Grinding/ scraping from front end while in 4wd

[Mike_92]

Hi all,

I'm getting a scraping/ grinding noise when 4wd is engaged and I'm looking for possible causes. I'll try to describe it as best I can and give you as much information as I can.

The truck is a 2000 Mazda b4000 4x4. Standard transmission. Electronic T-Case. 75000 miles on it. **it has a live front axle** NOT the Pulse vacuum hubs. Everything is stock essentially.

The noise started recently and suddenly. I went on a 130 mile trip on logging roads. Nothing too rough but there were a lot of potholes and a few water bars. As well as a few small sections of steep hills with loose rocks on them. Had it in 4wd low for the steep sections and in 4 wd high for a couple of the water bars but mostly in 2wd. As far as I could tell the water never went above the bottom of the axle (the deepest was right up to the bottom of the axles and everything else was much shallower) After this trip I didn't use 4wd for a week or so. Next time I engaged it I heard the noise immediately.

The noise only happens in 4wd and is most obvious at 30 mph+ . 4X4 high and low both work properly, I just get that scraping noise. It sounds like it is from the front driver side or below the pedals sort of.

My own thinking was T-case cause it is the only thing not turning in 2wd right? Could it be something that only gets agitated when torque is applied to the front drive train?

Any ideas or suggestions would be greatly appreciated!! Let me know if you need anymore information

-mike

 

[Andy D]

Check the lube levels in the front end and the transfer case. And generally look at stuff when you're under there.

 

[adsm08]

Get it up on 4 jack stands and throw it in 4-hi, let her roll. The thing that is odd about this is that everything is always spinning, even the transfer case, it just isn't always powered.

 

[97RangerXLT]

What ADMS08 said.

because you have a live axle everything is spinning and that would mean your front wheels are constantly turning the front driveshafts and gears.

check all of the bearings in the front wheels (I believe you have a sealed unit on each wheel, so if it is shot, you will be replacing the hub along with the bearing as an assembly) you might have a bearing going out but since it is early in its failure, you only notice noise when the axles are getting power put to them instead of the wheels spinning the axles.

AJ

 

[Mike_92]

Thanks for the replies everyone.

I had planned to check all the fluid levels and did so this afternoon. everything looked good.

That's a good point, I guess the T-case is being turned in 2wd as well.

I will try the jack stands trick this weekend.

The odd thing is it wasn't there at all until after that trip. Which components are most likely to fail rapidly like that, in your guys' experience?

thanks,
mike

 

[JoshT]

Don't get mad at me for this, but are you positive that you have live axles. 2000 was the transition year so some had it.

When I read this earlier I was thinking the same thing ADSM said, with live axles everything under there is always turning. That was the only scenario I could come up with.

 

[tmcalavy]

Stuff breaks whenever it wants...doesn't matter whether it's sudden or gradual, noisy or quiet. Put it up in the air and take a look underneath, just make sure any jackstands you use are worthy of the job...it's hard to lift a vehicle off of you, so work with a spotter and a backup jack or two.

 

[Mike_92]

No worries always good to double check. Yea I'm positive, mine was built in the second half of 2000.

I will definitely make sure the vehicle is solidly supported!

I guess what I meant is something like wheel bearing goes out gradually usually doesn't it? Whereas something like a suspension or drive train component might fail more rapidly with off road use. Anyway, thanks again for the replies!

-mike

Don't get mad at me for this, but are you positive that you have live axles. 2000 was the transition year so some had it.

When I read this earlier I was thinking the same thing ADSM said, with live axles everything under there is always turning. That was the only scenario I could come up with.

 

[ab_slack]

I agree with adsm08, a noise from the front end like that just doesn't make sense if it is a live axle. All the front driveline would be spinning anyway. So that means it must be transfer case. I suppose some binding due to something at transfer case cause something different with the front driveline than when it is driven by the wheel. Or maybe something busted on one axle shaft causing it to be decoupled from the wheel so it only spins when in 4WD but you would expect the other wheel connected to the shaft would cause something.

