My tranny is giving me a ton of problems. Lately it is shifting 1-2 at 4000rom most of the time, and the same 4000 rpm for 2-3. It hardly ever gets into 3rd and 4th cruising. However, once today it shifted normally through 1 and 2. Today under WOT it started shifting at about the same 4000rpm if the shifter is left in (D). If I run through the gears manually, (bumping into next gear at 5000 rpms) it will upshift perfectly. I have not had a 2-3 full throttle upshift in months....It just used to freewheel. However, today, shifting manually, I can consistently get a 2-3 WOT upshift. What the hell is going on here? Can a TV cable go bad, or is my tranny dying?

Also, Is there anything that can go wrong in the valvebody to dramatically increase the line pressure? Sometimes when shifting from Neutral to drive it will hit so hard the car lurches forward. Other times it does it stock.

It will also not downshift. If you want to downshift you have to do it manually.

The tranny is an 89 and has 92K miles on it!

Please help before I rebuild!!

 

I hate it man, but this sounds a lot like what happened to my tranny when it died.

 

Your cable should have an adjustment on it..I would try and adjust the cable and change the fluid and filter and see if that fixes the problem before i rebuilt it..I just had one rebuilt and it cost me $900.00

 

Don't sweat it, man. The TV boost valve is getting stuck in the bore. GM had problems with this. Thats why some are sleeved, some aren't, and so on. They kept experimenting to find a way to get it to stop getting stuck. Mine didn't start doing it untill I hit about 130,000 miles, but then it quit before I could fix it. Basicly, when you go WOT, the TV valve is getting stuck in the MAX position, so the tranny is shifting like you are at WOT when you arn't. You will get 4th gear, but you will need to hit about 65-70 before it will shift.

What they taught me in the GM Transmission school, was to loosen the valvebody bolts and retorque them to the minimum spec. (I don't know what they are off hand, but usually you will see like 8-14 nM, just use the lower number). This is supposed to keep the bore from coming distorted and thus the valve won't get stuck. Otherwise, you will need a new valvebody. If the valve is sleeved, you can get just the valve and sleeve. You could also try some tranny treatment like Lucas, and see if that doesn't keep the valve from getting stuck. Good luck.

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If you live in Southeastern US, check us out!
South East Thirdgen

"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Boxed LCAs, 8mm Accel wires, Flowmaster, 16" GTA rims.
'97 Bonneville SSE

 

GM tech ...great info

 

All I gotta say GMTech, is DAMN man. We need more people like you on this board.

Thanks!

 

If I'm not mistaken, the TransGo SK700 and SK700-Jr(not really shift kits), include fixes for a number of common 700R4 problems, including the stuck TV.

TransGo also has replacement performance TV boost valves.

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1984 Silver Z28, 383 cid 4 bolt, ARP Fasteners, 2 1/2" Cowl Induction Hood, 600 cfm Performer Carburetor, Torker II Intake, Performer RPM Heads, XE268H Cam, Magnum Roller Tip Rockers, MSD6AL Ignition, Blaster2 Coil, HEI Distributor w/ Adjustable Advance, 700R4, TransGo SK, 2.73:1 Limited Slip Dana 44, Terminator Headers, Custom 3" TIG Welded Stainless Exhaust, Flowmaster Muffler, 4 Wheel Disc Brakes, Oil Cooler

 

I forgot to specify, only loosen the four bolts around the TV valve. If you do them all and accidently break the seal of the VB gaskets, you will have crossleaks and shifting problems. Just do the bolts around the TV valve.

I have heard that Lucas products work great. I know that they can be found at discout auto parts.

If the Transgo kit has a new valve and sleeve, then there ya go. No excuse not to fix it!

------------------
If you live in Southeastern US, check us out!
South East Thirdgen

"I used to have a handle on life, but then I used it as a plunger and broke it" -The Wave

ASE Master Tech + L1
Savannah, GA
'87 Trans Am-K&N,Cold air induction, SSM SFC, Boxed LCAs, 8mm Accel wires, Flowmaster, 16" GTA rims.
'97 Bonneville SSE