New Tremec transmission

[olddog]

I think the TKO was the top pick for a Cobra. All things considered.

That said The high rpm shift is slow. It takes a bit of time for the synchronizers to do their job, and you can feel the shifter stop moving for a moment. A moment while your engine is free reving at 7000 feels like an eternity. I would compare it to the old bow tie Saginaw. The Muncy was far superior to it. Ditto on the top loader. The 2 - 3 shift is a real pain to shift fast. I gave up trying years ago.

So although I would recommend the TKO, there is nothing that sticks in your craw more than getting told there is nothing wrong with a product (the problem is your fault) and then the new model comes out bragging about the new model resolving all the problems you asked for support to fix on the old model that they had claimed had no problems. That is the reason for getting it off our chest or dissing them. I know that was a run-on sentence, but I had to blurt it out.

[eschaider]

Originally Posted by twobjshelbys

I don't get all the dissing of the TKO600. I still think it was one of the best, snappiest shifting transmissions I ever had. As good as the Ford GT.

It has to do with decades of Tremec and a large number of their resellers denying the existence of the 2-3 shift gate problem and pushing back on the buyer that the problem was related to something they were doing wrong — when in actual fact it was directly related to Tremec design decisions when the box was originally designed and built. When you couple this with a reticence to correct the design flaw with an engineering change order so follow on production would provide a better driving experience, it leaves a bitter taste for those who experienced the problem.

The 2-3 gear change or any other gear change in the transmission will be affected by bell housing alignment. There is no escaping that. It is interesting however, that if the misalignment is causing a 2-3 gear change problem, why doesn't the same misalignment cause a 1-2 or 3-4 or 4-5 gear change problem? The answer is obvious, the alignment while important is not the primary cause of the 2-3 shift problem.

The 2-3 shift problem is rooted in a 1960's synchronizer design style and technology (simple brass ring vs muti cone modern designs) in conjunction with a poorly designed 2-3 interlock timing built into the shift rails when they were manufactured. The two changes that Liberty makes to the transmission that correct the problem are the higher co-efficient of friction carbon fiber faced synchronizer rings and the replacement shift rails with modified interlock timing.

Many of us never experienced the reason for the availability of the TKO 600. It was the 2 piece countershaft of the TKO 500 that used a relatively small woodruff key to lock the front and rear halves of the countershaft together. That key would shear off in service when the car had a good grip on the ground and the engine had north of 450 ft/lbs of torque. Another buyer beware design oversight that Tremec never chose to fix in the TKO 500 product line but instead just left current owners out to dry — a business practice they would revisit all too often in the years to come. BTW the TKO 500 still uses that same woodruff key design today, not even a hardened steel square key, a woodruff key!

The Tremec fix for the TKO 500 countershaft problem, was a new transmission, the TKO 600 (is this starting to sound familiar), with a one piece countershaft (which was a good idea) that had the countershaft third gear and the mainshaft third gear offset by approximately 0.200" (not such a good idea) so the chips from the countershaft third gear machining operation had an escape path. The TKO 500 countershaft did not have the chip escape path problem during manufacturing because the shaft was a two piece shaft that split right next to third gear allowing an ample exodus path for the machining chips generated during manufacturing.

Here is a picture of the misalignment and the carnage that it generates when you hook up the tires and put (in this case) 480 ft/lbs of torque through the transmission.



Notice the mainsheet / countershaft third gear misalignment.

At the time this occurred, the reseller (who is no longer in business under the same name) had Tremec look at the transmission for warranty purposes. Tremec's position was the damage was caused by operator error — specifically a missed shift (of course! what else could it possibly be from). Tremec maintained that the transmission was forced into third gear, after the clutch was full engaged following the missed shift, causing the gear teeth on the mainsheet and countershaft to collide with each other, while the clutch was fully engaged, producing the damage!

The explanation sounds sort of plausible until you remember that these are constant mesh transmissions with all gears fully meshing at all times! Gear selection is accomplished through synchronizer engagement / disengagement not sliding one gear into engagement with the other. Tremec knew this all along, after all they did design and manufacture the transmission. This was obvious obfuscation and an attempt to sidestep responsibility for a poor design that resulted in component failure well below the transmission's advertised torque transmission capacity / capability.

