It's an 86 305 iroc, some upgrades... heads, cam, headers. pushes about 260 HP. The tranny blew the day i bought it w/ 80k miles so it was rebuilt. 20k miles later, i added a transgo reprogramming kit. Now 10k miles later... at high rpm, maybe 3200, it slips bad into 3rd. If i don't let up, it just slips out and revs, no friction, just revving after 4k rpms. I checked fluid. I have a summit cooler on it. Everything looks ok visually. The fluid left some black on the paper towel. Last night I put it in 1st and left it there, at 4k rpms it slipped right out. It will also slip from 3-4th if i don't let off the gas. Could someone please offer some advice other than rebuild. Even after i added the reprogramming kit, it still never shifted hard enough to bark the tires. The weird part is, if i floor it at 55 to get a downshift 3-2, she grips and goes everytime. It's only the upshift slipping.
Thanks for any and all help.

 

Is it your shift bands? When the transmission was rebuilt did they replace them?

 

First thing -check the fluid level, it must be "full when hot"
on these tranys. Very critical. Mine was doing simular things
to yours and i added an additional 1/2 qt of ATF and the problems went away. Try it...Next make sure the TV cable is adjusted properly.
Next pull the pan and drop the Pressure regulator valve assembly
and clean it. Next do the same with the tv valve. Double check to see if the Transgo parts for the TV valve are installed right. To clean the other shift valves, you'll have to drop the valve body.
(new separator plate gaskets required.) Inspect the valve body and separator plate mods (transgo instructions) while you have the v-body down. If its still acting up
after this, I'd get a trans shop to pressure test the trans.
(Could be a bad pump).

 

So, the other day, before i left for florida... i'm cruising about 55 mph in overdrive, not doing anything strenuous to the tranny and all the sudden nothing. I here a noise like something is rubbing but no friction. Come to a stop, no gears, just revs. All i have is park. Is the tranny fried? Should I just swap a t5 or t56? thanks

 

Sounds like the converter let go. As far as a manual goes, that is a matter of personal preference. I would stay with the 700 and have this one done properly, install a TruCool cooler and bypass the radiator and use a quality converter.

 

I was hoping Transfixleo would reply. Would it be difficult to install the clutch springs the kit came with while the tranny is out? I still have the pack. Also, what converter does everyone recommend? I've heard to use a 2200 stall from an S-10. I'm having the tranny pulled tomorrow but I had guessed it was the converter. So, even though it was slipping at high rpms, that was still due to the converter? As far as I know, the converter was never replaced. Even when the tranny was rebuilt.
Thanks

 

The springs are a little bit of a pain but not that bad. The S-10 is good and as long as you get it from GM it is top quality but it will depend on your power band. If it starts to pull in that area you will be fine but don't expect to drop 3 tenths on your ET!

If you run it over @5000 RPM then you run the risk of slipping the 3-4's W/O the TransGo springs installed. You also want the high rev pump ring kit too or you can drop pressure at those RPM's too.

 

OK... something that has always bothered me... driving about 85 with wide open throttle and it downshifts sending me way over 5000. Could you please give me some part numbers on what I should replace while it's out??? Should I get a hold of a vette servo? I'd like to get crisper shifts. Right now it's a summit cooler mounted in front of the radiator with plenty of air flow. Where can I find these parts? What year S-10 converter would be appropriate? Any part numbers? As you can tell, I know nothing about trannys. I installed the shift kit laying on my back, now I can't stand the smell of tranny fluid.
Thanks!

 

There is a 3-4 Shift TV valve kit available from GM, ##8673948. Be aware that you will likely have to fine tune it for proper shift points which may mean purchasing something along the lines of the full TransGo Shift Kit to get different springs and more pan drops to get it right. One tip is to install the roll pin in from the bottom so that you can pullout the valve W/O dropping the VB.
The 'Vette Servo has nothing to do with 4th.

The converter number people mention is #24202310. Now this is a quality converter and depending on power will stall in the 2000-2200 range. Someone got mad at me when I recommended this and they didn't see incredible results so let me qualify this.

IF your vehicle STARTS making power in the 2000 range then this will be a good choice over stock (@1400). It will NOT make your car into a NHRA record holder. IF you want that you better build an engine that starts making power @3500 RPM and up and stick in some 4.56 gears too.

 

I think I do have the full trans-go shift kit. It's the one from Summit for $130. Only thing that was left out was the spring pack. Correct me if I'm wrong though.
News on the tranny. I guess my kit doesn't even matter. I called today to ask what he'd found out. "Catastrophic" was the word he used. I worked with him at a chevy dealership a few years ago and he's worked on my tranny before just to replace a front seal and look things over. He said he's never seen anything quite like this before... the torque converter near the shaft snapped sending a chunk of metal into the pump dislodging the pump and frying the transmission. He said he didn't even recommend a rebuild and that it was toast. He said he builds about 100 700Rs a year and that he had one he just finished. Corvette servo and a larger valve... (can't remember which) but it was as large as it could be... .500. He said it's a remanufactured torque converter, stock stall about 16-1800. Anyway... I was really happy with the price I guess I should just ask your opinion. $750... rebuilt tranny w/ shift kit/ reman. torque converter and labor to pull and replace. Oh, and he towed it on a flat-bed to his garage. I thought it was a hell of a deal. And I know he'll warantee for as long as I have it.

 

"$750... rebuilt tranny w/ shift kit/ reman. torque converter and labor to pull and replace. Oh, and he towed it on a flat-bed to his garage"

Sounds like he is only charging you for the parts. That is a hell of a deal as long a it is true.

 

tranny is in the car... I had to leave to come back to school so I don't get to drive it. I'll go home to pick it up sometime this week. Dad said it's a neck snapper. Thanks for the help. If I have any problems with the new one... I'll be sure to ask ya Leo. Sounds like you really know your stuff. Appreciate it.