How easy is it to slap a TF727 out of a wagoneer between my 258 an NP431? What is involved, as far as shifters, kickdown linkage, torque converter, etc? I need as much detail as possible.

thx

np 431?
im not fameliar with that, but if its a round 23 spline ( typical New Process pattern) itll bolt up.

the shift linkage is as easy as a cable type aftermarket shifter.

the kickdown, Lokar sells a cable type, or you can find a 6cyl junkyard kickdown, or modify a V8 kickdown.

OR you can modify the valve body to fully manual and forget about teh kickdown, if you dont do this, and you run without a kickdown you will ruin the tranny QUICK.

first figure if the trans is lockup converter style or non lock up, then get a rebuilt converter ( local tranny shops should have an exchange program) lowest stall possible and match the lockup status, for a Grand wag with 258/tf727
the converter is probably the same as the V8 applications but im not sure, I dont know too much about the 258 stuff.


get the proper flexplate also

install a brass mesh filter in teh trans pan, and an ad on trans cooler, and enjoy it for a long time.

i'm reasonably sure that all tf727s used in full size jeeps are non lockup.

as for going behind a six banger and in front of an np231 (what i think you meant to type), it should bolt right up. you might need a new flexplate tho.

hehe... i didn't know you had to have a kickdown linkage to run an auto... no wonder i was gettin messed up shifts when i installed the carb from my manual cherokee into my auto J10 :rolleyes: :laughing:

I had a 1980 WT chero that had a lockup trans, and Ive helped a buddy rebuild a 727 in a 81 wag and it was a lockup also.

granted I never felt my cherokee shift that last time ( the lockup on the highway) but it had the converter, and internal fluid circuits for lockup.

so yeah, SOME Fullsizes after1980 had locklup converters.

and if that kickdown linkage isnt working properly, or bypassed somehow ( either by manually shifting or bailing wire holding pressure agains the throttle pressure valve) itll ruin the trna sin short order as it tries to climb a steep hill from a dead stop after shifting into 3rd gear.

extreme example, only to illustrate how the tf727 will act with an incorrectly wrking kickdown linkage.

I usually get them adjusted tighter than the manuals suggest, it helps the downhills a bit with teh engine braking.

OOps, you are correct, I meant to type 231, not 431. This is some good info. I think it will help alot.
What about an automatic flywheel, what will work, and will it work with my starter? What is normally done with the t-case shifter bracket? Is there a place to mount it on the 727? And does anyone know the case length compared to an AX-15 and if I will need to make any driveshaft modifications? Sorry for all the questions, just trying to get a pretty accurate guesstimate on how much this is going to cost me.

thx

I did this in my 85 CJ-7
shifter- I used wagoneer column,some mods but fairly easy.
kickdown- Lokar (nice)
torque convertor & flexplate- made for FSJ w/258 and 727
starter should be fine ( not positive about yj )
trans mount -combo of stock and waggy (had to drill 1 hole)
$-depends on where you get your parts .I would say 400-1200 ,low end all salvage...high end rebuilt tranny, good convertor
Any body doing this in a CJ the front driveshaft will hit the tranny
(pass. side drop ) you need a minimum of 4" suspension to clear...The more the better.:beer:

Did this swap in my brothers 87 a few years back. The AX-15 was giving him fits (again).

A few of the stumbles we ran into. You need the CJ starter the YJ starter didn't work. This also caused a few wiring headaces. The CJ stlye starte has all the wires going to the built in seleniod, The YJ is all on the fire wall. So some wiring work is in the mis. Nothing complicated though. Also do your self a favor and pull your 231 before you do anything. The early 231's behind the AX-15 were 21 spline inputs. We ended up scrambling to find the 23 spline input Tcase. The 727 is 23 spline output. The 258 has a unique flex plate as this moter is balanced different then a V8. You need a flex plate from a 83-86 CJ that came equipped with the 258 & TF999, any tranny shop can hook you up.

Listen to all the comments on the Throttle modulation linkage. It's not kick down as most call it. The TF trannies have to have this in proper working order or the tranny is toast, quick!!! Basically in a nut shell the linkage increases line pressure in the tranny the more you step on the skinny pedal. If not hooked up the tranny assumes no throttle is a pplied and you maintain minimum line pressure, hence discs and bahds slipping, hence toasted tranny. The LOKAR cable system is the shiat. It can be made yourself out of an rachet shifter cable too.

Correct me if I'm wrong, but I thought the AX-15's weren't used in the YJ's until mid 89, and that all AX-15's were 23 spline output. Before that the YJ's had a BA 10/5 which came with 21 or 23 spline output.

just try to get the np208 to go behind it from a FSJ. you just have to make the linkage.

Okay, picked up the 727 this weekend. Any other tips or tricks before I get started? I have absolutely no experience with an automatic, so any and all information will be helpful.

thx