Specifications
P/N 712512
35
JEEP T18 - This 4 speed transmission has a case length of 11.875”. The casting number is T18, 1301, or shifter
(1965-79) top cover casting T98. There are over 14 variations of this 4 speed transmission. These transmissions
can have either a 4:1 or 6.32:1 1st gear ratio. This transmission is an excellent choice for Chevy and Ford
conversions. The biggest problem that we have with this transmission is the various lengths of the front
input shaft. To select the correct adapter, you will be required to determine your stock input shaft stickout
length.
O.A.L Tooth Jeep Warner
Year of Input Shaft Count Number Number
1980-81 (T18) 15-7/8"- 8 Cyl. S27-L17T 8132656 T18-16P
1977-79 (T18) 10"-6 Cyl. S27-L17T 8130260 T18-16J
1979 (T18) 15-3/4"- 8 Cyl. S27-L17T 8130258 T18-16G
1975-78 (T18) 16"- 8 Cyl. S27-L17T 8125946 T18-16K
1967-78 (T18) 12"- 6 Cyl. S27-L17T 941110 T18-16F
1976-79 (T18C) 10"- 6 Cyl. S27-L23T 8126875 T18C-16N
1972-75 (T18C) 12"- 6 Cyl. S27-L23T 8121360 T18C-16B
1973-74 (T18C) 16-3/4"- 8 Cyl. S27-L17T 8123036 T18C-16D
1971-73 (T18C) 12"- 258 6 Cyl. S27-L23T 8122416 T18C-16B
1971-72 (T18C) 16-3/4"- 8 Cyl. S27-L23T 998602 T18C-16C
1968-72 (T18) 15-3/4"- 8 Cyl. S27-L17T 991394 T18-16K
1965-72 (T18C) 14"- 8 Cyl. S27-L17T 940505 T18-16D
In order to assist you in determining the necessary adapter plates for both the T98 and T18 transmissions, we have listed the
adapters that correspond to the transmission stickout length. The stickout length is usually 2-5/8” less than the O.A.L.
O.A.L. GM Kit Ford Kit
Stickout Of Input Shaft Number Number
7-3/8" 10" 712528 712529
7-3/4" 10-3/8" 712512 712514
9-3/8" 12" 712521 712522
10-1/4" 12-7/8" 712517 712518
11-3/8" 14" N/A N/A
13-1/8" 15-3/4" 712516 N/A
13-1/4" 15-7/8" 712516 N/A
13-3/8" 16" 712516 N/A
14-1/8" 16-3/4" 712516 N/A
On any transmission that has a 17 tooth input shaft, you have the option of installing a new shorter input shaft. If you are using a
T98 or T18 in a short wheel base vehicle, drivetrain length is crucial. These input shafts have a 17 tooth gear and allows us to use
a 1/2” thick adapter plate. P/N 712512 for a T18 and P/N 712512-T98 for the T98 transmission is to a Chevy engine. P/N 712514
for a T18 and P/N 712514-T98 for the T98 transmission is to a Ford engine. These adapters are 1/2” thick adapter plates (thin
design) that come complete with a new input shaft for your transmission.
The other adapters listed are for when you are retaining the stock input shaft. The transmissions with a tooth count of S17-L23T
must retain the stock input shaft, since there are no short-style 23 tooth gear input shafts. The longer transmission input shafts
are normally retained on long wheel based vehicles. If you attempt to use the short style adapter on a long wheel based vehicle,
you will have trouble with the shifter & linkage.
For vehicles that have the longer input shaft (O.A.L. of 15-3/4”, 15-7/8”, 16”, and 16-3/4”), we offer Part No. 712516. This kit requires
you to modify the existing aluminum spacer between your transmission and Jeep bellhousing. It will eliminate the need to change
the stock input shaft and will possibly eliminate the need for driveshaft modifications.
Jeep T98 & T18 Bellhousing adapters:
P/N 712549 - Chevy bhsg. (input shaft stickout 7.375”, 1-1/16” 10 spl. normally used in 1976-79)
P/N 712529 - Ford bhsg. (input shaft stickout 7.375”, 1-1/16” 10 spl. normally used in 1976 only)
P/N 712521 - Chevy & Buick bhsg. (input shaft stickout 9.375”)
P/N 712522 - Ford bhsg. (input shaft stickout 9.375”)
P/N 712517 - Chevy & Buick bhsg. (input shaft stickout 10.250”)
P/N 712518 - Ford bhsg. (input shaft stickout 10.250”)
P/N 712516 - Chevy & Buick bhsg. (13 to 14” input shaft stickout)
P/N 712512 or 712512-T98 - Chevy bhsg. to kit (input shaft stickout 7.750”)
P/N 712514 or 712514-T98 - Ford bhsg. to kit (input shaft stickout 7.750”)
Motor mounts and clutch components are listed on the next page
identifying the stock transmission (1941-79)