Trans vibration or no?

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MOPARJ

MOPARJ

What can I upgrade now?
Joined
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What are the thoughts on a cause of minor vibration, more like elevated harmonics between 2800-3100 rpm, either driving or in park or neutral? 318 with 904. Seem like motor mounts, flywheel, flexplate, converter? Above 3100 rpm, I don’t really seem to notice the vibration/harmonics near as much, and nothing below 2800 rpm. The transmission and converter seem to shift and operate great. Converter is stock 11”, built up to yield 2600 rpm stall speed. Tran-go shift kit in transmission, with no external or add on cooler. 3.91 gears in rear.
 
The first thing that I would do is remove the belts from the front of the engine and run it like that. You say it does it in park so this test should only take a minute of run time. That will eliminate anything up front like the fan, water pump ect.
You also might want to take a look at the dampener to see if it's in good shape.

Ted
 
Good point.

Water pump is good, about 4 months old, maybe 600 miles on it. Replaced fan clutch about 3 months ago. Might switch back to the old one on hand to see if it makes a difference. Need to check the balancer (pretty sure its at least partially spun since the timing mark doesn't line up anymore).

What's the best way to check on the balancer/dampner?
 
MOPARJ said:
Good point.

Water pump is good, about 4 months old, maybe 600 miles on it. Replaced fan clutch about 3 months ago. Might switch back to the old one on hand to see if it makes a difference. Need to check the balancer (pretty sure its at least partially spun since the timing mark doesn't line up anymore).

What's the best way to check on the balancer/dampner?
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"Balancer" There is a clue in that word. :D
 
Haha.

Yes I will check the balancer as a precaution. I will try to move it up and down and side to side for play and check the rubber seal. It's the same balancer from 73 with about 170k miles on it
 
OK. Just to be clear, you have stated that the balancer appears to have spun because the timing marks do not line up any more. So even if this is not the cause of your vibration it has to be replaced!!!
Do it before it really causes some damage. Who knows it just might fix your original problem too.

Ted
 
I think to check the balancer, you need to remove the number one plug. Put in a piston stop. Rotate clockwise till it stops.mark balancer. Rotate counterclockwise until it stops. Mark balancer. Measure between the two marks, finding the center. Mark this. This is actual tdc. If it doesn't line up with the factory mark, the balancer is spun.
I had a torque convertor that wasn't balanced properly. Caused a vibration like you describe.
 
furyus2 said:
I think to check the balancer, you need to remove the number one plug. Put in a piston stop. Rotate clockwise till it stops.mark balancer. Rotate counterclockwise until it stops. Mark balancer. Measure between the two marks, finding the center. Mark this. This is actual tdc. If it doesn't line up with the factory mark, the balancer is spun.
I had a torque convertor that wasn't balanced properly. Caused a vibration like you describe.
Click to expand...

The marks have been off for a bit. Checked this morning with distributor rotor pointing at number one plug wire as a quick check. The factory timing grove is still out of site at that point, right near the bottom of the balancer.

I think it has been like that ever since I rebuilt the motor a few years back (46k miles since). The machine shop put the balancer on; could they of put it on wrong, or incorrectly clocked?

As mentioned, the harmonics (not really vibration) has been taking place for the past 1200-1300 miles.
 
MOPARJ said:
The marks have been off for a bit. Checked this morning with distributor rotor pointing at number one plug wire as a quick check. The factory timing grove is still out of site at that point, right near the bottom of the balancer.

On the compression stroke??

I think it has been like that ever since I rebuilt the motor a few years back (46k miles since). The machine shop put the balancer on; could they of put it on wrong, or incorrectly clocked?

No.

As mentioned, the harmonics (not really vibration) has been taking place for the past 1200-1300 miles.
Click to expand...
..
 
MOPARJ said:
The marks have been off for a bit. Checked this morning with distributor rotor pointing at number one plug wire as a quick check. The factory timing grove is still out of site at that point, right near the bottom of the balancer.

I think it has been like that ever since I rebuilt the motor a few years back (46k miles since). The machine shop put the balancer on; could they of put it on wrong, or incorrectly clocked?

As mentioned, the harmonics (not really vibration) has been taking place for the past 1200-1300 miles.
Click to expand...

Do I really need to do this again? :D

It's called a "_______" balancer for a reason and it sounds like yours is almost 180 out of place.
Being 180 out of place will double the "______" instead of countering it like it was designed to do.


They go on a keyway on the crankshaft, so no he couldn't have put it on wrong.
(Well, unless he didn't put the key in it)
 
Bad Sport said:
Well, there is that, lol.
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That was meant as a joke for the most part, but you never know.
I have seen people pay someone to end up doing worse on this site.

