[transmission] What now?

Discussion in 'Fox 5.0 Mustang Tech' started by kck6894, Sep 4, 2008.

  1. Well I broke my Pro-shifted Tremec 600 for the second time. :notnice:

    The first time I broke it I blew 3rd gear up, broke the case and destroyed the cluster. I had it in my 94 Cobra behind my 347. The car weighed like 3500lbs so I kinda chalked it up to the heavy car. The motor only makes around 425 at the wheels, so I shouldn't be over powering the tranny.

    Well after repairing the tranny we put it in a 91 Notch along with my 347. The 91 weights like 2800. I only got about 30 passes on the car before taking about 6 teeth off first gear, breaking the case and cluster again.

    The tremec works great. Shifts amazing after pro-motion did the pro-shifting for me but it doesn't seem to be holding together.

    What now? I don't want to go auto and I don't want something that's gonna shift hard or not be streetable. Anybody got any suggestions? :shrug:
  2. Little bit OT, but how badly do the T56 conversions hold up?

    I know its $, and it's a little heavier; but that's the route I want to go when mine goes.

    G-Force rebuild?

    Id find out if my case is flexing or not...what's the mounting situation? Chassis work?
  3. Yeah I wouldn't be against going T56 but I'm not sure if they will Pro-shift one. I guess I should ask.

    The mounting is pretty much stock, it's hooked to a lakewood scatter shield. It's not really breaking like it's mounting problems. It Broke around the bearing retainer.

  4. Hmm, this is a true TKO 600 that Pro Motion did? That tranny should not have these issues behind that motor, in either car I would think. Did the guys at Pro Motion have any ideas on what it could be? There isn't much left, a proshifted T56 would be insane, but I also have never seen one. Are you hell bent on Proshifted? I know just how great they are to race, we had one for years and it is literally childs play to drive, but a non proshifted T56 would be smooth and strong.

    Also are you clutching when shifting? Not that this would cause the damage your seeing, but I have heard if you repeatedly shift without the clutch, they wear and break much faster.
  5. Yup! It was actually an old style TKO before the 500 and 600's but they put all the heavier 600 stuff in it when it was in the heavier car. They said I needed to run smaller tires and less clutch and I'd stop breaking it. That didn't sound like the right option to me. Anything I do in the future would need to be pro-sifted. After racing one you couldn't ever go back. They are amazing. He said it could have just been from all the wear and tear on 1st gear and that maybe we could put a girdle on the case and that it "might" stop it, but I'm just not sure I want to throw another $1k at fixing it if it's just gonna break again.

    I do use the clutch when shifting at the track.
  6. Hmm, you used 2 different cases right? The first you broke, and I assume you replaced with a new one? I'm not sure if the older style cases were any different than the TKO stuff, or if it was just internals. What clutch/flywheel set up are you running? A hard clutch might have something to do with it... you never know? How much street driving, and are you hard in gear, or matching the RPMs, what about downshifting?

    Also, Off Topic, what are you looking to get for the Locker, just an idea? :D
  7. yeah it was a brand new case. As far as I know the only real difference is the quality of the gears.

    It's a spec stage 3+. I always used them in my 94 because it was so heavy. They hit HARD and there is no doubt about that but it lasted for 4 or 5 years like that without any problems now it breaks twice in a row.

    Every time we've pulled it down it doesn't look like it suffers from the street use. I put quite a bit of miles on it. I drove it almost every day and had a pretty good knack of how to drive it without grinding or harming it. It took a while though :D
  8. Someone beat me to it... I was going to suggest the (costly) T-56 route.
  9. g-force makes a really fancy viper spec t-56 supposedly rated for 900 ft/lbs
  10. Expensive but good options. Might be worth it to look into, but my guess is your going to lose the proshifted quality. It is going to suck going from one back to a synchronized tranny, but the T56 will most likely last forever!