TKO Upgrade

[MaSnaka]

Thinking of upgrading my Toploader to the TKO600 mainly to add a 5th speed. I will need a new bell housing and I want to ditch the internal hyd throw out bearing and use an external slave and fork actuated throw out. I have hydraulic linkage which I would like to keep. Any thoughts or ideas as to which slave unit will work? I know space may be limited. I have a big block 390FE.

Thanks,
John

[Double Venom]

John,
Talk to MIKE FORTE, when it comes to TKO's and hydraulic set up Mikes the guy. He's also a Motorsport/Ford Racing distributor.

[RICK LAKE]

MaSnaka John, Overdrive trannies are nice IF you have the right motor and setup. Need a motor with alot of lowend torque at 1,500 rpms to 1,800 rpms. What endratio do you have? Is your current trans a wide ratio or narrow ration trans?
Most FE motors make great torque down low. It depends on the camshaft. It may be simpler to change the rearend ratio that swap the trans.
If you lug the motor at low rpms, over time you will damage the drivetrain. The clutch will only absorb so much vibration of the motor lugging.
Another main thing and this to me is the biggest, OIL PRESSURE. What is the pressure running at theses low rpms. FE motors have poor oiling systems. If you are running 50-60 psi at 1,200 rpms, this is fine. If you are only running around 30 psi, IMPO, you are starving the back of the motor of lube. Yes I know that the motor only needs 10 psi to float the crank shaft and in some motors like an LS1-LS( that's fine ). This is not a gm motor.
If you get a trans with the right ratios that's great. getting a final 5th gear of .65 and a low rearend ratio in the low 3.00's you are not going to be happy.If you do go though with this get a final ratio of . 87 for 5th gear.
You you going to be cruising all the time?
Last note, TKO have come along way to making a better trans. Need a fair amount of parts to swap into your car. May even need to replace the drive shaft.
If you have time, look into a Richmond super street 5 spd with OD. This trans will also hold 600/600 of HP and torque. Direct swap. May need to change just the clutch disc and pilot bushing in the back of the crankshaft. Top loader and Richmond are the same length. Shifter location same hole. TKO you may have too change holes to get it to fit. Different shifter between old and new trans. Some thing to check out the think about. Good luck Rick L.

[Double Venom]

Hey Rick,
Thank you for filling in the blanks. I assumed Forte would do that for John, but you have hit all the bases!

[MaSnaka]

Thanks Rick and DV,
I will give Mike Forte a call. Also Bret Lykins had some good info for me at another site. My main question is about the external slave set up and was hoping you guys or someone familiar with CR's might have already invented something to work already.

About my car though, 390fe, I currently have a close ratio 4 speed toploader (works fantastic), rear end ratio is a 3.70 9", w/ Tru Track, mild cam, hot oil pressure (10/30 VR1) is normally 55psi cruising and only drops slightly at lower RPM's but at idle will drop to 20psi. Not a race car (yet) but a little overkill for a street cruiser. What happens is at freeway speed I am taching 3800rpms and would really like to drop that into the low to mid 2's. I have checked the ratios from the TKO600 and the .64 od seems to be the best fit.

If anyone needs a well sorted that has been rebuilt toploader RUG-AJ from a 1969 428 Torino, let me know. Located in So Cal.
Thanks,
John

[xb-60]

Originally Posted by MaSnaka

....currently have a close ratio 4 speed toploader (works fantastic), rear end ratio is a 3.70 9", w/ Tru Track, mild cam.....

John,
If you stay with the 3.7 rear and change from a CR Toploader to a TKO600, the first gear ratios for the two gearboxes are very different. You would probably notice a massive difference in first gear capabilities. That may not be what you want.
Cheers,
Glen

[1795]

Unfortunately there is give and take in everything. If you go with the TKO the overdrive should be in a range that you will use on a regular basis. The .82 will allow you to get into overdrive at a lower speed, with the .64 you will not be able to functionally use it until 65-70 and the lower gearing in 1st and second may not be what you want. If you change the rear end you would have to drop considerably, my top loader with a 3.54 rear end runs about 2800 rpm at 60 and 3200 rpm at 75. The trade off is that with a ratio in the 3.23 range you are going to have trouble getting into 4th gear until about 50.

What you have to decide is the typical driving that you do and what level of performance you are looking for. I have thought about getting a .82 overdrive for my car so that it would improve long range mpg and be a little quieter down the road. However, for the most part I am driving in the 60-65 mph ranger on country roads and that puts me at the beginning of the power range of my cam and the car loves it. Good luck with your decision and try to keep the cost within means.