The failure was 100% attributable to the reduced gear tooth face width contact that produced reduced torque transmission capacity. Coupling that with 480 ft'lbs of torque and a tire that is hooked up will produce the kind of damage you are looking at in the photo. The potential for this type of failure in a Cobra replica is mitigated because of both the light weight of the car and the fact that it is very hard to hook up one of these cars under full power in almost any gear, so the tires spin before the transmission can be fully loaded.

Tremec tried to stiff the guy and in the end would only provide him a replacement mainshaft third gear and a replacement countershaft but would not repair the transmission — he had to go elsewhere for the actual repairs or do it himself. In fairness it was not Tremec who provided the replacement parts. To their credit, it was the reseller, if I remember correctly.

This sort of customer service / treatment was / is an all too common after purchase experience, with Tremec. Simply stated the Tremec response would amount to, you are wrong and we are right, please go away now. Sometimes there was considerable emphasis on the 'go away now' portion of the messaging.

Additionally, in those days, another fairly common whoops was to have your TKO lockup in whatever gear you happened to park it in, with no ability to shift it at the next engine start. Over time they eventually minimized but did not eliminate the problem. While users were getting stuck wherever they parked the car and this problem occurred, Tremec consistently denied its existence and put the cause and cure back on the user.

These people are poster children for the kind of manufacturer you do not want to do business with if you have any alternatives.

Originally Posted by ERA 626

I agree, I am being told (from a very reliable person who has installed hundreds of them) that 98% of the so called shifting issues is due to the bell housing not being dialed in properly. All these people here recommending to have liberty blueprint a brand new transmission? I would be really pissed off If I have to have a shop rebuild a brand new transmission. I would pull it out and send it back to tremec at that point, why pay liberty to fix a brand new transmission? makes no sense to me at all.

Bellhousing misalignment is certainly a contributor to it, but it is not the primary cause of it. The primary cause is the 2-3 shift rail interlock timing and the inadequate, small, 1960's style brass synchronizer rings.

If the bell housing alignment were the root cause of the problem, then the problem would exist for all gear changes. It does not. It only exists for the 2-3 gear change. That said, bell housing misalignment definitely will aggravate the problem but it will not cause the problem as is evidenced by it's lack of occurrence in all other gear changes.

Originally Posted by patrickt

Yep, my TKO-600 shifts as good or better than any transmission I've ever owned, including high-end German stuff. But it took an entire day to get the Lakewood bell housing dead on straight. A lot of mechanics would have put a half hour in to that little task and called it "good enough."

The appearance of the 2-3 shift problem is related to both the transmission internals (and yes bell housing alignment) along with how aggressively the driver's shifting skills allow him to change gears. Drivers who have the skill and manual dexterity to execute very rapid gear changes will definitely reach the limits of this transmission's speed shifting capabilities very quickly. The use of a mid-shift conversion with a Pro 5.0 (or similar quality shifter mechanism) can substantially improve the experience. In fact tight internal shift rail linkage from the rear shift well to the center shift well on the transmission is also a contributor to improving the shifting experience.

If you couple the midshift upgrade with the Liberty modifications, the transmission is actually a fairly good shifting transmission — admittedly not as good as a T-56. A T-56 however, is a modern, initially OEM targeted, transmission that later became available as an aftermarket transmission. It is the result of generations of both Detroit and Tremec spawned improvements. A Detroit manufacturer would reject a TKO600 synchronizer or gear misalignment problem out of hand for no other reason than the potential for adverse warranty service expense. The cost to warranty the bad design would outweigh the cost to properly redesign the transmission - or use a different transmission..

Some drivers will not push the TKO shifting mechanism hard enough to consistently (or perhaps ever) experience a hang up in the 2-3 shift gate and then of course, others will. The spectrum of user experiences will run the gamut of no problems to OH WOW! If someone does not experience the hang up in the 2-3 shift gate that is good on them and they will be a happy owner. As the owner becomes more proficient at speed shifting then the problem will have an increased probability of rearing it's ugly head.

