Did you check the transmission fluid level?

 

Transmission level is good/full and fluid doesn't smell burnt.

 

Can has only 133,xxx miles on it. Any clues?

 

You might try testing in the individual gears instead of just "D" and "R". Try "1" and "2" to see if that provides any clues. You could also try flush and refill with new tranny fluid. If that doesn't work, probably looking at rebuilding the unit or swapping in another one.

 

The dipstick shows in the OK range with the engine running so it's probably something not so nice.

If this was a 4L60E I'd say you lost the forward sprag or the sun gear reaction shell cracked. The evil noises she's making aren't a good sign. You likely need to get a rebuild done by a competent shop. The 4T65E-HD isn't an easy transmission to do right and there are a bunch of things that need to be done when rebuilding it to head off future problems.

Contact Dave at Triple Edge Performance in FtWayne IN.

Triple Edge Performance

Specializing with High Performance transmission rebuilds for over 20 years. 4T65E Transmission Rebuilds are all custom built and upgraded for added durability!

tripleedgeperformance.com

If you're in the Amarillo Texas area contact Precision Transmissions.

The rest of the country? I have no idea who might be worth working with.

 

I just acquired a 2008 Impala SS and was told the transmission is shot. I'm not quite sure that's the problem but looking for some expertise on this one before I swap out the tranny (Car part, not human. haha)

I picked it up. It had been sitting for a while (about a year maybe) so the battery was dead.
Jump started, it took a little charge time but that was expected.
Started up and motor sounds good. A little rattle coming from the transmission area but contributed that to sitting for so long.
Drove the car up on the trailer, tied her down to the trailer and left it running the 65 mile tow back home. Motor was still purring, no overheat. Shut it off.
Untied and started right up. Still heard the rattle but shifted into reverse and she drove off the trailer just fine.

Went to take it for a drive and she got 200 feet (+/-) and she stopped rolling. motor revs but no go. Put in reverse, no go. One thing I did not check was if park would hold the car. Maybe check next time.

It acts like it is getting kicked into neutral. With the motor running, nothing you do will switch this condition. While no drive or reverse, there is also no rattle.

Shut the car off for about a minute and restart. Rattle is back and drive/reverse are operational again.....for a very limited time. then nothing again.

All corresponds with that rattle. When engaged, she will light up the tires and no slip. I'm just not convinced it's not a "limp" or "safety" mode kicking into effect.

Anyone experience this before? I know this is why the car got parked. Would like to see if I can get it fixed half way easily.

Thanks in advance guys!

 

I’m having the same issue did you ever figure it out?