SYE vs SYE quality question

[Lowrange2]

The pinion should point at the t-case output. Whatever that angle is.

 

[Tony_SS]

You should get that XJ book written by Eric.... it's really helpful with this sort of stuff. Best $25 I've spent in awhile.

 

[bugout]

You should get that XJ book written by Eric.... it's really helpful with this sort of stuff. Best $25 I've spent in awhile.

Ive got it and read it front to back. Ive just never really understood why a sye would help since you still have to adjust the pinion angles???

 

[Tony_SS]

It explains that... IIFC the SYE pushed the shaft out further so that the correct angle can be achieved.. sometimes you don't need to even adjust after the SYE.

 

[bugout]

Help me understand why I can't just replace the rear drive shaft with the front one with out an SYE???

Please forgive my ignorance......

 

[the_weirdo]

A stock rear driveshaft does not bolt onto the Tcase output - it slips over the output and slides in and out when the rear suspension flexes. That is why it is called a Slip Yoke - it slips (slides in and out) on the output shaft when the suspension flexes and the driveshaft needs to get longer or short.

You cannot use a front shaft without first doing the SYE because there is nothing to bolt the front shaft to on the rear output. So you buy the SYE which gives you a new flange to bolt the shaft to, it also reduces the angle of the ujoints because there are 2 joints on the driveshaft, and the new shaft has a slip joint in the middle of the shaft.

 

[Boost_Retard]

I bought a rough country labeled sye, looks exactly like every other sye I have seen and it leaked at the yoke seal from day one. I installed it correctly, just cheap low quality parts. Whatever brand you go with be sure to wash it well before install, mine was full of swarf

 

[bugout]

As always, thanks for breaking it down to the lowest common denominator.....much appreciated!

 

[Happytrails]

SYE Quality story...

Here's my SYE story. FWIW.

Bot an RR kit from one of the many good 4x4 equipment retailers online. Good price. But shipped from Georgia, not the retailers location. Came in a OMIX-ADA box. Instructions were Rugged Ridge document which is easily available online also.

Easy enough to install. Did it on my XJ in the driveway. All seemed well.

Had the front DS out beforehand so as to isolate any noise/vibe issues to the back. What I did not notice right away was that TC got stuck in 4H once I shifted it to check linkage function before installing rear DS wrapping up the project. Shift lever would go back to 2H but the fork and rod would not. (Spring was correctly installed).

Removing the plug over the end of the shift rod on the SYE and tapping the end of the rod, it spring forward with ease moving the fork out of 4H back to 2H.

Here is what was happening: The recess in the RR SYE for the shift rod is misaligned. The rod was binding on the side of the recess just slightly. In fact so slightly that just a moderate tap on the plug would dislodge the rod and the spring would pop the TC out of 4H.

To solve the problem I loosened the five SYE mounting bolts and rotated the unit ever so slightly and retightened. Problem solved. Shift rod no longer got bound.

But as I suspected, the RTV no longer sealed and it leaked like crazy. So I took the whole SYE off and reinstalled with new RTV.

While having the SYE off, I put into my drill a mushroom shaped burr for woodworking and hogged out some of the soft aluminum sidewall of the recess inside the SYE where the shift rod backs into. This took away any chance of it binding on reinstall. Problem solved. Reassembly proved no binding and no oil leak.

However, this whole experience left me wondering about the quality of the main SYE casting. It mounts with no alignment pins, relying solely upon the five bolts to center and align the rear bearing and the shaft correctly with the front bearing of the shaft. The is about 1 mm of slop in the bolt holes, so the whole unit could randomly be correctly aligned, or probably out of alignment between front and back shaft bearings, meaning bearing axes are not the same.

Misalignment could cause noise, wear, vibes, oil seal leakage, or in my case, shift rod binding.

Just my story. Put it in your own pipe and smoke it FWIW.

 

[Ex Jay]

So I know I can use a h&t sye with a front shaft at like 3.5"+ of lift no prob as you simply hack it where you need it. So what about when using the "real" sye? what lifts does it generally work with the stock front shaft? I've always just ordered a new shaft in the past. Thanks!

 

[REVROK]

You cannot go wrong with any of the kits running Dana yokes or the JB conversions... quality parts do matter.

 

[Happytrails]

I would have spent a few extra bucks to get better stuff. But when they all say theirs is better, stronger, unique, etc, only find out is the same old thing when you turn the lights on after the dance, how do you know ahead of time? Sharing this knowledge is important. Thanks.

 

[REVROK]

I would have spent a few extra bucks to get better stuff. But when they all say theirs is better, stronger, unique, etc, only find out is the same old thing when you turn the lights on after the dance, how do you know ahead of time? Sharing this knowledge is important. Thanks.

Go to the JB Conversions website and they actually list the cases using Dana yokes... JB makes their own (in the USA). Frankly they (JB) are the best... (as our president would say) period! But the Dana SYE's they list are also very solid.

 

[2001XJ]

Porch makes a great sye(similar to AA) and has a great price to match.

X2.......PORC is QUALITY!