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.

 

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

 

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

 

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

tim72

 

could it be a band mis adjusted?

 

How do you make aband adjustment?

 

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..

 

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?

 

Sounds like you should be reading, instead of posting.

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

 

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...

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

Anyway have a good one...
Robert

 

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

 

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