how to tell the difference between a t-18 and a t-18a

[Gwamp]

I have a t-18/D-20 combo that I am going to be selling and I am wanting to know which of hte T-18's I have. It is marked T18 1B on the case. Does this make it the closer ratio 4.02 first gear instead of the 6.32 granny geared T-18a?

t-18-1b is the 4 to 1 rate

[Gwamp]

Originally posted by mandoneer:
t-18-1b is the 4 to 1 rate

thanks, that is what I thought. I just wanted to make sure.

[Crazy_Jeepman]

Ummm I would double check that, I have seen the 6.32 to 1 in the 1B case. Put it in 1st, T-Case in Hi, turn the t-case output once, count the trans input, 4 turns 4.02, 6 1/4 is the 6.32. If it came out of a FSJ, I would bet it to be a 6.32 to 1

[Knucklehead]

Hey Gwamp, what do want for that set up?

Jon

I will check mine too I assumed that it was the 4 to 1 but who knows

yep 4 turns

http://www.off-road.com/jeep/tech/trans/t18.html good info on a t-18

[Gwamp]

Originally posted by Crazy_Jeepman:
Ummm I would double check that, I have seen the 6.32 to 1 in the 1B case. Put it in 1st, T-Case in Hi, turn the t-case output once, count the trans input, 4 turns 4.02, 6 1/4 is the 6.32. If it came out of a FSJ, I would bet it to be a 6.32 to 1

I will have to try that tomorrow to make sure. Thanks for the tip!

[Gwamp]

Originally posted by 66HD:
Hey Gwamp, what do want for that set up?

Jon

Probably $250. I just pulled it out and got it inside today. I need to open the cases up and make sure everything is in good shape. the tranny seems to shift fine in and out of gear. The T-case is sticky and needs to be "worked" a bit

[Knucklehead]

Let me know what you find. I'm interested if I can figure out the shipping. You want a new th400 and high range q-trac?

Oh yeah, and what bell housing does that t-18 use (as jeep used about 14 different t-18s)

Jon

[ December 31, 2003, 08:14 PM: Message edited by: 66HD ]

[scotty]

Originally posted by mandoneer:
t-18-1b is the 4 to 1 rate

the casting number has absolutely nothing to do with the ratio. both my t18(from behind a 360) and my friends t18(from behind a 6 cyl) are cast T18-1B as well,and both are the wide ratio-little over 6 1/4 turns in 1st. the only way to verify is to count the turns.

if the t18 is from a FSJ its prolly a wide ratio,i have never know a fsj to come with a 4:1,close ratio t18

if its from a cj,it doesnt really matter,cause the cj guys will pay big bucks for the short input shaft t18,regardless of the ratio [img]smile.gif[/img]

also,just a FYI, the link above has one bit of incorrect info- the 80+ t18/208 has a 31 spline output,not 23

[Crazy_Jeepman]

Originally posted by scotty:
</font><blockquote>quote:</font><hr />Originally posted by mandoneer:
t-18-1b is the 4 to 1 rate

the casting number has absolutely nothing to do with the ratio. both my t18(from behind a 360) and my friends t18(from behind a 6 cyl) are cast T18-1B as well,and both are the wide ratio-little over 6 1/4 turns in 1st. the only way to verify is to count the turns.

if the t18 is from a FSJ its prolly a wide ratio,i have never know a fsj to come with a 4:1,close ratio t18

if its from a cj,it doesnt really matter,cause the cj guys will pay big bucks for the short input shaft t18,regardless of the ratio [img]smile.gif[/img]

also,just a FYI, the link above has one bit of incorrect info- the 80+ t18/208 has a 31 spline output,not 23</font>[/quote]Yup I agree, have seen the same, and have never ever pulled a 4 to 1 out of a FSJ, though that has only been a couple dozen over the years. [img]tongue.gif[/img]

[scotty]

now that i think about it,another friend has a t18 out of a 77 chero,from behind a 360 and its t18-1B as well. im pretty sure that even the t18/208 a friend is running in his xj from an 83 j20 is also cast the same.

[Grantshire]

Weren't the T-18B's all the long shaft FSJ T18's? I have never seen one that didn't have a 6.32:1 first gear. Don't the CJ, Scout and Ford T-18's have short(er) shafts? I think it was some of the Scout T-18's that also came with the 4:1 ratio.

[scotty]

Originally posted by Grantshire:
Weren't the T-18B's all the long shaft FSJ T18's?

nope.as mentioned in my 1st post above,a friend is running a 6 cyl t18 in his cj,wich is the "medium" shaft,with a short 1" spacer between the tranny and bell. it is cast t18 1b.

if by "long shaft" you mean a tranny with any spacer between the bell and tranny, i guess that is possible. it may be that "t18 1b" is the designation for any t18 used in a FSJ,as i have not ever really checked any t18s from scouts,fords,or cjs...

[Knucklehead]

Hey Gwamp, what is this combo out of? I'm still interested.

Jon

[Grantshire]

I am by no means an expert on this subject. However, in preparation for my TH400/QT to T-18/Dana 20 swap I have been doing a lot of "investigating". Along the way I have picked up two T-18's. One is a long input shaft T-18B (6.32 1st gear) that came from a mid 70's V8 FSJ. Becasue it was behind a V8 the spacer between the transmission and bellhousing is over 4". The other T-18 (don't know if it is a "B" or not yet - just got it, but it has the 6.32 1st gear) is in the 79 J10 donor truck I just bought and is attached to a 258 6 cylinder. Because the 6 cylinder is a longer engine than the V8 the spacer between the transmission and bellhousing is only about 3/4" thick. The two bellhousings appear to be identical so my bet is so are the front T-18 shafts. The J10 was originally an automatic (based on the steering column) so I don't know its T-18's vintage. Bellhousings from earlier FSJ's were very deep and, therefore, did not have the 4+" or 3/4" spacers.

I also have a 74 Scout II with a T-18/Dana 20 combo. However, it has the close ratio gears (4.?? 1st gear). I have not climbed under it to see what markings are on it but I know it has a much shorter input shaft than my other T-18's. All of the Ford T-18's are also shorter than the FSJ T-18's.

[Gwamp]

Originally posted by 66HD:
Hey Gwamp, what is this combo out of? I'm still interested.

Jon

It came out of a 74 J-20. I haven't had a chance to check to ratio. The combo is still in the wheelbarrow in my basement. Do you have a Forward air near by? That is about the only reasonable way to get this to you.

[Knucklehead]

I'll check and see.

So what will I need to get this on the back of a 360. Does this setup have the extension on the front of the tranny and the long input shaft?

thanks

Jon