Time for upgrade...

[Mtbcoach]

So, here is the pic of the Inchworm installed.

Took it for a test ride and the noise that started this process is still pervasive. I had my daughter drive me around while I was hanging out the back to see if I could better locate the origin of the sound.

Without a doubt, its coming from the rear diff, don't know why I didn't do this sooner.

So, the quest continues. I'll be tearing the rear end apart to see if its something other than the ring & pinion. One of those mysteries since I can't imagine doing it during the radically challenging runs at the Spring Tide Ride...

 

[Capt Sensible]

That sucks. At least your inchworm is back together and put back in. Good luck.

 

[Mtbcoach]

And it's purdy...

 

[LT]

Is it a growling/whirling noise? If so then the backlash on your ring gear has gone bad creating the noise while driving. Recheck the play on the driveshaft, if there is excessive movement then it is time to change out the gears in your third member.

 

[1911]

Pulled my rear output shaft seal today; it was definitely leaking but did not look bad, neither does my original 27-spline chromoly shaft. Got two new Timkin seals at the bearing house (one spare) and will put one in tomorrow morning when it's cooler. Hope this fixes the leak. Bearings have a tiny amount of play.

Sorry to hear about your diff Jerry - gears are expensive.

 

[Mtbcoach]

Is it a growling/whirling noise? If so then the backlash on your ring gear has gone bad creating the noise while driving. Recheck the play on the driveshaft, if there is excessive movement then it is time to change out the gears in your third member.

I'd describe it more like a scraping/rubbing sound, only when on the gas/under load, seemed like a wheel bearing at first. I'll put it on stands in the morning and listen with a scope to see if I can isolate it further. Thanks for the suggestions...

Pulled my rear output shaft seal today; it was definitely leaking but did not look bad, neither does my original 27-spline chromoly shaft. Got two new Timkin seals at the bearing house (one spare) and will put one in tomorrow morning when it's cooler. Hope this fixes the leak. Bearings have a tiny amount of play.

Sorry to hear about your diff Jerry - gears are expensive.

Luckily, East Coast Gear Supply is less than 10 miles away and I know they'll have it set up (if I need it) before I could pull the 3rd and get over there.

Good to hear yours doesn't need to be removed and torn down ...

 

[LT]

I'd describe it more like a scraping/rubbing sound, only when on the gas/under load, seemed like a wheel bearing at first. I'll put it on stands in the morning and listen with a scope to see if I can isolate it further. Thanks for the suggestions...

That's when you will hear a bad ring gear the most when power is being applied to the rear end. Coasting or deceleration will not generate the noise since the ring gear is not having pressure applied to it. To check drive shaft play you will want both rear tires on the ground to properly check the backlash on the ring gear. The rotation should not be more than a slight twist one way or the other, anything greater than 1/8 - 1/4" turn is bad news.

 

[Mtbcoach]

That's when you will hear a bad ring gear the most when power is being applied to the rear end. Coasting or deceleration will not generate the noise since the ring gear is not having pressure applied to it. To check drive shaft play you will want both rear tires on the ground to properly check the backlash on the ring gear. The rotation should not be more than a slight twist one way or the other, anything greater than 1/8 - 1/4" turn is bad news.

Thats been my feeling and fear, I'll try your test before I start tearing it down any further.

Thanks again...

 

[Mtbcoach]

Here is a quick video of the slop in the rear driveshaft. I didn't take any "hard" measurements but it sure looks to my eyes that it has more slop than LT referred to above...

drivetrain noise oil leak :: Driveshaftslop.mp4 video by mtbcoach - Photobucket



Looks worthy of further teardown and giving Chase a call over at ECGS to see if he has a built 3rd with 4.88's for me...

 

[LT]

That isn't terrible, but could be indicative of a ring gear starting to wear out. Could also be a bad bearing too if you re-used your original bearings instead of new ones.

 

[Mtbcoach]

That isn't terrible, but could be indicative of a ring gear starting to wear out. Could also be a bad bearing too if you re-used your original bearings instead of new ones.

Thanks again for your feedback.

I paid the installer for a master kit, I can only assume it was used. In any event, I'll be breaking it down for at least a visual inspection as well as the pinion bearing, etc...

