot bushings can be anywhere from 0.001 to 0.003-inches larger diameter than the opening in the crankshaft; and this can sometimes affect the inner bushing diameter after installation (which can be opened again with a drift or reamer).

Be careful, NOS can have different meaning to different companies. They may call old on the shelf aftermarket bushings NOS. Make sure they are actually NOS factory bushings.


Some aftermarket replacement Oilite bushings are made overseas and have a high iron content. A good bushing will not be slightly magnetic.



Regards, Bill