Jump to content

Rumble and Shake in 4WD?


QuasarDecimari
 Share

Recommended Posts

I have a 2001 Pathfinder, 6.5" Lift and SFD, Old Man Emu .5" Medium Duty Lift Coils, 33" mud tires, brand new CV axles, manual locking hubs, new tie rods, new struts, new ball joints, alignment in spec... and yet, faced with a new problem.

Winter finally hit us in Longmont Colorado, and we got some snow and a good sheet of ice on the roads for a day. Other than on the trails in 4LO, I haven't needed my 4WD on the roads since I did the SFD and added the bigger tires, so I have never faced this problem because there's no reason to use 4WD on dry roads. As for the issue, when I put the transfercase into 4HI, everything is smooth up until about 35 mph. Anywhere above 35 mph, the whole car (mostly front end) begins to shake violently, as if the tires were all falling off or something. No noise from the suspension or axles, they aren't binding, but it's VERY aggressive with the shaking and vibrating.

I've done some troubleshooting. I locked my front hubs and put it in 2WD, just to see if it had anything to do with the axles rotating with the wheels and so on. I could easily drive with no shaking or vibration at high speeds with the hubs locked, felt no different than when they're disengaged. One thing that was noticeable, however, was that it took quite some time for the tcase to actually disengage 4WD, it wouldn't do it parked, low speeds, high speeds, or anything, it would take over 5 minutes of the shifter being in 2WD before it would disengage finally, which is an issue I have never observed before.

On slick roads with ice and such, like what was on the roads the other morning, people really weren't going above 35 mph, and as long as I was on slick roads, I never noticed the vibrations. When I got on dry roads that parted the sheets of ice, that's when I would feel the shaking suddenly.

I understand that in 4WD, the front wheels pull while the rear push, so it can cause imbalances on dry roads. The reason this is shocking for me at the moment is because I remember when it was nearly stock, I could hit dry roads in 4WD up to 60 mph or so with no issues, but then again, it wasn't lifted and didn't have 33" tires on it...

 

Am I answering my own question here? Is it the fact that it's lifted, leveled, and has bigger tires that makes this a problem? The fact that it takes so long to shift out of 4WD makes it rather difficult to switch back and fourth from dry and slippery roads. I can handle fine with 2WD but the security of 4WD is definitely much nicer in these conditions.

 

Any advice is, as always, appreciated. I have checked most everything I can, having swapped and rebuilt a lot of this thing at this point, but I'd love some more experienced people to add in any advice.

Thanks!

Link to comment
Share on other sites

Sounds like the front ujoint to me. Pop under there and jerk on the front driveshaft.

 

If that’s not it and it starts at 35mph; what does it do at 34.5mph? Is it completely smooth until BAM and it’s rumbling like crazy? Is there any onset to the rumble? If so, try to use the onset to locate the general area before the entire vehicle begins to resonate the vibrations.

 

I’m thinking it’s that ujoint man.. I hope that’s what it is anyway.

 

 

Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

Sounds like the front ujoint to me. Pop under there and jerk on the front driveshaft.

 

If that’s not it and it starts at 35mph; what does it do at 34.5mph? Is it completely smooth until BAM and it’s rumbling like crazy? Is there any onset to the rumble? If so, try to use the onset to locate the general area before the entire vehicle begins to resonate the vibrations.

 

I’m thinking it’s that ujoint man.. I hope that’s what it is anyway.

 

 

Sent from my iPhone using Tapatalk

That would definitely make sense.

If the front hubs are engaged, then the axles rotate and the front diff rotates too, but because it isn't engaged the front driveshaft shouldn't rotate nearly as fast as it would under load. Plus, on the trails in 4LO, it doesn't rotate very fast at all, since I'm not going over 10 mph generally on the trails I go on. It's a blizzard out here right now, just hit us and I'm at work, so I'll have to check it when I can...

Link to comment
Share on other sites

Update: Got more snow last night, roads are nice and slick. I definitely notice less vibration past 35 mph up to maybe 45 (Wasn't really wanting to go that fast with the conditions this morning, however). The one biggest thing I notice is that the wheel seems to pull to the left a little, which doesn't happen in 2WD or at high speeds, and I just recently got an alignment. No grinding or slipping noises heard in the wells or cv axles, as far as I can tell when driving, so I don't believe anything's binding.