[olddog]

I have a TKO600 with the .64 OD in my car. I don't like the huge step between 4th and 5th. It is like having a 6 speed with 5th gear removed. I would much rather have the .82 ratio 5th gear. If that isn't tall enough then change the rear end ratio.

I think you should try to find someone with this transmission and drive or ride in it before you pull the trigger. Changing the 5th gear ratio is quite expensive, as the hole shaft has to be replaced, so once you buy it your stuck with it.

Hope that helps.

[patrickt]

Listen to olddog and run your exact speeds with the TKO600 gears, your rear, your tire sizes, and how those speeds correspond to the RPMs of your engine. For me, and my 15" wheels, 3.54 rear, and my .64 OD, it's absolutely perfect. My engine runs at its "quietest spot" at 2200 RPM, which corresponds to 75 MPH for me. One of my favorite things to do is head out on one of our lightly travelled interstates and just "quietly cruise" at 75MPH, which will not get you pulled over either. That is the only thing I ever use the OD for.

[eschaider]

One of the things you are going to miss with the TKO, John, is the smooth shifting the top loader had. The TKO is abysmal as shipped from Tremec. The problem is multifaceted.

Some of it is the synchros and there are replacement carbon fiber faced pieces that do a great deal to improve the gear synchronization. Sometimes these new synchros have worn out quickly because of a difference in the angle on the gear's synchro cone and the lining face on the synchro. For the most part this has been fixed but there might still be some old stock skulking around out there.

Some of it is shift fork friction face related and many transmission shops today have the bronze shift fork facings to help in this matter. Some of it is yet still related to the shift rails and Tremec's OEM shift rail timing problems. The stock rails can not be fixed, they have to be replaced.

The one stop shopping spot for all the fixes (and I have not talked about the front countershaft bearing yet) is Liberty's. They can do the whole shebang (including the front countershaft bearing) for you at one place and one stop.

When you are all done with the fixes the transmission will actually shift very nice — not like your old top loader but quite nice. The headaches however are not over, yet.

Hiding inside your new TKO 600 is a Tremec created fundamental design flaw that affects third gear. As luck (or rather lack of prior planning) would have it third gear on the main shaft is misaligned with third gear on the countershaft. If you want to believe the Tremec engineers the misalignment is only 0.140"!! Here is a picture of what it looks like;



The pic also shows the damage the incomplete tooth engagement causes when you hook up your power to the ground in third.

While the problem is fixable it involves machining off the third gear synchro, shortening that portion of the gear, then a respline of the gear for a replaceable synchro like used on the input shaft and finally making a spacer to move third gear forward on the main shaft to properly engage the countershaft gear.

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!

If you haven't purchased parts yet I would strongly encourage you to look at a T-56 Magnum. It'll fix you up with a land speed record sixth gear (0.63) but a fairly nice 0.80 fifth gear like the TKO RR option. Big differences are;

◉ The shift quality approaches that of your top loader,
◉ The trans is rated at 700 ft/lbs TQ capacity,
◉ The gear spreads/spacing make the car a dream to drive,
◉ You don't have to use the 0.63, 6th OD if you don't want to,
◉ The car drives beautifully on the highway in 5th @ 0.80 OD.

Real nice solution, essentially the same price, no reliability or U/G expense BS to get the trans to do what it should do right out of the box.

All things considered, not a bad alternative ...


Ed

[joyridin']

I have a T56 with 3.7 gears in the rear. Works great! My 6th ratio is .54. At 70 MPH it pulls about 1900 RPM. A little low, but on flat land or at 75 MPH, it cruises great.

It is a big transmission though physically. Make sure it will fit.

[JBCOBRA]

The .64 overdrive on the 600 trans just too tall. Been there. Get the .82!
It makes 5th gear a real gear that comes in handy for guys that really drive their cars

[RICK LAKE]

