RE SYE vibration and Runout problem

For those with RE SYE how much runout does your flange have???
And did you experience a drone about 65+mph and what you did to fix it?


Last week I installed a New RE SYE hack and tap in my 2001 XJ on a 242 TC (no HD unit for it). I took it out on the freeway and noticed a loud drone(can't even carry on a conversation with passagers) at 65+mph. Went home and pulled the rear shaft and noticed the flange had a slight amount of movement. (.020) I double checked the bolt to make sure it wasn't bottoming out.
With the jeep in drive, idling about 25mph the flange has signficant runout. I took the jeep back out onto the freeway with only front shaft in and was able to go 85mph without any drone. So I am sure that the flange is the culprit.

Any help would be greatly appricated
Thank You in advance
PS I am working with the place I purchased it from for warranty or what ever we come up with.

What do you mean runout? Is the flange sliding on the shaft? Who installed the SYE? Sounds like the flange isn't bolted down all the way. The flange should be seated flat against the end of the shaft, so either the bolt isn't tightened down all the way, or whoever installed it didn't drill or tap deep enough for the bolt to tighten down on the flange. Also, did you install shims?

Tom Woods Drive shafts will not knowling make a drive shaft for a vehicle using the hack and tap for the very reason you stated. the hub works loose and then all hell breaks out. They recommend a new output shaft like the advanced adaptor one

What a bunch of crap. If properly installed the hack and tap SYE is a great kit, and won't work loose. He doesn't want to build shafts for hack and taps because they aren't his SYE's.

The classic problem I have seen is that the output bearings on the NP231 can get pretty worn. I recommend replacing the bearing when you do the hack n tap. The bearing is less than $10.

You mentioned runnout. I guess I should ask, do you mean there is .020" slop if you grab the shaft and try to wiggle it, or is that a measure of the face of the flange not sitting perpendicular to the shaft?

I would recommend having your driveshaft checked for balance. I know it is supposed to be balanced, but I have seen supposedly well balanced shafts be off enough to cause problems. The other thing is the pinion to shaft angle on the rear dif. The dif should be pointing about 1 degree below being inline with the shaft.

Now that is a quick responce
Gottabejeep: I installed the SYE. I doubled checked the bolt and even went and got a shorter bolt and still have the same problem. As far as deep enought I used all of the threads on the tap(1 3/8") and the bolt they gave me is only an inch long. The problem seems to be that the washer inside the flange is too loose. With the washer tight the flange still can move in and out a hair. Plus when I put my flange on the first time It slide right on, no heating or hammering, none of the problems that I have been reading about.

And yes I put in shims 2.5* up with a 3.5 actual lift. I am about 2* down from centerline of driveshaft.

Oldman: As far as the bearing the jeep only has 58,000 miles and I checked that as well I grabbed hold and gave her hell and the only movement there is in the tranny mount. And as far as runout I mean perpendicular to the shaft. Like the flange ain't cut straight.
As far as the shaft needing balancing That is kinda of a warranty issue. That was my first thought before I found the wobbling flange. I mean I ordered the shaft ten days ago. I really don't want to put more money into it until I find out about this flange.

Ve6nn: Yea I wish I would have gone TW but it is still only a factory shaft that they cut for you. I like the yoke better then the flange.

I know a few other have had similiar problems Safari Ary, RCP phx, and I think a few more names that I have found through search

Thank you lets keep the ideas coming.

I guess I need to come up with a better start to a sentence then "as far as"

I cant speak for the NP242,mines a NP231!As far as your issues go,make sure the stub is square!Heres the big difference!

Yea I WISH there was a HD kit for the 242 :bawl:

Now for straightness is it possible to be too straight i mean of the tail shaft. I spent a lot of time getting it perfect. I am a tight arse about that kinda thing. My grandfather is/was (retired) machinist and nothing less then perfect is allowed. And he taught me most thing I know.
With my "machinist square" I get an even horizon of light across it, for every which position I look at it.

Back to too straight IF the tailshaft and washer were perfectly straight it would allow the flange to move in and out. Does that make sense. If you have every held the flange in your hand you can see how the washer moves in and out of the flange (.020)

Thank you

ve6nn said:

Tom Woods Drive shafts will not knowling make a drive shaft for a vehicle using the hack and tap for the very reason you stated. the hub works loose and then all hell breaks out. They recommend a new output shaft like the advanced adaptor one

Click to expand...

