My car is a 90 350 iroc. The trans was toast and i just had it replaced with a 700 out of an 86 305. The mechanic checked out the new trans and installed it and everything seemed fine. When i first picked it up and started driving it i was surprised because it was shifting so soft i couldnt even feel it, but somewhat disregarded it because my old trans had a shift kit in it and this doesnt. Well i get about half way home and it all starts falling apart. If you accelerate slowly from a stop it wont shift till much later then it should and if you get on the throttle a bit so that it should be shifting where it wants to anyways it shifts so soft you cant feel it. Any ideas on what he might have messed up?

 

My guess is the TV cable was not adjusted right. If it shifts to early, that can do a lot of damage to a 4l60 as there wont be enough line pressure to apply servo's to engauge a crisp shift, slipping the friction and steels, and basically making a big carbon mess in you clutch drums...

What I am trying to say is you will destroy that 4l60 if you drive around like that...take it back.

Later,

Erik

Oh PS...if you can take it out and get an '87 or later 4l60...as they had an abuse valve and some other nice updates.

 

Ya im thinking tv cable my service manual is confusing the hell out of me as to how to adjust it so my buddy is coming over in a few minutes. It wasnt shifting too early it was shifting too late and i am pretty worried about any damage that might have been done

 

adjusted the tv cable and its still the same, i dont even see how you could improperly adjust it.

 

Um 700's should be with what there specs are like your replacement was for a 305.. it wont last very long... it will last a year or two... depends on how you abuse it...

 

Sounds like your torque invertor is heading south.........I had a prob with mine aswell......it would not disengage properely......take it back as soon as possible......dont do more damage to your trans.........

 

No amount of adjustment is going to put friction material back. Sadly, the transmission is already toast. 700r4's are really sensitive to TV cable adjustment.

To adjust a TV cable you press the button, then slide the black sheath as far back towards the firewall as possible. Then from inside the car you'll need to mash the gas as far as possible. Do this with the engine off though.

Its not the "perfect" way to do it, but its almost impossible to screw it up this way.

 

The preferable way to do this is to do all of that but turn it from the butterfly. You shouldnt use the pedal because it doesnt necessarily go to 100% WOT which would give you an incorrect tv cable.

The torque converter is new and i wasnt expecting to use this trans for more then a month or two. This trans has been sitting for a while so im thinking the trans might have internal problems such as the front pump not doing its job.

Im just going to park my baby until next spring and save up for a t-56. Also talked to the mechanic again and he said he also noticed that my rear end had a bunch of play in it. When i bought the car the previous owner said both the trans and rear had been rebuilt and the mechanic who did the swap said it seemed like they were both done improperly.