A simple confirming test for live axle is to just jack up one front wheel with it in 2WD and then spin the wheel. The axle shaft and drive shaft should turn when you turn the wheel while the other axle shaft remains stationary.

 

[LilGreen]

I'm thinking u got some grit or water in there and then let it sit to ferment which brought out the part's weakness.

 

[jck_p]

Don't know if this is your issue but you might check out TSB Article 01-11-4 (Supercedes TSB 01-4-11, yeah the number re-arrangement is kinda weird) . It discusses halfshaft (excluder) dust seals making noise on ONLY 4x4's.

Excerpt:

"Some 4X4 vehicles may exhibit a high-pitched “squeal” or “whistle” type noise from the front of the vehicle at speeds from 16 to 64 km/h (10 to 40 mph).
This noise may be caused by the front halfshaft excluder (dust) seals (-3K070-) as they rotate against the inner front hubs. The noise may be more pronounced in cold weather conditions."

Though the TSB specifies 2000-2001 Rangers, I have the problem with my '99 and I'm looking for an easy fix. The kit available referenced in the TSB won't fit my '99 hubs because of a lip they have that won't allow the new seal over them. (New Front Halfshaft Excluder Seal YL2Z-3K070-AA and High-Temperature Wheel Bearing Grease E8TZ-19590-A). I'm currently researching to see if I can get 2000 hubs on my '99.

In my case it is definitely a "squeal" and NOT a whistle. At speeds above about 35-40mph I can't hear it, but that may be due to road and wind noise being louder than the squeal.

BTW - this only happens when I have the hubs locked into 4x4 but am not in 4x4 drive. I have manual hubs. When I have them free wheeling - no problem. When I have the hubs locked in and am 4 wheeling - no problem. It's only when I have the hubs locked in but I'm NOT in 4x4 drive (Hi or Lo) that I get the noise. It appears to be the axle shafts chaffing against the excluder seals - and that's what I believe the TSB is addressing.

Just something to check. I can TEMPORARILY silence it by using spray lube up into the joint. But that doesn't last long. If anybody has figured a more permanent easy fix, I'd love to hear it!

jack

 

[jck_p]

Here's another description I found somewhere a long while ago, perhaps even on TRS somewhere. I can't find it again though, and it's not mine. I can't take credit for some else's write-up but maybe this will help you as well...

"That noise is coming from the wheel seal. On Rangers and B4000's with pulse vaccum lock hubs there is a seal located inside of the steering knuckle behind the hub. It is also known as a vaccum daiphram. This seal mates to the axle shaft on the backside of the steering knuckle. The design leaves it partialy exposed to dirt, water, salt etc. these seals are lubricated with wheel bearing grease. If not lubricated, as they wear they start to whistle when the axleshaft turns. Eventually the seal fails and the 4x4 ceases to operate.

Remove the hub/wheel bearing assembly and the shroud on the back of the steering knuckle. push lightly on the axle shaft until you can see the sealing surface. If the seal looks bad replace it. Check the mating surface on the axleshaft for scoring. the seal in the steering knuckle is spring loaded and if it is exposed it can score the surface on the axleshaft.

Some people will tell you that this seal doesnt matter if you have changed to manual locking hubs. This is not true. Even though the hub/wheel bearing assembly is a sealed unit there is one roller bearing pressed in the hub that the axleshaft rotates in. If that goes you can damage the axleshaft and that repair isnt fun to do.

My 4x4 stopped working on my 98. I ended up replacing the hub and seal after all kinds of other parts were replaced. the cause of all the problems was that stupid seal. A $50 part at ford cost me hundreds of dollars."

jack

 

[Mike_92]

problem update!

I've got an update on my truck. I finally got around to putting it on 4 stands and running it while having someone look/listen.

We found the following: The front passenger wheel doesn't turn while in 4x4. It only moves slightly or not at all. The driver side behaves as expected. The other thing I found was it looks like the upper A-arm ball joint has been rubbing on the inside of the wheel. This is where I think the scraping is coming from, is it possible that it only rubs in 4x4?



