Scout Dana18 t-case

[Joe J-Truck]

I scored a D18 (I think) from a 60's scout. It has the twin shifters and I heard somewhere these have a lower low-range than our standard jeep d20. Is there any difference in the input shaft splines or will this be a straight bolt in?
Any other info would be cool, how to ID, etc...
Thanx!

[scotty]

more than likely it will have a "small hole" case. the d20 has a 4" index hole in the front of the case. alot of the trannies that used the 18(such as the t90) used the xfer case also as the rear bearing retainer,so the index hole is much smaller,and the input gear must be pulled thru an access plate in order to remove the xfer from the tranny.

in order to use it,it must have the 1.25" intermediate shaft,and then you must assemble the guts into a later model,d20 housing to get the large index hole. this is not a big deal cause you have to disassemble the case and remove the interlock pill in order to get 2wd low range.

the bad news,is that you cannot get a FWD only with the d18,due to the way it simply couples the front output to the rear output shaft and gears to create 4wd.it does not have a set of high/N/low gears for each output like the d20.

the later years(somewhere round 55 and up) that used the 1.25" intermediate shaft did indeed have a lower low range at 2.46:1.

hopefully you got the input gear as well,as you cant run the 2.46 gears without it. most trannies used the same 6 spline tailsafht,so in most cases the input gear is swappable. an exception is the t14,wich used a 10 spline input gear.

i am currnetly on number 4 spicer 18 behind a t18 and 258 in my GW. it held up nicely when i babied it,due to rear end breakage issues. now that my rear doesn break,my driving style is more assertive,and this case cant seem to stand up to the sudden shockloads of bouncing and spinning tires very,very fast :eek:

people wil say the case itself is week,and the housing will crack in half(another reason to use the 20 housing-its stronger) and will also say the 10 spline output shaft will break. i personally would think the front output coupler would break,as the front output is pretty unimpressive assembly.

however,i have not broken any of these things. i have stripped teeth of of the gears themselves.the first and the 3rd were the worst,stripping darn near all the teeth of of every gear :eek: with the third locking up completely. number 2 just had some chunks missing from the input gear.

the rear output is offset and very low,making it good to use with an offet rear,and with high lifts,cause the output is a good 6" lower than a d20. with a 4" block my rear drivesahft has very little angle

thats bout all i can think of off the top of my head. i will prolly be swapping a d20 back in till i can get my 435/203/205 done smile.gif we shall see if it holds up any better than the 18

feel free to let me know if ya have any other ques

[ February 12, 2003, 08:54 PM: Message edited by: scotty ]