T-56 Six Speed is Now One Year Old

[GWHITE75]

It's been one year since I put my vehicle back together with a fresh 454, new Tremec T-56 Six Speed, New Vintage Air A/C, Autometer gauges and Pioneer Tuner/CD changer. All parts are still working without incident and I have put over 5000 miles on it. It is not really a daily driver, due to travel distance to work, so 5K is a pretty good accomplishment for me in a year.

I am new to this site, but have been involved in others and I documented my six speed installation at http://temp.corvetteforum.net/c3/gwhite75/index.htm. I have pictures of the A/C installation and Autometer Speedometer and Tach installation. Some others might have already posted these retrofits, but in case you want possibly a different perspective, just shoot me an e-mail. gwhite@foxboro.com

 

[MsSchroder]

awesome!

 

[70 LS1]

Sweeet!
I hope I can put some more miles on my LS1 T56 combo soon.

 

[zZArAZz]

Awesome,
I have had a 6 speed sitting in my garage for ever. I wanted to do the conversion but ended up switching to a 400 Turbo instead.
If you could email me your walkthrough I would appreciate it!
Thanks!

 

[GWHITE75]

70 LS1 Good job. How hard was it to mate the hydraulic clutch and bell housing system to your car? I initially planned to put an LS1 in mine and liked the .50 final gear, but I decided to just use my existing hardware, when I found the aftermarket T-56 at Fortesparts.



zZArAZz Nasty looking motor. What kind of HP? I went to a 400, then to a 700R4, before I went back to a manual. I missed the manual and really enjoy all the gears.

If you go to the web site in my initial thread, it chronicles my installation. If your six speed is an OEM from an F-body car, then you might want to speak with Jeff (70LS1) about his installation, because it is different than mine.

 

[70 LS1]

The hydraulic cluth was actually one of the easier things in the conversion. I modified the 99 Camaro mounting bracket and used it to mount the master cylinder on the firewall. The linkage hooked right up to the pedal and the travel is perfect. I took out the stupid helper spring that the Camaro had. That makes it a little stiff, but gives good feedback.

 

[fredfryguy]

Awesome 6 spd job!!

Hey Gary, I just checked out your website on the 6spd install. Great job! I want one! I'll have to wait to I get motor souped up, maybe late next year. Fred

 

[GWHITE75]

fredfryguyThanks, the site was put together by a friend on another forum, good guy. You're gonna love the transmission. If for nothing else, the overdrive. Also, you'll never lock up the shifter again.

 

[fredfryguy]

Shifter lock up?

Gary, I owned this 71 vette for 5 weeks now. I had it tuned up, brakes adj, clutch pedal adj and the shifter set to the short threw set-up. I had trouble gettting it into second if I did a quick shift and thought the problem was linkage adj. Well it still refuses to go in on quick shifts. Can it be a worn sycro? What do you think. Fred

 

[GWHITE75]

There could be several reasons for your second gear issue. The shifter could be one, but I would look at other areas as well. Did the problem exist before you made the changes? If not, the shorter throw increases your shifting speed and can create the condition you speak, if the transmission does have high wear in its parts.

I had a similar problem with my old 4 speed, when the snap rings would not hold the 1-2 cluster together on the input shaft. I had a high torque motor and utlimately went to a Doug Nash 5 speed.
Even then, I had to increase the air gap between the disc and flywheel for quick shifts. For this, I needed an adjustable fork ball.

Other issues:

Your timing could be off on the shifting sequence now that things are different. Practice speed shifting slower and work your way up.


The clutch might not be releasing enough, when you disengage it to shift due to a now tighter readujustment of the clutch. You should have at least 1/2" to 3/4" of freeplay on the pedal, so the throwout bearing disengages, but the main thing is the air gap between the disc and flywheel when disengaged. Those specs you would need to get from your transmission or clutch manufacturer.

The input shaft bearing in the flywheel might be spinning the input shaft when you disengage during quick shifts, due to misalignment of the transmission/bell housing to motor.

You could have worn synchros. When they get bad or broken you will hear and feel a grind while speed shifting.

Also, they type of fluid and additives you run, in the transmission, might not be adequate or might be old.

One suggestion would be to not speed shift as fast. If the transmission works under normal and moderate acceleration, then just slow down your shift a tad bit when going to WOT. Trying to shift as fast as possible won't get you there much, if any, quicker, plus it causes undue shock to the drivetrain. 1st and 2nd gear are the hardest on the whole drive train. I know quick speed shifts sound good, but your equipment will last longer if you slow it down a bit.

Just my opinions.

 

[fredfryguy]

I'll be shifting slower for a while!

Gary, Sometimes when I shift briskly without winding up the motor-maybe 3500rpm it takes two or more pulls to get it to go in second. The clutch use to engage 3/4 of an inch off the floor and I had it adjusted to 2-3 inches off the floor or about 1/2 the way up. So I don't think it's the clutch. I will have the mechanic check it out when I put the CC 268 cam in mid Jan! I ordered the cam kit, roller rockers and pushrods tonight!Thanks for your advice. Fred