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242 advanced adapters sye shaft install advice/writeups needed

4

4x4JeePmaNthINg

NAXJA Forum User
Location
Colorado
lads,

I have an 99 NP242 and currently a TC drop. I would like to keep the 242 for all obvious reasons that make it a terrific TC.

Thus I have two options to get rid of the drop:

. hack n tap

i feel comfy chopping it off, but ive never tapped anything and i dont see this being a wing it option for a DD, nor without having a very quality tap. if option #2 is much more sound then i would prefer this as to half assing the 242 SYE.

OR

. SYE output shaft altered by machining:
http://www.rustysoffroad.com/advance-adapters-np242-slip-yoke-eliminator-kit.html

I am looking for those that have cracked the 242 open and installed this SYE shaft. ( ive read needle bearings can go all over) is this something to not mess with or am I fretting nothing?

Does this require special know how, tools, preparation, or can a wrench savy lad achieve this install with little experience?

at the end of the day my goal is to get the drive line corrected properly, no TC drop, allow for more lift and Hopefully a long arm (requiring this sye fix)



:pirate1:
 
The AA SYE is nice, I have it on mine. I bought from Tom Woods back when he was the exclusive seller but would buy from AA direct now.

There are a few photo albums and videos out that will walk through an entire rebuild. Suggest looking through those and asking questions.

You need a good set of lock-ring pliers (*NOT* snap-ring pliers) for any work inside the transfer case. Lisle makes a decent pair and you can buy those at Advance or order online

Also need some kind of assembly lube. I use 50/50 ATF and mineral spirits as a cleaner / lubricant and vasoline as an assembly gel. Can buy all that stuff locally and they are petroleum based and won't damage the plastic and seals.
 
It really isn't that bad. The needle bearing caution should be taken more as an FYI that they're there and they will more than likely fall out. I set the planetary on blocks over top a large "tupperwear" container to catch them if they fall and remove/insert the main shaft from the underside. A little bit of grease to hold the bearings in place helps.

Two bigger issues IMO are the shift fork shaft (if you're replacing the input bearing) and the retaining ring that holds the AWD/chain sprocket assembly onto the main shaft. A second set of hands to help push the retaining ring into place is all but required. The shift fork shaft just requires the right size punch and a bit of care. I was able to pry the fork away from the pawl on my 88 but my 94 required me to remove the spring pin.

The AA/TW SYE replaces the rear output bearing/seal so no worries there, but I'd at minimum replace the front output bearing and seal and the input seal while you're there. I didn't replace the blind bearing on the front output since I didn't have the tools and it looked good. The input bearing requires removing the shift fork and the 4LO planetaries but otherwise it's easy to get out. The needle bearings are the hardest to find outside of a kit, but the next time around I'll really try to piece together the parts. I bought a kit from one of the trans/t-case specialists and the input bearing was clunky like a cheap bicycle or skateboard bearing. The Timken I got to replace it was smooth like a machine tool bearing.

You absolutely need the right pair of retaining ring pliers and the right size punch if you're replacing the input bearing. I'm 95% sure Lisle 44900 is the pliers I used.

I also suggest loosening the yoke nuts while it's still in the vehicle. Trying to restrain it otherwise is "fun"...
 
ehall is correct. I used vasoline instead of grease. I didn't have any and asked a woman friend of mine if I could have just a little bit. I got that look and she practically threw it at me and pulled her hands back and up over her head like she was going to catch a disease. "I don't want to know what you and your Jeep do while nobody is watching" Jeeze.
 
if you are hesitant to do a hack & tap, which is easy. but you are considering doing a sye which involves opening the TC ? heres an option, pull the TC , take it to a shop & have the sye kit installed by a pro then reinstall the tc. get the new driveshaft & its done. you will have the peace of mind the kit was properly done. but ive had a hack & tap on my 242 for 5 years w/ a new cv drive shaft, no vibes at all. i can run 70 mph on the hiway w/ 35 " tires & i have done lots of rugged 4 wheeling as well. nothing wrong w/ the hack & tap method & a whole lot cheaper too. just a thought to consider.
 
