[BRB2020]

Our Wolverine 350 has a loud squeaking noise that I believe is coming from the front end somewhere. It’s constant and rhythmic to either a tire rotation or some other moving part upfront. It increases and decreases with speed and seems loudest at slower speeds. There is no squeaking when the ATV is idling and not moving. It gets so loud that you can hear it over the exhaust and actually draws attention. I had it into a shop and they replaced the wheel bearings, but the racket is still happening.
Any thoughts on what might be causing this? I’m actually embarrassed to take it out.
Any help will be greatly appreciated.

 

[Mech]

Your observation that it's in time with the wheel rotation is important. There's a bit of a difference between rubbing plastic, rubber or steel. They can all squeak but the steel is shriller.. Do you think it's steel on steel ?
Brakes squeal sometimes. Does the noise go away or change if you apply the brakes ?
Does the noise change if you swerve hard on a good surface, like a road or dry dirt track ?
If you swerve, does the noise get louder one way more than the other ?
Have you checked the axles aren't rubbing somewhere ?
Do the axles all have their rubber boots and are they in good order ?
Have you checked the front diff for oil ?
Does it do it as soon as you go for the first ride or does it only do it after things get warmed/used a bit ?
Have you tried jacking the front end up and turning the wheels by hand ?

 

[BRB2020]

Thanks for the great reply Mech, it’s very much appreciated. I will try to go through your suggestions to the best of my limited mechanical ability. I’m pretty sure it’s metal on metal, as it’s quite shrill and very loud. It starts as soon as the ATV starts moving and doesn’t go away when everything heats up. I’ll try the brake while operating to see if it stops. I’m hoping the shop checked the front brakes when they replaced the wheel bearings, as the rears were completely done. It does seem to go away a bit at higher speeds, but that might because the exhaust is louder and I can’t hear it. I was also thinking diff oil. Unfortunately, the previous owner destroyed the fill nut, as all the tips are worn away and no wrench or socket will work. I’ve tried vise grips but can’t get it to budge.
Thanks again for your help. If I discover anything I’ll let you know.

 

[Mech]

Onya.. Since it starts straight off it's most likely to be a brake thing.. Disk brakes can get a little rock stuck in them against the disc and that can make a lot of noise.
Bearings are worse warm or cornering hard.
If you jack it up, and can get it to mae the noise turning the wheels by hand, and try to load the wheels as you turn them by pulling top or bottom as you do it, which might make the noise better, thenyou might be able to trace the noise with your finger tips, feeling for the vibrations. Try a finger on the wheel hub for instance, or on the brake calipers..

 

[BRB2020]

I’ll give that a go today and fingers crossed I can find something.

 

[Mech]

I thought in the night.. It could be the driveshaft to the front. Dry universal joints make a squeak or screeching noise under load. They don't generally make the noise being turned by hand though.

The drive shaft turns about four times faster than the wheels, but they can be only making a noise one quarter of a turn and sound like they are in synch. If you put a strip of that strong brown plastic packing tape on the front wheel, from inside across the tread and onto the other side, then go for a ride you will hear exactly the speed the wheel's turning at. The diff won't be exactly at four to one ration and if it's the u.j. there will be a discrepancy in the patterns. If that doesn't help confirm it, check for play or stiffness in the shaft and uj, and/or douse the uj with oil and see if it shuts up.

 

[Maddevill]

I was going to say, if its 4wd take a look at the driveshaft and axle U joints.

Mad

 

[BRB2020]

Thanks Mad. I have it jacked up now and taking look. I’m limited in my mechanic abilities but I will identify those items and see what I can find out.

 

[Mech]

I just got a video Mad and it does sound like a uj or axle bearing.. It's a real chirping sound, not a long squeal.. Perhaps run the video past Mad too Brb..

I'd check the rear axle bearings too Brb.. They have a lot of load on them and can make a lot of noise.

 

[BRB2020]

The dry rusty u-joints needed an oil bath! Soaked them good and just came back from a ride. All quiet and no squeaks!

Thanks very much Mech and Mad for taking the time to reply to my post and help me out. It’s really appreciated.

