NP241 mod [Archive] - BB.BC4x4.COM

: NP241 mod



PANZER
May 12th, 2011, 05:35 pm
So I just picked up an NP241 and I know that there are slip yoke eliminator kits available but they are expensive and i was wondering if its possible to convert to a flange style rear output by simply securing a flange to the existing output shaft? I figure that the end of the shaft could be drilled and tapped and a bolt could be used to secure a flanged yoke to the shaft.

fish4life
May 13th, 2011, 08:54 pm
So I just picked up an NP241 and I know that there are slip yoke eliminator kits available but they are expensive and i was wondering if its possible to convert to a flange style rear output by simply securing a flange to the existing output shaft? I figure that the end of the shaft could be drilled and tapped and a bolt could be used to secure a flanged yoke to the shaft.

it's been done. Google hack-n-tap SYE ... i think it's kind of redneck-y but seems to work

http://www.yuccaman.com/jeep/pics/sye_seal.jpg

PANZER
May 14th, 2011, 09:08 am
I really have no problem with redneck mods if they work. Thanx for the search suggestion, I thought this should be possible.

kore
May 16th, 2011, 08:38 pm
its not redneck, its called "backyard engi-beer-ing"
drink a couple beers, get an idea, then finish it before you run out of beer, or before the beer store closes!

fish4life
May 23rd, 2011, 08:22 pm
well, i'm just not a fan of taking something not overly strong to begin with and drilling a hole in it ....

PANZER
May 23rd, 2011, 10:08 pm
I don't think its weak by any means, the OD of the tail shaft is 1.375" and the hole only needs to go in at most an inch. That hole will then be filled with a bolt and the slip yoke will increase the amount of metal holding up the drive shaft too. Your hack and tap google search suggestion lead me to this http://www.driveshaftsuperstore.com/drive_shaft_SYE.htm I highly doubt that even a half inch bolt hole in the end of the shaft will any serious affect on its overall strength. The SYE kits that are out there also shorten the shaft and are aimed at jeep guys with shorter wheel bases to help reduce their drive shaft angles.

fish4life
May 29th, 2011, 10:04 am
hmm perhaps not in that case. I was under the impression that a much longer hole had to be drilled and tapped for the bolt. Maybe i should just do this instead then, as i've been considering an SYE and longer driveshaft so I can raise the t-case skid plate on the TJ higher up .... hmmmm.

PANZER
May 29th, 2011, 10:13 am
The advantage for the jeeps to shorten the tail housing and output shaft is to make the drive shaft longer there by reducing the drive angles at the t-case and diff reducing the stress on the u joints.

fish4life
May 29th, 2011, 03:50 pm
The advantage for the jeeps to shorten the tail housing and output shaft is to make the drive shaft longer there by reducing the drive angles at the t-case and diff reducing the stress on the u joints.

... which is what i said ... longer driveshaft lol :)

DH_4_ever
March 2nd, 2012, 07:59 pm
I ran a hack-n-tap on my 4.7L stroker and never had problems, only went to an AA SYE because it was already installed on a built up case (with 4:1 and a wider chain) the hack-n-tap is a decent setup, just remember, most of the torque is transfered on the outer sections of the shaft, not the core (why in some industrial situations they actually use hollow shafts)