I tried some key word searches in archives and couldn't find an answer for this to come up. I am sure its been here a hundred times before. Here it is again.

I am rolling down the road in overdrive. I punch the throttle and occasionally there is no downshift, just a tach sweeping across the guage as the engine rpms fly up. Wheres my upshift? I suspect something is slipping internally in the tranny. What is worn out or cracked or busted or whatever that is causing this? I will add that My IROC Convertible was owned by an older lady who put the first 77,350 miles on it from 1988 to Sept. 2000. She did not drive this car hard. It was her garaged baby. I have 115,000 miles on it now. I get on it but I have not dogged it. It is my daily driver. As you can see I have put 38,000 miles on this car in 10 months.

I had 148,000 miles on my 1985 Z28 with no tranny problems when I traded it in. I was younger then and ran that one hard all the time.

I have a feeling this tranny is going to have to come out to fix this problem.

Tranny gurus, whats happening here? Can I drive it if I take it easy on the upshifting? Is it going to get worse even if I am easy on the upshifting?

Thanking you in advance for any input.

Steve

'89 IROC Convertible
22 Option "Daily Driver"


By The Way: There are great third gen Camaro deals out there to be had. I did not want a Convertible. I was looking thru the paper for a hard top IROC when an ad caught my eye. "ONE OWNER" caught my eye. A phone call revealed it to be a woman owner claiming her baby was unhit and very unmolested! I blew off lunch and hauled *** across town. She kept asking me if I wanted to drive it while I was inspecting it. You know, I did not want a convertible really. So I was looking underneath the car, hood, and rearend for body repairs, overspray etc. Something to give me a reason to walk away because the car was not unhit like she claimed it was. The more I looked, the more I could hardly contain myself. It was/is so damn original and unmolested I could hardly believe it.
Since I did not really want a convertible, I lowballed her at $5,000.00 cash so she would say no and I could walk away. She laughed at me and said no way. Well, exactly one week later, she calls and tells me she has had enough of the joy riders and wants out "Right Now". Come and get it at $5,000.00. I got a TPI motored Convertible IROC with 22 options at that price. Window stickered out at $24,000.00.

 

Your input sprag is bad. Be carefull as it is possible to do some real parts damage when this happens IF the sprag decides to 'catch'. You see the parts get spinning at @3X engine speed when this happens. You do the math!

 

Transfixleo thank you for taking the time to post a reply for me.

A couple more questions. My IROC is my daily driver. Like 3,300 miles a month. So, the car needs to be driven every day.

1.I want to keep the original tranny in the car. If I buy a 700R4 outright to put in while mine is being rebuilt and upgraded, how much is a fair price for a used one?

2.Will the input sprag likely stay together if the upshifting under strong acceleration is avoided for say the next two months. IE: Will it last 7,000 miles longer if it is babied?

3.The motor is going to get bumped up to 300-325 hp. I am sure this tranny will need to be gutted and completely rebuilt to handle that. What areas need upgrades for that hp range?

I have a 2.73 rear posi and will most likely stay there or a 3.08. I drive from Houston to Dallas 2x a month and my driving is rather spirited shall we say.

Thanks in advance for your time.

Steve

1989 IROC Convertible

 

Well put it this way. I have an '88 V-6 (they have lower axle=increased sprag wear) with the original tranny and close to 140K. If I need to downshift into 3rd, I do it manually, then I give it gas. I have no simptoms but I am not in a hurry to take it out either.

A working (key) used one is probably worth at least a couple of hundred, just don't expect the correct tranny.

For O/H I recommend these parts: 4L60E sprag assy and 3-4 clutch pack. NEW GM Sun Shell. Corvette rear planetary. TransGo Reprogramming Kit and Hi Rev Pump Ring Kit. All Borg Warner frictions. TruCool LPD cooler and bypass the radiator. .422 TV boost Valve and .282 Int/Rev Boost Valve. At least the 553 servo(Vette 093 if you really want it).