TKO Upgrade

[blykins]

I've sold a lot of TKO's and I've never had one go back for 3rd gear issues. The shifting issue is there, but it appears that the TKO needs a break-in period before it smooths out. If you're needing to speed shift about 6000-6200, then I would suggest some blueprinting work to the shift finger, gear cones, and synchronizer hubs. An aftermarket shifter works wonders as well.

Not a fan at all of the Magnum T-56. In comparison to a TKO 600, you get a transmission that is much longer, heavier, much bigger around, and much more expensive. The 6th gear is not a perk in most cases. If you're trying to get one to bolt up to an engine (especially an FE) with a twin disc, then it requires more machine work to the midplate, along with some extra parts.

We offer the TKO 600 with some upgrades that will extend the capacity past the 700 lb-ft mark, and will still come out cheaper than a T-56.

[Silversmith]

Very good post, thanks to all.

[maurice19]

John,
I replaced my internal hydraulic tb with the Kirkham setup. A perfect, simple ( thank goodness) bolt on.

Maurice

[MFE III]

Hey John; I second the endorsement of Mike Forte's solution. I purchased his bell housing with external mounted slave and it was an easy setup. No problems in nearly 5 years of use, whereas a number of my/our friends with SPF and CSX cars have had problems in this area.
http://http://www.fortesparts.com/cl...el-bellhousing

[Double Venom]

John,
Just a comment on blykins post. Never blew third gear at all. Never heard of one blowing it, like I said (3-56's) and all three of them would do a little grinding (during speed shifting only) going into third. Almost like there wasn't enough clutch release???

Of course the T-56's and the tko's are different animals!

[Ram427]

as I understand it, you can keep the toploader bell housing if you use a different length (shorter?) input shaft.

I got this from Mike Forte when I was investigating the same swap.

the new input was a $100 ish option, but this was about 4 yrs ago

TCET4617 was my TKo600 of choice.

kept the toploader in the end as the mileage each year doesn't warrant the change.

good luck.

Roger

[joyridin']

I put a T56 in my car. It is a HUGE transmission in physical size and it is heavy. Looking back, I would have been much better off with a TKO 600. I got the T56 at such a good deal, it was hard to pass up at the time.

The only time I use 6th is on the highway cruising at 70 MPH or above. You cannot use it for anything less than that. The RPM's even with 3.70 gears are just too low unless you have EFI and other additions to make your car drivable at very low RPM's. I use 5th gear most of the time at 70 MPH or less on the highway.

[blykins]

I mainly had trouble with these statements:

"As long as you do not hook up your tires in third gear under full power and/or do not have a relatively robust engine you are not likely to have a problem. On the other hand if you nave a relatively robust engine and you also hook up in third you are in a dance with the devil. It is unlikely (but not impossible) to break it on the first attempt however repeated WOT third gear operation with the tires hooked will kill it."

"This is a royal PITA when everything goes right. When things go bump in the dark it'll blow you mind and your patience. This is something Tremec has known about for a decade (maybe more) and chosen to do absolutely nothing about!"

"While it is not an absolute that you will get shot every time you play Russian Roulette, it is true that the more often you play the more likely you are to get shot, again sort of a similar phenomena here. I think the number of Cobra's who can load their third gear, gears to their breaking threshold is relatively small, more because of the car weight and the spectacular experience available in car at WOT in third gear. That however does not mean that they will not fail. Importantly if and when they do fail the attendant gear tooth shrapnel is capable of expanding the scope of the failure if it gets into other gear sets inside the transmission."

Those statements infer that:

1. Any car with a TKO 600, a handful of horsepower, and good traction will most likely shatter 3rd gear.

Of course that's not true. I forgot to mention the '69 Mustang that belongs to a customer of mine with a 529 inch Boss headed big block...740 hp and 700 lb-ft of torque. No issues.

2. There are instances throughout the world of TKO 600's breaking 3rd gears and clustershafts because of a 'known' manufacturing defects and they choose to simply not do anything about it.

Of course that's not true either. If I were a multi-million dollar company making 1000's of transmissions at a time, I most likely wouldn't do a re-design, tooling change, etc., for just ONE instance of a failure.