The fix is eminently doable, Tremec just chose not to spend the money on the TKO 600 product line (just like they did with the older TKO 500 2 piece countershaft / woodruff key problem). Because the T-56 product line was doing so well and also so profitably, the TKO product became a distant memory. When it came to allocating resource for design improvements or engineering change orders, the TKO was sort of like the red haired step child in the family. Now there is an interest in redeveloping those markets. I wonder how much of that initiative is driven by EV technology where these sorts of transmissions (read T-56 OEM business) are going to be phased out in the coming years because of the EV conversion in Detroit.



Ed

[RUFdriver]

Just to add to the discussion...operator error?
https://www.google.com/url?sa=t&rct=...kIzSfQ8LzUXtwx

[ERA 626]

I called Tremec today and the guy said there is nothing he could do in terms of a swap. I then called Modern Driveline, the place I got my TKO-600 from. He was almost willing to do a trade with me but I would need to pay for shipping, (both ways) and the difference. This would be about $400 or so for shipping alone. But I had them also install a short input shaft so I can use the Kirkham clutch setup. At that point he said the short input shaft for the new TXK was out until mid 2021... At that point I said screw it. I hope my TKO will work. I will make double sure the bell housing is perfect. Ill keep you posted.

[eschaider]

The shifting technique in the YouTube video is a technique that Dennis Oltoff and many others, Tremec included, have coached TKO owners about for about as long as most of us can remember. Make no mistake about the fact the technique will provide some relief from the gear change hanging in the 2-3 gate but only to a point.

The 2-3 shift gate hang up problem is a multi faceted problem and the shifting technique modification only partially addresses one facet of the problem. The spring bias that returns the shifter to the neutral gate when moving the shift arm forward to third gear can help, but only to a point.

When the speed of the shift exceeds the spring loaded shifter's ability to find the neutral gate because the spring pressure was too low to accomplish the job at the speed the shift was executed at, you still have a missed shift. In fairness you really need to be capable of impressive gear change performances to bump up against this limitation — but it is there and people have discovered it because of how quickly they can change gears.

So if that's the case, then for mere mortals (like most of us) this should fix our problem. But it doesn't and it hasn't. The reason for the doesn't and hasn't unhappy ending involves the other two facets of the gear changing mechanism / event — the diminutive 1960 style brass synchronizers and the timing interlocks on the ½ and ¾ shift rails.

The interlocks are designed to prevent you from engaging two forward gears, simultaneously. When you shift very fast, the spring loaded interlocks need to make a go / no go decision in a fraction of a second. The decision is centered around whether two forward gears are about to be engaged simultaneously. If this occurs the transmission will lock up and so will the rear tires. Microseconds later the car spins out of control and likely crashes.

This, as luck would have it, turns out to be a pretty big deal — not just for the driver but also for Tremec. So they err on the conservative side and you have interlocks that can impede a 2 - 3 speed shift. Liberty's modified interlock design on the replacement shift rails which they sell corrects this problem.

The last piece of this sordid puzzle is the synchro's themselves. The size of the gears in a TKO are substantially larger and heavier than 1960's four speeds. When you use 1960's style synchronizers to speed up the TKO sized gears they fall short of the mark.

To the driver, the sensation he will recognize is the feeling of hitting a wall in the 2-3 shift gate and not being able to engage third gear. The reason (assuming your speed shift got this far) is the synchronizer's inability to speed up the gears internal to the TKO to allow, what Tremec calls, the synchronizer collar to engage third gear. When the speed differential is too great the completition of the shift is preempted to protect transmission internals.

The spectrum of drivers and their speed shifting skills runs the gamut from slow to stunningly fast. If you are at the slow end of the scale all this talk is going to sound like just so much sour grapes because you have first hand knowledge that belies it all. On the other hand if you have speed shifting skills that fall into the good to great window you will know exactly what all this banter is about.

If you have never had this problem, God Bless and be happy. If you have had the problem, at least now you understand the why and you should now know how to mitigate although not eliminate it. To eliminate the problem you will need to replace the TKO with a TKX (hopefully it actually fixes the problem) or a T-56 which absolutely fixes the problem but presents cost and potential fitment issues with some Cobra replica's.

