4L60E transmission no drive in 4th gear

[bairdmw]

I've got a 4L60E transmission behind a 355 stroker (original VT SS 5.0L) that was running fine, but now I have an issue where I can't get any drive in 4th gear. I can accelerate through 1st, 2nd and 3rd to 100km/h, as soon as i back off, my revs drop back to idle as if the box is neutralising. When I accelerate again, I get drive in 3rd gear at 3200rpm (at 100km/h). I just can't get the box to drive in 4th gear.

The interesting thing is that if I manually shift back to 3rd gear, the box behaves the same under acceleration, but the revs only drop back by 300-400 rpm (ie. it holds 3rd gear on overrun).

I have had the motor in and out a few times lately (replacing the front end) and the only wiring I've changed is the TPS - I re-routed this down the opposite side of the engine loom. I know the TPS is working OK as I can see an accurate throttle position reading when I plug in the laptop.

The trans did sit for 12 months, so I'm wondering if it could be a sticky 3-4 solenoid? I don't know much about autos, so I'm hoping it's an easy fix.

Any idea what could be causing this? TIA!

 

[losh1971]

Sometimes the 4th gear servo can cause problems with it not shifting into 4th.

 

[EYY]

Probably the 3/4 clutchpack.
In 2nd, the band is applied. In 3rd, the 3/4 clutches are engaged. In 4th, the 3/4 clutches are engaged AND the band is applied.

How does it feel in 3rd? What’s your diff ratio?

 

[BlackVXGTS]

To support EYY's post, the item below is from "4L60e Common Problems":

6. No 3rd or 4th gear: “3-4” clutches are worn out. R&R. The car is safe to drive (in 2nd if you have no 3rd) until you can get it fixed.

R&R = Remove & Repair (or Rebuild) = Transmission must be removed to fix the problem and may have to be rebuilt or replaced.

 

[Sparki]

I've got a 4L60E transmission behind a 355 stroker (original VT SS 5.0L) that was running fine, but now I have an issue where I can't get any drive in 4th gear. I can accelerate through 1st, 2nd and 3rd to 100km/h, as soon as i back off, my revs drop back to idle as if the box is neutralising. When I accelerate again, I get drive in 3rd gear at 3200rpm (at 100km/h). I just can't get the box to drive in 4th gear.

The interesting thing is that if I manually shift back to 3rd gear, the box behaves the same under acceleration, but the revs only drop back by 300-400 rpm (ie. it holds 3rd gear on overrun).

I have had the motor in and out a few times lately (replacing the front end) and the only wiring I've changed is the TPS - I re-routed this down the opposite side of the engine loom. I know the TPS is working OK as I can see an accurate throttle position reading when I plug in the laptop.

The trans did sit for 12 months, so I'm wondering if it could be a sticky 3-4 solenoid? I don't know much about autos, so I'm hoping it's an easy fix.

Any idea what could be causing this? TIA!

Hey Mate, I have the exact same issue with my VRSS 355 stroker. Any luck with finding fault?

 

[losh1971]

Don't like your chances of hearing from the OP. He made 1 post and it was over a year ago since he was last on.