mkotz

So quick story

Driving down the highway having fun with the corvette I believe the car was in mid shift from maybe 3rd to 4th gear and I heard a "bang or pop" but the car was still abme accelerate and drive but when I got to the stop light and trying to accelerate it is basically useless. The car will move extremely slowly and only at a high rpm... like 2500+. The car will go in reverse with the same issue.

What did I don't to my car?

Thanks

Kevova

Sounds like something in transmission broken. I would pull pan and check for debris. If you use manual 1st and 2nd does it accelerate better?

mkotz

All gears accelerate the same way. No difference.

Kevova

A guess. : a sprag is slipping.

mkotz

What is that?

65Z01

That is an A4 rebuild, IMO.

Kevova

It's a mechanical one way clutch. It will allow a component to rotate one way and not the other. Automatic transmissions use several for the different gears.

mkotz

Complete rebuild or an easier fix? Trying to figure out my cost on this.

Kevova

It will have to come apart to accurately estimate. You could price a rebuilt exchange which may not be s bad thing. There were a lot of parts updates until 1989. So replacement should have all the updates. C4 transmission is different than all others; it slightly shorter and and extension housing is unique. If it out and apart I expect to rebuild it with a warranty.

mkotz

just limped it home

Car will drive extremely slowly. drove all the way home in mostly 3000+ rpm. The interesting this is once I get it over 30mph the car did shift and rpm went down but it was still extremely sluggish.

arbee

No so necessarily depending on what sprag you are talking about. The front sprag is independent of reverse gear and the OP stipulates the same results are present in both forward and reverse gears. More likely a fault in the hydraulic system such as pump or the roller clutch on the torque converter itself.

Blackcorvette_85

first thing I would check is the tranny fluid, just to be sure you wernt leaking any and it got low or maybe that bang was you hitting the pan on something you didnt see on the road . Most likely not though and the tranny needs a rebuild. In my area Ive seen several places advertising 8-1200 for a rebuilt updated one with an exchange if you do the install yourself thats not to bad. Mine has a bunch of miles on it, expect it to go one of these days so Ive been watching prices

arbee

You never want to do a direct "exchange" with a Vette 4l60. Yours should be rebuilt and put back in.

mkotz

Clean fluid and no leaks

mkotz

Final Update:

Transmission was toast along with the torque converter.

The sprag was part of the issue as it was destroyed but all the clutches were burnt. The shop did a complete rebuild with as many original gm parts as possible (NOS) and used upgraded parts were GM originally fell short. They also has a NOS GM Torque converter that they obviously had forever. They told me to come by when it was all apart and explained everything which was very cool. So $4000 Canadian dollars later I have a brand new transmission that was guaranteed to give me a 'mild orgasm' when driving it. They were not far off, this thing shifts so smooth it is incredible, it has never been this smooth.

My 35th Anniversary is a happy girl again.

Mark

arbee

4000.00 ??? Hf!

mkotz

Yeah some how $1800 dollars of parts went into it lol. That's what happens when there's no competition in town.

arbee

So 2200.00 labor for an 8 hr. job?