I have a '99 with a 242 and did the hack-n-tap myself. I'm not a machinist and don't have any fancy tools, but I found the hack-n-tap really easy to install and it came out flawlessly. I know you're looking for advice on the SYE output shaft installation, but for what it's worth, I think you are imagining installation of a hack-n-tap to be trickier than it really is. I have no regrets about having gone that route.
 
Nimrod said:
I have a '99 with a 242 and did the hack-n-tap myself. I'm not a machinist and don't have any fancy tools, but I found the hack-n-tap really easy to install and it came out flawlessly. I know you're looking for advice on the SYE output shaft installation, but for what it's worth, I think you are imagining installation of a hack-n-tap to be trickier than it really is. I have no regrets about having gone that route.
Click to expand...

yes i also did mine myself before the drilling jig was available, would have been even easier w/ the iron rock jig. tapping the threads was just go slow & easy, mine came out fine too.
 
srb531 said:
if you are hesitant to do a hack & tap, which is easy. but you are considering doing a sye which involves opening the TC ? heres an option, pull the TC , take it to a shop & have the sye kit installed by a pro then reinstall the tc. get the new driveshaft & its done. you will have the peace of mind the kit was properly done. but ive had a hack & tap on my 242 for 5 years w/ a new cv drive shaft, no vibes at all. i can run 70 mph on the hiway w/ 35 " tires & i have done lots of rugged 4 wheeling as well. nothing wrong w/ the hack & tap method & a whole lot cheaper too. just a thought to consider.
Click to expand...

Nimrod said:
I have a '99 with a 242 and did the hack-n-tap myself. I'm not a machinist and don't have any fancy tools, but I found the hack-n-tap really easy to install and it came out flawlessly. I know you're looking for advice on the SYE output shaft installation, but for what it's worth, I think you are imagining installation of a hack-n-tap to be trickier than it really is. I have no regrets about having gone that route.
Click to expand...

ultimately the hack n tap only worries me because if you crack a tap or bit your kinda screwed.

heres a link i came across while researching between the two options. does this seem valid?
http://www.4xshaft.com/Hack-n-tap_vs_our_sye.html
 
A H-n-T will only get you "x" far in lift!
 
srb531 said:
the end result of either method is a cv style yoke at the end of the tc for a cv double cardon style driveshaft, why would one be better for more lift then the other ? please explain.
Click to expand...

Big difference! The size and spline count of the output shaft is real!
 
I meant to say length also!
 
Properly installed, a H&T SYE is no less strong than the stock output shaft arrangement, and is certainly strong/durable enough for most Cherokee owners. I don't see that the amount of lift has any effect upon the strength/durablilty of the H&T SYE.
 
You are more likely to break a 27-spline stock tailshaft (HnT) than a 32-spline tailshaft (SYE). Especially as you get into bigger tires/gear ratio/harder climbs. Not an issue for most people doing easy/moderate trails but it matters after a while
 
I may retitle a new thread for these questions, but ice spent some time looking further into my 242 sye options.
Perhaps an engineering background will have good input.

. A hnt requires cutting the "stock" 27 spline stock shaft. AS offered both 27, or 32 spline for the true she. So...

How much strength will or will I not be loosing by shortening the shaft(hnt cutting)? It would seem to me that the length of splines that are left after cutting would still provide almost the maximum strength of the stock set up. I conclude this only by the design being a slip yoke and therefore never having a consistent amount of spline engagement, beyond that of max/min suspension travel. I don't claim to know better here, though I question whether or not it really is adding benefit to have a 32 spline output on stock 99 hpd30, c8 25 arb and 4.56,33s-35s. Ide expect other drive train components to give first ?

Beyond and official sye, it is said the output bearing may suffer for having a fixed yoke bolted to a lengthier hnt shaft. I'm a bit confused here as before either option the output is far longer with weight being suspended of a slip yoke. Does a fixed yoke and double cardan really put much more stress on the output bearing, or is this simply a marketing gimmick?
 
Beats me but I found the instructions that came with the 242 SYE to be easy enough to follow for a first timer when I did it 4 years ago. Yes there are a bunch of needle bearings but its not a big deal. Use a bit of grease or vaseline to hold them in place for the install. The output shaft seal that comes with it of questionable quality with more than one person reporting needing to replace it after about 3,000 miles. The replacement is NAPA CR 18662.
 
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