What Did You Do To Your G-Body Today? [2023]

[Built6spdMCSS]

I haven't had much luck with my T56 but guess I should know by now that nothing works the way it should for me

What's been the issue?

I build them as well, know quite a bit about that transmission.

 

[mclellan83]

What's been the issue?

I build them as well, know quite a bit about that transmission.

I believe there was a bad synchro when I first bought the GTO, it would only happen the first time it would go into fourth but would have a very audible clunk then would be fine until the car sat again. Fought with the dealer for years about it but since I would drive it in to them it wouldn't be reproduced until I left it for them to have it happen from cold which they then dismissed since it only did it once. Eventually I took it to a transmission shop and they diagnosed the fourth and one other synchro going bad and only replaced those since the warranty would only replaced failed parts.
Jump forward near the end of my extended warranty and synchros were making noise again, go back to another dealer so it can be handled and jump through all of their hoops of trouble shooting. Even with the car turned off the car wouldn't properly go through the gears, they fight me and say that there has to be a throw out time between gears..... So go back to the original dealer who after some major back and forth because of the warranty running out while it was at their shop for a number of issues to get coverage while still under warranty. They finally rebuild the transmission once again only replacing some synchros, I provide an LS7 clutch since it was coming out anyways. I drive it home and don't even make it there before the line blows out because they didn't replace the slave while it was apart and part of their guidlines to do when replacing a transmission. Once all of it was said and done it drove nice for years.
Then last year I started having a very random grinding at times, would come and go doing it at very different times. Sometimes would do it when I first started the car and it was in gear, other time it would start fine. Some times it would grind going into a gear and other times I would drive it with zero grinding. My one buddy suggested it may be a piece of the clutch floating around and getting caught at times. Let another buddy drive it to the Pizza Power Tour for him to diagnose what he thought, by the time he was done driving it that day it was grinding all of the time pretty much. Let it sit for the winter and back to very randomly happening, now it seems that getting into third and fourth cause some grinding and at times grinds when started in gear pushing the clutch in. In the mean time I am getting some driveshaft shake which I think is from either the carrier needing to be done again or the donut replaced by the rear end as well as probably broken transmission mount bolts again.

Boy aren't you glad you asked

 

[Built6spdMCSS]

To me it sounds like a hydraulic issue, not fully disengaged. You have a speed bleeder installed on the Slave at all?

Throw out time between gears..yeah maybe if its cold. Mine warmed up I can rip 1-4 pretty fast.

How did it brake a trans mount bolt?

 

[mclellan83]

To me it sounds like a hydraulic issue, not fully disengaged. You have a speed bleeder installed on the Slave at all?

Throw out time between gears..yeah maybe if its cold. Mine warmed up I can rip 1-4 pretty fast.

How did it brake a trans mount bolt?

No speed bleeder unfortunately
Yeah same here, but to me it isn't relevant when just pushing the transmission through gears without being on
No idea, I brought it in today to finally look at it. Been meaning to but with all thats been going on with the Monte I was slacking. Last time I believe I had the carrier go bad and replaced it, then a while after had to replace the donut. When the donut went bad I believe there was enough vibration to break the bolts in the mount which was surprising

 

[Built6spdMCSS]

So it only does this grinding stuff with the car on? What type of fluid is in it?

 

[mclellan83]

So it only does this grinding stuff with the car on? What type of fluid is in it?

I believe so, want to check that when we go over it after work to confirm though. That is the debate with the mechanic, on the side of the transmission it says Dex3 ATF so thats what I put in it last year when I flushed it when the grinding started. He says he doesn't think it should take that

 

[Built6spdMCSS]

That is the debate with the mechanic, on the side of the transmission it says Dex3 ATF so thats what I put in it last year when I flushed it when the grinding started. He says he doesn't think it should take that

He doesn't know sh*t about T56 6spd Transmissions then. 4 quarts of Dex III, nothing else.

If something else was put in that may be the root cause. If Dex III was put in, I'm leaning towards a hydraulic issue.

"This label is here spec'ing the fluid but I don't think it should take that"... 🙄

Tell him I said he is a potato.

 

[mclellan83]

Pulled the Sniper off the intake and drained the fluids

 

[mclellan83]

He doesn't know sh*t about T56 6spd Transmissions then. 4 quarts of Dex III, nothing else.

If something else was put in that may be the root cause.

"This label is here spec'ing the fluid but I don't think it should take that"... 🙄

Tell him I said he is a potato.

Hahaha, no don't think anything else was put in. He did give the disclaimer that he is a DSM guy so doesn't know Tremecs and didn't believe me until I said that it was literally a sticker on the side of the transmission saying that.

 

[Built6spdMCSS]

Yea I'd be looking into the hydraulic side, some Slave cylinders need to be shimmed.

Damn import guys..