Tko 600

[Mr Barnwood]

I’m thinking of changing my Toploader close ratio four-speed to a TKO 600 and was wondering what you guys thought, I have read that the TKO’s do not shift as well as the top loader? I love the way my toploader shifts but I would like an overdrive. Lastly if any of the members are in the Rippon California area you have a place to stay I have a huge home with a huge shop with a lift in it and I’m retired so you’re always welcome to stay here for free.
Thank you
Joe

[sea2jet]

If I was going with a new TKO 600, I would talk to Liberty Gears and either purchase it from them if that’s an option, or send one to them to be modified before installing it in your car.

[MKS427]

Joe,
If what I have heard (I cannot say where, but someone who would definitely know) is true, you may want to hold off until ~ July. There may be a better option that is a direct replacement for the TKO.
Mark

[Anthony]

Another option would be to replace your close ratio toploader with a wide ratio, and change your rear gears to 3.07 or something like that .

[eschaider]

Joe,

The TKO's as delivered by Tremec are a shifting disappointment especially when you compare them to transmissions like top loaders. The Liberty mods will go a long way to correcting the shift quality but it will not feel as smooth as a top loader or other OEM transmissions from that time period.

If you are replacing a top loader you ought to look into a T-56 Magnum. Strength is stunning and so is shift quality. Even better the gear spacing seems to have a gear available for just about any situation you might find yourself in. It is heavy at, I believe 135 lbs, but it is a dream to drive and shift.

The transmission is basically a very nicely architected 4 speed with two overdrives which allows you to run a 3.70-ish ring and pinion and still cruise at nearly 70 mph @ 2000 rpm in 6th gear using a 295 x 55 rear tire. The shift quality substantially exceeds a well prepped top loader and Tremec rates the transmission at 700ft/lbs of torque.


Ed

[twobjshelbys]

I liked mine. Standard 5 speed config. I was an old 4-speeder and pretty much forgot that it had 5 but it did make crusing on the freeway a lot nicer.

[FredG]

I have the TKO 600 in my Backdraft with a 550 HP Roush engine because that's what it came with. It's adequate. The only time I ever get into the 5th gear is on the highway. The M-21 Muncie I had in the 60's with a Hurst Comp plus shifter was a much better shifting unit. I wish this unit shifted like it. I wouldn't even attempt a full blown, pedal to the floor, power shift with the 600.Speed shifts only. The Muncie had shorter, tighter and smoother throws but I don't know how it would be handling this much HP. I am not that familiar with the toploader thinking it was Fords version of the Muncie. If what you are considering is an older rebuilt transmission my only concern would be where it came from and what was in it.

Fred

[saki302]

The TKO600 in my car shifts fine.

I'm running ultrashift fluid from Cobra Valley, and the previous owner put about 38K miles on it, so I'm not sure if the extra mileage helped.

I installed a short shifter when I pulled the thing to reseal the input flange and swap the output shaft gasket.

[Dimis]

I recommend the steeda tri ax shifter.
It will sort the shifting issues of a tko600.
And gets better with time.

Enjoy.

[blykins]

The TKO will never shift like a Toploader, even with modifications, but it will do quite alright.

I've never been a T-56 fan. I just can't get my mind wrapped around having a transmission that's that long, that big around, that heavy, with two unnecessary overdrives. Most guys can't even use the TKO 600 overdrive because of gear ratios and camshafts. Why do you need another one?

[Jim Vander Wal]

The unfortunate thing about transmission selection, like motor selection is, unless you have prior experience in a similar car, you won't really know what you may or may not like until you've made the selection and driven it.

I started with 3.73 rear gears with a Ford diff, 1st gear was mostly useless, changed to Torsen T2 and 3.27s, a much better combo for my motor. Very pleased but not cheap. I've tried many different lubes and finalized on RedLine MTL. Had Liberty do their mods on the TKO-600 .64 OD, it's OK, not great. It's still a TKO.

I'm considering a T-56 Magnum for the current build, a FFR Challenge Car. IRS and a really short driveshaft, wouldn't even consider it with a solid axle. What I like is the two ODs as it has the option of the "road race" and "street" ratios. Should be able to keep the RPMs in the range for the type of road and driving conditions. I still don't expect to shift into an OD gear when on road tracks, 140 in 4th is plenty. Yup there's a price to pay in $$ and weight (about 35#) in the middle of the car.

I spent a lot of time looking at gearing/speed calculators then comparing this to HP/TQE curves in an attempt to evaluate how it would perform. In the end it was recommendations from friends that had experience that provided the better guidance.

Jim

[olddog]

Personally I like the TKO 600 ratios and the OD. Mine has the 0.64 OD, which I would much prefer the 0.82 OD. I plan to get the upgrades put it mine, as it does not like to shift well at high rpm.

It is very nice to have enough gears to keep the engine down around 2000 rpm. At these rpms the wind is louder than the pipes, and you can talk with your passenger. You cannot talk much with the engine up near 3000 rpm, unless you want to loose your voice.

