When it comes to the Tremec T5’s they come in two versions.
A question we are asked a lot is: “How do I tell if I have a World-class or Non-World-class version?”
Important- Please Read before calling us:
Casting numbers on the side of the main case or extension housingCANNOThelp you ID a transmission simply because the same case is used in a variety of models.
The Transmission TAG will have a stamped number on the tin METAL TAG bolted to the tail housing. ( we can help you decipher what the tag information is)
No other numbers on the case, tailhousing, or cover are needed or will tell you anything.
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 today By Tremec.
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 easily.
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 gearbox using bronze synchro rings.
The T4 was an improvement of this design, using tapered input and output shaft bearings combined with a drawn cup roller bearing counter gear.
The T5 NWC was a T4 with an added 5th gear.
NWC T5’s were issued in 1982.
The 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 counter gears 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-10s and Astro Vans.
By mid-1990 most of the GM T5 installations were all World Class.
If the Transmission is still in the vehicle or attached to a bellhousing, the best way to tell is:
Remove the Oil fill Plug and look at the Synchronizer rings.
If the transmission is out of the vehicle or you can see the front of the transmission the best way to tell is:
The front of the Transmission will have a bearing cover located just below the Input shaft.
This cover will be round and either has the word ‘Timken’ or some other letters on it.
If the cover has no writing on it it is a Non-World class… this is true for all Tremec T5 assembly part numbers.
See below.
Identifying Marks on T5s
All T5s originally came with an identification tag attached to an extension-housing bolt.
The tags can bedeciphered, however, due to the modularity of the T5 the tag may not match the contents.
It may be easier to identify the application of a GM T5 by some of its unique external characteristics.
Year of Manufacture
The year of manufacture can be found in the center of a circle on the main case and on the extension housing (Figure A, Figure B).
Figure A:
Year of Manufacture – Main Case
Figure B
Year of Manufacture – Extension Housing
GM vs. Ford
All GM T5s (1983-1992), except Tbody (Chevette), have a standard GM bellhousing bolt pattern.
All Ford T5s have a bellhousing bolt pattern that looks similar to that of a Top Loader, though it is different.
All 1983-1992 GM V8 T5s have a 26-spline ´ 1⅛-inch input shaft, a 2.95:1 first gear ratio, and a standard GM bellhousing bolt pattern.
All Ford T5s have a 10-spline´11⁄16-inch input shaft.
Most GM V6 and 4-cylinder T5s have a 14-spline ´ 1-inch input shaft, either a 3.50:1, 3.76:1, or 4.03:1 first gear ratio, and a standard GM bellhousing bolt pattern.
Avoid these transmissions for V8 applications.
they are weaker than the V8 transmissions. There is no 10.5-inch clutch disc available for this transmission, only a 9⅝- and an 11-inch disc.
Beginning in 1993, there was no T5 available with the GM V8.
All fourth-generation Non-V8 F-body T5s have a Ford T5 bellhousing bolt pattern (Figure C).
The 26-spline ´ 1⅛-inch input shaft is similar to the earlier V8 input shaft, but the pilot is longer than that used in the earlier models (Figure D).
The front bearing retainer is the same as used on the 1983-1992 GM T5.
Figure C:
Fourth Generation F Body T5 – Front View
Figure D
Fourth Generation F Body T5 Input Shaft (left) vs. Earlier Input Shaft (right)
World Class vs. Non-World Class
A World-Class T5 can easily be distinguished from a non-World Class T5 by examining the front countershaft bearing race.
The non-World Class T5 countershaft rides on flat roller bearings that are retained in a stamped steel shell, which has a smooth outside surface (Figure E).
The World Class T5 countershaft rides on tapered roller bearings. The front 1/4″ wide bearing race is cast and is embossed with a bearing number; e.g., Timken LM67010 (Figure F).
Be careful when inspecting this the text may be located under the main shaft bearing retainer
Figure E
Non-World Class T5 Front Countershaft Bearing Race
Note: there is no text on the bearing retainer face
Figure F
World Class T5 Front Countershaft Bearing Race
All GM T5s manufactured from 1983-to 1987 were of the Non-World Class design.
From 1988-to 1992, all GM F body V6 and V8 T5s were of the World Class design, but T5s designed for the other GM vehicles, such as the S10 truck, were still of the Non-World Class design.
The T5 5 Speed was originally manufactured by Borg-Warner Automotive.
The first T5 5 speeds were manufactured as far back as 1982.
The T5 was the only American-made standard transmission to span 40 years of production. Before the GM’s Muncie 4 speed held that honor.
Because of the large quantities of T5s produced, many parts are interchangeable, allowing one to create interesting 5-speed combinations. No other transmission allows this to be done quite this easily. 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 lightweight, with ball bearing and needle-bearing counter gearbox using bronze synchro rings.
The T4 improved this design, using tapered input and output shaft bearings combined with a drawn cup roller bearing counter gear. The T5 NWC was a T4 with an added 5th gear.
NWC T5s were issued in 1982. The 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, and 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 counter gears 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 kept NWC boxes in S-10s and Astro Vans. By the mid-1990 most of the GM T5 installations were all World Class.
Tremec acquired all of Borg-Warner around 1995 and has been the sole manufacturer of T5 transmissions since.
