The T5 page - by Jack Halton and John Martin

These pages are an attempt to provide information on the popular Borg Warner T5 transmissions. We'll add information as we get it. Please let us know (E-mail webmaster) if you notice any mistakes as this is very much a work in progress!

These gearboxes are getting a lot of attention and interest because

A) They all include an overdrive 5th gear

B) They use the standard GM bell housing bolt pattern.

The first feature means that the T5 can provide a solution for the miserable 3.90 and 4.11 gearing used on most early GM pickups. T5's come in two different bell housing bolt patterns - GM and Ford. The Ford pattern was also used on AMC and Nissan. Many internal parts are interchangeable, but there are two basic "grades" of T5 : World Class (WC) and Non World Class (NWC). WC is a later version with many upgrades for smoother operation and improved reliability.

There are several T5 applications to consider. Those used in the GM S-10 pickups from 1983 to 1987 are good candidates, but do require some modification to work with the earlier clutch and flywheel packages. For an excellent report on the details of this swap, see Grant Galbraith's article at Stovebolt.com. Also check out Robert French's Solution using the Vega clutch hub.

Here is some information you can use to identify which S10 T5 is right for your truck. These entries were taken from a variety of sources. Some were superceded by later numbers. The 4X4 variants are highlighted in green as they can be easily identified by the transfer case instead of the tailshaft, although internal parts of the tranny are the same.

The BW model number can usually be found on a bar code tag somewhere on the main body of the transmission.

These are all NWC transmissions.

BW Model

Original application

Engine

1st gear

2nd gear

3rd Gear

4th gear

5th gear

1352-005

1984 - 86 Chevette

1.6 L4

3.76

2.37

1.49

1.00

0.86

1352-010

1982 S10

all

4.03

2.37

1.49

1.00

0.86

1352-012

1982 S10

2.4 Diesel

4.03

2.37

1.49

1.00

0.86

1352-013

1983 "T" truck

4 & 6 cyl

4.03

2.37

1.49

1.00

0.86

1352-014

1983 "T" truck

4 cyl all

4.03

2.37

1.49

1.00

0.86

1352-033

1983 S10

2.0 L4, 2.8 V6

4.03

2.37

1.49

1.00

0.86

1352-042

1984 - 85 S10

2.8 V6

4.03

2.37

1.49

1.00

0.76

1352-043

1984 - 85 S10

2.8 V6

4.03

2.37

1.49

1.00

0.76

1352-055

1984 S10

1.9 L4 Isuzu

4.03

2.37

1.49

1.00

0.86

1352-056

1984 S10

2.0 L4

4.03

2.37

1.49

1.00

0.86

1352-057

1984 S10

1.9 L4 Isuzu

4.03

2.37

1.49

1.00

0.86

1352-058

1984 S10

2.0 L4, 2.8 V6

4.03

2.37

1.49

1.00

0.86

1352-101

1985 Minivan

4.3 V6

3.50

2.14

1.39

1.00

0.73

1352-102

1985 - 86 Minivan

2.5 L4, 2.8 V6

3.76

2.18

1.42

1.00

0.72

1352-107

1985 S10

2.2 L4 Diesel

3.76

2.18

1.42

1.00

0.72

1352-108

1985 - 86 S10

2.5 L4, 2.8 V6

3.76

2.18

1.42

1.00

0.72

1352-110

1985 S10

2.5 L4, 2.8 V6

3.76

2.18

1.42

1.00

0.72

1352-136

1985 S10

2.2 L4 Diesel

3.76

2.18

1.42

1.00

0.72

1352-145

1985 - 86 S10

2.5 L4, 2.8 V6

3.76

2.18

1.42

1.00

0.72

1352-146

1985 S10

2.8 V6

4.03

2.37

1.49

1.00

0.76

1352-148

1985 Minivan

4.3 V6

3.50

2.14

1.39

1.00

0.73

1352-149

1986 Minivan

4.3 V6

3.50

2.14

1.39

1.00

0.73

So, which tranny is right for you? That depends. The major differences are in the ratio spacing and first/OD ratios. The original truck 3-speed had a 1st gear ratio of around 3:1 and the 4-speeds (Granny gear) were about 7:1. So if you are replacing a 4-speed, ANYTHING would be an improvement. Some users have reported that the 4.03 1st gear models are too low for normal street use with a 235. If you haul a heavy load or do any towing, you may need the 4.03 1st. But tire size matters too. Most of the S10 trucks used relatively small tires, so changing to a taller (larger diameter) tire will offset this somewhat. A taller tire will result in a higher (lower numerically) effective ratio in all 5 forward speeds. The lower 5th speed ratios will give you higher, quieter top gear cruising speed due to lower engine RPM.

Another T5 option is the Camaro / Firebird "F-body" transmissions. These are desirable for the better ratio spacing, higher first gear and ease of adapting to the early bell housing and clutch, but the shifter location is all wrong for an old pickup. Click on the link below for more info on the F-body T5.

CAMARO T5 Hybrid