In the 1960's Chrysler could not find a 4 speed transmission that would stand up to the torque of their drag race versions of the Hemi engine. In the end they ended up licensing / OEMing a Ford light truck transmission to get the required reliability they wanted for the drag cars. Chrysler called it the A-833.

The transmission was strong but the synchros were incapable of reliably changing gears above 6000 / 6500 rpm. Chrysler came up with a non synchronized version of the transmission for racing only that later would become known as a crash box. Below is an in car video of Ken Montgomery and his rare, for 1965, four speed A-833 crashbox version of the transmission. The more you approximate the way Ken can shift, the more problems you will have with the TKO. BTW Ken passed on a few years ago but his car and his shifting are impressive, even today.

Here is the video (below), a little eye and ear candy for the racer in you.

Click here => Ken Montgomery


Ed

[KDubU]

Originally Posted by twobjshelbys

I don't get all the dissing of the TKO600. I still think it was one of the best, snappiest shifting transmissions I ever had. As good as the Ford GT.

Agreed.

[eschaider]

I don't believe a factual representation of the transmission's performance, service issues, manufacturer / reseller community postures and reaction to those service issues associated with the transmission is dissing. This is nothing more than a factual representation of what happened.

There are those however, that will feel differently and they are entitled to their opinion. Potential buyers are entitled to know prior to their purchase the demonstrated performance of the transmission, service challenges past purchasers have had and responses that the manufacturer and reseller community have provided.

How important the issues presented are to a given buyer are personal decisions. Readers are always free to both choose what is important to them and also what to believe. Factual representations of actual inservice product ownership experiences and manufacturer / reseller support are valuable knowledge prior to making any significant purchase.

As the saying goes, beauty is in the eyes of the beholder. There may be those who either do not believe the reported experiences or do not find them relevant to their purchase decision. All that is fine. Everyone needs to decide what is most important to their own situation.


Ed

[Grubby]

I say TREMEC put there time and money into the OEM production transmissions like the TR6060. They were well aware of the issues with the TKO and said screw it. It was the only trans on the market and they could sell them.

It is interesting they finally decided to address the shift issues.

FYI - I had my last bellhousing dialed in very close (don't remember the number) and it had a pronounced shift issue from 2-3. The 3 rail design and 50's era syncros are the problem.

John

[rodneym]

I've had 3 TKO600's, all aligned within spec.
First one on the KMP was bone stock and shifted like a pig, especially on the short handle I had (leverage wasn't on my side).
Second on the KMP had an upgrade by Liberty. I call it "satisfactory". Honestly, with the Twin Paxton, last thing I need to do is shift "fast".
The third was on my CSX, upgrade by Anaheim Gear. That shifted as smooth as a T5.

[Anthony]

This is a short video of Ken Montgomery's Triple Nickle 1965 Hemi Belvedere -4 Speed - 9.21ET at 148mph on a 1/4 mile drag strip

Originally Posted by eschaider

Chrysler came up with a non synchronized version of the transmission for racing only that later would become known as a crash box. Below is an in car video of Ken Montgomery and his rare, for 1965, four speed A-833 crashbox version of the transmission. The more you approximate the way Ken can shift, the more problems you will have with the TKO. BTW Ken passed on a few years ago but his car and his shifting are impressive, even today.

Here is the video (below), a little eye and ear candy for the racer in you.

Click here => Ken Montgomery


Ed

WOW !!! Very Cool !!!
If his belvedere is one of the original super stocks, 1 of 100, it is a pretty rare piece of history, especially the 4-speeds which I think they made about 10 of them. Acid dipped body panels, bumpers, etc, aluminum head hemi !!!

[eschaider]

Ken's car was an original which he bought brand new. He owned and raced the car just about up to his death. I am not sure what the family did with it after his passing but they are both certainly a part of Drag Racing History. Didn't perform too badly either for a 55 year old car.

