Vehicle; 1991 Z28 5.7L 700R4 - all stock.

Let me start off by saying I do not know a lot about automatic transmissions but I do know that I am not happy with mine in the Z28. It runs and drives just fine if your just getting groceries or going to work.. it is not so bad running down the highway and passing cars, and it is ok in town/city giving it a bit of a jab to be the first off a green light or from a stop sign with moderate throttle. However WOT is another story, it is an undecided sloppy and tired old girl.

From a stop or even just rolling around and you stab it into WOT there is no firm shifts, hell its hard to tell when it does finally shift it is soo mushy. From a stop when I hammer it, it will launch hard in first gear then it will slip and moan and whine its way in and out of second gear revving up high until it finally, finally after way too long it will be pulling in 2nd and starts to go again. The two to three shift takes an eternity as it can't decide whether it wants to shift or not revving up and down.. I find it is better to let off the throttle from WOT to like 3/4, let it shift, then WOT it again. The three to four shift at WOT, well I don't know.. don't think I've held it to the mat long enough to find out what happens at WOT between third and fourth.

I am hoping you guys will be able to give me advice/tips and your thoughts on what could be going on. I had a mechanic friend go over the car for an inspection when I brought it into Canada a couple years ago and he did say the cable is properly adjusted but I needed to bring it back as 'something wasn't right'. I'm thinking with 150,000 miles, perhaps the cable is stretched? ... or?

I'm unsure at this point whether I should throw money at the thing trying to repair or rebuild it, or just spend roughly the same amount of money right away and purchase a new/aftermarket transmission? ..or swap in a manual transmission? Or am I getting ahead of myself here?

Thanks for any tips and help!

EDIT - I should mention it does shift better and somewhat firmer when shifting manually at WOT, but it certainly does not chirp the tires or shift how I think it should.

 

I did'nt read the entire post _ sorry. I will tell you this. if you kept up with tranny services, fuild,filter apprear clean not burnt and If you don't have any slipage during shifts with lower miles less then 120K lets say I would put in a transgo 1-2 or 2-3 and I'd also flush the old fuild out and replace with some decent fuild brand. Maybe slap in a $50 trans cooler too

Other wise you might be rollin the dice!

 

well a few things you can do is install a Corvette servo and a Corvette governor to adjust your shifting points... the servo will give you firmer shifts...