Caterpillar 3406e engine oil leak

[kenneth hofer]

Hey guys, I have this cat 3406 engine in a 1995 t800 Kenworth. The engine has a leak at the fan mounting fixture. The oil is leaking out behind the mount, just wondering what could be behind it that is leaking. Also the four 19 mm bolts were not tightened enough. Just wondering if anyone has experienced this before?

 

[kenneth hofer]

Engine serial number is 5ek30861

 

[Nige]

The engine Serial Number you posted doesn't relate to a particular type of fan drive. Sometimes happens, a bit of data falls through the cracks during building the engine. The problem is that there appear to be at least a dozen different type of fan drive.
Try posting a photo of the area so that someone can see what type of fan drive you have.

 

[RZucker]

Probably the two 1/2" studs at the top of the front cover. for some reason the gasket will go bad around them behind the timing cover. It doesn't sound kosher... but i have cleaned stuff up good and smeared silicone sealer on the studs and screwed them back in with no leaks afterward.

 

[kenneth hofer]

 

[kenneth hofer]

This is a photo of the serial number. I will try to post a photo of the fan drive tomorrow.
So if I remove the studs, clean them up and just silicone them up , then screw them in that might fix it. Sounds good I will also try that. Thanks

 

[Truck Shop]

RZ is correct, those studs will get to leaking.

 

[kenneth hofer]

So the studs with the double nuts on are the ones that I plan on sealing . The one on the right side is very oily. Just have to loosen the mount to slide it down so I can remove the studs to clean them up as they are around 6” long .

 

[kenneth hofer]

So there you have it. Right side stud is really oily, the other one dry with some gasket maker on it.

 

[kenneth hofer]

Thread also looks beat up on the one, will probably replace both studs

 

[Nige]

So there you have it. Right side stud is really oily, the other one dry with some gasket maker on it.

Is that gasket maker or Loctite.? Hard to see from the photo.

 

[kenneth hofer]

Seems to be some of that ultra blue permatex gasket maker.