Ed

[eschaider]

Although there is no video, that I am aware of, which illustrates the interlock problem of the ⅔ gear change there is a good video on 3550 / TKO assembly / disassembly done by Paul Cangialosi. At the 27:00 minute point in the video Paul gives a pretty good description of the TKO synchronizer problem. As he points out the TKO synchro's are essentially 1960's Top Loader synchros being asked to do a job they were never designed to do.

Check out the video it's quite good and if you have never done a manual transmission before or are contemplating servicing your TKO this is a great primer for you. Even if you are not it is a pretty graphic demonstration of the synchronizer problem. The whole video is a whisker over an hour long, the synchro story begins at the 27 minute mark.

Click here => TKO Disassembly / Assembly Vid


Ed

[Anthony]

Originally Posted by eschaider

Ken's car was an original which he bought brand new. He owned and raced the car just about up to his death. I am not sure what the family did with it after his passing but they are both certainly a part of Drag Racing History. Didn't perform too badly either for a 55 year old car.

Ed

That’s a great story about Ken. It is so sad that Ken, and so many more of those old racers are no longer with us, for us to enjoy their company/stories. There’s a local guy here in the Cleveland area, who purchased new and raced a 1965 dodge coronet Superstock, setting an ahra record at one point. Oh, being around Harm is fantastic. His stories are second to none.

https://www.hotrod.com/articles/gary...-coronet-a990/

[eschaider]

Originally Posted by Anthony

That’s a great story about Ken. It is so sad that Ken, and so many more of those old racers are no longer with us, for us to enjoy their company/stories. There’s a local guy here in the Cleveland area, who purchased new and raced a 1965 dodge coronet Superstock, setting an ahra record at one point. Oh, being around Harm is fantastic. His stories are second to none.

https://www.hotrod.com/articles/gary...-coronet-a990/

If you enjoyed that you might get a kick out of this also. My partner and I owned a 1963 light weight front end Max Wedge Plymouth and a 1964 Dodge Coronet with the llight weight Hemi package (fenders, doors, glass etc.). The '63 car won the AHRA Summer Nationals at Gil Kohn's Long Island National Speedway on Woodstock weekend.

Here is a pic of the car at the meet somewhere near the top of first gear,



Sitting still the front wheel well was about midway down the front tire sidewall. We had just put a new small diameter converter in the car for that weekend, that Chrysler had come up with and it was like you added a hundred horsepower. The car would normally run 11.60 to 11.70 at about 120/121 mph. The first pass down track at Long Island it ran an 11.65 at 90 mph shutting off early. We were wowed to say the least.

Saturday evening instead of running Top Stock Eliminator we ran Street Eliminator on an 11.40 break to get a sense of how quick the new converter was. We broke out in the semi-finals against a very good Hiner & Miller Camaro that ran right on their number which I think was 11.20 or so. We didn't feel too bad though because we needed to get a handle on the car's performance for the Top Stock Eliminator on Sunday. We knew we would have a lot of sand bagging to do though because when we broke out we ran an 11.0x (don't remember the "x" number) at 124 or 125mph. Needless to say we were stoked.

Back in those days we would tow the '63 to the track with either my partner Joe's daily driver which was a '66 396/375 Chevelle SS or my daily driver which was a '66 Hemi Satellite. We couldn't afford a trailer! To get to NY we borrowed a converted school bus from one of our racing buddies to transport the car. He had cut the back of the bus off and installed a garage door with ramps on the inside that matched the ramps to get up and in so you could work on the car off the dirt in the pits.

Here's a pic of the car carrier school bus at the AHRA meet;



I can't believe how hard we worked to enjoy racing during those years. Youth is a wonderful time — even if we whern't too smart


Ed

[RUFdriver]

Love the old AHRA stuff, I have lots of fond memories from KCIR in the early 80s.
Concerning the new Tremec, the TKX seems like an improvement, I’m a little pissed they kept it so close to the vest. The 2-3 up shift issue probably is operator error in a number of cases, but when you see the upgrades to the TKX it gives you pause. Have there been any upgrades to the newer TKO 600s?

