Stock 4t65E 4th Gear Shaft Wear

This is a picture of the 4th gear shaft I replaced in my transmission, when I did a rebuild about a month or two ago. It's worn out, and worn out bad. The tune I was using had a pretty hard shift into 4th gear. After seeing this, I will NEVER tune 4th to be that stiff again. Look at the splines and how worn out they are.




It was replaced with a hardened version, which I assume won't do this. The oil pump shaft was the exact same way. I also replaced that with a hardened version. I thought I took a picture of it, but apparently I didn't. I'm actually glad that the forward band broke first, otherwise some SERIOUS damage would've occurred if either one of these shafts let go.


Here is the band that broke. It actually wasn't the band that broke, but the tab that pinches it together.


I still need to upload more of my trans pics.....

Thats gnarly. 

:: takes aftermarket pcm out after seeing.this::

What year is your Riviera, Scott?

Why was the tune shifting so hard into 4th? Did you custom tune it that way, or was it part of a PCM tune package? Or for some other reason?

Heh, I forgot to put that back in my Sig lol. It's a '98. The tune that I had was loaded like 4 years ago? I think? I never changed it back or fixed it. I just recently got my tuner working again for the trans rebuild. The old tune shift times were set to .01 seconds, and the line pressures were maxed at 96 psi. It was a modified .bin file that I got from somebody because, like your tuner, it wouldn't read my PCM. As long as you were on the throttle, it felt great. It was normal driving that banged into gear. I never got the chance to re-tune it.

Reason I asked about the year, I remember something about our HD transmission getting a better 4th gear at some point. Might have been when they switched to 4t65e from 4t60e. Maybe I'm wrong, but thought they upgraded it at some point.

.01 secs shift time is fine, but YIKES, MAX PSI for all shifts! That's just crazy talk right there. Here's what I've been running for the 4th gear shift for about 150k miles:

Step 00 = 2 PSI
Step 01 = 2 PSI
Step 02 = 2 PSI
Step 03 = 2 PSI
Step 04 = 2 PSI
Step 05 = 2 PSI
Step 06 = 2 PSI
Step 07 = 5 PSI
Step 08 = 7 PSI
Step 09 = 11 PSI
Step 10 = 17 PSI
Step 11 = 20 PSI
Step 12 = 22 PSI
Step 13 = 25 PSI
Step 14 = 28 PSI
Step 15 = 32 PSI
Step 16 = 36 PSI
Step 17 = 40 PSI
Step 18 = 43 PSI
Step 19= 45 PSI
Step 20 = 47 PSI
Step 21 = 49.5 PSI
Step 22 = 53 PSI
Step 23 = 57 PSI
Step 24 = 60.75 PSI
Step 25 = 64.75 PSI
Step 26 = 69 PSI
Step 27 = 73.25 PSI
Step 28 = 77.5 PSI
Step 29 = 82 PSI
Step 30 = 86.75 PSI
Step 31 = 91.5 PSI
Step 32 = 96 PSI


Torque management:

Step 00 = 0%
Step 02 = 0%
Step 04 = 3.6%
Step 06 = 4.8%
Step 08 = 4.2%
Step 10 = 3.6%
Step 12 = 4.5%
Step 14 = 15%
Step 16 = 15%
Step 18 = 15%
Step 20 = 15%
Step 22 = 15%
Step 24 = 15%
Step 26 = 15%
Step 28 = 15%
Step 30 = 15%
Step 32 = 15%

I hardly even feel the 3rd/4th shift most of the time. Once in a while it drops in kind of heavy when I let off the gas near the shift point.

Maybe I'll copy that and load that in. Right now, 4th is bone stock. I only tweaked 1-2 and 2-3. After seeing that shaft, it kind of freaked me out, so I decided to leave it alone. The HP clutches firm it up enough.
I need to go in and lower my line pressures for 3rd gear anyway, so I'll give it a try....I apparently ramped the pressures it bit too fast. There's a "flat spot" between ~30%-45% throttle where it bangs a little.