I've been thinking about upgrading my TKO600 as well, not so much for shift quality as strength. Both American Powertrain and Modular Mustang Racing sell a box they call good for ~900 hp, but from what I can tell besides some similar mods to what liberty is doing they are mostly just cryo and rem finishing the gears and claiming that strength upgrade. I also recently called LIberty, and the guy there said that cryo/rem is good for maybe an extra 100 hp ? but that there is no standard for "rating" a transmission by hp or lb/ft level (obviously you would need to know the weight and gearing and tire of the car to even begin to make this claim). So anyway I've been considering that since I have broken the 3rd gear cluster before.

But one thing I don't hear anyone mention about the TKO is the damn noise. My box sounds like a coffe can full of rocks anytime you "lug" it below 2500 rpms, which if you think about it, is like 50% of your street driving. Its very annoying. And every tremec I've had has done this behind multiple engines, some worse than others. Even though I could have LIberty or someone else upgrade this tko, I've been thinking very seriuosly about dropping the big bucks on a T56 magnum even though I have no use for the extra weight or gear. But I just feel like the T56 is a much more OEM style transmission with bigger and better designed internals.

Just curious if anyone else complains about the noise their tko makes ?

I put in a new set of gears at the same time I put in my 4 link, it howled like crazy. changed out the gears several times, then realized my driveshaft was to long. I shortened it up a tad and it got super quiet. I still have the 4th gear noise you talk about but was still figuring I needed to play with the rear end a little bit..But if this is a common noise then yes mine has it.

Update. Got my trans back today. I need to add some undercoating to the car so if I can get that done I will stab in the trans this weekend..

Then I will let you know how it shifts around 7k...Let see if my RAM bearing can stop leaking...Wish me luck!

Shifting the TKO
 

I have a TKO-600 behind a 383 LT1. The internal rail type shifter is spring loaded and I have found that if you simply pull straight back with your finger tips on the 1-2 shift it goes fine. Same on the 2-3 shift, if you try to grip the ball and guide the shift it will miss. If you just palm it forward it never misses third gear. This method was suggested by Grant R. at Kiesler.

Oh yeah! My 67 Nova has quite a cam in it and thus.......same thing.

How's it goin Chuck? You Prowlin the streets again with the new trans yet?

Ya Chuck, lets do this man. I'm sick of being the whipping post around this joint. :unibrow:

Liberty's number are going to be realistic because they've been doing racing gear boxes for a lot of years. AP has only been in business since around 2005 when I got them started by providing them a distributorship along with my Jag V12 performance line of product to sell. They are not racing people. They are sales people - nothing wrong with that if you get the truth!

The noise you are talking about is common with TKO. There are typically two types of gravelly noise - low rpm lugging where the TKO sounds like a school bus taking off, and a noise that is especially apparent in neutral with the clutch pedal not depressed. The latter is usually due to an incorrect preload of the taper roller bearings on the mainshaft and/or countershaft. There are other causes for noise, but these are the most common in the TKO.

Preston, if you are looking for the shift quality of the T56 Magnum, you should check out our KEISLER Rallye Sport RS 5-speed here.

TKO 600 Modifications
 

We don't advertise this, but we do offer the following upgrade services for TKO:

Modifications of Synchro for factory brass blocker ring - $200, and FREE to purchasers of our Tremec PF kits if you mention Lateral-G

Aftermarket blocker rings for 1-4 - brass with friction liner

Brass Fork Pads for 1-4

Proshifter with internal stops, tunable spring return bias (preset) - included with purchase of our Tremec PF kits

All of these things help the TKO, but are far from making the TKO a truly great shifting transmission for motorsports applications. The TKO was designed from the tremec mexico light truck/van transmissions, just for aftermarket. Trucks and vans have a very different requirement.

If I could stop screwing around with other things then yes...Now that i have the trans out I rewiered the car, now I've been reading your guys posts about what to do for a radio..hahaha

So no I have not tossed it back in there...I guess i should just to get it over with.