Found my noise!!

[BillR]

For anyone that hasn't been following this, I had a noise that was driving me (and the mechanic!) NUTS!
A friend has a chassis ear, and we hooked it up today and went for a ride. The noise is coming from the front diff. All I can figure is it must be the Torsen-Gleason LSD. The gears have been reset twice, and all of the bearings have been replaced.
I know this is not a common LSD, but I was wondering if anyone has heard of this LSD being noisy when new.
At least I know what it is now!!

 

[RCP Phx]

Hey Bill,That is interesting!Although your LSD has planetaries in it they should not even be moving unless youve got different size tires on front.Other than that have you checked the run-out in the ring gear?

 

[BillR]

Hey Bill,That is interesting!Although your LSD has planetaries in it they should not even be moving unless youve got different size tires on front.Other than that have you checked the run-out in the ring gear?

I haven't checked personally, but I really wouldn't know what I was looking for. The guys that did my diffs said that the gears set up fine, and they've had to do it again after replacing all of the bearings.
I DID buy the gears used, however. They only had 25K on them, and are OEM Dana gears.
Good point about the Torsen gears not moving in a straight line...

 

[RCP Phx]

Again your thread has gone over several weeks.As I recall this noise exists w/o the front driveshaft in?Do you have access to a dial indicator?If you cant get this figured out locally let me know!Ive got all the tools for gears.

 

[BillR]

Again your thread has gone over several weeks.As I recall this noise exists w/o the front driveshaft in?Do you have access to a dial indicator?If you cant get this figured out locally let me know!Ive got all the tools for gears.

Yes, the noise IS there when the front driveshaft is out.
The frequency of the noise is faster than the ring gear turning, which should be the same as the tire speed, correct?
Something in or on the pinion gear would have the same frequency that I'm hearing.
BTW, with this chassis ear we put sensors on the front and rear diffs, t-case, bellhousing, and one on each spindle in front. The one for the front diff was the one picking up this sound, so it's SOMEWHERE in there.
As for getting it figured out here, I think the guys I have doing my gears are pretty baffled. I wouldn't mind another set of eyes looking at it...

 

[satan]

Faster than tire rotation = Pinion?

Also - measure your tire circumferences and adjust em with air pressure try matched and mis-matched values -- that could easily identify the Torsen-Gleason as the culprit or eliminate it as a source --

Does your buddy have the solid transducers for his ears? try running em on the ring-side carrier bearing and the pinion bearing...

 

[BillR]

Faster than tire rotation = Pinion?

Also - measure your tire circumferences and adjust em with air pressure try matched and mis-matched values -- that could easily identify the Torsen-Gleason as the culprit or eliminate it as a source --

No other attachments for the "ears". Tires are within 1/2" in circumferance.
The pinion make sense, but the sound doesn't change when going from coast to acceleration. I thought a gear mesh issue would change like this.
What about the hub(s)? They only have 46K on them, but I don't know what the've been through before I got it. The ear that was attached to the spindle picked up the noise a little, but it was much louder at the webbing of the diff.

 

[Safari Ary]

you could always let some air out of one tire to make them unequal in size to see if the sound gets more pronounced. In other words, eliminate or identify the LSD's guts as the culprit. Just an idea. Peace

Ary

 

[BillR]

The noise IS coming from the front diff, either from the r&p or the pinion bearing. Finding out was VERY expensive!

I was told by several people to remove the axle shafts and reinstall the hubs to eliminate the front r&p turning. DON'T DO THIS!! I tried it Saturday, and the noise was gone for 30 seconds. At that time, the hubs seperated without the axles to hold them together. The driver's side wheel came off; the steering knuckle broke when it hit the pavement; and I trashed 2 new hubs and the calipers and rotors in the process. :anon:
Again, DON'T TRY THIS AT HOME. Your results may vary...

 

[Matt]

I am very sorry to hear that but you learned the hard way that to run without the inners you still need the stub shafts attached - you luck no one else got hurt and you may pass along your displeasure with whom ever gave you that advice - they probably meant well but should be edjucated as to your misfortune and the reason behind it...

Matt

Nothin like a little SPOBI to put some "fun" it your day

Edit: forgot to mention - I have an extra knuckle or two; there your as long as you pay the shipping from WA

 

[BillR]

I am very sorry to hear that but you learned the hard way that to run without the inners you still need the stub shafts attached - you luck no one else got hurt and you may pass along your displeasure with whom ever gave you that advice - they probably meant well but should be edjucated as to your misfortune and the reason behind it...

Matt

Nothin like a little SPOBI to put some "fun" it your day

Edit: forgot to mention - I have an extra knuckle or two; there your as long as you pay the shipping from WA

I ALMOST jumped on the freeway to check for the noise. I'm REALLY glad the wheel seperated at 5 mph and not 50! SPOBI
Matt- If you have an extra driver's side knuckle for a newer XJ, I'll gladly pay you for the shipping! Let me know...

 

[STRYKER]

Got one question for you...

Does it "sing"
or does it "moan"?

Singing is ring and pinion teeth misalignment or wear.
Moan is a bearing or two.

Don't ask how I know.

 

[BillR]

Got one question for you...

Does it "sing"
or does it "moan"?

Singing is ring and pinion teeth misalignment or wear.
Moan is a bearing or two.

Don't ask how I know.

Neither
It's a purr sound like a cat, or a card in bicycle spokes, but MUCH quieter.

 

[RCP Phx]

Hey Bill !!

My offer still stands if you want a second set of eyes on it!

 

[BillR]

Re: Hey Bill !!

My offer still stands if you want a second set of eyes on it!

That sounds great! Will you be in Flag anytime soon? I don't have a problem driving to the Valley, either!

 

[RCP Phx]

Unfortunately you would have to come down If you need to do it right away.Mine is my only vehicle and its coming down this week for the new lift and long arms.I expect to be off/on running for the entire month of May.I just picked up steel for the crossmember today!

Ps:Sorry about the knuckle,I got lucky last year when I found out!My brakes went to the floor right around the corner,it didnt take long to see what was happening!

 

[STRYKER]

Neither
It's a purr sound like a cat, or a card in bicycle spokes, but MUCH quieter.

You did throw about 4 oz. of "Equa Trac" in with the gear oil, right?
Sounds like clutch chatter to me. Does it click or pop when you enter a tight slow curve? Do you hear the clutches "whirring" in tight turns?

 

[RCP Phx]

This is a gear driven unit,they dont have any clutches!

 

[STRYKER]

This is a gear driven unit,they dont have any clutches!

Had to go back to the original post and pick out the particulars...
Torsen-Gleason LSD

There does seem to be some sort of chattering amongst the gears...but I've never had the pleasure of opening one of these units.

My bad....

 

[BillR]

Unfortunately you would have to come down If you need to do it right away.Mine is my only vehicle and its coming down this week for the new lift and long arms.I expect to be off/on running for the entire month of May.I just picked up steel for the crossmember today!

Ps:Sorry about the knuckle,I got lucky last year when I found out!My brakes went to the floor right around the corner,it didnt take long to see what was happening!

PM me with your contact info, and we'll hook up in a few weeks. I have finals through next Tuesday, but after that will be fine.
Are you coming up for the AZ XJ run on the weekend of the 10th-11th?