Borg Warner has sold to Tremac(1997) the original T5 plans made w/ about 250 completely interchangable parts to fit many applications. jeep(6cyl.), mustangs(V8's), fords, chevy camaro - firebirds(V8's), S 10 & 15, astros, (4-6cyl.). The T5 5 Speed was originally manufactured by Borg Warner Automotive. The first T5 5 speeds were manufactured as far back as 1982 and are still being made at the time this page was written ( 2001 ). The T5 was the only American made standard transmission to span almost 20 years of production. Before the GM's Muncie 4 speed held that honor. Because of the large quantities of T5's produced, many parts are interchangeable, allowing one to create interesting 5 speed combinations. No other transmission allows this to be done quite this easy. There are now over 260 different T5 transmission assembly part numbers.
There are 2 basic kinds of T5 5 speeds. Non World Class ( NWC ) and World Class ( WC ). The T5 is an evolution of the Borg Warner SR4 4speed. The SR4 was a lightweight design, ball bearing and needle bearing counter gear box using bronze synchro rings. The T4 was an improvment of this design, using tapered input and output shaft bearings combined with a drawn cup roller bearing countergear. The T5 NWC was a T4 with an added 5th gear.
NWC T5's were issued in 1982. First applications were in S-10 Blazers. By 1983 Ford started using them in the Mustang, GM had them in the F body Camaro and Firebird Cars, AMC had them in the Eagle and Jeep lines. AMC dropped the T5 by 1985 to make room for cheaper Peugeot and Toyota boxes. By late 1985 the first WC boxes were used by Ford. The WC boxes had 1st, 2nd, and 3rd speed gears riding on roller bearings instead of solid shafts. The countergears saw an upgrade to tapered bearings. The bronze synchro rings were replaced by fiber lined rings and dual cone designed rings to improve ring surface area. GM started using WC boxes as early as 1988 in the Camaro / Firebird line but still kept NWC boxes in S-10's and Astro Vans. By the mid 1990's most of the GM T5 installations were all World Class.
NWC T5's were issued in 1982. First applications were in S-10 Blazers. By 1983 Ford started using them in the Mustang, GM had them in the F body Camaro and Firebird Cars, AMC had them in the Eagle and Jeep lines. AMC dropped the T5 by 1985 to make room for cheaper Peugeot and Toyota boxes. By late 1985 the first WC boxes were used by Ford. The WC boxes had 1st, 2nd, and 3rd speed gears riding on roller bearings instead of solid shafts. The countergears saw an upgrade to tapered bearings. The bronze synchro rings were replaced by fiber lined rings and dual cone designed rings to improve ring surface area. GM started using WC boxes as early as 1988 in the Camaro / Firebird line but still kept NWC boxes in S-10's and Astro Vans. By the mid 1990's most of the GM T5 installations were all World Class.
The T5 I had built is an S~10 housing but has camaro V8 gears inside. I believe that IS the best way to go w/ these T5's. A true HYBRID.
T5 w/ flathead V8 -
http://www.vanpeltsales.com/FH_web/t5_fivespeed.htm http://www.flatheadv8.org/t5-swap.htm Making the T5 Stronger
While it may seem a 300 lb-ft rating is easily surpassed with today's cylinder heads and camshafts, in reality most T5's can easily endure well over that figure when used in street driven applications. In fact our experience has been that shifting style, and not torque rating alone, is the biggest factor is the life of a T5. We've seen power shifted T5's snap behind stock 5.0L engines, while on the other T5 hold up mile after mile behind stroked Windsor's. In fact, our own Project '67 has been running a stock 1990 T5 for nearly five years. We've made over several hundred 11 and 12 second passes launching at 5000 rpm on slicks. Admittedly we are biding our time with this T5, and with the recent addition of a supercharger, we're not pressing our luck any longer.
It used to be that once you got in to the 500 horsepower range you were well beyond the capabilities of any T5, and it was time to think Tremec TKO (incidentally, TTC, the company which owns the Tremec brand, bought the T5 design and tooling from Borg Warner in 1997.) However no longer is this the only option. G-Force Transmissions, the maker of some pretty stout competition gear boxes, also manufacturers high strength gears, shafts and other internals for the T5 transmissions. When properly assembled the G-Force T5 can handle 500 lb-ft of torque. While there are still strength limitations of the stock T5 case (G-Force does offer their own T5 case) the stronger internals are the key to keeping a T5 together behind a stout small block. G-Force offers their T5 gear sets in synchronized and dog-ring versions. Dog-ring refers to the modification of blocking rings for synchro-less engagement. This make shifting easy at high rpms but at the expense of tougher gear engagement at lower rpms. We selected the fully synchronized kit for good streetability.
While the G-Force components are built to be bullet proof, that is only half of the recipe for an indestructible T5. The other half is in the proper rebuilding of the T5. In fact, most of the nations major T5 rebuild shops offer their own "G-Force T5" versions, which include their own personal, and often closely guarded, secrets for success. We spent the day with Bruce Couture of Modern Driveline (see side bar) to document the steps involved in how he builds the Modern Driveline G-Force T5.
