TKO shifting issues at high rpm's

[6D9]

I am considering going with a TKO 600 for my next tranny. But I remember quite a few posts on the Mustang boards about these trannys not liking to go into third at high rpm's. They said the sucker flat out wont have it! Also will these things handle clutch dumps with ET streets and a 500HP 408sbc??? Thanks Ron

[camcojb]

Originally Posted by 6D9

I am considering going with a TKO 600 for my next tranny. But I remember quite a few posts on the Mustang boards about these trannys not liking to go into third at high rpm's. They said the sucker flat out wont have it! Also will these things handle clutch dumps with ET streets and a 500HP 408sbc??? Thanks Ron

I think most times a high rpm shifting issue is the clutch not releasing cleanly or trans alignment more often than not. I have not used the TKO600 but have used the TKO500 and done many 7500 rpm shifts with it and no issues.

[Damn True]

From what I understand they are particularly sensative to bellhousing alignment. As long as you carefully check all measurement points you shouldn't have a probelem.

[Speedster]

Walt at ProMotion Performance recommends changing the synchros if you are going to be shifting above 7000 rpm. Then no issues whatsoever.

[6D9]

OK, So set it up right and no issues with 6000 or 6500 shifts. How have they been living behind slicks and 500 fpt with clutch dumps at the strip??

[camcojb]

Originally Posted by 6D9

OK, So set it up right and no issues with 6000 or 6500 shifts. How have they been living behind slicks and 500 fpt with clutch dumps at the strip??

Very well. The Mustang guys have been beating on them for a long time with 10 second and quicker cars.

Jody

[Speedster]

Originally Posted by 6D9

OK, So set it up right and no issues with 6000 or 6500 shifts. How have they been living behind slicks and 500 fpt with clutch dumps at the strip??

Here is a clip from another thread earlier this year and I agree with Jody, the Mustang guys have beat the crap out of these.

Here is some Tremec TKO info that may of interste to you:

Tremec rates the TKO600 to handle 600 ft.lbs of torque. With that said, we know of guys that are running high horsepower cars 700+HP with the TKO's and they have not run into any problems with the Tremec handling the HP. I regularly talk with the guys at Tremec (last time was 2 days ago to re-confirm this info) and ask them if they have heard of any TKO failures due to high horsepower applications and to date the answer has been "no". With that said, I am sure that someone will eventually break a TKO due to a high horsepower. It is posible that someone has broke one but I have not heard of it yet. When you play in the high horsepower arena eventually something will give - be it a clutch, driveshaft, rear end, or TKO transmission.
During my call 2 days ago, the Tremec guy did tell me that they ran into a case where a TKO input shaft was twisted. The transmission did not fail but the owner noticed that the input shaft was slightly twisted when he was changing his clutch. The car that did the twisting was mid-9 second race car with a 680 HP blown motor, 10.5" slick tires and that regularly launches at 5800 RPM's. This car is exclusively a race car and the input shaft twisting occured after a season of racing (approxiamtely 100 passes). Tremec is currently testing the input shaft to see why it twisted. This is the only report that Tremec has receievd from a TKO owner since the TKO was released 2 years ago.

The Tremec TKO gig testing was done on a static gig where the output shaft was secured and the input shaft was hit with increasingly higher torque loads. The gig ended up breaking at 1400 ft./lbs of torque while the transmision was undamaged.

The one negative issue on the TKO's that we have seen is high RPM shifting at 6500 RPM's and higher. The TKO does not seem to want to shift properly at these levels. This is not a shifter issue, rather it is a transmission internals issue. The TKO can be moded to help this problem - the mod involved removing teeth from the blocker ring - the amount and location of tooth removal depends on whether you are drag racing or road racing.

The bottom line is that the TKO is an excellent and very strong street & strip transmission that is suitbale for most of our applications - even the high horsepower applications.

The cases where the TKO may not be the first choice is if you have a dedicated race car where you need to be shifting at 6500+ RPM's.

I hope this helps.
__________________
Jeff Mortenson
Classic Chevy 5-Speed
www.ClassicChevy5Speed.com

[6D9]

Thanks guys....great info!