MaSnaka John your playing, I gone a secret. The easiest thing to do for your car is the change the rear end carrier. A 9" rear can have the center swapped in 35 minutes with basic tools. #.70 is great for racing 1/4 mile or auto cross of using 1or 2 gears only. We don't have the first gear ratio of the trans. Guessing in the 2.40-2.60's. Final is 1-1. If you have to cruise this car, you can find a rebuilt 9" for about $1,000.00 with gears. need a gasket or RTV and fluid. Basic work is you and free. If your motor is a torque monster and low end power, a 3.00 will give you the long legs to cruise. If you are looking for a happy middle, 3.25 would be ideal. Keep the trans you have, skip the modifications to the car. Enjoy. Cost saved about $2,000.00. Down the road if you want to get more power, then look at changing the trans.
Others here have the correct info on TKO. I beleive that their info said the trans is 600 pound torque rated. That's not 600 under full load or abuse. This is way I said to look at richmond. I have heard that these trannies are being built in China I still like the design and support of the shafts over a tko. I have an early version of the Richmond 6spd when they came out in 95. Great trans. It also has a couple of problems. gearing of a 3.25 first is a waste with 3.31 rearend. First shift within 30' Used 2nd gears to startup all the time. Overdrive is .87 used it and my motor would lug at 70 mph. This was 438 ft of torque at the wheels. Heat, when racing the shifting would get tight. My tunnel is fire proofed and air getting to the back of the car is none through the tunnel. Problem was fixed with adding a 4" bilge fan and pulling air from r/f foot duct. No shifting when hot. Know your limits, this trans has only a 450/450 torque and HP rating. It will bind if powershifted. This is why I went to a G-Force for racing. Only thing I didn't get was a 2.80 first gear and stayed with 3.05. With a 3.07 or 2.88 gearing, this trans will be perfect for all a round. I am still getting a super street for my 498 motor. This is all trial and failures over the last 15 years. Clutch, You might want to look at a Street twin from Mcleod. You will never need another one. Great holding, takes a ton of abuse, Soft pedal with just enough feel for engagment. Bylkins sold it to me. best money I spent. It's worth the up grade. This twim makes no noise when driving either. Some do. Good luck. Rick L. Ps the money you justsaved on not doing the trans will give you enough for this clutch setup and a cruise.

[MaSnaka]

Thanks for all the info guys. Eshader you are the only one I have heard with a complaint about the Tremec TKO600. Very discouraging to hear. Does any one else have trouble with shifting and worse 3rd gear getting chewed up? Not sure I'm interested in a 6th gear though.

Rick thanks for mentioning the Richmond super street 5, that sounds like a good alternative. I'm looking and listening.

Truth of the matter is I want the 5 speed to use 5th gear to settle in for freeway cruising. Drop the rpm's to a reasonable level and keep 1st-4th for performance driving.

My toploader is close ratio and just changing the rear end will drop rpm's some in 4th but 1st gear becomes very tall.

I have not heard any one with specifics regarding the external slave conversion. What units or part numbers do you have that will fit the CR with a big block?

I still have some homework to do and will get back with what I find.

Thanks,
John

[eschaider]

Originally Posted by MaSnaka

Thanks for all the info guys. Eshader you are the only one I have heard with a complaint about the Tremec TKO600. Very discouraging to hear. Does any one else have trouble with shifting and worse 3rd gear getting chewed up? Not sure I'm interested in a 6th gear though. ...


Thanks,
John

If you will be driving the car in a less than 'spirited' and/or non -competitive manner the TKO600 is a fine transmission. If you drive it in a competitive fashion and attempt to rapidly change gears from second to third it will not cooperate the way it is delivered from Tremec.

Some guys call it notchy some guys call it other names but rapidly changing gears from second to third is a problem in the transmission as delivered by Tremec since time immemorial. Attempts at doing it more often than not end up in a missed shift from second to third.

The problem is the interlock timing that Tremec built into the shift detents on the internal shift rods to prevent engaging two gears at the same time. They erred on their design in a fashion that precludes rapid gear changes. Changing shifters, synchronizers, trans fluid, shucks even the air pressure in your right from tire has no effect on the underlying design miscue. On the oither hand, Tremec does have replacement shifter rods that will correct the interlock timing whoops and importantly also the second to third shift quality.

The third gear alignment problem is present in all TKO600's according to Tremec engineering. The issue (reportedly) had to do with their transition from a two piece countershaft on the TKO500, that was prone to shear it's woodruff key under load, to the newer design TKO600 one piece countershaft. Now instead of shearing a countershaft key we can shear teeth off of two gears at exactly the same time!

To provide clearance for the machining chips the gear hob creates as the countershaft third gear is hobbed, Tremec needed to leave a gap for the chips to escape. That gap (between the countershaft second and third gears) is the origin of the 3rd gear countershaft misalignment with the mainshaft third gear. When they changed the gear placement on the countershaft they did not do the same for the main shaft.

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.

Part of the good news is that WOT in third gear is a relatively inspiring phenomena in one of these cars and most people (unless they are racing) don't do that very often, if at all. If you do then the game of Russian Transmission Roulette is alive, well and on.

