NP231 / AW4 Mating problems

I'm having problems getting my rebuilt NP231 to mate and pull up tight to the my AW4 tranny. After I slide the NP231 in, it stops about 3/8" short of pulling up. It is almost as if there is a bind where the pump housing goes into the machined concentric recess in the transmission.

I have tried slidding it in as far as possible and using long bolts to try to pull it up but only resulted in binding things to the point that the yokes on the TC could not rotate.

Where have I screwed up?

FNF

Sounds like your t-case input shaft is to long,is this an originally mated pair?
Check here for more info:http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

No, the 231 was purchased from someone else, I will do some measuring.

FNF

if it came from a jeep that was standard it will not work if i remember correctly. the output shaft on the aw4 is longer than the ax15

RCP Phx said:

Sounds like your t-case input shaft is to long,is this an originally mated pair?
Check here for more info:http://www.novak-adapt.com/knowledge/np_nvg_input_gears.htm

Click to expand...

Yeah, I measured things and the snout on the input gear is too long. It is about 3/4" longer than a 99 NP242 I have laying around. (What I was calling the pump is actually the bearing retainer)

My service/parts manual calls for a part# of 4798 113 for my 99 but the t-case is a 96 according to the tag. (well the build date is 12/19/96 maybe this makes it a 97 if so it is a different part# altogether) My manual is only for 97-99. To compound things, I installed a chain and planetary gear set out of a Dakota in order to get the 6 gear/wide chain.

Novak confuses me even more with wide/narrow bearings, short/med/long shafts etc. This is going to take some investigation.

FNF

well you can do a couple of things... you can swap inputs on the tcase, or you can cut off the input with a 4 1/2 grinder... i have seen it done, and it works... just put the tcase in 4 low and attach a drill to the front or rear output, and slowly cut into it... basically make it into its own lathe. just be sure to tape off the vent holes and try to protect the seal back there.

I hate to say it, but I did consider it. I ended up ordering a new input gear from Novak. It should be here tomorrow or the next day.
FNF