I took my car ('87 iroc, 350 tpi, 700R4) to the dealership for what I thought was a problem with my engine, low power and bad milage. They told me that my engine and all related components were in perfect working order and it was my tranny that was causing these symptoms. They claim that my car would not downshift to first when it was susposed to. The fact is that my car has been shifting like it has sence I first got it, when I was pleased how it was performing. The only time it goes into first is when I am almost stopped and it does so with a sort of thud. Never would it downshift into first as a response to WOT, no matter what speed. A couple of notes: I have my TV cable adjusted correctly, and I possibly have a shiftkit(how do I know?). Well, is my tranny shifting right? And on another note how can you tell if your tranny is slipping? Will it slip in all gears or just problematic ones? Help me, I don't now jack!

 

ive owned several different cars/trucks with the 700r4, and have a few friends who have owned a couple as well.
I have NEVER seen a 700r4 that will shift into first gear when floored, unless u physically shift it.

 

Drive it at minimum throttle, as soon as it shifts from first to second floor it and it should downshift back to first. If it doesn't something may be wrong.
You can calibrate upshift and downshift points by changing governor inner weights and/or springs. Check to make sure your tv cable is adjusted right and the throttle lever geometry is correct if its not an original 700R4 carb.

 

It's supposed to shift like a MAN! Bute grunt force

------------------
87 IROC-Z Bright Red, New 305 TPI, Soo to get new body work and paint job, Also 1st to get new Tranny. Virtually Stock, except to get new SLP Runners and Headers...

 

my trans used to shift into 1st at WOT but that's probably why it blew...hahaha

 

Below @30 MPH at WOT it should downshift to 1st. Do this: To adjust the TV Cable skip the book method and do this: Press the D button on the adjuster and loosen the cable setting. Now, have someone floor the gas pedal while you check to see if the throttle plate is open all the way. Usually they are off a little and will wiggle. Do whatever you have to do to get it open solid. Now, with the pedal still floored, press the D button and pull the cable casing (the black tube) back as hard as you can and release the button. You now have the engine, tranny and gas pedal all in sync at WOT. Mark the cable so if for some reason it gets moved you can know where to put it again. The problem with the 'self adjust method' is that it bends things and puts them permanently out of whack. It is also the full TV setting, which is theoretically what the GM method does.

 

I have full confidince that my TV is adjusted correctly, I have checked and re-checked using the methods above, so I don't consider that to be a possibillity. Back to some of my original questions: Does anyones 700R4 make a thud when it goes into first when slowing down to almost a complete stop? and how can you tell if your tranny is slipping? Thanks for the info fellas!

 

Don't use the @30mph method. That depends on your gears. Do what he said above: Let it shift into second then floor it--it should kick down into 1st gear.

------------------
350 with stealth intake, holley carb, 470 lift cam. 700r4 with .5 boost valve, vette servo, tci lock-up kit, B&M megashifter. Richmond 3.73 gears, powertrax locker, timkin bearings, synthetic lube. Custom 3 inch single into 2 2.5 pipes. 1 1/2 drop springs, 1 5/16 solid front sway bar, 1 inch rear bar, custom subframe connectors, custom LCA relocation brackets. Kobel ground FX, currant red metallic paint. Lots of other stuff...
82camaro

 

That almost sounds like the TC isn't disengaging until you slow enough for first gear to unlock it.

I had an 87 Celebrity that did that for a while, then it got to where it wouldn't unlock at all. I would come to a stop, and it would die like a manual trans when you didn't push the clutch pedal at a stop.

All it was in that car was the little switch sensor thingy. Costs like $30. I don't know if our cars have that same sensor.

Take it back to the dealer and have them check it.

AJ

 

It is not uncommon for a 700 to clunk on the coast downshift. In fact they all do it and it shows up best in the D position. As far as how to tell a slip, the engine will race rather than drive at the RPM's you are used to.

 

I have an 87 IROC, and it behaves like you describe. It down shifts to first while slowly coming to a stop and has somewhat of a 'clunk' noise when it does. As far as downshifting to first at WOT I don't know, I don't put it to the floor very often. My car does have a 2200 rpm torque converter, but otherwise is stock.

If it were my car I would get it away from that dealership fast as I could. If you don't know for sure the last time the trans fluid and screen were changed, get that done. Then try another mechanic and tell him you think it needs a tuneup; change the O2 sensor, new plugs, clean throttle body, check MAF, check timing, new air filters and anything else you think it may need.

 

Is the Tranny Bracket broke.. when i first got my car... i would give it a little gas and as i took off 1st to second i could hear and feel a THUD.. it was the braket.. didnt notice it downshifting though.... I might be the tranny bracket though?