All right ya'll, here is a puzzle that is baffling me.
I've hit a roadblock in my brain with my engine
It's a Universal 5444 (4cyl diesel) that it's about 32 years old with reportedly 1900 hours (1982, Pearson
#42). I just got done rebuilding the engine
(I stripped it down to block and head
, sent that to machine shop to deal with pistons, honing, valves, etc..). I then reassembled it and it runs (surprised the hell out of me, but it runs). It runs smooth, shuts off quick and starts within a second. I am really impressed with its behavior. I thought there was nothing wrong with the old engine, but I sure was wrong. I guess if you don't know something is wrong, you don't know it's wrong.
The only problem is a creaking noise
emanating from somewhere in the bell housing area of the engine. The noise
also has a corresponding vibration that can be felt in many parts
of the engine: crankshaft, transmission
riser, raw water
hoses, and many other areas, except the larger metal chunks like the block and head
. It kinda sounds like the creaking a rubber impeller makes when it's dry.
While reassembling the engine, I turned it by hand and never heard the noise, which did not appear until after first run of the engine (last Saturday). Noise and vibration cannot be heard or felt when engine is running because of all the other noise/vibration sources. That doesn't mean it is not present, just that I can't perceive it over the other racket that the engine makes. As engine shuts off, vibration can be felt momentarily.
Noise is very apparent when hand cranking the crankshaft. It does no matter if transmission
is in fwd, rev. or neutral.
It does not matter if the decompression lever is on or off
I removed the bell housing (to which the transmission is bolted) and the noise was not apparent.
I put the bell housing back on (with transmission) and loosely fitted it (about 1/4" gap between bell housing and block mating surfaces): no noise
I tightened the bell housing bolts and as the bolts closed the gap to about skinny a 1/4 to 1/8", the noise became apparent.
The noise is related to how close the bell housing is to the block. When the bell housing is completely mated to the block, the noise is readily apparent.
The damper plate is new (old one exists, but rattles a bunch).
I put the old damper plate on and there was no noise, even with bell housing firmly bolted to the block.
Another important note is that with the new damper plate, I could put the bell housing on up until about a skinny 1/4" gap, then I had to use the bolts to close the gap.
With the old damper plate, I could close the gap without any bolts, just as if there were no damper plate. It just slaps up right against the block
The damper plates have the same part number, they should be identical.
The new damper plate is much quieter than the old one (except for the creaking noise)
1. What is the relationship between the nose and the new damper plate?
2. Is there a break-in period for damper plates, during which they will make this creaking noise?
Link to page that has pictures and a video of me cranking the shaft and hearing the noise:
Edit: One possibly important observation is that when I turn one direction (clockwise) the noise is present, then when I turn counter-clockwise, the noise is absent for about a 1/4 turn, then resumes.