transmission problems

[Kory]

Hi I have a 350/350 combo in my 85 s10 and recently I have been hearing a slight knocking noise that sounds like it is comming from my transmission. Its not an engine knock it occurs sometimes right when i start it up then it quits. Then it usually does it again shifting into secong and third. But once its in third i can floor it or whatever and no noise. The transmission isnt slipping or anything and the combo only has about 30,000 on it. At first I thought it was the torque converter and now Im leaning towards something being lose but I looked and saw nothing

[mommasboy]

My bet would be the converter or the front pump..more than likely the converter though.

[80Harley]

I agree with Lightweight. One more possibility is a loose or cracked flexplate. Unfortunlately you will have to pull the tranny to find out. http://www.s10v8.com/images/smilies/icon_biggrin.gif

[mommasboy]

If it were the flexplate he would be having hell with his starter. Also a loose flexplate wont only affect it when he shifts. It would make one hell of a racket too.... http://www.s10v8.com/images/smilies/icon_mad.gif

[ZZ4Blazer]

My flexplate was loose on my 81 chevy. Never had any prolems starting. Did make a bunch of racket though.

[80Harley]

Chris - Just to set the record straight I do this for a living and have been doing it for 35 years. I am a ASE Master Tech and have seen numerous small block Chevys with a cracked flexplate. No starter noise just an occasional knock and if bad enough you\'d swear it was a rod knocking. I\'m not saying you are wrong, just another possibility. Its real hard to diagnose a problem (especially a noise) over the PC. LOL http://www.s10v8.com/images/smilies/icon_smile.gif

[4more]

i(also ase gm tech) have seen flexplates broken all the way around the crankshaft mounting bolts it has no place to go so it still starts and makes just a slight knocking sound at higher rpm (shifts) also have seen where the outer gear (teeth) breaks the weld major noise and major starting problems--i\'d first check to see if the converter to flexplate bolts are tight i\'ve seen those a little loose cause noise