Drive train clunk

tim72 · March 16th, 2009, 04:17 PM

I have a TH 350 that was rebuilt. the car now clunks when i put it into gear. I added abigger stall converter and a shift kit. I have checked the drive line and installed new u joints etc. Rear end seems to be fine. I had no clunk before the trans was rebuilt. I am no expert on transmisions. Is there some type of adjustment that can be done? Does the higher stall effect putting the car in gear? How much would the Vacumm modualtor effect the in and out of gear shifting? Does the shift kit make for a harder engagement?

Any help would be appreciated?

Thanks

tim72

joe_padavano · March 16th, 2009, 06:20 PM

Quote:

Originally Posted by tim72

I have a TH 350 that was rebuilt. the car now clunks when i put it into gear. I added abigger stall converter and a shift kit. I have checked the drive line and installed new u joints etc. Rear end seems to be fine. I had no clunk before the trans was rebuilt. I am no expert on transmisions. Is there some type of adjustment that can be done? Does the higher stall effect putting the car in gear? How much would the Vacumm modualtor effect the in and out of gear shifting? Does the shift kit make for a harder engagement?

Any help would be appreciated?

Thanks

tim72

If the rebuilt or shift kit installation included mods to raise the line pressure, then yes, the engagement will be harder.

tim72 · March 16th, 2009, 07:40 PM

Joe,
I have two TH 350 transmisions both out of a 72 olds cutlass supreme. The vacuum modualators are different one being considerably bigger than the other with an adjustment screw on the outside. The one that I say clunks has the smaller modualtor. Am I missing soemething ? Does the vacuum possibly have anything to do in how hard it shifts?

Thanks for you help!
Tim

J-(Chicago) · March 17th, 2009, 12:49 AM

I'd guess, either the trans mount split open, or the converter is too tight.

tim72 · March 17th, 2009, 09:50 AM

Can you explain what you mean by a converter being to tight?

tim72

American Lead · March 17th, 2009, 10:57 AM

could it be a band mis adjusted?

tim72 · March 17th, 2009, 07:04 PM

Quote:

Originally Posted by American Lead

could it be a band mis adjusted?

How do you make aband adjustment?

American Lead · March 18th, 2009, 07:38 AM

Good question, I know mine needs special tools but i think you should be able to adjust yours without any special tools, but i did find out there is no external band adjustment on the 350....but to be honest i have no clue.... A google search could be helpful... I have no idea... Before you do anything you should wait to see what other folks think.... It's just a thought and I'm no expert... Maybe someone more knowledgeable like norm can chime in and give us some help..

J-(Chicago) · March 19th, 2009, 12:01 AM

Put the car in neutral. What Rpm does it idle at?
Then put it in gear. How much does the converter bog your Idle down?
Did you hear the clunk?

If you're fighting the drive wheels with the brakes or the converter is bogging your motor down a lot really quickly......It's too tight.

Also, did you check your driveline angles?

88 coupe · March 19th, 2009, 05:02 AM

Quote:

Originally Posted by American Lead

........ but to be honest i have no clue ........ I have no idea ........

Sounds like you should be reading, instead of posting.

Quote:

Originally Posted by American Lead

........ Maybe someone more knowledgeable like norm can chime in and give us some help..

Norm will "chime in" when he has enough information to make an accurate diagnosis.

So far, it looks like J-(Chicago) is asking the right questions.

Norm

American Lead · March 19th, 2009, 06:48 AM

Quote:

Originally Posted by 88 coupe

Sounds like you should be reading, instead of posting.

Yeah your probably right but it was just a thought... it's what mine did when backyard joe rebuilt the transmission before me... He frigged the case and the carrier bacause the bands were fighting each other and everytime it shifted there was a big pause and a jolt and a clang...