 

[Mtbcoach]

Today's update...gave my confidant Bud a call to discuss the issues. He gave me a nice idea to peak into the diff via the fill plug, might be able to "shine a light" onto an issue. I wasn't able to see anything of significance, teeth were still there.

I did put it on stands, put it in gear and crawled under to isolate the noise. Surely the inside the rear diff, not in the area of the pinion bearing. I could feel the noise through the housing.

So, tear down continues to get the diff cover off to take a look inside. I'll post up pics once I can get a good look...

 

[Mtbcoach]

I took the time to give things a good look. The biggest hassle of the whole job is getting the E-brake apart on each wheel. But for that, it's pretty straight forward.

I got the axles out and the 3rd out. Now, I'm no rocket scientist or even a fair mechanic and I didn't even sleep in a Holiday Inn last night but, I think I found the problem.

Experts, please chime in to verify...

I really like how this piece found a nice, safe place to hide...

Here are all the pieces I fished out of the diff housing...

Three different spots, approximately 90 degrees from each other. What surprises me is that none of these pieces showed up when I drained the fluids.

I can only imagine one place where it might have happened. When we did the VA border run, one of us stopped to check something on his trailer. When we pulled back onto the road, a car was coming, causing me to get a little happy with the throttle and I hit some loose sand when doing so. I never heard anything but I do recall that it didn't "go" as well as it should have, like it spun.

Oh well, stuff happens and hopefully learn something along the way. I just hope ECGS has a 3rd on the shelf with 4.88's so I can maybe make our club event this weekend...

 

[Capt Sensible]

WINNER!

 

[1911]

Three different spots, approximately 90 degrees from each other.

I'm no expert Jerry, 'cause I've only blown-up one, but that ring gear looks like a time bomb. My stock one looked very similar (broken teeth in three separated radii) after hopping it locked on Wipeout Hill. I drove it home more than 1,000 miles with no problems but it finally got noisy and started clacking as it broke off more teeth.

Hope that ECGS gets you set up pronto.

Not to hijack your thread, but on a related note I replaced the rear output shaft seal on mine and it seems to have completely fixed my leak. I was worried because the old seal was not visibly bad. But the flange nut seemed a little loose to me, it looked like it had come unstaked. Tightened 'er up real god when I put it back on, with some Loctite and re-staked it with a chisel. Hope that holds it.

Original 27-spline chromoly output shaft. Did not look worn at all.

New Timkin seal in. I don't like the (Chinese?) seals that Inchworm uses in these cases.

 

[Mtbcoach]

My nut looked like it moved also, enough that it was almost past the notch for putting the stake...

 

[Willbur]

How many miles roughly were on these gears?

I wish I could have met you at overland rally last weekend!

 

[holmanm]

I'd describe it more like a scraping/rubbing sound,<snip> ...

Because of the "cursing sensor" the red words above were showing up as s****ing/rubbing, so I thought pooping/rubbing would be a terrible sound to hear from your FJ. So I went into Options and cleared the cursing sensor field and realized it was c r a p that was the offending letters, which made much more sense.

 

[Mtbcoach]

How many miles roughly were on these gears?

I wish I could have met you at overland rally last weekend!

Miles = 31k, installed summer of '08, survived Rubicon, 2 trips to Moab, many runs locally, destroyed on OBX event...go figure.

I was very depressed about missing the Overland Rally but stuff happens...

Because of the "cursing sensor" the red words above were showing up as s****ing/rubbing, so I thought pooping/rubbing would be a terrible sound to hear from your FJ. So I went into Options and cleared the cursing sensor field and realized it was c r a p that was the offending letters, which made much more sense.

Your right, pooping/rubbing would not be a good thing. I didn't see the sensor edit. Be sure that the only pooping going on is when I took the 3rd out and found the damage...:whoops:

 

[BMThiker]

I took the time to give things a good look. The biggest hassle of the whole job is getting the E-brake apart on each wheel. But for that, it's pretty straight forward.

You know there is a trick that saves you this step...
Just remove the clips on the frame and lower control arm that hold the e-brake line. This provides enough slack in the line that you can slide the entire hub & axle shaft out of the housing. No need to disassemble the hub and e-brake - just the 4 bolts that hold the unit-bearing to the end of the housing. You will also need to remove some of the brake's hydraulic line clips on the axle housing, if you opt to not remove the calipers too.