T18A output splines

[joe]

Does anyone know if the 1980 and later J-20 T18A's(w/np208) had the same spline count(6) output shaft as the pre-80 FSJ T18A's w/D20 did? Thanks.

[Cecil14]

The later ones had a 31 spline output whereas the earlier ones used a 6 spline output.

Anthony

[joe]

Thanks Anthony!

[scotty]

further,the bolt pattern for the adapter is also different. the 80 and up t18 is basically a ford t18 with a long input shaft,so you are stuck with running the long factory tranny to t case adapter and a 208 transfer case(or a 205 with some mods)

[joe]

Thanks Scotty. What I'm trying to do is match up an early(mid-late 70's) FSJ T18A to a 208(23 spline?). The trans was behind a 360 and will now go behind a 258 so it looks like a trans input shaft swap is needed to a shorter one. Mine's 10 1/4" or so. Then an output shaft swap too to the 31 spline version, then an input shaft swap in the 208 to 31 spline. I think I'm headed in the right direction anyway? If there's any thin ice I'm crossing here feel free to grab me by the collar. smile.gif

[scotty]

sorry,joe,it wont work. :( the bolt pattern is different fo the adapter,so you wont be able to bolt the 208 adapter to the eariler trans. a frined runs the later version in his xj,and we did quite a bit of comparing.

if youre looking for a granny 4 spd and to keep a driver side diff,your best bet is to use a ford t18 or np435 and whatever case comes with it-208 or 205.

your run of the mill t150/t176 bell more or less bolts onto the ford trannies,making the swap easy with an AA pilot bushing. just use the amc pressure plate and ford disc smile.gif

[joe]

Originally posted by scotty:
sorry,joe,it wont work. :( the bolt pattern is different fo the adapter,so you wont be able to bolt the 208 adapter to the eariler trans. Thanks Scotty that saved me some grief...oh well off to Plan B. smile.gif

[scotty]

glad to be of service smile.gif sorry wasnt the info you wanted,but better to find out prior to handing over non-refundable $$

we learned the hard way about the 31 spline tailsahft and the differences betwen the late and early trans. my xj friend is currently running it(t18 from an 83 j20) with a modified ford 205

[ April 02, 2003, 10:02 PM: Message edited by: scotty ]

[joe]

Originally posted by scotty:
glad to be of service smile.gif sorry wasnt the info you wanted,but better to find out prior to handing over non-refundable $$Amen to that. I appreciate the info Scotty. You and others here have more than once keep me from making a financial or labor intensive boo boo smile.gif

[scotty]

Originally posted by -joe:
keep me from making a financial or labor intensive boo boo smile.gif [/QB]tongue.gif

[Panther]

-joe,
Are you looking for something to swap into your cherokee with T5 or is this another project?
With the 258 it makes things a little bit easier and a 4x4 ford granny tranny is probably the best way to go. scotty's right on about the info, I was looking into all of my "theories" a year ago and he really helped my out. You da man scotty.

Not to go off subject but my machine shop tech said that all the f*rd NP208s he had seen are slip yoke, is that the case or did some have a fixed yoke?
Lee

[scotty]

i had kind of assumed them to be fixed yoke,since all the ford 205s ive seen are fixed yoke,and the jeep j20 is a fixed yoke-seems reasonable the 208 behind the t18 in the j20 is prolly the same unit used in fords.

i have crawled under very few fords,however smile.gif so they could very well be slip yokes on the 208

one cold easily swap in a jeep tailsahft and housig to fix the prollem if that were the case smile.gif

[joe]

Originally posted by Panther:
-joe,
Are you looking for something to swap into your cherokee with T5?Yeah Lee that was Plan A. We be on Plan B now. smile.gif
Any idea what year Ford donors I should be looking for?

[Panther]

scotty that's good to know about the slip yoke 208s, I wasn't sure if that was possible.

joe, I sure don't know any specific years for the f*rd NP435 and T18. I did an extensive online search for the 4x4 T18 to see if I could find out what years and models they were offered but no dice. But why not regear the axles to something lower and keep the overdrive?

[joe]

Originally posted by Panther:
But why not regear the axles to something lower and keep the overdrive?That's about Plan D or E. ;)
This is my daily driver and I really like getting 18 mpg's on the hwy. That's w/o using OD gear which is totally useless anyway w/2.73 axle gears. The AMC "engineer" that came up with that combo should have been fired and sent back to school to learn another profession.
Anyway it's not a hard core use rig at all but I do like to venture off and "see where that old logging road goes" while traveling. Even with the poor hwy gearing the T18a would give me a crawl ratio of 45:1 which is better than most stock FSJ's have and better than a some modified ones do. At the same time I wouldn't miss the OD gear of the T5 so my mpgs shouldn't drop noticebly either. With the HEI I'm about to install and the de-smog, de-computer plan I really do expect to see 20 mpgs on this rig on the hwy(motor is fresh).
I could re-gear and keep the T5 and finally get to use the OD function and prolly end up at the same end mpg wise but not crawl ratio wise and I'm not a big fan of the T5's strength.(I have one in a CJ8) I'm amazed it still even works after all this time.
Two different ways to get to sorta the same place I guess but the T18a swap would get me there with a better trans and crawl ratio and be a cheaper deal than 2 R&P swaps. Well maybe not cheaper now since you folks pointed out I can't use the T18a that I already have. I may get to Plan D or E yet anyway. smile.gif

[ April 03, 2003, 05:51 PM: Message edited by: -joe ]

[Panther]

I understand your reasoning. I ran a T18 with 2.73s in my scrambler before the axle swaps. It was great, you shift to 4th at 50-55 mph and the first gear lasted up to 15 mph. I know the T5 has a poor reputation but I never had a problem with the one I ran in my cj7 and I was not nice to it ;)

Since you already have a T18a, you might want to think about an AA or Novak adapter. Now hear me out before you shoot me down (everyone seems to hate spending $ on adapters). I have the AA in my scrambler and it works out well (I have a link on the scrambler page). You would need the T176/150 bellhousing and have to convert the tail shaft. The adapter is somewhere between 2.75 and 3" and what this means is that the T18 and adapter are the same length at the T5 so NO new DRIVESHAFTS. Eventhough you have a 208, the length between the BH and tcase is the same so it doesn't alter your driveshafts. After that it's a pretty straight forward swap. No excuses has the AA for $404
www.800-923-jeep.com/ (http://www.800-923-jeep.com/)
It might be cheaper then new gears installed.

Anyway, I'm throwing ideas out there.....

Personally, I think your chero is cool with the stock drivetrain and I would like to have one to see if I could double the gas mileage in my chero.

[joe]

Good info Lee. That sounds like a possibilty for sure. I'll check it out. Thank you.

[scotty]

joe,i thinbk youre right on track,the t5 is marginal at best,the strength of a np 435 tranny would give you alot of piece of mind. the 435 has a slightly lower 1st gear at 6.69:1

pre 80 ford 4x4s will prolly have the 435/205 while sometime early/mid 80s will have switched trnasfer case to the 208.

like lee said,there does not seem to be any rhyme or reason to occasionally stumbling across a t18. every 4x4 ive looked at with my own eyes has been equipped with a 435. the general consenses was that the t18 was used for the most part in 2wds,and the few that ive talked to people about that were in 4x4s have always had a 208 behind

if you do allready have a t18,then prolly spending $400 on an adapter is an acceptable solution,wen you figure a a going rate for a trann/transfer case is anywhere from $200 to $500. if you would need to purchase a trranny and an adapter,it is worthwhile IMO to just purcase a ford tranny and run whatever case happens to be behind it.