Farmer Matt ran hack and tap and put it through hell and AFAIK he didn't have any problems......
Anyways I have a hack and tap and my vibes come now from bad pinion angle (got taller springs). Before they came from my rear driveshaft when I ripped off a weight on a rock, but once I got it balanced it worked fine!
Btw, did you run it lifted for a while without the SYE?
Also getting back to your movement does this mean you can slide it in and out? then there is definately something wrong: is your cust nice and square? are you sure you're not bottoming out the bolt? Is there anything that could get caught underneat?
Btw with the flange off can you screw the bolt in all the way (or almost all the way?) Btw, careful not to strip the threads when you're testing (if it gets hard to tighten it towards the end don't overdo it)

Dang Ketchup beat me to it - I was out driving around this evening and wondered the same. Is your tapped hole deep enough to seat the bolt fully? However, that still doesn't address the ease with which it was installed initially. Every hack-n-tap I've heard of, including my own, had to be coerced on to some degree or another. Yours sliding on with no force required seems rather questionable to me. Give RE a call tomorrow and see what they have to say about it

XJourney, my flange got loose over time. It was not initially a problem at all. My problem arose from running a lot of miles with a bad CV joint in the rear DS and the slop worked the flange loose. After I replaced the tailshaft and flange with another unit and had the CV rebuilt everything was/is fine. So I guess I'm not much help. The one thing that does concern me is how easily you say your flange went on. I couldn't get mine to go on for the life of me. I had to take a dremel and bevel the tips of the splines and then use a 3lb dead blow hammer to get the damn thing to seat.

Ary

Kejtar: Yea I know Farmermatt ran it with out a single problem. Strength is not an issue on the hack and tack(no more then the stock tailshaft)
I ran with a lift for about 5 months with no SYE. Had a SLIGHT vibration (35-40mph)with no tc drop, put the TC drop in and quit all the way to as fast as I would go.
I was way better off without the SYE at this point.

As far as the bolt goes I have had the shaft/flange out 7 times now each time double checking the bolt, I even went and bought a 3/4" and a 1/2" bolt Hasta I am positive the bolt is not bottoming out. I hav had to buy several flat washers cause they are being cruched flat and not reusable.

I think the problem lies in the fact that I didn't have to file the edges or even use a bit of force or heat. In fact the tailshaft was hot compared to the flange and it still slide on easily
So either the flange was cut too big or my tailshaft is too small. And if it is my tailshaft is too small I wouldn't think it was from wear????? The jeep only as 58,000 miles on it. And isn't the stock slip yoke made of soft metal meaning that it would be the wear item.

On the warranty issue I am talking to my salesperson, still waiting on a phone call, I suspect that they will send me a new flange, and if the problem continues then my tail shaft is the problem. At the point I will sell my SYE with LOW(250miles) and get TW

Looking for stock 242 staft
how much shippped to 98264 :gee:

Hans
Thanks I am tired of beating my head against the wall.

back to the top

I'm having the same problem with my hack and tap for my 99 231 tc. I have the RE 3.5" full leaves with 4 degree shims and a highangle driveshaft. I get vibes above 55 that get progressively worse as I speed up. Highangledriveline sent me a new shaft but I have the exact same vibes. I did a face runout on my flange and found out it was .015 off. I have a straight cut because I cut the shaft while the shaft was spinning. The flange had to be hammered on and it is very tight. I suspect I have a bad flange, because it was missing parts when I ordered it (snap ring)

I put a t-case from a 2001 TJ into my 1988 XJ and installed the RE Hack and tap kit. The flange they supplied slide on easily much like you are describing. I also developed movement between the flange and shaft within a few days but have been running it like that for a little over a year now. I can't possibly see how people get their flanges to sit tight to the shaft since the washer that is held in by the lock ring on the flange has a pretty good amount of for and aft movement to it. Even with the bolt tightened fully....it only holds the washer against the end of the shaft...it's the washer that holds the flange on the shaft and if there is movement between the washer and flange then you'll have a little axial movement between the flange and shaft.

It is strange though how some have to hammer their flanges on and others they just slip on.

danald said:

I'm having the same problem with my hack and tap for my 99 231 tc. I have the RE 3.5" full leaves with 4 degree shims and a highangle driveshaft. I get vibes above 55 that get progressively worse as I speed up. Highangledriveline sent me a new shaft but I have the exact same vibes. I did a face runout on my flange and found out it was .015 off. I have a straight cut because I cut the shaft while the shaft was spinning. The flange had to be hammered on and it is very tight. I suspect I have a bad flange, because it was missing parts when I ordered it (snap ring)

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Wait, are you saying Jess actually built you a driveshaft for a hack 'n tap?? Last time I talked to him he absolutely refused and practically hung up on me. Every other experience I've had with him has been pleasant and great except when discussing the RE SYE, then he just gets quiet.

Ary

Jesse builds them for Dirk for the hack and tap. I don't know if he does it for anyone else but him right now.

Safari Ary said:

Wait, are you saying Jess actually built you a driveshaft for a hack 'n tap?? Last time I talked to him he absolutely refused and practically hung up on me. Every other experience I've had with him has been pleasant and great except when discussing the RE SYE, then he just gets quiet.

Ary

Click to expand...

I got my driveshaft through Dirk