Like this supposed X pipe a shop did.
 

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TrailBeast said:
That was meant as a joke for the most part, but you never know.
I have seen people pay someone to end up doing worse on this site.

Like this supposed X pipe a shop did.
Click to expand...

:laughing:

That X-pipe is funny. Pretty sure I could weld better than that and I am not very good at it.

As far as the keyway, the machinist could of left it off but who knows. All and all, I just need to order a new balancer to take care of that regardless.

Anybody think I am in any real danger of a failure on the road? Wont get to it until after the weekend and I have a few shows to attend this weekend. I'm personally not too concerned since its not severe and has not worsened or changed pattern at all.
 
I may try swapping my old fan clutch back on as well from a few months ago as well. This new one seems to whirr and be engaged while revving (noisier)even when cold.
 
MOPARJ said:
:laughing:

That X-pipe is funny. Pretty sure I could weld better than that and I am not very good at it.

As far as the keyway, the machinist could of left it off but who knows. All and all, I just need to order a new balancer to take care of that regardless.

Yes, TrailBeast, I did laugh at the "HARMONIC balancer" joke:D
Click to expand...

Yea, it's all meant in good clean screwing with you. :D
Everybody knows I'm a terminal smartass, but I can take it too.

MOPARJ said:
I may try swapping my old fan clutch back on as well from a few months ago as well. This new one seems to whirr and be engaged while revving (noisier)even when cold.
Click to expand...

Just in case, they do spin at full speed for a bit but then are supposed to slow down as higher RPM's continue.
Just a guess on how long would be about maybe 10-15 seconds at sustained RPM's
They can be soooo different, as I had one on an RV that would NEVER free spin (not even dead cold of winter) and I hated that damn thing.
Come to find out the part number crossed to a HD unit. (why it never released I guess they could have just made it solid):D
Replaced it with a standard pickup truck unit and it was fine after that (and never got hot)
 
TrailBeast said:
Yea, it's all meant in good clean screwing with you. :D
Everybody knows I'm a terminal smartass, but I can take it too.



Just in case, they do spin at full speed for a bit but then are supposed to slow down as higher RPM's continue.
Just a guess on how long would be about maybe 10-15 seconds at sustained RPM's
They can be soooo different, as I had one on an RV that would NEVER free spin (not even dead cold of winter) and I hated that damn thing.
Come to find out the part number crossed to a HD unit. (why it never released I guess they could have just made it solid):D
Replaced it with a standard pickup truck unit and it was fine after that (and never got hot)
Click to expand...


Yeah I think this guy is an HD unit. Definitely hear it engaged at low speed at any temperature just after starting it up.

I'll try that swap then look into the balancer after I get done with the shows and 100 or so miles of driving this week. Luckily like I mentioned, its nothing jaw jarring or intense "harmonics :D" wise. If anything, I want to get it replaced just to have my timing marks lined back up again!
 
MOPARJ said:
Yeah I think this guy is an HD unit. Definitely hear it engaged at low speed at any temperature just after starting it up.

I'll try that swap then look into the balancer after I get done with the shows and 100 or so miles of driving this week. Luckily like I mentioned, its nothing jaw jarring or intense "harmonics :D" wise. If anything, I want to get it replaced just to have my timing marks lined back up again!
Click to expand...

Well, like I asked. When you checked it, was it top dead center on the compression stroke?

If not, that would account for it being off.
 
Bad Sport said:
Well, like I asked. When you checked it, was it top dead center on the compression stroke?

If not, that would account for it being off.
Click to expand...

I didn't have the #1 plug out when I checked this morning before work. Only eyed the rotor positioning relative to #1 plug to get a rough idea and timing mark was not close to TDC on the indicator on timing cover. I will pull the plug and check the "correct way" when I get home in an hour or so.
 
MOPARJ said:
I didn't have the #1 plug out when I checked this morning before work. Only eyed the rotor positioning relative to #1 plug to get a rough idea and timing mark was not close to TDC on the indicator on timing cover. I will pull the plug and check the "correct way" when I get home in an hour or so.
Click to expand...

Well, if it was pointing toward #1 on the cap and the mark was on the bottom, it slipped.
 
Bad Sport said:
Well, if it was pointing toward #1 on the cap and the mark was on the bottom, it slipped.
Click to expand...

Yeah, I will check again tho. It is easy enough to do and easy enough for me to have screwed up this morning before drinking coffee. :D
 
Checked to see if rotor was pointing to the #1 plug when the mark on the balancer pointed to TDC on the timing cover indicator. Actually it was pretty damn close so it might not be spun after all. Tried pulling belt off of water pump and fan and running it....no difference. If not balancer, starting to wonder about the worn out Motor mounts maybe.
 
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