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Torque Converter or Flexplate?

  
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Torque Converter or Flexplate?

 
tchavers92 tchavers92
New User | Posts: 24 | Joined: 09/11
Posted: 09/27/11
12:57 PM

I have a 1992 Silverado, It started making a rattling type noise when it is neutral. I can give it a little gas and it will stop. It also seems like its not as bad when the truck gets warm after driving for a little bit. It does shift hard and doesnt shift when its should sometimes. Torque converter or Flexplate/Flywheel?  

waynep7122 waynep7122
Guru | Posts: 1130 | Joined: 08/09
Posted: 09/27/11
04:10 PM

this is time to invest 10 bucks in an automotive stethoscope..   available in most parts stores..

this will let you narrow the rattling noise down...

from the cats.. yep .. they can rattle inside when the monolith overwrap fails..

to the torque converter.. when internal parts fail.. like the torque converter clutch linings or the vanes inside the converter..

the front pump can also fail... as can several internal parts in the transmission..

and yes.. the flex plate can crack...     this usually happens on cars and trucks that have had the transmission replaced already... and one of the trans to engine alignment pins got lost..  so the alignment between the 2 is slightly off.. sometimes it just comes from excessive use of the throttle tearing and twisting the flex plate...   excessive crankshaft thrust clearance...  where the crank moves forward and backward more than the tiny amount is supposed to..

you did not mention which motor you have..   some of the 4.3 motors have a balance shaft above the cam..   the bearings can fail in those...  

4.3 v6 cranks have BEEN KNOWN TO BREAK between the first main  and the first rod journal.. and STILL RUN...


question... do you have a throttle valve cable down to the transmission .. OR NOT...    if not.. its an computer shifted transmission.. and a scan tool will be required to  get farther into it..

you will want to jump the A and B terminals of the ALDL under the drivers side anyway and pull codes . then post them...

ever done that????  not hard.. just ask..

to the  

tchavers92 tchavers92
New User | Posts: 24 | Joined: 09/11
Posted: 09/27/11
06:00 PM

I have already narrowed down the sound to where the torque converter is located. Having my luck the muffler shop ran the exhaust pipe over the dust cover so i cant remove it without cutting it. It will jerk and make a noise under the truck when in gear with foot on brake and if i get on it a little it seems like its just spinning and not getting anything to the wheels. Sometimes its like its sitting there spinning then it catches.

It is a 5.7 and I'm pretty sure it has the throttle valve cable...it is 1992 model? I dont know if this makes a difference but when I replaced the timing gears and chain I was able to move the crank shaft back and forward about 1/8 to 3/4  of an inch. Just saying because you mentioned the 4.3 cranks breaking.

I am in the process of building a pretty mean motor and I need to figure this out before I drop it in.  

waynep7122 waynep7122
Guru | Posts: 1130 | Joined: 08/09
Posted: 09/27/11
07:16 PM

one additional thought..

was the starter motor assembled properly????

i ran into a start on a front wheel drive GM.. that the starter would kick in and grind the flywheel when you turned left...

but not when you turned right..   this had been going on for weeks when it was driven into my service bay..

i check the electrical system.. could find no faults..

took the starter off...  reached in..  pulled the starter drive out into the opening so i could examine the gear teeth.. after looking for several minutes.. i realized.. that i SHOULD NOT be able to pull the starter drive out with my fingers.. its spring loaded by the big spring on the solenoid plunger.. when i took the solenoid off.. there was NO spring..

take the starter out...   use a breaker bar or big ratchet with a 5/8 socket on the front and slowly rotate the engine while you look at the flex plate through the opening where the starter is..  

tchavers92 tchavers92
New User | Posts: 24 | Joined: 09/11
Posted: 09/27/11
07:26 PM

Ill check this out and let ya know  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 09/28/11
01:11 AM

my neighbors caprice was makeing a similar loud rattling noise.   yep, all the converter bolts were loose.  i tightened them up & the noise went away.   hopefully thats all it is.  

skyeking skyeking
Addict | Posts: 2738 | Joined: 08/09
Posted: 09/28/11
05:25 PM

Laugh  Smile Hi Agent 69.
  Howzit going these days???  All the best Cool  Smile  
skyeking

tchavers92 tchavers92
New User | Posts: 24 | Joined: 09/11
Posted: 09/28/11
06:25 PM

Yeah i bet that is it.Either loose or broke around the bolts.  

redneckjoe69 redneckjoe69
Addict | Posts: 2337 | Joined: 03/10
Posted: 09/29/11
01:53 AM

yea, my neighbors car was making so much noise, you woulda thought the bottom end was gonna fall out.   only at idle or real slow speeds.   id cut that dust cover off & fix it before you get more problems.   they make plastic ones that you can wiggle back in there,...hopefully. lol.   ive seen broken flexplates too, but they usually give you alot of starter issues/noise.                 hey skye! Laugh  everything is good.    how goes it with you?  

tchavers92 tchavers92
New User | Posts: 24 | Joined: 09/11
Posted: 09/29/11
10:29 PM

thanks for the info!  

Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 09/30/11
06:44 AM

I would check the transmission bolts that hold the trans. to the block as well.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

skyeking skyeking
Addict | Posts: 2738 | Joined: 08/09
Posted: 09/30/11
05:30 PM

HI Poncho man!!!!!!!!!!!!!!!!  
skyeking

Pontiacman2 Pontiacman2
Moderator | Posts: 8956 | Joined: 09/08
Posted: 09/30/11
05:41 PM

Hi skyeking!!!!  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

papacharlie papacharlie
User | Posts: 223 | Joined: 12/09
Posted: 10/01/11
08:31 PM

you say the crank endplay was 1/8 to 3/4?that is waaay too much. the crank is movving back and forth,most likly the flexplate is hitting or the timing gear on the block or cover. look for somethig hitting when you get the cover off. myself, i wouldn't cut the pipe, just unbolt it and let it drop. you should see the shiny spot from the flexplate pretty clearly from it hitting. if no marks, it is most likely hitting internal. better do some serious investigating underneath. good luck.  

tuffnuff tuffnuff
Moderator | Posts: 7827 | Joined: 12/09
Posted: 10/01/11
09:52 PM

1/8 to 3/4,,,,,,,,,,,,,,,,,, no comment.
Start over with good stuff,

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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