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Noise on my 70 with new muncie

5K views 36 replies 18 participants last post by  kef3992 
#1 ·
70 Chevelle. Took the 400 out put new m22 it’s new clutch etc. first install , vibration was so bad I couldn’t drive it. Removed tranny and had clutch balanced with the old flex plate that was with the 400. Vibration better but definitely not smooth. Shifts great but now I’m getting noise when clutch pedal released. I’m thinking either the imput bearing or the throw out. Only about 100 miles or so on the new setup. I want to get rid of the vibration. Not sure if I should be looking at alignment issues, driveshaft, imput bearing should not have gone bad this soon. I haven’t checked oil level yet on the Muncie. Any ideas as where to start. Vibration increases with higher speeds. Tracy.
 
#3 ·
There could be a lot of things going on. So prepare to check lots of things

1) did you ensure there was an airgap between throwout bearing and clutch fingers? If the bearing was touching, it would wear out within about 100 miles. I know this, cause it happened to me.

2) Did you check your bellhousing alignment? If your way off center, it can cause issues. Though usually it'd create shifting problems

3) Can you explain the noise? Does it sound like it's coming from front of transmission? Does the noise happen while driving and goes away if you push in the clutch?

4) Check your driveline angles. Ideally you want equal and opposite operating angles of the U joints under 2*. Sometimes that is not always possible. Download the Tremec driveline angle finder app, it's free and easy.

5) where is the vibration? Is it in the shifter, or your pedals, or the whole car?
 
#4 ·
Pull the whole thing and start over. Align your bell housing, replace the input bushing, check the input bearing on the trans. Inspect all the parts for signs. Your disc may be bent too. But usually, this would creat release issues.

Sounds like the clutch disc is being allowed to move and when you release the clutch the disc is not centered causing the vibration.

When you are sitting stationary and rev the engine with the clutch out you should be able to feel the vibration if the above is the case. The vibration could at times be less or worse depending on where the disc settles and how far out it sits. You may not feel the vibration with the clutch in when you rev the engine.

Using an externally balanced flywheel on an internally balanced engine could also cause the vibration.

Check your u joints. You would have no vibration when reved up if the issue was further down the driveline.
 
#13 ·
454 big block uses a different flywheel than 396 or 427.Small block Chevy 400 uses a different flywheel than all the other small blocks.If what flywheel you used is not the correct one you'll never fix that vibration.
Up to this point you haven't said what engine just "70 Chevelle"
 
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#14 ·
Ok, it’s a Chevelle ss 454. I just dropped the driveshaft and am having it checked for balance just in case for process of elimination. I revived in neutral and no appreciative vibration. The sort of knocking noise when I release the clutch was not there this morning on a cold start. I’m ch cling on correct flywheel. I bought new a couple of years ago with all the clutch parts. Just got around to the swap. .
 
#15 ·
Ok. I called summit where I purchased flywheel. It still was on file. It’s a 11” diameter disc with 1 1/8 diameter shaft with 26 spline. Part number 700180. I’ll research it. I do remember it as being balanced out of box seeing the drilling marks. Any info would be helpful.
 
#18 ·
I just looked at the flywheel you bought and it is not for a 454 BUT . . . in your original post you said that you had it balanced to match the flexplate you had on the engine with the TH400 ? Correct ? If that is the case it should be fine.

So . . . . .

If you dont have a vibration in neutral then it is probably not the flywheel or clutch. Most likely the driveshaft or something else from the transmission back.
 
#20 ·
I am confused. You keep talking about balancing the clutch to a flexplate. Flex plates are for automatics and I assume you are calling your SFI rated flywheel that you bought which BTW is for an internally balanced small block. The 400 SBC and 454 BB use an externally balanced flywheels so if you are using the part number Summit 700180 on a 400 or 454 its wrong. Am I missing something here?
 
#25 ·
If that part # is correct , you have an INTERNAL BALANCE flywheel , whereas a 454 is EXTERNALLY balanced meaning it literally has a slug of metal bolted to the wheel. If that is true, the vibration ought be there always.

Driveshafts out of balance usually feel like it at 55-60 mph.
 
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#26 ·
Didn't read all the replies, but, some things to think about..

Gene is right on with the flywheel.
If that is true, it could be bad news.
My engine builder balanced the rotating mass together.
That means the crank, rods, pistons and flywheel and harmonic balancer. He did drill the flywheel some.