When I had my TKO600 modified by Liberty I believe the cost of all the parts was about $400. I don't remember if there was also a labor charge or if it was included. Either way, price wise your TKO very quickly looks like a T-56 Magnum — pricewise. A telephone call to Liberty can quickly get you the current pricing. Don't forget to add freight up and back unless you intend to do the mods yourself. And of douse don't forget this only corsets the shifting problems. You still have the nicely misaligned third gear problem.

As the Liberty rep at the time suggested to me I would have been better off to use the T56 if I were starting fresh w/o any parts bought yet.

Here are the dimensions from Tremec for a TKO;



Here are the dimensions from Tremec for a T-56 Magnum;



While not exactly the same they are close enough either transmission can easily be made to fit.

It simply comes down to builder preferences and what is important to you — as do most choices in these cars.


Ed

[blykins]

I would refrain from using absolutes...

I have numerous 600's in road race, drag race, and super hot street stuff and have never had a customer break a gear. This is up to 600-650 hp, launching on wrinkle walls and shifting at 7000.

[eschaider]

Originally Posted by blykins

I would refrain from using absolutes...

I have numerous 600's in road race, drag race, and super hot street stuff and have never had a customer break a gear. This is up to 600-650 hp, launching on wrinkle walls and shifting at 7000.

I understand what you are saying Brent and while the third gear breakage was (to my knowledge) not experienced at launch in first or third gear it was experienced in a gear change from second to third, in a drag car, with a medium power level (but torquey) big block, in a heavier car than a Cobra.

The Tremec designed third gear misalignment in their TKO600 transmissions unnecessarily loads the engaged third gear, gear teeth higher than they would otherwise be loaded with a full face contact design. Whenever you do that to a driving and driven set of gears they will fail sooner than the same gears with full face contact — it's just the mechanics of the gear system. This is a similar phenomena to getting the pinion depth wrong on a ring and pinion. Will they fail right away? Probably not. Will they fail sooner than a properly set up ring and pinion, yup.

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.

So where is that magic line in the sand you don't want to cross? I can't say with any certainty. We do know Tremec claims the transmission is rated at 600 ft/lbs. They don't say if that is true for all gears some gears or only one set of gears. They also, to my knowledge, don't say if that is a sustained torque loading or a shock loading like we might see launching the car in a drag race style fashion. My suspicion (and that's all it is — a suspicion) is it is a continuous duty loading for a single gear set probably first gear.

If that is true (and that's a big if) it means 600 ft/lbs of torque and more represent a potential component failure threshold in third gear, again if everything is hooked up and really transmitting that much torque. How often can you do it with the misaligned gears? I don't believe there is any test data to give insight to that elusive number. However, we do know it happens and we do know those gears are misaligned 0.140" (if you believe Tremec).

Does this mean we should all forsake our TKO600's, probably not. Is it appropriate to make the knowledge available to someone who is contemplating the purchase of a new Tremec transmission? I think so. I know I would have liked to have had the knowledge before spending my monies and I think others might also. Will it or should it change everyone's mind? I doubt it and I don't think so but it will make some reconsider what they are about to buy and potentially allow them to make a better decision — for themselves.

In the final analysis if you are going to spend $2,400+ on a transmission why not buy the most robust unit with the highest torque rating and the best shifting qualities that will fit into your car for the dollars that you are about to spend?


Ed

[blykins]

Ed,

I appreciate all your input that you provide on Club Cobra and I usually take time to read your posts and digest your information.

However, in this one instance, I'm going to have to strongly disagree with the information you have provided.

Just in case I was out in left field, I emailed my Tremec supplier, since he is a dealer and is a Tremec-authorized repair facility, and asked him how many instances he has seen where the 3rd gear has eaten itself away or the cluster shaft gear has been eaten away because of misalignment.

His reply is that it's a new one to him, and if that were the case, he would be seeing a lot of irregular gear patterns, 3rd gear bearing cage damage, or just warranty repairs in general to fix the issue.

As I mentioned before, I've never heard of this, and I sell quite a few TKO's, as well as put them behind a lot of hipo engines that I provide. Some of them go behind road race engines, some go behind drag race engines, and some go behind 650-700 hp street engines.

Now, with that being said, the TKO's don't have a reputation of being the best shifters, especially at higher rpms. This gets better as the trans wears in, but we often do upgrades to correct gear cone and synchronizer hub surface finish, as well as upgrading the shift finger, blocking rings, etc. That usually takes care of the shifting issue, all the way up to 7500 rpm.

The TKO 600 is rated for 600 lb-ft of continuous torque on a trans dyno. If I'm not mistaken, this is rated in all gears except for overdrive. I can recheck this.

