DriverX
NAXJA Forum User
- Location
- Asheville, NC
Finally. After suffering high speed vibes for at least 5 years now, it's finally all over. I just went up the highay at 85+ with barely the slightest rattle from the coins in the ashtray. For those who don't want to read the whole story, I'll start with the end. It was a bent output shaft.
The probably too long story:
I have a 99 auto w/231 and 8.25. Yeah, the worst combo for vibes, and I found out as soon as I bought it (new) and it wasn't as smooth as the 200k 89 model it replaced. Returned it to a dealer several times with no results. That's when I found
, doing internet research about the vibe prob. with later models.
Anyway, I love XJs so I just accepted the issue and lifted anyway, starting with a Rustys BB. Of course, vibes got way worse, so shortly after I invested in a RE Hack and Tap. Ordered it sized for a 3" lift and added added 1" blocks and extra coil islolators at the same time. Acceleration vibe solved but high speed (60mph+) gets progressively worse over next few years, and yes, I had rear pinion angle perfect thanks to info found here.
Around 2001, I went to an OME 2.5 lift with full packs, and retained the BB (and made shock mount extentions) for a settled total of 3.5". Still the high speed vibe but by '03 it's seems to be getting better and not really an issue until 70 or so. Then one day I'm under the jeep doing something and I grab the ds and find that the RE flange is loose on the output shaft splines. I call RE, they tell me send it back and they replace it free. I put the nice tight new one on and CRAP, the vibe is back as bad as ever! I should have known at this point that the output shaft was the culprit, but for some reason it did not occur to me (or RE). I wonder for a year or so if the new flange is defective, or if the 8.25 is the culprit. I have the universals all replaced, and the ds rebalanced a few times. I come to accept that we'll use the wifes '96 for road trips forever.
Then one day a light bulb appears above my head, and I run out to the garage and remove my ds at the flange and start the engine and put it in drive. Sure enough, the flange wobbles. Either I got a really wack part from RE(unlikely) or the output shaft is bent. The latter would explain why the last flange finally became loose (and helped the vibe situation).
As money is always an issue, I lived with it until I come across a new 231 output from a guy here in the classifieds (my apologies, I can't remember his name). Price is right and I have it a few days later. I had a machine shop hack and tap it to eliminate any variables and call the best drivetrain guy in NC, Jody Treadway at WNC Custom Jeeps(.com) to open the case and replace the shaft. I had considered doing it myself after reading some writeups here, but I really wanted to get it done right so I pulled the case and took it to Jody. It's ready in one day for a really good price, and he reports the internals are in great shape otherwise. I should have had him look at it years ago and saved myself all the frustration. I could tell it was fixed even at 45mph. It's now way smooth through the whole range.
I believe the cause of the bend is a too long ds. When I re-installed the t case, I noticed that I could only compress the shaft about 1.25" away from the flange. That's at 3.5" lift. I had run it for years at 2" lift and it would have been even less. I've pulled trailers, I've been through Tellico twice, and surely over compressed the ds and put who knows how much pressure on that little output shaft. It's all my fault really as I should have recognized the ds was too long the first time I installed it, but I could compress it a little and I assumed that was how it should be since I had given RE all my measurements. Live and learn. Hope this is helpful to somebody out there suffer from high speed vibes, go check to make sure that flange is spinning true.
So as I'm about to go and get the ds shortened, I ask the masters at: How much? Jody said the 1.25" I have was not enough but I would still want more extention than compression, but I was wondering how much compression all you guys with SYE setups are getting out of your ds's.
Thanks for all the years of help on this and a million other things,
-mike
The probably too long story:
I have a 99 auto w/231 and 8.25. Yeah, the worst combo for vibes, and I found out as soon as I bought it (new) and it wasn't as smooth as the 200k 89 model it replaced. Returned it to a dealer several times with no results. That's when I found
, doing internet research about the vibe prob. with later models. Anyway, I love XJs so I just accepted the issue and lifted anyway, starting with a Rustys BB. Of course, vibes got way worse, so shortly after I invested in a RE Hack and Tap. Ordered it sized for a 3" lift and added added 1" blocks and extra coil islolators at the same time. Acceleration vibe solved but high speed (60mph+) gets progressively worse over next few years, and yes, I had rear pinion angle perfect thanks to info found here.
Around 2001, I went to an OME 2.5 lift with full packs, and retained the BB (and made shock mount extentions) for a settled total of 3.5". Still the high speed vibe but by '03 it's seems to be getting better and not really an issue until 70 or so. Then one day I'm under the jeep doing something and I grab the ds and find that the RE flange is loose on the output shaft splines. I call RE, they tell me send it back and they replace it free. I put the nice tight new one on and CRAP, the vibe is back as bad as ever! I should have known at this point that the output shaft was the culprit, but for some reason it did not occur to me (or RE). I wonder for a year or so if the new flange is defective, or if the 8.25 is the culprit. I have the universals all replaced, and the ds rebalanced a few times. I come to accept that we'll use the wifes '96 for road trips forever.
Then one day a light bulb appears above my head, and I run out to the garage and remove my ds at the flange and start the engine and put it in drive. Sure enough, the flange wobbles. Either I got a really wack part from RE(unlikely) or the output shaft is bent. The latter would explain why the last flange finally became loose (and helped the vibe situation).
As money is always an issue, I lived with it until I come across a new 231 output from a guy here in the classifieds (my apologies, I can't remember his name). Price is right and I have it a few days later. I had a machine shop hack and tap it to eliminate any variables and call the best drivetrain guy in NC, Jody Treadway at WNC Custom Jeeps(.com) to open the case and replace the shaft. I had considered doing it myself after reading some writeups here, but I really wanted to get it done right so I pulled the case and took it to Jody. It's ready in one day for a really good price, and he reports the internals are in great shape otherwise. I should have had him look at it years ago and saved myself all the frustration. I could tell it was fixed even at 45mph. It's now way smooth through the whole range.
I believe the cause of the bend is a too long ds. When I re-installed the t case, I noticed that I could only compress the shaft about 1.25" away from the flange. That's at 3.5" lift. I had run it for years at 2" lift and it would have been even less. I've pulled trailers, I've been through Tellico twice, and surely over compressed the ds and put who knows how much pressure on that little output shaft. It's all my fault really as I should have recognized the ds was too long the first time I installed it, but I could compress it a little and I assumed that was how it should be since I had given RE all my measurements. Live and learn. Hope this is helpful to somebody out there suffer from high speed vibes, go check to make sure that flange is spinning true.
So as I'm about to go and get the ds shortened, I ask the masters at
: How much? Jody said the 1.25" I have was not enough but I would still want more extention than compression, but I was wondering how much compression all you guys with SYE setups are getting out of your ds's.Thanks for all the years of help on this and a million other things,
-mike