 

[Mech]

Ok.. good stuff. You know how to change universals ?

 

[BRB2020]

I do not

 

[BRB2020]

I thought I was doing great getting it jacked up, the wheels off and squirting oil everywhere. I did have my coveralls on, though (ha..ha 😁)

 

[Mech]

Ok. Well it's all pretty simple to get them apart. You take the circlips out/off and then rest one yoke across the open jaws of a vice, then hit the other yoke downwards to drive one cap half out, then flip it and repeat the process with the other cap. Then use pliers to pull those two caps right out. One yoke will come off then. Then you rest the bare crosses shafts on the vice and do it again with the other two caps.
To get them back together you clean up inside the yokes with emery tape and give them a grease. You take all four caps off the new cross and make sure they are full of thick grease and use a finger to spin around inside there checking all the little needles are sitting nicely. Inspect the cross. If it has a grease nipple in it's center, then there will be one yoke with longer arms to give clearance for the grease nipple. You have to fit the cross the right way over if that's the case. Leave the grease nipple out for now,
Then work the cross into one yoke and poke one end out of the hole in the yoke as far as possible, fit a cap carefully on there making sure you don't dislodge a roller. Now keeping the cross into the cap so no roller can get dislodged, tap that cap right in, and use a socket to tap it through more than needed so the other end of the cross is poking out far enough that you can fit another cap, again fitting it carefully so no needles get dislodged. While you are tapping that first cap and cross through you need to hold the cross backwards so it stays in the cap. That requires holding the yoke and the cross in one hand while keeping a bit of pressure on but it's pretty simple. Then tap that second cap into it's hole pushing the cross and both caps into the center. Fit the circlips to those two and then repeat the process with the other yoke and two caps.
The danger is dislodging a roller, but that can't happen as long as you keep the cross fully into the caps as you work. You push the cross in and through too far so you can get the second cap on fully without needing to pull the cross out at all. The whole secret to doing it successfully is in pushing the first cap way through the yoke before fitting the second cap on. Sometimes they need pushing through until they are almost coming out inside the yoke, but most bike uj have a bit of recess that means that's not necessary. Take care no to push the first cap right through or it is hard to get back into the yoke. There's a bit of leeway.. You'll see.
It's simpler to fit the cross to the long shaft first, they you only have to hold and manage a short yoke for the second set of caps.
It's not essential, but after it's all together with the circlips in/on, hold the long shaft and tap on the sides of both yokes and wriggle the cross around a bit to settle things into place and centralise them. The cross should feel free and smooth to move, if it isn't, tap it some more..

 

[Mech]

Haha.. if the uj sounds too hard, pull the driveshaft and take it to a shop.. that will save you a lot of money.

 

[Mech]

Here's a picture of what's in there to clarify..

Front differential for 1999 Yamaha WOLVERINE 350 WOLVERINE 350 (N) | USA sales region, , 14551060-810148

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[Mech]

oops.. that's like a suzuki and the yokes are attached to the diff.. You can't pull the shaft without dismantling the cross in place.. I don't think you should try that..
It's the same procedure as I just wrote, but done down under the bike.. It's a bit harder..

 

[BRB2020]

Thanks Mech! I’ll have a look at the u-joints and and the drive shaft. I see a big nut on the inside which I assume is how the drive shaft connects to the transmission and differential. if it’s looking too complicated, I may just take it in to a shop. I’ve done a few vehicle u-joints but they seem much easier than this. Worth a try to save money though.

 

[Mech]

If you can get that big nut off with the uj intact then ok, but on most the nut's real tight and need a socket, so the uj has to be dismantled first. That nut is tightened to a specific torque too to set the preload on the diff bearings. You need to mark the shaft and the yoke, so you can do it up to the same place.

 

[BRB2020]

You’re right, the u-joint is in the way of that nut. I think I’ll tackle the u-joint dismantle once I order up a couple of new ones. Looking at the exploded diagram, it’s similar to the dismantling I did on ones from an older vehicle. Fingers crossed everything comes apart and goes back together without many issues.