From the novak transmissions web-site: part II....
Jeep t18
Jeep released 12 known versions of the t18 transmissions from 1966 and 1984, with the greatest variations being in input shaft configurations and gearing. The battle of working with these is compounded if you did not actually witness the transmission's removal from the donor vehicle.
All Jeep t18's locate their pto port on the driver's side.
Generally, most cj t18's from 1972 to 1975 had the close-ratio, fitted with a front adapter plate in cast iron to the amc bell housing. These transmissions had the narrow ratio gearing (4.02:1 first gear). These 1972-1975 Jeep cj t18's can adapt to GM engines.
1976 was a crossover year for the Jeep cj t18, featuring either the 4.02 or 6:32 first gear and no front adapter as previously. Both these and all cj t18's through 1979 had the shortest of the Jeep input shafts, measuring 7.43" of stickout.
All Jeep cj's from 1977 to 1979 had wide-ratio t18 with the 6.32:1 first gear. No front adapter plate is present on these models. 1976-1979 t18 transmissions can be adapted to GM v6 or v8 by use of a t18 adapter kit that we manufacture, kit #1879. Jeep cj t18's from 1976-1978 May be cast with #13-01-097-907.
The 1979 Jeep cj t18 is similar to the 1976-1978 versions, except that it features a wider front bearing and a different top cover with aluminum shift forks and a different shift pattern with reverse gear being over to the right and down. These t18's May have a case casting number of 13-01-065-904 and a top cover casting of #13-01-065-906.
Ford vs. Jeep t18's
The Ford t18's are clearly the best conversion choices in that they are far more standardized, easier to find and often more affordable. Replacement parts (namely, gears and shafts) for the Ford t18 are easily less expensive. Many, if not most, of the Jeep specific gears are no longer produced, making them painfully problematic to own if anything ever goes wrong or if parts interchangeability is required for a specific, non-standard adaptation.
As a general rule, all fsj t18's featured varying lengths of input shafts - all too long for installation into short wheel based jeeps. These were fitted with a variety of factory adapters and deeper bell housings to accommodate the deeper bulkheads of these larger jeeps. We get many calls from individuals attempting to adapt these versions into cj jeeps - many of them being sold under the unscrupulous pretense that they are inexpensive and direct replacements. Individuals get caught in often fruitless salvage searches for the rarest of the Jeep t18 input shafts and bearing retainers in an attempt to make the project succeed. As a solution for wide ratio (6.32:1 first gear) Jeep t18's, a new modified input shaft and retainer assembly can be installed. There is currently no solution for the narrow ratio (4.02:1) Jeep t18's.
Ford t18 & t19 2wd or 4wd bolt pattern (figure omitted)
the Jeep & IH t18 & IH t19 4wd rear bolt pattern, 1966-1979
casting numbers commonly found on Jeep truck t18's are #13-01-192, #13-01-193, #13-01-209, #13-01-210, which are typically the close ratio versions of the Jeep t18 transmission.
IH t18
The IH t18 was available only in three versions: the t18 featured the same gear ratios as the wide-ratio Ford & Jeep t18's; the t18a close-ratio version featured 4.02, 2.41, 1.41, 1.0 ratios; the t18c close-ratio version featured 4.02, 2.41, 1.52, 1.0 ratios.
This transmission is a good unit, but not recommended for Jeep conversions due to its unique input shaft and front, stud-mounted style front face.
IH t18's locate their pto port on the driver's side.
Ford t19 specifications (figure omitted)
Ford & Scout t19's
Very much similar to the t18 in appearance and build is the t19. This four-speed transmission is different from the t18 and others in that it usually features taller gearing and a synchronized first gear. It was introduced in Ford trucks in the 1968 model year.
Three gearing options were available for the Ford t19. The t19 was available with a 6.32:1 first gear. These were only in rarer Ford 500-800 series hd trucks. The very most common t19 available in Ford applications was the t19a with the 4:02:1 first gear ratio. For two years (documented from 1983-1984) there was a Ford t19 with a 5.1:1 first gear. All ratios listed had a synchronized first.
We've learned that the 1983 to 1986 Ford t19's, as installed behind the 460 and diesel had the 4.02:1 first gear, in a 2wd application, or a diesel 4wd application. The 460 4wd truck got the 6.32:1 first gear, purportedly from 1983 to 1986 f250's.
The t19 transmissions are equipped with dual pto ports. An individual May find the cast numbers of 13-09-065-911 in Ford t19's.
13-09-065-905
The IH Scout t19 was available from 1975 to 1980 with close and wide ratio options. Individuals May encounter a casting number 13-09-065-905. Like for the IH t18, the t19 had a unique case and input shaft that make most Jeep conversions impractically expensive.
transfer case adaptability
All Ford versions of the t18 are automatically compatible with novak adapter assemblies and these transmissions make for excellent conversions due to their adaptability into most jeeps. Both 2wd and 4wd versions of the t18 can be used equally well, and there are no inherent advantages to either one once you have installed our adapter assembly.
The Ford t18 can be adapted to the popular Jeep (and many IH) transfer cases, including the:
Dana 18, 1941-1971
Dana 20, 1962-1979
Dana 300, 1980-1986
new process Jeep 208, 219 & 229
new process 207, 231, 241or, 242 & 249
the Jeep and most IH t18's can be adapted to the Jeep Dana 300 and to the new process transfer cases with equal ease.
bell housing adaptability
Ford engines:
as the reader will conclude, the Ford t18 will marry directly to Ford small block style bell housing.
Amc Jeep engines:
the Ford t18 is also an excellent candidate for amc Jeep bell housings made from 1976 to 1986 that were married to the t150, t18 and t176 transmissions, or otherwise have an available bell housing bolt pattern of 8-1/2" wide by 6-5/16" tall. They are readily compatible with these engines and bell housings, and need only a custom pilot bushing. Note that these pilot bushings are usually part of our transfer case adapter kits when ordered properly. For more details, see adapting Ford transmissions to amc bell housings for details.
The 4.0l Jeep i6 (both renix and mopar systems) is adaptable using the same method as above, with the addition of installing a crank position sensor (cps) into the aforementioned bell housing. This is a service that we provide affordably and in quick turnaround.
When filling your t18 / t19 with gear oil, we recommend that you select a conventional mineral oil or a para-synthetic in lieu of a full synthetic oil. Properly assembled manual gearboxes do not have the thermal strains seen by combustion engines or hypoid gears. Synthetic fluid in these gearboxes, while not harmful, is probably an economic waste.
Hypoid gear oil is sulphurized higher than transmission oil and can be mildly corrosive to the non-ferrous alloys used for synchros, bushings and thrust washers in these transmissions.
An 80w-90, api-gl5 or mt-1 rated fluid is very good. Some claim faster shifts from using a 50w engine oil in their transmission and we do not consider this to be contraindicated unless you operate your vehicle in a very warm environment.
GM engines:
The Ford t18 has two extra un-drilled ears cast into the front face of the transmission case. This is important if you intend to run it behind a GM bell housing. The transmission having these extra un-drilled ears will greatly simplify its use with GM engines. For more details, see adapting Ford transmissions to GM bell housings. The t19 does not have this feature.
Adapting Jeep t18's to GM engines
certain versions of the Jeep t18 can be married to GM engines. Read more about this process here.
rebuilding the t18:
The t18 and t19 are relatively simple to rebuild. Many shade tree mechanics do very outstanding rebuilds if they have access to a press, snap ring pliers and bearing pullers. Many choose to do a full rebuild during the adaptation process.
