Turbo-Geist

I have a 99 C5 with a TR6060 from a 2008 C6Z. It was having a hard time shifting into 1st and reverse and the other shifts seemed very slow. I figured the stock clutch master cylinder was getting weak and installed a Tick master cylinder.

The new master cylinder seemed to cure all of the issues. Very easy to go into 1st and reverse while stopped and the other shifts were now lightning fast. I went to a half mile test event and on the shift to 5th at WOT it felt like it was in gear but nothing engaged and the car hit the rev limiter. No grinding, just felt like something was blocking it from fully engaging. During normal and moderately spirited driving it would still drop into 5th.

Prior to the next run I needed to back up and it would not engage reverse. It would click into gear, but as soon as the clutch started to engage, the shifter would pop out of gear. If you tried to hold it in reverse, it would just grind and not make any difference.

Troubleshooting:
-I've checked to make sure that the reverse lock-out solenoid is functioning properly and it works.

-With the car on jackstands, you can put it in reverse and let out on the clutch and the rear wheels will turn normally.

-If you put the emergency brake on with the wheels off the ground, it will pop out of reverse as soon as the clutch starts to engage.

-1st - 4th gears work fine and will go into gear during high rpm shifts. As mentioned, 5th gear will not engage at high rpm. Once the RPMs fall, it will drop into gear.


Any ideas on what might need to be repaired? Has anyone experienced a similar issue?

tmtraylor

I would confirm the shifter position/adjustment as a next step. With all the problem gears being on the upper extreme sides of the shift pattern, the shifter box may need to move slightly towards the rear of the car.

I haven't tinkered with the 6060, but it doesn't take much movement or out of aligment on the set screw in the shift rod on the T56 to cause issues. Good luck!

http://www.rpmtransmission.mobi/file...adjustment.pdf

and Froggy47 even did a video tutorial...

neutron82

check the bolt that holds the shift rod to the box, mine came loose and I had issues like you are experiencing as well as the shifter feeling very sloppy... I ended up using a header bolt with loctite to replace the torx bolt... header bolts are 10.9 grade and the same thread pitch as those torx bolts

Turbo-Geist

Thanks. It goes into every gear fine during normal driving. The main issue is that there is no reverse. I'm using the new style MGW shifter with the billet lower box. I used their alignment tool and have verified that the connection is tight.

If the rod was loose, there would be issues with other gears and a sloppy feeling right? There is no sloppiness here. It will bang gears as fast as physically possible for a quarter mile.

Turbo-Geist

I figured more people would have experienced this type of failure. I'm planning to take it apart anyway, but it would have been nice to know what I'm up against.

o1Z0sick

I have exactly the same problem and just started the process of removing it. It's a 6060 brand new from GM, 2013 model/design. I actually have to put it in 4th before reverse to stop the prop shaft from spinning or else it will grind. But I frequently have to hold pressure on the shifter while releasing the clutch and then it pops in.

My 5th gear is giving me the same problems too. I think all this is due to a dragging floater plate disc and the large twin disc MOI. I about to get a Mantic 9000. If I rev it in gear while stopped, at about 5000 rpm it will try to move forward.

i am going to go ahead and take the 5/6 and rev syncros out and replace with carbon like I did for 1, 3/4, 2nd was already the new design hybrid synchro.

TastyBacon

I know that the 6060 is different, but for what it's worth, my T56 had the same reverse gear symptoms. When I took the extension housing off, I found most of the mangled guts of the reverse gear synchro stuck to the magnets on the bottom of the case. A piece of the broken synchro had also found its way into the 5/6 cluster and broken a tooth off of 6th.

neutron82

I was still able to shift fine when racing but initially getting into first and reverse was sometimes iffy and regardless of which gear it was in the shifter itself had slop when rocking it from left to right... this was when I still had the t56 though, I figured the shifter was wearing out or something and I was about to pull it for a 6060 swap anyway so I waited to look into it and when I started to tear it apart it was obvious... when moving the shifter from side to side the lower part of the box was moving independently of the shift rod and the bolt had a flat spot wore into it... I tried to clean up the threads but as you can see in the pic below it wasn't 100% so that's why I looked into an alternative and ended up using header bolts to replace all the torx bolts... why it happened I have no idea, maybe hard shifting

o1Z0sick

Turbo Geist, any update to the TR6060 shifting?

I just got around to taking it apart. Upon inspection, the reverse syncro is toast. There are heat marks in the steel blocker ring where the brass cone ring makes contact. Don't think I could have put that much heat into it by just trying to select reverse a few times while not moving. I really think the reverse syncro was trying to get selected in the 4th to 5th shift. Where when I thought I was trying to get blocked out of 5th it was actually trying to go into reverse?

I could be totally incorrect in the assessment of the reverse syncro and that it was actually getting burnt from normally selecting reverse while not moving. I definitely had a warped twin disc friction plates that would have contributed to 5th blocking itself and burning up reverse. Meaning that there are no problems internally with the transmission. I just don't see any abnormal wear on the 5th syncro, blocker or gear that would indicate being blocked.

I'll post some pics this evening and I'm going to tweak a few more things while I'm in there but I really hope this new LT1-R twin releases like a champ.

FYI: Even the 6060 in the ACR Viper has problems (https://driveviper.com/forums/archiv...hp/t-9266.html). Same sequence of events, high speed 5th shift, seems blocked but it's actually frying reverse, next time in reverse it grinds. I really think it is trying to engage reverse.

cyberGS10

I know this thread is a few months old, but the same thing is happening in my '10 grand sport. I had the high-speed 4-5 grinding and i'm really thinking it was trying to go into reverse also, now that my reverse gear is shot. I guess i'm gonna go ahead and yank the trans. Any tips or tricks on getting the tranny out?

malize89

Dkiefert