Rubicon Tranny Problem

[CoraC143]

[color=00FF00]I\'m posting this up for Jared, one of our newer members with the sweet black Rubicon with a long arm and trick new tube fenders. [/color]


Wondering if you could take a minute and brainstorm what my next move should be for my Rubicon.  On the way to work last Thursday, I downshifted approaching a red light only to be greeted with a less than pleasant growling noise and slight vibration.  After a bit of test driving with a few people we concluded that it appeared to be coming from the clutch/throwout bearing.  I spent all last weekend under a lift replacing everything between the engine and tranny just to eliminate that chunk of moving parts.  Weekend and cash wasted. Noise is still there.  Checked the driveshafts yet again, (this was my first check before i dug into the tranny) and everything still appeared fine. Today we get it up on the lift at work and i put stress on the parts, i.e. accelerating and downshifting and with his stethoscope one of my mechanics seems fairly confident to have pinpointed the noise to the tranny itself. Bad syncro gear possibly? I\'m stumped as to where to go next. Do you guys dig into tranny work at all? Know a reputable shop? Should i beef anything up? I\'m not really in good financial shape to dish out hundreds or *gasp* thousands of dollars to fix this thing but it\'s my daily driver so I\'m in a pinch. Then again, it\'s possible that the noise might not even be from the tranny....


Any help would be greatly appreciated, and thanks for your time!

Jared

[CoraC143]

There are a couple transmission shops in Texas and Florida that specialize in cheap, re-built tranny\'s. Often times, even with shipping, they are cheaper than buying one up here and having it rebuilt.... of course I don\'t know any names, but I can get a name from one of Erik\'s employees who had a rebuilt tranny sent up from FL.

[Wingman]

What year Rubicon?  They started with the NV3550 then went to the six speed something-or-other.  The NV3550 is a good trans and is often used as an upgrade for the AX-15.  Failure is unusual.  Should be able to find a used replacement pretty easily since they were in GM products too.

I\'d suggest the Jeep forum if no ideas spring from here.

[jACeL86]

It\'s the 6 speed...2006

[CoraC143]

First post!! Welcome :)

[Wingman]

hmmm, not finding much on the NSG370...

[JCJ]

OK, been thinking about this a bit so here\'s my 2 cents.

  Most of the time when a trany is taking a dump it will talk to you and let you know it\'s not real happy, usually grinding or at least funky shifts. Not always, but enough that it makes me wanna look elsewhere some more before throwing more, bigger, expensive parts at it

I am suspicious of all U-joints unless brand new and installed by me and even then it\'s a crap shoot.. You have lifted that thing a bunch and altered the drive line geometry, have you modified the shafts or are they crying out for help?  You can poke and prod all you want but bad U-joints have a nack for hiding themselves while static. They can pass the wiggle test and still be the problem.  If you have it, try putting the transfer case in neutral and running it up the gears or disconnect the shafts from the transfer case and try it..

Also have a real good look (again) at the tranny/transfer mounts, on a CJ when the trans mount even starts thinking about getting lazy it can/will vibrate and chatter like the thing is going to explode.

I\'m also suspicious of slip joints on drive shafts or transmission/transfer case output shafts.  Altering the ride height even a little really changes the working area of any slip joint.

Changes in drive line angles can cause components to become very unhappy, sometimes a stack up of bad tolerances so that any one part wont be the obvious smoking gun you hope to find and can possibly only evident after several hundred miles/thousand miles of driving in it\'s new position.

[jACeL86]

I\'ll get it on a lift asap and give this a try. Thanks for the input! The rear drive shaft has been upgraded to a Tom Woods double cardon piece that was packaged with my lift. You never know though. I\'d really like to nail it down with some certainty to being the transmission if I have to take it into a shop. Any other part and I\'ll gladly get my hands dirty, but at this point all those gears and parts still scare the crap out of me.

[jACeL86]

So my worst fears didn\'t come to pass. It IS the rear driveshaft. I\'m definitely a newb when it comes to cv joints and apparently I\'ve missed greasing the ball socket. Almost impossible to get any movement out of the thing, but it sure makes noise. Now... I could either ship the thing back to Tom Woods and have it rebuilt to their standards and balanced for $155 or drop it off in Syracuse (they only have the spicer 5-153x joints available) for a bit less than $100 with no balancing. The piece was already balanced when I first received it. Any thoughts?

[JCJ]

If you mark it so it goes back together the exact same way I see no need for balancing,

Grab some Spicers and have at it..

[Wingman]

Whew, glad you avoided the big bullet there!

[ollllllo]

Check with vic in canandaigua. He builds drive shafts and prob could rebuild yours. Ontario machine.
Sorry I don\'t have a #.

[MrMindless]

Ontarioengine.com I believe.