Transmission not shifting into top gear.

**sseilmnop** · 08-23-2012

Been having intermittent problem with tranny shifting into top gear. thought it was a ground problem but still happens. Driving at 65mph and car decides to shift down a gear. Won't shift back up for 2 miles. Then decides to shift up and be fine rest of way to work.

First time it happened I pulled over and shut he car off and it would crank but didn't want to start. Wiggled the ground loop on the top of the supercharger by the front left bolt and it was loose. After wiggling the car started and shifted top gear. Cleaned ground and even added a ground wire from here to body. Worked for a week until tonight on the way to work.

**Iced Iridium** · 08-23-2012

The 4th gear clutch hub recently shelled out on mine. It's pretty common from what I understand. GM now has a hardened clutch hub for a replacement. Should cost around $1200-$1500 parts/labor for the rebuild.

**sseilmnop** · 08-23-2012

Mine really feels electrical. Doesn't work for seconds or minutes but then works fine.

**sseilmnop** · 08-23-2012

Originally Posted by Iced Iridium

The 4th gear clutch hub recently shelled out on mine. It's pretty common from what I understand. GM now has a hardened clutch hub for a replacement. Should cost around $1200-$1500 parts/labor for the rebuild.

Are talking about 4th splined shaft stripping the teeth of? If so I have a new hardened one.

http://www.tripleedgeperformance.com/No_4th_Gear.html

**Iced Iridium** · 08-23-2012

Originally Posted by sseilmnop

Are talking about 4th splined shaft stripping the teeth of? If so I have a new hardened one.

No 4th Gear

Yes, that's what I'm talking about. The teeth at the top of those pictures stripped out, as well as the opposite coupling that meshes with the hub. Both needed to be replaced in mine.

**sseilmnop** · 08-24-2012

My tranny is rebuilt and has the hardened shaft.

**sseilmnop** · 08-24-2012

Are these wires all grounds?

**BillBoost37** · 08-24-2012

Yes...forget them though. The newer ground packs are pretty solid.

Similar/kinda issue that I've personally experienced. Check/swap your coils if you have spares. Literally I went through some trans issues for about a year including the "didn't want to lockup/hit 4th" and it ended up being a bad coil. Made rpm seem to spike 1k for a second and then back to gear etc. Odd behavior like you are suggesting is often ignition related.

**sseilmnop** · 08-24-2012

Thanks, I will swap out some coils. I have spares.

When it didn't shift into top gear it was turning 3500 RPM's for 2 miles (65ish mph). Seems to happen only once or twice a per week (300 miles).

**BillBoost37** · 08-24-2012

Yeah.. I found that putting mine into and out of perf mode would allow it to lockup etc. Goofy, but it persisted after I swapped the trans. Pissed me off to swap a perfectly good 186K mile trans out of a car..lol

**sseilmnop** · 08-25-2012

Ended up cutting the ground off crimping new ring connector on and soldering it for good measure. When I was playing with it I pushed down on it and the starter would not crank. Pulled up on it and starter cranked and started car.

Also swapped out all 3 coil packs. Hope that's the end of it.

**sseilmnop** · 08-29-2012

Did it again.

3 new coils and new ground did not solve it. Pretty sure it's dropping to second gear. Some times it won't shift out of second when pulling out and sometimes it will drop to second if I'm up to speed. Never does it for long but then it just goes away and runs fine.

**BillBoost37** · 08-30-2012

Scan it.. get it to do it and look over maf/tps/map.

**sseilmnop** · 08-31-2012

Did it again.

TPS read 99 percent and stayed there. Pulled into Lowes and come back out and guess what, car won't start with TPS still reading 99%. Pop the hood, my boy watches the gauge and as soon as I lift the hood it goes to 0%. N* with zzp adapters all look good, will have to do some poking around while someone watches the the gauge.

Thanks Bill!!!!!
You ever need anything let me no!

**Swiggles** · 08-31-2012

Perhaps you have a bad tps sensor?

**sseilmnop** · 08-31-2012

Could be! At least now I'm looking at the right system. Also explains why the car did not want to start the one time.

Transmission problems = check TPS

**sseilmnop** · 09-04-2012

Got a chance to look into the problem, its the easy performance N* TPS adapter. There is a small circuit board in the wiring. Doesn't even have to be plugged into the TPS sensor and you can wiggle the wires and get it to jump from 0% and 99%. The board is potted in epoxy or something and you cant get at the connections.

Ordered new adapter, $15 isn't to bad.

**sseilmnop** · 09-05-2012

I have the $79 version of the harness with the circuit board in the the wiring. I can get it to jump from 0% to 99% without the TPS even being plugged in.