Front Differential Noise

I’ve done a lot of searching and found lots of possibilities, but most seem to point to the needle bearing in our front differential.

However, my noise is when I’m in 4wd. Noticed it last week and thought it was the snow/ice on the road. But then heard it on more dry pavement. It doesn’t happen all the time, but seems to be getting more frequent.

It’s a grinding or roaring type of noise. Again like if you were driving on ice and it was being kicked up in your wheel well. It does NOT make this noise in 2wd. Started mostly as you started coasting, but now is doing it under load as well.

I had my shop change out the front and rear differential fluid along with the transfer case. They looked at everything and didn’t see or hear anything.

Taking it back in next Wednesday as I stopped by the shop today and gave them a ride to hear it. I think it’s coming from the front differential as it sounds like front driver side.

Anyone with any ideas what it could be?

 

Just to say, you are not supposed to be in 4hi on dry pavement.
I get some kind of noise when I’m in 4hi going 60mph+ but that’s because you’re only supposed to use it at lower speeds also from what I’ve been told.

 

Could be a couple of things, or nothing at all. Driveline noises are very difficult to diagnose since the noise easily travels through the driveline components and can sound like they are in one place when they are coming from something else entirely.

As @Mbril noted, 4wd shouldn’t really be operated on dry pavement. In a straight line for a short distance is fine; anything involving turns is bad as it binds up driveline components to the point of failure.

If the noise is only present in 4wd (assuming it isn’t the driveline binding and groaning from being operated on dry pavement) it will most likely be coming from either the transfer case, front driveshaft, front differential, front axle half shafts, or wheel bearings. I would start with inspecting those components for damage like torn boots or dry u joints, or excess wear, particularly the half shafts and driveshaft as they are easier to inspect. If there wasn’t an appreciable amount of wear material (metal) in the differential and transfer case fluids, then you stand a better chance of the issue NOT being in the transfer case or differential.

Another thing to note about 4wd vehicles is that the front drive axle can create more noise in the cabin since it is closer to the driver and mechanically connected to the wheel via knuckles, steering linkage, and and the steering wheel. This means that tire wear that was not bothersome in 2wd is now noticeable/noisy in 4wd. The alignment is setup differently for 2wd vehicles than 4wd vehicles, and rear drove vs front drive. The front tires on a 2wd rear drive vehicle are always being pushed down the road and will toe out a little when driving, so they are toe’d in a little setting the alignment. The opposite is true for front wheel drive vehicles - the wheels pull the car forward and toe in as you apply power, so they are set toe’d out initially. Part time 4wd vehicles have to split the difference somewhere between the two, so where your tires are used to being a toe’d out a hair when in 2wd, they naturally toe in when put in 4wd and have power applied to them. This can cause a faint growling that gets louder when power is applied (more power pulls the toe in more and scrubs the tires more, creating more noise). So it may well just be the tires making some noise - a bit bothersome but nothing wrong with the vehicle. This would be more pronounced on dry pavement.

 

That would explain the noise I was talking about. Thanks for sharing that info.

 

Great explanation guys! Thanks.

When I say the pavement was dry, it was those areas on the roadway that gets clear for a second or two and then back to slush or snow packed. It was always driving in a straight line while in 4hi and if I was turning it was just to enter a parking lot or turning at a light at slow speeds.

In VA they do an OK job of clearing snow, but we don’t get enough consistently for the state to invest in the equipment that much. Lots of it is done by contractors. The last time I had the truck in 4wd was two years ago when we did get a significant snowfall.

They said the fluid me from my front/rear diff and transfer case all looked good. Old, but good. So I’m hoping the noise is something simple or nothing at all.

 

Keep in mind you need to put the truck in 4WD about once a month to keep the system lubricated and functioning correctly. You don’t have to drive it around or anything just shift into 4WD and shift it back IIRC.

 

So maybe a stupid question, but let’s say I have to replace my front differential, can/should I just replace with air lockers and plan to do the same to the rear at some point. Is that possible?

 

Shop is saying it’s the transfer case. Is there anything aftermarket that’s better than OEM I should be looking at?

 

AWD SEQUOIA CASE!! AWD SEQUOIA CASE!! AWD SEQUOIA CASE!! AWD SEQUOIA CASE!!

 

So you think the AWD Sequoia case huh? lol

What all does that entail?

 

Its on my to do list. The transfer case and parts are sitting in my garage… Look up AWD conversion on the site - there are a couple of threads here but it’s pretty straightforward. Sequoia t case, sequoia 4wd computer (NOT engine ECU but body control type module) a switch, and shortening the rear driveshaft 1.25”. Otherwise should be bolt in and you have true AWD and selectable 2Hi/4hi/4Lo.

TBH, the stock transfer case is quite robust. Failures I’ve seen are rare and often from using it when not appropriate (on wet roads for example instead of slick roads). The sequoia T case is just as robust but gives you real Awd. I tell my wife to put the sequoia in 4wd center diff unlocked (which is AWD) as soon as the snow starts flying and just leave it till the snow is gone. It’s amazing.

 

I’ve got a 12” lift, so that may have something to do with it. lol

would I still need to shorten the drive shaft?

 

Ok, if I can get some help my shop is willing to do this conversion for me. I’ll go down this rabbit hole later tonight, going to birthday dinner for my daughter now, and see what all I need to buy.

If anyone is willing/able to help me identify the parts I’d be extremely thankful!