[Gaz64]

The gearshift selector finger only needs to have the corners chamfered off. Then it can't pick up two shift rails at the same time.
The end should be a circle with two flats.
That comment from Tremec about jamming into 3rd as the cause for gear failure is garbage. Clearly the reduced torque capacity from less than designed gear tooth contact width and the applied torque, is the cause.
Gary

[eschaider]

Originally Posted by Gaz64

The gearshift selector finger only needs to have the corners chamfered off. Then it can't pick up two shift rails at the same time.
The end should be a circle with two flats.
That comment from Tremec about jamming into 3rd as the cause for gear failure is garbage. Clearly the reduced torque capacity from less than designed gear tooth contact width and the applied torque, is the cause.
Gary

I couldn't agree more Gary. That kind of repeated customer service and behavior is what is so disappointing about the company. It is a pattern that disappointingly repeats all too often — which means it is not coincidental.


Ed

[Anthony]

Originally Posted by eschaider

If you enjoyed that you might get a kick out of this also. My partner and I owned a 1963 light weight front end Max Wedge Plymouth and a 1964 Dodge Coronet with the llight weight Hemi package (fenders, doors, glass etc.). The '63 car won the AHRA Summer Nationals at Gil Kohn's Long Island National Speedway on Woodstock weekend.

Here is a pic of the car at the meet somewhere near the top of first gear,



etc !!!

Back in those days we would tow the '63 to the track with either my partner Joe's daily driver which was a '66 396/375 Chevelle SS or my daily driver which was a '66 Hemi Satellite.

I can't believe how hard we worked to enjoy racing during those years. Youth is a wonderful time — even if we whern't too smart


Ed

WOW !! What great memories ! Fantastic ! So, is your partner still around ? talk much ? what happened to the cars ?

[Anthony]

A little Tremec history .

The Tremec Company purchased the manufacturing rights to some of Ford's manual transmissions in the mid-Seventies and continued to build the Toploader, along with a three-speed unit, in Mexico for many OE production applications in Europe and elsewhere. During these years, Tremec was also inventing the TR-3550 five-speed that was later featured in the 1995 Mustangs Cobra R. Although this gearbox was originally designed for light commercial trucks, it found a home behind plenty of Ford's 5.0 engines after establishing a reputation for itself with Mustang enthusiasts as an excellent upgrade to the factory T-5 manual five-speed.When Tremec decided to increase the shaft sizes on both the input and output to strengthen the TR-3550 in 1994, the TKO series was born. By 1996, Tremec, now owned by Transmission Technologies, had purchased the transmission portion of Borg-Warner and used its steel gear designs to improve the TKO and produce a fifth-gear overdrive ratio of 0.83:1. New TKO-500 and -600 transmissions with a first gear ratio of 3.27:1 and an overdrive fifth gear ratio of 0.68:1 were released during 2004. The latest offering has performed exceptionally well in some 600-plus-lbs.ft. drag-race applications. It performed so well, in fact, that Tremec discontinued the TR-3550 and earlier versions of the TKO-500 and -600 in 2004 and '05.

[eschaider]

Originally Posted by Anthony

WOW !! What great memories ! Fantastic ! So, is your partner still around ? talk much ? what happened to the cars ?

Joe is still around and kicking. He is retired these days. He was in Law Enforcement and retired as a Police Chief a number of years ago. We still talk and reminisce about the "good old days"

Sadly the cars were sold for pennies on the dollar compared to what they would be worth today. Both were original factors lightweight race only versions of the cars and were special to me. Depending who you talk to there were either 50 or 100 of these extraordinary cars that Chrysler ever made. The 64 car had one of the 2% relocated wheel bases that preceded the 1965 AFX versions that visibly moved the front and rear wheels substantially forward.

The '63 car was my favorite race car. It raced a total of 998 times and won 993 of those races. I have never had a car like it before or since.

The '64 car was just chock full of neat little race oriented features like the A100 seats, no rear seat, aluminum doors, no window crank mechanisms (a strap to pull up the window) plexiglass side windows, thin Corning glass rear window and a bunch of other nice race car touches. Here's a pic of the car over the winter while we were freshening the engine.



— fond memories ...


Ed