'05 Cam Synchro Failure = Engine Destroyed

[adsm08]

I'm curious what the root cause of the failure is:

Does the bearing fail (lubrication problems?) causing too much drag, and excessive wear on the gear?

Is the gear too soft, eventually wearing badly and causing side thrust on the bearing?

Bevel gears need to slip as they turn - is it a lubrication problem causing gear wear?

And how did Ford screw up a distributor drive, which was worked out 75 years ago?

I have to think it is a bearing issue, and most likely caused by lube issues.

The gears are lubed directly by the main oil system, and the same parts used in the distributors that didn't seem to have this issue. The bearing is probably lighter since it shouldn't have as much load on it. It isn't a huge difference in weight, but the distributor's vane wheel and rotor weigh more than the little vane jobby on the syncro.

 

[decipha]

I hate to be the bearer of bad news but the cam synchros fail due to running the improper oil viscosity.

Back in the early to mid 90s when the crown vic went from the 5.0L engines to the 4.6L modular's (around 1992?) there was a sudden in-rush of thousands of reports of engine failures from police and fleet vehicles. Many were even blowing the oil filters off during high speed pursuits or when driving at highway speeds. Every single one of those cases were positively identified to be due to running improper oil viscosity. In those days the only oil that was readily available in bulk by distributors to police and large fleets was 20w50 which they used for everything. After ford identified the problem and the fleet and police maintenance shops got wind of the cause the problem miraculously went away over night.

Unless you designed and built the engine yourself. You should use the recommend oil viscosity the engineers that actually designed the engine to use recommends. Chances are they know more than you about their engines they designed and if you do so choose to go against their recommendation you cannot be upset if an engine failure results.

 

[8thTon]

I have to think it is a bearing issue, and most likely caused by lube issues.

The gears are lubed directly by the main oil system, and the same parts used in the distributors that didn't seem to have this issue. The bearing is probably lighter since it shouldn't have as much load on it. It isn't a huge difference in weight, but the distributor's vane wheel and rotor weigh more than the little vane jobby on the syncro.

The thing that is curious then is the gear wear shown. Given that the power to drive the oil pump also flows through that bevel gear, it's hard to imagine the synchronizer bearings could compare to the power used to drive the oil pump. Think of a cold engine with thick oil. But there are the reports of people hearing bearing squeal - unless that's not what the sound is from?

I hate to be the bearer of bad news but the cam synchros fail due to running the improper oil viscosity.

Back in the early to mid 90s when the crown vic went from the 5.0L engines to the 4.6L modular's (around 1992?) there was a sudden in-rush of thousands of reports of engine failures from police and fleet vehicles. Many were even blowing the oil filters off during high speed pursuits or when driving at highway speeds. Every single one of those cases were positively identified to be due to running improper oil viscosity. In those days the only oil that was readily available in bulk by distributors to police and large fleets was 20w50 which they used for everything. After ford identified the problem and the fleet and police maintenance shops got wind of the cause the problem miraculously went away over night.

Unless you designed and built the engine yourself. You should use the recommend oil viscosity the engineers that actually designed the engine to use recommends. Chances are they know more than you about their engines they designed and if you do so choose to go against their recommendation you cannot be upset if an engine failure results.

The wrong oil could surely cause those things, but specifically I'm having a hard time accepting it would directly hurt the bevel gear. It might prevent oil spray from going up that little drilled bore to lube the synchro bearings? Then again too heavy oil would increase the drag from the oil pump, increasing the force and wear on the bevel gear.