The Magnum T-56 is not (IMO) the solution to everyone's needs. In addition to the extra requirements to fit them behind some engine combinations, they are much more expensive, about 4" longer in length past the bellhousing, and much bigger around. This proves to be a big issue in some transmission tunnels, and in the case of a Cobra replica, with an already short driveshaft, shaving another 4" off the body length doesn't leave much.

The one failure from 8 years ago, that you have talked about and showed pictures of, seems to have been an isolated case. I just don't agree with making a blanket statement that says that all TKO's are timebombs, or that each prospective buyer needs to sit down and let this weigh heavily on their mind.

In my own mind, it's a non-issue.

[eschaider]

Originally Posted by blykins

Ed,

I appreciate all your input that you provide on Club Cobra and I usually take time to read your posts and digest your information.

However, in this one instance, I'm going to have to strongly disagree with the information you have provided.

...

The one failure from 8 years ago, that you have talked about and showed pictures of, seems to have been an isolated case. I just don't agree with making a blanket statement that says that all TKO's are timebombs, or that each prospective buyer needs to sit down and let this weigh heavily on their mind.

In my own mind, it's a non-issue.

I think we are actually closer together in our positions than you might suspect Brent.

My summary comments about the transmission were:

Originally Posted by eschaider

If that is true (and that's a big if) it means 600 ft/lbs of torque and more represent a potential component failure threshold in third gear, again if everything is hooked up and really transmitting that much torque. How often can you do it with the misaligned gears? I don't believe there is any test data to give insight to that elusive number. However, we do know it happens and we do know those gears are misaligned 0.140" (if you believe Tremec).

I went on to say;

Originally Posted by eschaider

Does this mean we should all forsake our TKO600's, probably not. Is it appropriate to make the knowledge available to someone who is contemplating the purchase of a new Tremec transmission? I think so. I know I would have liked to have had the knowledge before spending my monies and I think others might also. Will it or should it change everyone's mind? I doubt it and I don't think so but it will make some reconsider what they are about to buy and potentially allow them to make a better decision — for themselves.

I suspect what may have wrankled your (and possibly others) sensibilities was the clarity of the failure description and the publication of the Tremec design miscue in terms of gear tooth face alignment. I can well appreciate how the sudden awareness of a design flaw of that type in anyone's transmission can cause anxieties that did not previously exist — after all I own one also. It is however, none the less important and our obligation to be as informed and knowledgeable as reasonably possible so we can best decide for ourselves. I believe I also spoke to that in my closing paragraph where I said;

Originally Posted by eschaider

Does this mean we should all forsake our TKO600's, probably not. Is it appropriate to make the knowledge available to someone who is contemplating the purchase of a new Tremec transmission? I think so. I know I would have liked to have had the knowledge before spending my monies and I think others might also. Will it or should it change everyone's mind? I doubt it and I don't think so but it will make some reconsider what they are about to buy and potentially allow them to make a better decision — for themselves.

I think it is better for a potential purchaser of these types of components to have as much information as possible, both good and bad, prior to making a purchase decision about these or for that matter any other high value component in the car. When we use that information in our own decision/selection processes we will not all come up with the same choices but, we will come up with choices we think are best — for our own builds. Which when you think about it, is what the world's largest non-biased cobra site is supposed to be about and among other things foster? [Although in as much as we all own Cobra's we might have just a smidgen of bias ...)

In fact in my closing few sentences I suggest;

Originally Posted by eschaider

In the final analysis if you are going to spend $2,400+ on a transmission why not buy the most robust unit with the highest torque rating and the best shifting qualities that will fit into your car for the dollars that you are about to spend?

I chose to ambiguously identify that transmission because it could have been a variety of the Tremec offerings, a Richmond, a Top Loader, a G-Force or one of a number of other transmission alternatives. It is after all what the builder determined to be best for his purposes and his build given the information available to him at the time of selection/purchase.

In the end I don't think we are actually all that far apart. BTW I genuinely do enjoy and appreciate your perspective, input and insightful commentary on the site here.


Ed

[Double Venom]

John
Not to be redundant but the hydraulics are really simple. Again Forte makes all the parts for push or pull system, although he doesn't advocate the pull system often.

You know how much we used to drag race the "DV". Never a problem hitting third gear, but on a hard shift it always ground a little going in - always, not like a quality top loader at all, but the 5th rear was nice and sixth was really blah in my opinion. We used 3:08's. 3:55's, 3:73's, finally settling on 3:55's. 70 75 MPH we would run around 1,800 to 1950 RPM.

3:55's, depending on Tree traction some times I could just make the finish without hitting 4th. 3:73's I would have to go 4th and that cost to much time and torque.

Settled on 3:55's and a little learning curve..

DV