Thanks for the ideas JCK , sorry for the really late reply. I've been very busy at work and this problem wasn't a super urgent one (it only happens with 4x4 engaged). Also I didn't get an email update when you replied (i'll have to look into this). I don't think this is my issue. I don't have the vacuum hubs and it isn't a high pitched sound I'm hearing.

Here's another description I found somewhere a long while ago, perhaps even on TRS somewhere. I can't find it again though, and it's not mine. I can't take credit for some else's write-up but maybe this will help you as well...

"That noise is coming from the wheel seal. On Rangers and B4000's with pulse vaccum lock hubs there is a seal located inside of the steering knuckle behind the hub. It is also known as a vaccum daiphram. This seal mates to the axle shaft on the backside of the steering knuckle. The design leaves it partialy exposed to dirt, water, salt etc. these seals are lubricated with wheel bearing grease. If not lubricated, as they wear they start to whistle when the axleshaft turns. Eventually the seal fails and the 4x4 ceases to operate.

Remove the hub/wheel bearing assembly and the shroud on the back of the steering knuckle. push lightly on the axle shaft until you can see the sealing surface. If the seal looks bad replace it. Check the mating surface on the axleshaft for scoring. the seal in the steering knuckle is spring loaded and if it is exposed it can score the surface on the axleshaft.

Some people will tell you that this seal doesnt matter if you have changed to manual locking hubs. This is not true. Even though the hub/wheel bearing assembly is a sealed unit there is one roller bearing pressed in the hub that the axleshaft rotates in. If that goes you can damage the axleshaft and that repair isnt fun to do.

My 4x4 stopped working on my 98. I ended up replacing the hub and seal after all kinds of other parts were replaced. the cause of all the problems was that stupid seal. A $50 part at ford cost me hundreds of dollars."

jack

 

[ab_slack]

Is the side that it is rubbing on the side that isn't turning or the one turning or both?

With both wheels in the air at the same time nothing really forces the drive shaft rotation to share. If there is significant drag on one side (such as a stuck brake) the rotation will all go to the other wheel. Put it in 2WD and hand rotate each wheel, verify shafts move with wheel, see if one has more drag than the other.

If the ball joint rubbing is the wheel not turning that would explain why the other is doing most of the turning.

As far as 4WD on/off affecting the ball joint rubbing or not...I think there is some potential there. un-driven wheel loading will be pushing to the rear. With wheels driving there will be a pulling forward. I don't know how much this affects caster angle on a good suspension but if something isn't right, it may be moving it around more than normal.

Not knowing the geometry well enough, I can't judge as to how likely it is and what it would take to cause rubbing where you say.

 

[Mike_92]

Is the side that it is rubbing on the side that isn't turning or the one turning or both?

With both wheels in the air at the same time nothing really forces the drive shaft rotation to share. If there is significant drag on one side (such as a stuck brake) the rotation will all go to the other wheel. Put it in 2WD and hand rotate each wheel, verify shafts move with wheel, see if one has more drag than the other.

If the ball joint rubbing is the wheel not turning that would explain why the other is doing most of the turning.

As far as 4WD on/off affecting the ball joint rubbing or not...I think there is some potential there. un-driven wheel loading will be pushing to the rear. With wheels driving there will be a pulling forward. I don't know how much this affects caster angle on a good suspension but if something isn't right, it may be moving it around more than normal.

Not knowing the geometry well enough, I can't judge as to how likely it is and what it would take to cause rubbing where you say.

Thanks for the response ab_slack

I was mistaken, the wheel wasn't rubbing on the ball joint. Turns out my brake dust shield had completely let go around the three little bolts holding it on. It was just loose and scraping around. I removed it and now both front wheels turn properly in 4x4. I'll have to drive it to see if the original noise is still there.

This creates a new question: are those brake shields very important? Seems they aren't the easiest things to get a hold of.