Quote:

Originally Posted by 88 coupe

Norm will "chime in" when he has enough information to make an accurate diagnosis.

that makes one smart person in this post... i'm keyboard happy... what can i say lol

Anyway have a good one...
Robert

lshlsh2 · March 19th, 2009, 11:27 AM

MY quick thought. What about the u-joints. If they are orginal they can have alot of play in them and make a clunk when shifting into gear.
Larry

tim72 · March 19th, 2009, 02:59 PM

J
Driveline angles is a good question as I have a 455 attached to a TH 350. I did blow the motor mounts. I also had a problem with the drive Shaft hitting up under neath the floor pan. I took every thing one step at a time and made the adjustment. It still clunked. After the car clunks putting it in gear the car drove fine. I also checked the cross member. Would the Vacuum Modualtor have any thing to do with this?

tim72

March 16th, 2009, 04:17 PM	#1 (permalink)
tim72 Registered User Join Date: Feb 2009 Posts: 119	Drive train clunk I have a TH 350 that was rebuilt. the car now clunks when i put it into gear. I added abigger stall converter and a shift kit. I have checked the drive line and installed new u joints etc. Rear end seems to be fine. I had no clunk before the trans was rebuilt. I am no expert on transmisions. Is there some type of adjustment that can be done? Does the higher stall effect putting the car in gear? How much would the Vacumm modualtor effect the in and out of gear shifting? Does the shift kit make for a harder engagement? Any help would be appreciated? Thanks tim72

March 17th, 2009, 12:49 AM	#4 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 2,697	I'd guess, either the trans mount split open, or the converter is too tight. __________________ I'd rather have a numbers matching poker hand.

March 17th, 2009, 09:50 AM	#5 (permalink)
tim72 Registered User Join Date: Feb 2009 Posts: 119	Trans Clunk Can you explain what you mean by a converter being to tight? tim72

March 17th, 2009, 10:57 AM	#6 (permalink)
American Lead 2Blue 55 Join Date: Dec 2006 Location: Nova Scotia, Canada Posts: 455	could it be a band mis adjusted? __________________ Classic cars are my drug of choice

March 18th, 2009, 07:38 AM	#8 (permalink)
American Lead 2Blue 55 Join Date: Dec 2006 Location: Nova Scotia, Canada Posts: 455	Good question, I know mine needs special tools but i think you should be able to adjust yours without any special tools, but i did find out there is no external band adjustment on the 350....but to be honest i have no clue.... A google search could be helpful... I have no idea... Before you do anything you should wait to see what other folks think.... It's just a thought and I'm no expert... Maybe someone more knowledgeable like norm can chime in and give us some help.. __________________ Classic cars are my drug of choice

March 16th, 2009, 07:40 PM	#3 (permalink)
tim72 Registered User Join Date: Feb 2009 Posts: 119	Joe, I have two TH 350 transmisions both out of a 72 olds cutlass supreme. The vacuum modualators are different one being considerably bigger than the other with an adjustment screw on the outside. The one that I say clunks has the smaller modualtor. Am I missing soemething ? Does the vacuum possibly have anything to do in how hard it shifts? Thanks for you help! Tim

March 19th, 2009, 12:01 AM	#9 (permalink)
J-(Chicago) Seasoned beater pilot. Join Date: Jan 2007 Location: Chicago Posts: 2,697	Put the car in neutral. What Rpm does it idle at? Then put it in gear. How much does the converter bog your Idle down? Did you hear the clunk? If you're fighting the drive wheels with the brakes or the converter is bogging your motor down a lot really quickly......It's too tight. Also, did you check your driveline angles? __________________ I'd rather have a numbers matching poker hand.

March 19th, 2009, 11:27 AM	#12 (permalink)
lshlsh2 71 cutlass convertible Join Date: Sep 2008 Location: Trappe, MD Posts: 179	MY quick thought. What about the u-joints. If they are orginal they can have alot of play in them and make a clunk when shifting into gear. Larry

March 19th, 2009, 02:59 PM	#13 (permalink)
tim72 Registered User Join Date: Feb 2009 Posts: 119	J Driveline angles is a good question as I have a 455 attached to a TH 350. I did blow the motor mounts. I also had a problem with the drive Shaft hitting up under neath the floor pan. I took every thing one step at a time and made the adjustment. It still clunked. After the car clunks putting it in gear the car drove fine. I also checked the cross member. Would the Vacuum Modualtor have any thing to do with this? tim72

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