Help! Vibration Issue!!!

Quote:

---

To sum up if you have a vibration issue similar to mine first area to look is THE DAMPER. 360 engines are external balance and sensitive to being out of balance when damper gets old. Also try a different tranny mount. Rubber may cushion better than poly, maybe not if engine in good tune and balance.

---

Would be curious if you put on that new style poly prothane bushing whether it would add or not change any vibrations you have now.

I have heard that the poly trans mounts just magnify any vibration you have.

I know someone with a complete resto'd Challenger T/A that changed from poly to rubber and it helped a bunch. But after that, did a pinion angle correction and made a big difference.

The thing about the Summit brand balancer is a tough one to diagnose. I mean if it was new and didn't skip it marks, how could you check if it was bad?? Should we just avoid Summit brand dampners??

Hazwoy, did that Summit balancer show any sign of rubber gushing out or not looking uniform??

Quote:

---

For the life of me I cannot imagine why The Summit damper didn't work. It looks to be counterbalanced the same way and only one application for 1971-1992 Dodge 360. All I know is it looked great, ran straight but my problem was not resolved until I rebuilt and installed original damper. Stock has weight removed for proper balance, Summit instead has weight added to opposite direction and side. Can send you detailed pics of damper if you like (autoxcuda) Tried to post pics, didn't work.

---

Quote:

---

Here are the pics...

---

Did you notice anything thing wrong or different with your old dampner compared to when they rebuilt it?

Did Dampner Doctor mention what they found wrong with your old dampner?

What did Dampner Doctor charge? Sounds like a good resource. Will have to file that one away for future use or pass it along to others.

Quote:

---

No I did not notice anything wrong with damper upon inspection. It did have maybe 1/16" wobble at crank pulley compared to dead on straight with Summit or rebuilt damper. Here are close up pics. If you look at closely at about 1 o'clock you can see the rubber ring just slight deformed. On back side if you looked really close you could see just the slightest bulge at 7 o'clock (opposite side). Anyway bottom line- didn't really look like it was messed up to me.



Damper Doctor actually added a bit of confusion to the mix even tho they fixed the problem. My block is 1989-1992 360 truck motor (junkyard receipt) but Damper Doctor receipt said my damper was 1993. When I called to verify boss wasn't in, when I called back assistant said Doctor said receipt incorrect, damper was 1992. Never said if they found anything wrong, just rebuilt per request. Cost was $112 including shipping. Mailed Priority Thursday, got back Wednesday

---

Sometimes the hub can shift it position, in
relationship to where the TDC (0 Mark) is as
it was made in the factory. The movement could
be slight enough, that to the untrained eye it
could look normal. Rubber DOES deteriorate with
age, and that is a major contributor to damper
problems/engine vibration. As far as the noise
level and "droning", I believe that a good
exhaust setup with a crossover would solve your
noise problem. Part of the problem is the chioce in mufflers, some are not as good as others.
Check around before you plunk down your cash
for them. It is a matter of balancing noise/
quality/performance here, don't be afraid to do
your homework on this. You might be surprised to
choose a system that would net you maybe 20 hp
more than your current setup, and be a lot more
quieter while cruising. Food for thought! Also
your carb air/fuel ratio and jetting is involved in this too. Have it "fine tuned" after replacing
the system. You could pull a couple more "free
ponies" and make your ride more efficient too.
That would be easier on your wallet at the pump
and "Joe Law" would be happy too, not writing you a noise ticket. All in all a better cruiser.

Quote:

---

To sum up if you have a vibration issue similar to mine first area to look is THE DAMPER. 360 engines are external balance and sensitive to being out of balance when damper gets old.

---

There are 2 styles of factory 360 dampers - yours, which I call new style, and the old style (which I prefer) that the weight is ADDED to the center hub, not taken out of the outer ring. On the old style, (on the left in the photo from the archives) the weight is added to the outside of the center hub, so the "imbalance" of the outer ring doesn't stress the rubber cushions like the new style. The new style probably work well enough for you, since you probably don't spin the motor much above 5500. Above that, the RPM will start to work and wear the rubber ring, causing the outer ring to rotate or wobble, causing a vibration. I don't know the years that the old style ones came from, but I grab them when I see them.

Quote:

---

There are 2 styles of factory 360 dampers - ... On the old style, (on the left in the photo from the archives) the weight is added to the outside of the center hub, so the "imbalance" of the outer ring doesn't stress the rubber cushions like the new style.

---

Quote:

---

So I put back in the poly tranny mount to see if it made a difference now that the vibration is mostly solved with the rebuilt damper.

---

The transmission mount isn't a moving part and therefore can't be a source of vibration. Putting in a stiffer mount will certainly TRANSMIT more vibration from the transmission to the passengers, after all, it was put in there just for the purpose of isolation vibrations.

Quote:

---

Got rid of that last bit of annoying pulsating drone in the car at 2700 rpm. You would not believe it- it is the alternator/belt system.

---

I dont believe it