Borg Warner transmissions are now owned by Transmission Technologies Corporation (TTC), however, the design remains unchanged between the two transmission lines. Borg Warner transmissions, for the most part, use a single rail gear selector and carbon fiber lined steel synchro rings, where the TREMEC transmissions have a single rail that selects and moves three shift rods internally. These three rods have spring loaded detents that make the transmission feel notchy during shifting. Instead of carbon lined steel synchro rings, the TREMEC TKO line is built with solid bronze synchros with no linings. It is for these reasons that the TREMEC TKO does not like to shift well above ~6,000rpms unless modified.  There is a way to improve the shifting but is only used for drag racing when down shifting is not needed.

• New in 2004
  TREMEC changed its line of TR-3550 and TKO in 2004. (TKO-500/600 Press Release)  The TR-3550 was replaced by the TKO-500 and the TKO is now called the TKO-600.  There were several changes in the new line up.

  The all new line of TREMEC TKO 5 speed transmission are the most versatile, strongest transmission of the series.  With eight available shift positions, three unique cross member mounting configurations, three available input shafts, optional gear ratios, dual electronic and mechanical speedometer pick-ups, neutral safety switch, and back-up light switch, this transmission does it all! 

  How was this transmission improved?  The 83mm center distance was maintained, and upgraded the counter shaft from a 3 piece to a one piece design.  All the gears and shafts were upgraded to a higher alloy steel, while the aluminum shift forks were replaced with steel forgings and completely redesigned. 

  The shifter has been upgraded to performance status with a unique adjustable biasing system to tune to your exact preference.  Eight different shift locations means the shifter will likely fit in your stock console.  

  The TKO-500/600 features dual speedometer pick-ups, with both mechanical and electronic speed pickups. 

  All cast iron shift forks for improved durability reducing failures with non-adjustable positive shift stops so it can not be over-shifted. 

New TKO-500, 

Ford TKO-500 is torque rated at 500ft/lbs. 10 spline input shaft with a 31 spline output shaft. 3.27 first gear with a .68od. Standard shift location is the rear "Mustang" shift point. Mid and front shift kits available. Main case bolt pattern remains the "toploader" pattern. 

GM TKO-500 3.27 first gear with a .68od. Torque rating 500ft/lbs. Standard shift location is the rear "vintage Camaro" shift point but can be changed to several other shift locations. Main case bolt pattern is a "Muncie" 4 speed pattern. Call for details. 

New TKO-600  

Ford TKO-600 is torque rated at 600ft/lbs. 26 spline input shaft with a 31 spline output shaft.  Comes in two standard over drive configurations 1) 2.87 first gear .82od and 2) 2.87 first gear with .64od.  Standard shift location is the rear "Mustang" shift point.  Mid and front shift kits available.  Main case bolt pattern remains the "toploader" pattern.  

GM TKO-600 is torque rated at 600ft/lbs.  26 spline input shaft with a 31 spline output shaft.  2.87 first gear .82od.  Standard shift location is the rear Muncie 4 speed shift point.  Mid shift kits available.  Main case bolt pattern remains the "Muncie" 4 speed pattern.

Model	(ft/lb)	input spline	output spline	1st	2nd	3rd	4th	5th
TKO 500	500	10	31	3.27	1.97	1.34	1.00	.68
TKO 600	600	26	31	2.87	1.89	1.28	1.00	.82
TKO 600	600	26	31	2.87	1.89	1.28	1.00	.64

 

• Ford 3550,  a step up from a T-5z with 3.27 first gear and a .68od.  Torque rate increased to 375ft/lbs.  The input shaft has the same 10 spline input shaft as that of a 93 and earlier T-5.  The TREMEC main case bolt pattern is different than the T-5 so a TREMEC bellhousing is needed when switching out a T-5.  The output shaft is a standard Ford 28 spline that has been used since the C4 automatic and toploader 4 speed days.  Since the TREMECs have the same bolt main case pattern as the early 3 or 4 speeds, it can be bolted directly to the 3 or 4 speed bellhousing when the input shaft is shortened to match.  We offer both the shortened input shaft and bearing retainer as well as ready to install new shortened input TREMEC's.  Call us for details and/or check our product catalog on-line.
  
  The 3550 has been replaced by the new TKO 500. See New for 2004 (above) for further details. 
  
  GM 3550, is designed to provide a five speed replacement to the Muncie four speed transmission.  The input shaft and main case are ready to bolt to a four speed bellhousing.  Input shaft is a 26 spline with a GM pilot. Output shaft remains a 28 spline so the slip yoke will have to be changed.
  
• Ford 3550-II, the same as the 3550 with a .83 overdrive.  Great for road racing when the 1:1 ratio of a four speed is not enough and a .68 over drive is too tall.  Works well for off roading as well in 2x4 trucks and SUV's.
  
• Ford TKO transmission has the same layout and gear ratio as the 3550 but with stronger 26 spline input shaft and 31 spline output shaft and stronger 3rd gear. It is torque rated to 450ft/lbs.  A new 31 spline slip yoke is provided with every new TKO that is compatible with the standard u-joints.
  
  GM TKO, Again designed to be a replacement five speed transmission.  However this time the output shaft is a 31 spline with the stronger 3^rd gear.
  
• TKO-II, is the same as the TKO but is equipped with a .83 overdrive instead of a .63 overdrive.  Again great for road racing or off roading. Torque rating increase to 475ft/lbs but has been known to handle much more.

All four models have the same overall dimensions.  The 3550-II and TKO-II are best suited for road racing where the .83 overdrive comes in handy on the long straight-a-ways.