314C Rear Main Seal

[cric8192]

Recently had the hydraulic pump out of our 314C Cat excavator to be resealed. It was leaking from a couple different sealing areas.

Just wondering if there is anything that could of been done wrong on installation of the pump to cause rear main seal to go out less than 3 hours with resealed pump back in?

The flywheel never came off, the pump slid on and off dowel pins with a rubber dampener style coupling. The pump was a bit tight going back on the last half inch or so of the dowel pins but I assumed this was normal considering the weight of the pump.

Any help much appreciated.

 

[Bluox]

I'm going to bet the pump drive was installed wrong and you took out the thrust bearing on the crank.
Bob

 

[heymccall]

With hindsight being 20/20, I, just like you, have the learned the hard way to always check crankshaft end play when hanging any pump or transmission.
As stated above, I, too, suspect thrust bearing failure along with the seal.

 

[cric8192]

Some more info- I remember the pump re-builder sliding the center portion of the pump drive onto the pump input shaft and torquing the set screw with me wondering how he knew exactly where on that pump shaft to lock it down to. Assuming this was set too far towards the end of the pump shaft I guess that would take up the end play of the crankshaft and also explain the tough last 1/2" of the pump going back on?

First time doing anything like this-

 

[Vetech63]

that would take up the end play of the crankshaft and also explain the tough last 1/2" of the pump going back on?

Yeah, that's not good.

 

[cric8192]

This doesn’t sound good at all. Is there an end play spec from cat that I can reference to check the thrust bearings once the pump is off?

3064 engine
Serial #PCA01396

Thanks

 

[Vetech63]

Minimum is .004, Max is .020

 

[Vetech63]

That last 1/2 that was forced to get your pump bolted up pushed the crankshaft to one side of the thrust bearing. That load while running has more than likely burned up the thrust bearing. You could drain the oil in a clean bucket and check for metal filings to verify, or remove the pump and check the crankshaft end play off the flywheel. Continuing to run the engine will only destroy more components.

 

[Bluox]

This doesn’t sound good at all. Is there an end play spec from cat that I can reference to check the thrust bearings once the pump is off?

3064 engine
Serial #PCA01396

Thanks

PCA is machine serial number, engine is a 3064T should be a 6LK number. The good news is over size thrust bearings are available if it just wore the crank and not the block.
Bob

 

[cric8192]

Just trying to visualize what happened here, I’m sure it will make more sense when the pump comes off.

The pump drive was not set in a position where it extended past the end of the pump input shaft.

If the pump drive coupler was pushing against the flywheel wouldn’t that mean the input shaft would have to be as well?

 

[heymccall]

Yes. Inspection of the pump is warranted too. It's a little more forgiving, relatively speaking, than the engine.

 

[cric8192]

Thank you guys for pointing me towards the problem at hand.

The dowels on the flywheel bottomed out in the recesses in the pump drive and just kept pushing as the pump was bolted up. It was set too far forwards on pump input shaft.

Crank end play is near .050 with lots of fine metal filings in the engine oil.

 

[Vetech63]

Thank you guys for pointing me towards the problem at hand.

The dowels on the flywheel bottomed out in the recesses in the pump drive and just kept pushing as the pump was bolted up. It was set too far forwards on pump input shaft.

Crank end play is near .050 with lots of fine metal filings in the engine oil.

 

[kshansen]

Crank end play is near .050 with lots of fine metal filings in the engine oil.

Sorry to hear that!