4WD chirp

v10rick

Active member
Noticed this during the pre purchase inspection, but since the chirp was in 4wd only it was not high on my list of priorities.

The chirp is in sync with wheel rotation but is intermittent. Heard a clunk from the right front when pulling away from a stop, a few times.

It can be heard when drifting into the garage, with the gear selector in N. But when I get out of the RTV to diagnose the source, by rocking the rig, it does not chirp.

Flat out on a straight away the front end sounds noisy (gear noise) in 4wd, when its not chirping.

4wd is operational, but for how long?

BTW changed the front diff lube to 75-90 synthetic gear oil before diagnostics. Did not see any metal particles but it was coal black.

Did not come up with anything helpful using the search feature. An unusual problem for this RTV?
 
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does your model have a limited slip front diff??? could be that the gear lube is breaking down the clutches and the chirp you hear is slippage. also could be a CV joint going dry,i would check the boots for tears and cracks. could also be a U joint with one dry cap in the front driveline.
 
does your model have a limited slip front diff??? could be that the gear lube is breaking down the clutches and the chirp you hear is slippage. also could be a CV joint going dry,i would check the boots for tears and cracks. could also be a U joint with one dry cap in the front driveline.

How do I determine if it has limited slip?

Both CV boots are in perfect condition.

Spayed the U joints with PB Blaster, not certain yet if that made a difference.
 
You didn't mention what model machine you have, or the year. I can tell you that my new x1100c produces a lot of noise if the front end, when running 4 wheel drive. I too get an occasional grinding noise from the right front, if wheels are slightly turned, while motoring along in 4WD. I don't have any chirping though. My machine is a 2017, only has 26 hours on it.
 
You didn't mention what model machine you have, or the year. I can tell you that my new x1100c produces a lot of noise if the front end, when running 4 wheel drive. I too get an occasional grinding noise from the right front, if wheels are slightly turned, while motoring along in 4WD. I don't have any chirping though. My machine is a 2017, only has 26 hours on it.

Sorry...its a 2006 RTV900 with about 1200hrs. on the clock.

Sounds like the front noises should be expected with the age and hours but without the chirp.
 
Hi, I use Sudt2 in the front in on my 2011 RTV 900. I think thats what the book calls for. Mine is never past olive oil color when I change it so am thinking yours was neglected for it to be like coal.
I know its not located in the front end area but you may want to check the carrier bearing right below the seat- floor area- where the front shaft and rear shaft come together. It might chirp at times but for sure it can squeal like a banshee when it starts wanting to go out.. That lunking.... I'd check the rear ujoints for movement by jacking up and then rotating by hand while looking for play at the ujoints and shaft s there. The first time my rear u joints went out , there was a lunking just before it would "take off" . bordercollie

edit: I reread and saw where you heard the lunking noise from the front.. Keep an eye on those front cv joints and the drive shafts with ujoints.
 
"check the carrier bearing right below the seat- floor area"

This reminds me of the Cardon shaft center bearing used on the Porsche Cayenne. It maximizes ground clearance and the dealers bank account, because it fails about every 60Kmi.

While refurbishing this RTV I removed the center floor pan and inspected the center driveshaft bearing. Could not detect any side play from the bearing but the driveshaft had some.

The challenge...the same assemblies rotate in 2wd, but not under load.

This area is dead quite in 2wd.

Start changing parts until it goes away?
 
I would change the oil back to Kubota udt. That might help with some of the noise your hearing.

i agree. you should change the front diff oil back to UDT. another note>does your model have the oil filled compartments in the steering knuckle? probably should change and flush with UDT again there too. could be a wheel bearing getting dry. sometimes you just have wait for it to get worse to find out.:gotsmoney:
 
Rodger that on the UDT, the differential probably could use a second flushing anyway.

Will pull the wheels when it warms up to inspect the steering knuckle fluid. Nothing done there yet, under my care.

4wd works as it should, the few times that it was needed. Just ignore it until it breaks could be one solution. At least it wont let me sit, unless it locks up.
 
Rodger that on the UDT, the differential probably could use a second flushing anyway.

Will pull the wheels when it warms up to inspect the steering knuckle fluid. Nothing done there yet, under my care.

4wd works as it should, the few times that it was needed. Just ignore it until it breaks could be one solution. At least it wont let me sit, unless it locks up.

sounds like a good plan to me:myopinion:
 
OK it warmed up enough to pull the wheels.

Removing the bolts for the knuckle fill holes I could see no oil but when the drain bolt was removed oil drained.

So the level was low, but not completely dry?

Apparently this is equipped with a limited slip differential.

With 4wd engaged, front wheels off the ground the wheels could be rotated but with some resistance.

The differential input shaft could not be turned by hand.
 
You probably already figured this out but if you can consistently make it make the noise, try spraying wd40 on one thing at a time to see if it goes away.
 
I know its not located in the front end area but you may want to check the carrier bearing right below the seat- floor area- where the front shaft and rear shaft come together.

Hi
I cannot locate this carrier bearing on the parts diagram. Was this eliminated in later models? Is there a substitute driveshaft that does not require this bearing?
 
You probably already figured this out but if you can consistently make it make the noise, try spraying wd40 on one thing at a time to see if it goes away.

Yes I started in that direction but was sidetracked.
After changing the lube in the differential and knuckles I will resume this if the chirp continues.
 
Hi
I cannot locate this carrier bearing on the parts diagram. Was this eliminated in later models? Is there a substitute driveshaft that does not require this bearing?

The newer models have a one piece driveshaft. My 2005 had the 2 piece - it was known by owners back then as "the rattler" because it made so much racket after a bit of wear. There is a fellow that did a "fix" on those to hold the noise down.. . Its called the cornejo fix or something close to that. Member Mark S.Sibole had to replace a carrier bearing last I heard it was around $60. I replaced the '05s but it was many years ago - have to find the post to be sure of the date, anyway, it isn't hard to do.
My 2011 has the one piece shaft and no carrier bearing. There is a conversion kit for the old models to use the one piece design. But be warned that kit is expensive @ around $500. bordercollie

edit. http://www.cornejo.net/rtv900/DriveShaftRattleFix.htm
edit http://www.nettractortalk.com/forums...arrier+bearing
 
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Update...

Changed the fluid in the front differential and both knuckles to Kubota UDT but there is no change. Sound is definitely coming from the front end.

Additional details...its more of a binding sound that can be heard with the engine off, transmission in N, while drifting down a slope, with the wheels turned hard left.

Shift to 2wd and the binding sound is gone.

Is the differential the culprit?
 
since the front diff oil was so black i am going to venture a guess and say the front differential is on the way out. probably the pinion bearing or a spider gear. better find out pretty fast because when they go it will most likely grenade the case. you can sometimes get good used from ebay.
 
since the front diff oil was so black i am going to venture a guess and say the front differential is on the way out. probably the pinion bearing or a spider gear. better find out pretty fast because when they go it will most likely grenade the case. you can sometimes get good used from ebay.

Since 4wd is seldom needed I am inclined to leave as is. If a differential comes my way at the right price I will purchases as a standby unit.
 
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