Gotta fix the engine again!!!!!!!Cam gear issue!

[vinnimon]

Ive posted this before!Now its time to fix it.

I have a mid to late 70s 140 merc inboard,stern drive 3 ltr engine.Ive rebuilt it,you name it its been done.The second last time it failed,the composite fibre cam gear teeth were worn.Only one thrd of them.

2 months ago the engine did the same thing.Mind you I havent taken anything out except for the ditributor cap.Rotor wasnt turning while cranking the engine over.Thats a given the cams not rolling.WHY?Cause im sure for a fact that the composite gear that a merc dealer sold me failed!AGAIN!But it did last much longer this time!

SO! My question is!

Do I take a chance again with this plastic type gear(which is bunk) in my own opinion!)

OR, Do I pick up a metal gear to attach to the cam shaft?

Keep in mind,Ive rebuilt quit a few engines and never had an issue,!Total rebuilds!

Some of the work on this particular engine has been done professionally!

Ive done all the rest!

Thanks in advance

Ps it is a melling cam gear that I purchased both times,composite fibre gear.Purchased at a mercruser dealer in oakville/mississauga area near the ford plant.

[DRIFTER_016]

I would be getting an aftermarket gear set from a performance shop if it were me.

Nothing like good old metal gears in my opinion.

[SBCregal]

i'd worry about what other parts are gonna get eaten if you replace it with a metal gear. there has to be an underlying problem that is wiping out the gear.

[OhioFisherman]

How are the camshaft bearings? in good shape? proper oiling to them? It would seem to me that there has to be an underlying cause for repeated failures to the gear unless the gears in all the engines have a history of failure? Is the gear belt driven or chain?

[vinnimon]

Ohio fisherman: new cam shaft, new bearings

Dunner: origanally it was steel on alum,now steel on comp fibre

Drifter016: It was a merc dealer and a high performance marine/auto shop that supplied the upgraded parts from melling!In the miss/oakville area.

Just so you guys know its gear on gear.A matched gear set with no adjustments.Meaning no timing belt or timing chain.Cam shaft is new and bearings as well!

[vinnimon]

How are the camshaft bearings? in good shape? proper oiling to them? It would seem to me that there has to be an underlying cause for repeated failures to the gear unless the gears in all the engines have a history of failure? Is the gear belt driven or chain?

 

 

Gear on gear!

[DRIFTER_016]

Anyone ever check crank runout on the engine?

Could be an alignment issue.

 

Talk to the guys at Active Engines, they are pretty good at what they do.

 

They should be able to give you some info on what might be causing your issues.

[OhioFisherman]

old school, I like metal gears, but I would do some checking first? See if they are available? maybe a speed shop? and will any extra weight call for a different harmonic balancer? Just throwing out ideas, most of my experience is on small block chevys.

[vinnimon]

Anyone ever check crank runout on the engine?

Could be an alignment issue.

 

Talk to the guys at Active Engines, they are pretty good at what they do.

 

They should be able to give you some info on what might be causing your issues.

 

 

Thats where I purchased the parts