T56 High RPM (3rd) Gear Block Out?!?!

[itzstreetlethal]

Forgive the noOb thread but I tried a quick search and am an old 4L60E guy... Here's what I've got. During WOT runs (i.e. 1/4 mile passes) 75-80% of the time, I cannot get third near redline. I'm using the clutch/shifting normal, all other gears appear to shift really well. But going from 2nd to 3rd while at 5800 RPM or so is damn near impossible. I thought I read somewhere about this being common on T56 cars but can't find the threads so I figured I'd post. If you know of any links, solutions (besides the auto trans swaps!) or advice, please feel free to pass them on. Only fix I've found is shifting at 5500RPM or less which hurts the run a little. Anyways, thanks and take care...

[itzstreetlethal]

Just found the infamous DRILL MOD info, maybe an adj MC, install and rebleed.

[Joker Z28]

This is all new to me.
What is the drill mod?

[Spartan7]

The drill mod is mostly for LS1 hydraulics. Sounds like you have an internal tranny issue, like a bent fork.

[popo8]

x's 2 on the bent fork....

[AChotrod]

The Hydraulics probable have air in them or a leak. Drill mod is for LS1 cars not us.
I would re bleed the MC/slave assembly

[gregrob]

Do you have the stock shifter? If so, switching it would make a big difference

[itzstreetlethal]

Was told it's an "SS" shifter. I replaced the shift knob and checked out the base of the shifter, doesn't look like the "Hurst" in my 2000 LS1 SS. But it does shift well, very smooth and normal shifting is just about perfect. It's the near redline shifting from 2nd to 3rd that is just about impossible. I'll try to rebleed but hope it's not a bent shift fork. Any other ideas?

[itzstreetlethal]

Went to the track again, same issue. It's only when I shift @ 6000ish RPM, that it gives me fits. ALL other shifting is fine under normal use. No grinding, no difficulty in ANY way. The shift is not stock but not like the hurst shifter in my SS. Does the "bent fork" theory make sense if it shifts great everywhere but 6000rpm? I short shifted one run and it went to 3rd fine, shifted near redline twice and it sends me into 5th!!! Anyways, the fluid looks like dark coffee so that's to be changed!!! Any other advice or ideas? Thanks.

[MEAN LT1]

Im having the same issue with my tranny. Normal use its fine but when at the track at 6000+ rpm third gear will not engage. Its like the hitting a gate going into third. IMO I think its the syncros not slowing down enough to get third gear to go in. Makes sense to me.