I have a rattle that makes my engine sound like a diesel between 5-700 RPM when the car is in gear (automatic) and at a stop sign. The sound seems to eminate in the vicinity of the alternator. The sound goes away in neutral or park or when above the stated rpm. In my initial search I discovered that if I press on the tailpipe with my foot, the rattle ceases. Now I have to find a way to inspect the car from the bottom while it is in gear and standing still to determine the source. I am surely not going to do it with the car on jacks! I have steel timing gears so I don't believe it is my timing gear, especially since the rattle goes away when I step on the tailpipe. Does yours have the same symptoms?

I wiped a timing gear a couple weeks ago. This is only my second one
to lose teeth (about a dozen of them) but the noise was pretty similar
to previous cases, but it happened in less than 1/2 mile as opposed to
one failure in my 164 that happened over about 2 months and over 2000
miles, back in about 1978.

If the noise is coming from inside the timing cover that is DEFINITELY
the place to look. You may not see anything (if the gear is loose on the
hub). But you can pretty well count on the gear being bad.
Might want to look at my post. Not sure if this URL is still correct:
http://www.brickboard.com/RWD/?id=538529


--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma

I';m definately on the timing gear band wagon. I had one come loose from the hub and despite making a horrendous clatter at idle (I was sure a rod bearing had spun) it continued the rest of the 100 miles home on the trip. When I pulled the timing cover off the fiber portion actually fell out - it was only being held in place against the splined hub by the timing cover.

Steel timing gear kits (both gears, gaskets, thrust bearing, seals) are available from www.kgtrimning.com for $183. But frankly just a new fiber timing gear is sufficient for a stock cam in an engine that gets normal useage - only about $40 and it will last another 150,000 miles and/or 20 years.

Jim;

A long time ago, I had the nut which holds the timing gear onto the cam nose loosen, back off, and ping into the timing cover with a semi ramdom clatter not unlike that of a diesel...it was a freshly built B20 turbo (brand new fibre gear)...the noise started right after a big backfire while we were setting up the carburation (single HS8 in suck-through). I figure the impact of the backfire helped brake the nut free, and engine vibrations did the rest...but the cover is close enough that it wasn't able to fall of, so it just sat up against it and whacked it whenever it wanted to...you might want to pull your timing cover and have a look before pulling the whole engine...

I've noticed that the nuts fit pretty loosely onto the threads of most replacement cams, so having learned the hard way, nowadays I safety wire the nuts after torqueing...

Good hunting, and please let us know what you finally find.

For what it's worth.... I bought a 67 wagon last year that was making this noise. Drove it 500 miles home and back and forth to work for 3 months until a u-joint broke and I parked it. Engine sounded horrible but never quit. I don't know if I was just lucky but if my experience is typical, you might not have to fix it immediately.

Bob
6 Amazons in various conditions

I've had three or four fiber timing gears fail with just the noise you describe.

A set of steel gears, as used on the B30, will last longer than time itself. And they have a satisfying mechanical whine, too.

When you replace/install, use a new brass thrust washer and keep the steel spacer ring in mind....

...Also, be sure the brass oil nozzle is clean and aimed...

--
Don Foster (near Cape Cod, MA)

Timing Gear, they don't tend to fail completely on a B18/B20 but the fibre comes loose from the hub. They then just knock like a London Taxi.


Regards


Pete