It has a lot to do with what you use the car for. If all it is used for is running on a track and maybe driving to and from, then stay with the top loader. If it is only you in the car, maybe stay with the top loader. If you like cruising with your wife or someone else, then you likely want to talk and that can be difficult over the side pipes.

The engine has a lot to do with what gears you need, as well as where will you be driving. If you do a fair amount of interstate driving, maybe a 6 speed would be nice. If your engine is happy cruising down at 1500 rpm you may not need as many gears, as you have a wider low rpm range you can cruise at.

That's my thoughts.

[eschaider]

Shifting fine is a description I would never associate with a TKO. The transmission while strong, uses larger gears to get the torque capacity up to the 600 ft/lb threshold. When Tremec did this they did not do a corresponding upgrade to the synchronizers.

TKO's use a synchro that is basically an old top loader synchro from the 1960 generation top loaders. Those synchros worked fine in the 60's with the top loader gear sets but not so much today with the much larger and heavier gear sets in use for TKO transmissions.

In terms of shifting ease pecking order, the 60's transmissions sorted out lfrom best to worst like this:

• BW T-10
• GM Muncie
• Ford Top Loader
• Chrysler A-833

The strength pecking order exactly mapped against the shifting ease with the easiest to shift being the lightest duty box and the hardest to shift being the most durable box.

The A-833 Chrysler box was in fact a repurposed Ford light truck transmission with larger gears than the other Detroit four speeds of the day — which gave it the strength to handle launching a 3400 lb car with a Race Hemi in front of the transmission.

However, like the TKO's today the strength and corresponding size / weight of the gears meant the A-833 had "shifting issues" above 6000 / 6500 rpm. I don't recall anymore whether the first crash box was a Performance Parts modification or whether Ted Spehar and the Mowtown Missle gang first did the modification. Either way the transmission's high rpm shifting problems disappeared.

Joe Liberty improved upon the original Chrysler crash box design with his design which was marketed under the Pro-Shift name. This is what the difference between a Pro-Shifted gear and a normal synchronized gear looks like;



The lack of a synchronizer was made up for by the increased spacing between the engagement dogs on the gear and the corresponding receiver grooves on the shifting slider. This modification allowed for substantially reduced time between shifts no matter the skills of the driver. Skills not withstanding better drivers still had quicker shift times gear to gear.

Liberty productized the modification and made it available for any transmission. Today the original Liberty design has evolved and we now refer to as face plating. Without Pro Shifting or face plating a TKO they simply will not produce race quality gear changes. That doesn't mean that people with lesser gear change performance thresholds may not find the synchronized version of the transmission attractive.

Tremec was aware of the shifting issues with the TKO box but was unwilling to invest money in the "old" transmission. The T-56 was the new frontier and got all the new good stuff. The TKO not so much. When the T-56 Magnum came out the dual and triple cone synchronizers had been well sorted out and the newer stronger Magnum gear sets brought the T-56 up to a 700 ft/lb service rating with synchronized shifting qualities that were like putting a hot knife through butter.

After the shifting improvements, the dual overdrive in fifth and sixth provide a very nice highway solution. Even with a 3.73 ring an pinion the dual overdrive will give you essentially a 70 mph highway cruising speed at only 2000 rpm with 295 x 55 rears. If you drop the ring and pinion to 3.27 for a more useful first gear the 2000 rpm cruise speed jumps up to 77mph.

Be careful about going too tall with the ring and pinion, if you have an engine with a lumpy idle and poor low rpm performance. 2000 rpm sounds high but if your engine is just getting out of its lumpy performance range, your car will be bucking and misbehaving at highway speeds,

Aside from the improved shift quality, the T-56 gear choices seem to provide a gear for virtually every road condition you can find — which makes driving the car all the more enjoyable.


Ed

[Anthony]

Ed, a lot of good info !!

Yes, I know racers would take stock gears, and grind off every other synchro tooth, to enhance power shifting, strictly a racing modification, not for street, as the picture of your liberty gear showed.

GM modified the M21 close ratio gears, decreasing the tooth angle, which strengthened the teeth, I guess mainly for drag racing, and named the tranny M22, still using the same ratio's as M21.

Also, the higher the gear multiplication, the less torque the tranny can handle, so keeping all other things equal, a M21 (2.2:1) should be stronger than a M20 (2.56:1)

Chrysler had Borg Warner design a new tranny for the Viper's introduction, which was the T56.

Using the Muncie and Toploader as benchmarks, I think all current street 5 and 6 speeds are basically wide ratio 4 speeds with 1 or 2 overdrives. I can only think of one true street close ratio 5 speed, and that was the old Doug Nash / old Richmond Gear 5 speed, where 5th gear was 1:1, and all the gear spreads were truly close ratio.

[blykins]

I loved the TKO I had in my Cobra. It was behind a 6500 rpm 428.

That being said, nothing shifts better than a Toploader or T-5. The T-5 will break behind a 302 though.

[eschaider]

Originally Posted by Anthony

Ed, a lot of good info !!