Hopefully,

its the pressure plate out of balance, which is a long shot,

or the bushing in the end of the crank for the trans pilot shaft is missing or the wrong size.

If the flywheel was not bolted squarely with the crank flange, it would vibrate like crazy.

If the pressure plate were not fitting flat on the flywheel, it would vibrate like crazy.

If the bushing in the end of the tail stock for the drive shaft were wrong, worn out or missing, it would allow the driveshaft to run out.

Check your tranny mount for excessive play. you should have put a new one in there.

Do you have the wrong harmonic balancer on there?


When you find the problem, please post the solution.
 
#31 ·
Didn't read all the replies, but, some things to think about..

Gene is right on with the flywheel.
If that is true, it could be bad news.
My engine builder balanced the rotating mass together.
That means the crank, rods, pistons and flywheel and harmonic balancer. He did drill the flywheel some.

Hopefully,

its the pressure plate out of balance, which is a long shot,

or the bushing in the end of the crank for the trans pilot shaft is missing or the wrong size.

If the flywheel was not bolted squarely with the crank flange, it would vibrate like crazy.




If the pressure plate were not fitting flat on the flywheel, it would vibrate like crazy.

If the bushing in the end of the tail stock for the drive shaft were wrong, worn out or missing, it would allow the driveshaft to run out.

Check your tranny mount for excessive play. you should have put a new one in there.

Do you have the wrong harmonic balancer on there?


When you find the problem, please post the solution.
Thanks for all the info. A lot to consider. I took driveshaft and had it balanced. He said it was definitely out. I reinstalled and now it runs smooth tillabout60-70 mph then more vibration. Also getting the growling sound when clutch pedal released. Appears to only happen after warmup. One minute I think a pilot bushing, then I read about imput bearing, saw a video on clutches and was now thinking disc to light so springs making noise. Then I’m told drive angles. I guess I’ll have to pull the entire thing and examine. If I push clutch in the sound disappears. That tells me that would eliminate the pilot bushing and disc since the imput shaft is stationary. When pushed in, that would indicate the imput shaft bearing. I have two issues here. 1. Growling noise and 2. Vibration at higher spees(mph) revving in neutral does not give me vibration. I’m at a loss Thanks for letting me rant,
 
#29 ·
Bill, you are correct. That is what I had done,however I’m reading some post alluding to the fact I might have installed the wrong flywheel. The driveshaft was out of balance. I’ve reinstalled and no low speed( mph) vibration. I do have vibration at the higher speeds aron 60-70 mph. Also the noise when I release the clutch is there but only after car has warmed up. Shifts perfectly. I might have to pull the whole thing. The noise points to a input bearing on the m22 but it has less than 100 miles on it. Don’t ant to change the bearing until I find out why it failed
 
#32 · (Edited)
Might I suggest,


1. Look at where your throw out bearing is when your foot is not on the clutch pedal. If its misadjusted and riding on the clutch fingers, it will be spinning all the
time. Causing the noise when it warms up. There needs to be about 1/2" pedal play between the throw out bearing and the clutch fingers when your foot is off the pedal.
2. You mentioned earlier about checking the oil level. Do you ever to that? Because you never said you did. Since this is a new transmission, was it shipped dry? Although things do go south, even when new, I'm fearing the noises are from a lack of lubrication.
3. Someone made mention about the pilot bushing/bearing, Did one get installed when you installed the transmission? This would go in the back of the crank. This could be the reason for the front tranny bearing going out. I had a hard time trying to figure out if you did a tranny conversion, I'm guessing you did. Automatics don't require a pilot bearing, standard transmissions do. Might be the suspect for the vibration at high speed.


Just ideas to think about.
Chris
 
#33 ·
Does the car have aftermarket rear control arms or has anything been altered rear suspension wise? If so suspect drive line angles regarding the vibration.The faster you go the worse the vibration says it all...Dont ask me how I know.🤬The heat related noise is interesting...something is changing (expanding)with heat.The fact that it stops when you push the clutch in more or less indicates input bearing or perhaps an input shaft to output roller or anything else that ceases to rotate when the clutch is in.Manual transmission noises can be really dfficult to nail down..I once had a Warner ST10 that would howl like a wolf at the moon in 2nd gear ONLY turned out to be the output bearing was a little gritty....never understood that one.
 
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