 

My shop said they could only get OEM transfer case at $3,900 and the swap is calling for 10 - 13 hours and includes removing the transmission. They said they believe they can change it out without removing the transmission which should cut hours in almost half. Does all this sound right?

I’m really interested in that Seqouia tcase swap.

 

You have a lot of confidence in my mechanical ability. lol. But yes I have plenty of room. I’m looking more at time at this point as I really don’t want to be down my only 4x4 this winter.

 

I’m trying to work the part cost down with the shop right now. I can buy new online for $2,500 from Sparks Parts and other dealers but the problem is these are in National backorder. They’re in route to the states but no eta.

I really like the idea of the Sequoia conversion but I don’t want to put in a used transfer case. Just don’t know its history and how long it will last.

I think I’m going new OEM, just a matter of how soon I can get it.

 

I think someone on here is working an atlas t case in to their build, but I don’t recall who offhand. I recall him building an adapter for the transmission and putting different yokes on the driveshafts, but beyond physically installing it how difficult is it to make it play nice with the rest of the truck? I would think Nannie’s would loose their minds any time you shift in to low or twin stick a front dig. Just curious.

 

I think I’m around 92k miles. And I’m sure running the 12” lift and 38” tires contributed.

I don’t think I did anything that I shouldn’t like switching into 4wd while moving too fast or on dry pavement. Maybe not putting it into 4wd often enough? Before two weekends ago the last time I had it in 4wd was January 2022.

if this was any season other than winter I would take the chance at a used case and even attempt the Seqouia swap, but it’s my only 4x4 and my rwd 370z wouldn’t do well in winter weather. Maybe something to look at in the future.

 

That’s right. Cruzer. I could see his black and yellow California plate avatar in my head. I think his other thread with the actual build has an atlas ii going in.

@BoysandHisToys - ya, your lift and tires might have something to do with it… Did you regear the truck as well? Stock diff ratios aren’t bad, but 38’s would certainly put more load on the T case and transmission. Is there a chance it’s the front driveshaft and not the T case - asking because I recall most bracket lifts dropping the front diff, but the stock front driveshaft is designed to run at less of an angle (it shouldn’t really matter, but a 12” lift makes a more significant change in the shorter front driveshaft angle than a 4 or 6” bracket lift).

Also, as mentioned above, did the shop give you a specific or suspected failure mode for the transfer case? Such as, the bearings are toast, or the chain is stretched, or the case is cracked… That information would help determine what steps - if any - ought to be taken to prevent the same failure from happening in the future. Replacing the transfer case will fox the problem, but might not prevent it from reoccurring. Whenever I break stuff, I try to figure out why it broke so I can avoid doing it in the future, or implement a change that will prevent it from happening again.

I’m just curious because most transfer case failures I’ve seen come form a short list of causes: 4wd on dry pavement (cracked case, toasted bearings), 4wd and excessive throttle (stretched chain), 4wd and liberally abusive behavior on various terrains (stretched or broken chain, broken case, disintegrated bushings and bearing, general madness and mayhem), or lack of lubrication/maintenance/wrong oil (usually bearings and bushings). And then there’s the GM pump rub issue which was, IMO, bad engineering not designed for high torques and towing; it showed ALL the issues depending on how long it was run.

 

Also, IMO, most sequoias led easy lives especially considering how stoutly built they are. They are basically tundras with independent rear suspensions. Ours is grocery getter 90% of the time and pulls our camp trailer a couple times a year. It sees dirt roads on occasion and hauls our bike rack and camping gear, but it really has an easily life compared to my tundra.

Most used sequoia cases will most likely be in better shape that a tundra case - a utilitarian vehicle meant to haul stuff and pull trailers. I gambled on a used case knowing the new one was hard to get. It saved me some coin but I feel the easier life of a sequoia gives me a good chance of getting a solid, used part. And I don’t generally like used parts except in certain circumstances.

 

If it’s not the transfer case, then the shop is going to have some explaining to do. And cover my repair! They suspect the chain is/has let go or the gears. Might have them open it up to see and find out why they think it happened.

I bought the truck with the lift. I’ve had it for almost 3 years and 45k miles or so. I do. I think it’s been regeared as it looks to have the factory seals.

I’m pretty easy on it and don’t really go off road. I have only used 4WD a few times when it snows.

 

Looking into this more, and thinking back to the first time I used 4wd this year, I remember the 4hi light flashing for longer than normal on the dash. Seems it took some time for it to engage. But I think I was at a stop so I counted it as that. Wonder if the actuator in the TC is what went bad.

 

So more to this story. Shop got the transfer case in and installed. Didn’t make a difference. Put original transfer case in and swapped out front diff. Still same noise. So now they’re thinking the front drive shaft or maybe a bearing somewhere.

Anyone got any ideas?!?!?

 

Would a transmission possibly make noise for some reason when in 4x4 not not in 2WD?

 

Update, finally got the Tundra back after 2 months.

Ended up being a combination of the front diff and the angle of the front drive shaft. They said the angle of the drive shaft wasn’t bad itself, but that the transfer case tilts back a little and those two angles combined created the issue. It ended up damaging the front diff.

So they replaced the front diff, made a custom front drive shaft and I think put in a new u joint at the front diff and installed a centrifugal bearing by the transfer case. I think like a double cardan drive shaft? And then with that they had to cut the crossmemeber and box that in so the centrifugal bearing didn’t rub.

They said they’d be surprised if the lift didn’t cause that noise from day 1, but this year was my first time hearing it. Of course I’ve only run 4x4 a few times in snow.