3. Using a TKO 600 is just like rolling the dice everyday...

There were many insinuations in your posts Ed that were based on ONE known failure and, honestly, just a lot of your own opinions.

Thousands upon thousands of people read these posts and there's just no reason for misinformation to be passed around.

[eschaider]

Originally Posted by blykins

I mainly had trouble with these statements:

"As long as you do not hook up your tires in third gear under full power and/or do not have a relatively robust engine you are not likely to have a problem. On the other hand if you nave a relatively robust engine and you also hook up in third you are in a dance with the devil. It is unlikely (but not impossible) to break it on the first attempt however repeated WOT third gear operation with the tires hooked will kill it."

You are correct Brent, I think the absolute in my last sentence could have / should have been picked more artfully and carefully. To state, 'you will kill it', is not fair nor appropriate. There are any number of cars who will not possess sufficient torque, traction or weight to damage the transmission. What we do know is there are those that do, can and have. It is not speculation it is a matter of fact. What we don't know is how many, what types or how frequently.

Originally Posted by blykins

"This is a royal PITA when everything goes right. When things go bump in the dark it'll blow you mind and your patience. This is something Tremec has known about for a decade (maybe more) and chosen to do absolutely nothing about!"

This is simply a statement of fact. Unless you have taken the time and effort to shorten and modify one of the TKO600 mainshaft third gears to accept the replaceable synchronizer teeth like the high gear input shaft uses, you simply have no frame of reference with which to judge the process against. After the shortening and machining to look like the input shaft's replaceable synchronizer register, the job is not complete until a corresponding spacer is sized, machined and fit between second gear and third gear to properly position third with its driven countershaft equivalent, correcting the tooth face misalignment.

When I contacted Tremec engineering about this problem in late 2006 (if I recall correctly) to make them aware of it, they told me they knew when they designed the transmission that there was a misalignment and it amounted to ~0.140" (according to Tremec's doc at the time) moreover it was necessary in order to manufacture the one piece TKO600 countershaft. When I suggested the third gear fix to the problem the engineer informed me the transmission had never failed in service — a rather amazing service record for any mechanical device! When I sent him a pic of the destroyed gears he indicated the T-56 was the company's focus going forward and the TKO was what it was.

While you were not party to that conversation, I was. It represented a callous lack of regard for a known (to Tremec) problem and depending on application a discoverable problem for the end user of the transmission. It also said the company was focusing on other products going forward and not putting any further maintenance or development efforts into this particular transmission or problem.

That is all right and that is also the company's right and privilege. It is also something the purchaser/end user ought to at least be aware of in his selection process.

Originally Posted by blykins

"While it is not an absolute that you will get shot every time you play Russian Roulette, it is true that the more often you play the more likely you are to get shot, again sort of a similar phenomena here. I think the number of Cobra's who can load their third gear, gears to their breaking threshold is relatively small, more because of the car weight and the spectacular experience available in car at WOT in third gear. That however does not mean that they will not fail. Importantly if and when they do fail the attendant gear tooth shrapnel is capable of expanding the scope of the failure if it gets into other gear sets inside the transmission."

Those statements infer that:

1. Any car with a TKO 600, a handful of horsepower, and good traction will most likely shatter 3rd gear.

Of course that's not true. I forgot to mention the '69 Mustang that belongs to a customer of mine with a 529 inch Boss headed big block...740 hp and 700 lb-ft of torque. No issues.

The inference you have drawn is in fact your own and not mine, nor my words. My respective words are in blue above. While you are absolutely entitled to your own interpretation and inferences it is noteworthy it is your interpretation, your words and your inferences not mine nor what I said.

Originally Posted by blykins

2. There are instances throughout the world of TKO 600's breaking 3rd gears and clustershafts because of a 'known' manufacturing defects and they choose to simply not do anything about it.

Of course that's not true either. If I were a multi-million dollar company making 1000's of transmissions at a time, I most likely wouldn't do a re-design, tooling change, etc., for just ONE instance of a failure.

Those are not my words Brent. Those are your words. My words from post #8 above were:

This is a royal PITA when everything goes right. When things go bump in the dark it'll blow you mind and your patience. This is something Tremec has known about for a decade (maybe more) and chosen to do absolutely nothing about!