Yes, I know racers would take stock gears, and grind off every other synchro tooth, to enhance power shifting, strictly a racing modification, not for street, as the picture of your liberty gear showed.

Spot on Anthony. The Pro Shifted and any of the Pro Shifted variations are race only mods. They make for a very unpleasant street experience.

Originally Posted by Anthony

GM modified the M21 close ratio gears, decreasing the tooth angle, which strengthened the teeth, I guess mainly for drag racing, and named the tranny M22, still using the same ratio's as M21.

Correct again. I can't recall anymore but I believe they might have used a better steel for the gears also, perhaps a higher nickel and/or molybdenum content.

Originally Posted by Anthony

Also, the higher the gear multiplication, the less torque the tranny can handle, so keeping all other things equal, a M21 (2.2:1) should be stronger than a M20 (2.56:1)

Correct again! When you put the mechanical advantage in the transmission through the use of lower gear ratios the strain is transmitted through the mainshaft and countershaft to the actual transmission case. This is why Liberty offers their upgraded front countershaft bearing support mod for the TKO's. Of course if you can't hook up the case load falls off proportionately.

Originally Posted by Anthony

Chrysler had Borg Warner design a new tranny for the Viper's introduction, which was the T56.

Again I can't recall with absolute clarity but I believe GM may have first used the T-56 design in the Camaor and Firebird offerings before the Viper deployed it. Additionally the Corvette used a special T-56 for their line.

The Viper T-56 was a special T-56 also. The mainsheet was given some Vitamin C because of the very high torque the V-10 produced. That Viper mainsheet and several other internals were desirable upgrades for extreme service applications until the Magnum version of the trans became a production item and made most of the super duty or similar parts came in the T-56 Magnum offering as standard.

Originally Posted by Anthony

Using the Muncie and Toploader as benchmarks, I think all current street 5 and 6 speeds are basically wide ratio 4 speeds with 1 or 2 overdrives. I can only think of one true street close ratio 5 speed, and that was the old Doug Nash / old Richmond Gear 5 speed, where 5th gear was 1:1, and all the gear spreads were truly close ratio.

I would agree again with two comments;

The Rockland gear folks offer several different ratios for their Tranzilla version T-56 that they claim is 1000 ft/lbs capable. The standard T-56 is offered in either a 2.97 or 2.66 first gear, consistent with your wide ratio observation. The Rockland Tranzilla T-56 gear sets are available in 2.98, 2.71, 2.68 and 2.29 first gear ratios with correspondingly nicely spaced 2nd, 3rd, 4th, 5th, and 6th gears. The 2.29 first gear, gear set is a to die for package — really nice gear spacing! Not surprisingly a really nice (high) price point.

The second comment is that while the old Doug Nash / Richmond 5 speeds do have a 1:1 top gear they are not as strong as the T-56 alternatives. Their gear selection is quite broad however, I want to say they are basically wide ratio selections. If I remember correctly Richmond rates the transmission somewhere around 500 ft/lbs of torque. Again this is not a problem unless you hook up.


Ed

[Mike I]

Joe,

FWIW, I gave up superior shifting with my first trans (Super T-10, 2.64 1st) for a Doug Nash 5spd (noisy, stout and rough shifting) because I wanted more gear choice at the track, and eventually a TKO500 for the OD. I love the OD, and the TKO shifts well enough for normal driving, but the TKO has the dreaded 2nd-3rd shifting issue when under heavy acceleration. Bottom line, each trans swap requires a fair amount of mod work and commensurate cost to accomplish, and be prepared to give something up. In my case, I really miss the smooth shifting of the T-10 under all conditions.

[Anthony]

The 1992 Viper had the T56. I think Chevrolet offered the T56 in the 1993 Z28. I'm pretty sure Chrysler got BW to design the T56, because I don't think there was a manual overdrive tranny available to Chrysler in 1992 to handle the Viper's 488 ci torque. Not that it really is of any significance other just historical.

[saki302]

My old car had a tko500, this a tko600.

I never noticed a hard 2-3 shift, though my rev limit is set at 6000.

-Dave

[eschaider]

You will always find varying reports of shifting experiences with a TKO. The spectrum will go from terrible to awesome. Terrible is usually the owner that didn't believe the issue was an issue and then felt snookered when he experienced the issue first hand. The awesome report will come from the individual who drives the car almost like a daily driver never taxing the shifting mechanism of the transmission.

I have yet to hear of any T-56 Magnum owner complain about the shifting. For those who feel six speeds are too many gears to shift through, remember it is a four speed with two overdrives for highway. You won't shift anymore but you will shift much more smoothly and easily.

The T-56 is a bigger transmission than a TKO so some chassis might need a little lovin' to fit it into the transmission tunnel. It is heavier than a TKO. TKO's come in right around 100 lbs. The T-56 Magnum is typically around 135 depending on options like tail shaft choice.

The install is not a straight forward bolt in but it is also not a lot of pushups. They are strong, shift effortlessly and seem to have a gear for any road condition you are likely to encounter. They are not cheap.


Ed