Need help figuring out a noise/vibration I'm having

[42_NATO]

My first thought is I need new mounts. After replacing my stat and belt I was letting the engine warm up. And I was giving it some gas to speed up the process. I don't have a tach so I would have to guess I was slightly over 1000rpm. And I noticed a noise vibrating in the cab. Felt like an on off on vibrating sound. Any one have any idea on what it could be.

1965 c20 with a 350 v8 4 speed tranny

[padresag]

was it your phone?
ron

[dougf]

I would check engine/trans mounts and then body and radiator core support mounts, then doors to see if they are shut tight.

[42_NATO]

Originally Posted by padresag

was it your phone?
ron

Lol good one. But no I will get under there again and check all mounts . I did notice the body mounts are old and falling apart. Buy didn't think they would be it since it only happens under acceleration

[padresag]

was this revving the engine under load or were you just sitting there. under load when you rev it does the shifter move towards the passenger side; if so that could be eng mounts. did it do this before you changed the belt. could be the bottom rad hose collapsing. could be the speedo cable. you should try and pinpoint the noise, could be a lot of things and that is why I mentioned your phone. you are the only one actually there so you are going to have to do a better job of isolating it
ron

[42_NATO]

Originally Posted by padresag

was this revving the engine under load or were you just sitting there. under load when you rev it does the shifter move towards the passenger side; if so that could be eng mounts. did it do this before you changed the belt. could be the bottom rad hose collapsing. could be the speedo cable. you should try and pinpoint the noise, could be a lot of things and that is why I mentioned your phone. you are the only one actually there so you are going to have to do a better job of isolating it
ron

Thanks Ron. I was accelerating with no load. And didn't notice it before.since u mentioned the speedo sensor. My gauge doesn't work because of the gear inside the tranny . but not sure if that has anything to do with it or not.and my bottom radiator hose has some sort of cool to help prevent collapsing. I will try to get a sound clip today with some pics

[42_NATO]

there is cracking but how bad is it. Should they get replaced

[padresag]

if you didn't notice it before and you did afterwards that may narrow it down to what you did. is the new belt defective. to tight or to loose. forget to tighten something?
ron

[61K10]

In neutral--clutch in or out--in gear? grab the trans shifter, feel any vibs?

[SS317]

Did you make sure to tighten the bolts on the fan really good? I just added power steering and after I replaced and added belts I had a vibration, it was my fan bolts.
Just a thought.

[42_NATO]

Only bolt I touched was the alternator adust bolt and the belt is snug with minimal play only reason I noticed it was cause I was accelerating at idel not in gear or any pedal pressed.

[Mackie]

If the vib only showed up after your wrenching session then it's likely you are the prime suspect. I'm kidding...sort of.

But you might try running it with the belt off to see if it goes away.

[LostMy65]

Did you narrow down your issue?

[42_NATO]

No at his moment I'm leaning twords this truck is old as hell. But I have a bigger problem. A few weeks ago I was huling some large rocks from the river. And around the corner from our farm . I destroyed the clutch . as I went to put it in 4th it made an unusual grinding noise popped out and costed to a stop. She goes in gear fine but it looks like the clutch is no longer attached to the engine some how. Still havnt torn it apart. Cause I'm debating fixing the old or swaping in a t5 tranny if I can find one

[padresag]

all problems show themselves in the end if they are left too.
A t5 trans will show it's problems also if you use it for hauling to much stuff around the farm
ron

[jtrichard]

You may have just found your vibration cause

[61K10]

If i put my sm420 in neutral with the clutch out i get a vibration revving the engine some. cheap clutch out of balance? I use to spin the center out of my clutch disc when i was a kid--56 chevy 327/4sp/4.56 gears. I think they were $7.00 for a rebuilt lol!