The PITA comment was a direct reference to the remanufacturing effort associated with modifying the mainshaft third gear. The immediately following sentence which you can see in blue above is quite different than what you have asserted I have said, when in fact I did not.

Originally Posted by blykins

3. Using a TKO 600 is just like rolling the dice everyday...

There were many insinuations in your posts Ed that were based on ONE known failure and, honestly, just a lot of your own opinions.

You may choose (for whatever reason) to season the wording to fit your own purposes and that is alright — for your purposes. For my part I attempted to stay as factual as possible. The words in your point #3 above are again your words not mine.

Once again and concisely in one spot, the facts are as follows;

It is a fact that,

◉ Third gear has a 0.140" countershaft/mainshaft mismatch according to Tremec,

◉ Tremec has known of this mismatch since the design phase of the TKO600,

◉ Tremec intends to do nothing about the mismatch,

◉ Tremec stated the transmission has never failed in service, (in fairness they probably meant third gear),

◉ Despite their representations to the contrary, third gear has failed in service at least one time we are all aware of,

◉ We do not have an adequately broad enough view of the total TKO600 product sales to know how many more have failed and Tremec will not assist,

◉ We do know one has failed,

◉ We do know anything that has failed once can fail again,

◉ We are not privy to the threshold conditions necessary to fail the transmission,

◉ It is to our advantage to know about this type of failure when selecting a transmission so we can select in our own best interests.

I think the bulleted facts above can easily stand on their own. I don't believe I have intentionally included my opinions but rather stayed very close to known fact. If you have an example of my use of an opinion as fact I will certainly restate the bullet to reflect fact and remove or retract the opinion.

Originally Posted by blykins

Thousands upon thousands of people read these posts and there's just no reason for misinformation to be passed around.

I could not agree more with you on that point Brent. That is why it is important for potential transmission shoppers to know about this kind of 'stuff'. Maybe it will be a non issue for their build but on the other hand maybe it will not.

If it falls into the maybe it will not category, or close enough they don't want to take a chance, then we are doing for someone else what I would think most of us would hope someone would do for us if roles were reversed. That's a fairly honorable endeavor no matter how you look at it.


Ed

[blykins]

Thanks for your words, Ed.

I can only say that I wish every mechanical component that I come into contact with only had one instance of failure in over 8 years, across THOUSANDS of samples. That is an excellent record, and to be honest, if I were Tremec, I wouldn't address it either.

Considering the amount of people that frequent this site, I've yet to see anyone else who has ever mentioned anything else about this particular problem. Further more, my distributor who has seen hundreds and hundreds of these transmissions, had never heard of this problem before.

I would consider that a stellar product and it only further causes me to endorse it in the future.

I only wish to deal with parts that have high reputations. There are crankshafts that I will use and not use. There are rods that I will use and not use. There are even clutches that I will or will not use. In my years of selling clutches, I have only had one McLeod issue and no RAM clutch issues (aside from installation errors, etc.) that I can remember. It seems like the TKO has proven itself along side of those products.

[Lightingrod]

I have been trying to get around to swapping to a TKO-600 for over a year now! I now have a built GM 700R-4 in it now. I'm not happy with the converter, @ 3000 rpm stall I may have went a bit high for the cam I have. One would think that at 62 years old I would know myself a bit better? Mild cam and carb will be enough, NOT!

I have the CRII peddle setup and a Monza V8 bellhousing. I'm planning to go with a light weight flywheel and a good single disc clutch. I'm going to pull engine and trans out and do a cam and intake swap while I'm at it! I'm going up from the Comp 280 AR (.550" lift, 280*) to the 300 AR (.575" lift, 300*) and from an RPM Air Gap to a Victor single plan intake! This is on a SBC 388, 10-1 CR with AFR 210 Race Ready Heads (2.08" x 1.60" valves), it also has a Rev Kit on it. It should pull strong to 6700-7000 but the torque is going to take a pretty big hit below 3500. SOoooo I'm going to also put a (50-75 hp) NOS TopShot on it. This should keep even my old foolish azz happy at least for a while?

I have an drum brake 8.8" with 4.11 gears and a disc brake 8.8" with I don't know what! My plan is to leave the 4.11rearend in and see what's up with the RR TKO .82 5th. If 4.11 is to much I'll go with 3.73-3.55 when I install the disc brake rear.

If anyone is running a TKO, what shifter position are you using?

This will get DONE this winter!

:-)

[RET_COP]

I've been on the Ford websites a lot over the years and those guys Hamer the crap out of those transmissions, faceplated and all and i never heard of breaking third gear. Ive seen a lot of carnage in my years of drag racing, could this isolated incident just be a bad third gear from a metallurgy standpoint. I mean this stuff happens. I don't doubt that the .140 is an issue but does it directly result in a breakage problem the we all know about? Im not seeing that.

[RET_COP]

Tko 600RR steeda tri ax with a nice steeda shifter, in the rear position. 3.27 rear im on the fence about switching to 3.55. Trans has notchy shifting but does get better. After 500 miles it showed improvement. Without some work its not the best powershifting trans. I have a cable set up and i found out through experience when i slightly pre loaded the throughout bearing i had a big improvement in power shifting and speed shifting. Thats cable mind you.

[Lightingrod]

Originally Posted by RET_COP

Tko 600RR steeda tri ax with a nice steeda shifter, in the rear position. 3.27 rear im on the fence about switching to 3.55. Trans has notchy shifting but does get better. After 500 miles it showed improvement. Without some work its not the best powershifting trans. I have a cable set up and i found out through experience when i slightly pre loaded the throughout bearing i had a big improvement in power shifting and speed shifting. Thats cable mind you.

What shifter position; rear-center-front?

[eschaider]

Originally Posted by RET_COP

I've been on the Ford websites a lot over the years and those guys Hamer the crap out of those transmissions, faceplated and all and i never heard of breaking third gear. Ive seen a lot of carnage in my years of drag racing, could this isolated incident just be a bad third gear from a metallurgy standpoint. I mean this stuff happens. I don't doubt that the .140 is an issue but does it directly result in a breakage problem the we all know about? Im not seeing that.

The torque capacity for a gear set is a function of the steel used, the gear centers, the tooth style and also the face width of the gear teeth. The T56 Magnum has the same gear centers as a regular T56. The box's strength comes from increased tooth face contact (width), improves materials and also tooth pitch angle.

If you have a gear that is 1" wide and you make no changes other than reducing the tooth contact (face width) by 50% the torque capacity of the gear has been reduced by 50%. This is exactly (other than the percentage) what has happened to third gear in the TKO 600's. The torque capacity reduction is linear with gear tooth face width reduction.


Ed

[blykins]

Originally Posted by RET_COP

I've been on the Ford websites a lot over the years and those guys Hamer the crap out of those transmissions, faceplated and all and i never heard of breaking third gear. Ive seen a lot of carnage in my years of drag racing, could this isolated incident just be a bad third gear from a metallurgy standpoint. I mean this stuff happens. I don't doubt that the .140 is an issue but does it directly result in a breakage problem the we all know about? Im not seeing that.

Agreed....

I've moved a lot of TKO's and my supplier has moved probably 100x that....neither one of us have ever heard of or seen this failure before.

You can not preach this as gospel, when it's the only incident that has ever been shown.

[SPF1061]

I have had 3 TKOs in my SPF replica and logged over 50,000 miles on them. Road racing, drag racing and spirited street driving. The last 40,000+ miles have been behind a very stout running Roush 427R. I have yet to trash a gear. With all do respect, I think the 3rd gear failure fear is BS. I do think that the TKO 600 is very difficult to shift quickly and reliably at high rpm. Brent has mentioned mods that will help this. I am sure there are numerous folks that can do these mods. I can say for sure that these people do good work and that their upgrade makes the TKO 600 shift much smoother and very reliably at 6200+ rpm. WELCOME TO LIBERTYS HIGH PERFORMANCE

[MaSnaka]

I'm still in. Waiting on back ordered short input shaft to use with my existing bell housing. I'm patient.

John

[RET_COP]

Rear position

[Lightingrod]

^^Duh^^ Should have read your post a little better!

Do you think the mid position would be better? As in $350.00 better? I looked at your photos and I think the rear position would work for me, I have my seat all the way back!

thanks,