Link to comment
Share on other sites

You might jack it up and spin the front left by hand and just see if you can feel or hear any CV noise or bearing play. Might also be good to check a few fasteners, make sure the alignment shop didn't leave something loose.

 

I had some issues with the transfer in my '95 not wanting to leave 4x and a flush and fill solved it. I didn't have your rumbling issues, though. Does sound driveshaft-related to me, though that doesn't explain the pulling or, unless I'm missing something here, the slow disengagement of the transfer.

Link to comment
Share on other sites

You might jack it up and spin the front left by hand and just see if you can feel or hear any CV noise or bearing play. Might also be good to check a few fasteners, make sure the alignment shop didn't leave something loose.

 

I had some issues with the transfer in my '95 not wanting to leave 4x and a flush and fill solved it. I didn't have your rumbling issues, though. Does sound driveshaft-related to me, though that doesn't explain the pulling or, unless I'm missing something here, the slow disengagement of the transfer.

It might be purely a mental thing for the pulling, as it didn't always happen. I'll try and get it up on a lift or something soon. I JUST changed the fluid in my transfer but it wouldn't hurt to flush. I found if I roll back a couple feet in reverse, the 4WD will disengage fine. Good point on the fasteners as well, as I just had an alignment done after correcting my spacers for my SFD and installing new springs and such, so it wouldn't hurt to check torque on everything.

Thanks for all the input, I'll keep things updated!

Link to comment
Share on other sites

  • 2 weeks later...

Update: I pulled off the driveshaft, the upper u-joint was pretty worn (at the TCase), so I swapped both joints and cleaned it up and reinstalled it. Today the snow hit again, and I put it in 4WD, and its much better. 40mph and subtle vibrations, but nothing like the whole cars coming apart. Havent checked it yet on dry roads, but thankfully now I can actually depend on the 4WD without feeling like either the slick roads or my own car is going to kill me.

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

It's been a while, so I decided to update this topic with all the information I can give. Unfortunately, the issue is still here.

It's a 2001 LE 4wd Pathfinder, 3.5L Automatic with manual-transfer shift (so no dial or actuators, just gears and chains).



The problem I'm having at the moment is with my 4WD. When driving on the roads, whether wet, snowy, or dry, I get an extreme amount of vibration that shakes the entire vehicle at around 40+ mph. It does not vibrate the steering wheel, and the suspension doesn't wobble, it just feels like I'm driving on rumble-strips on a highway. There is a slight grind/binding sound coming from the driver's side, and the vehicle will constantly pull to the left a little while this is happening. Shift it into 2WD, and all is smooth as butter. The final issue with that, however, is that once it's in 4WD, it has a hell of a time getting out of it. I usually have to take a really good left-turn to get it to disengage, or put it in reverse and roll back several feet, for it to get back into 2WD. It seems to get stuck as soon as it's in 4WD, even after shoving the lever forward into 2WD.






What have I done to try and fix the issue? To begin with, I pulled the front driveshaft and replaced the U-Joints, as most would point at this for the issue. Unfortunately, even with it reinstalled the same way it came off, with brand new joints, the vibration hasn't changed in the slightest.



Another thing, I have manual locking hubs. No vibration with them unlocked, but even if they're locked and I'm in 2WD, there is no binding or vibration. This leads me to believe that, because the CV axles can rotate with the locked hubs without any issue in 2WD, even at high speeds of 75-80mph, the axles are not the problem.






To help rule out any additional items you might advise I replace, here is a list of everything I have already replaced very recently:



Ball joints, struts, springs, strut bearings, tie rod ends, inner/outer wheel bearings, wheel seals, CV axles, front-end bushings, front-driveshaft U-Joints, and all fluids.






ANY and ALL help or recommendations is GREATLY appreciated, as I'm totally stuck trying to figure out what's wrong. She still does fantastic on the trails, but that's at low speeds, and usually in 4LO. When the ice hits here, I need 4WD occasionally to get around safely.



Thanks everyone!

Link to comment
Share on other sites

I think you should check the splines inside your wheel hubs.

 

Also my wife’s MDX had a bad cv axel and it would shake the vehicle to pieces from 35-55mph. However if it was cold outside it wouldn’t shake at all. Also the moment you let off the gas the shaking would cease. So the shaking in our MDX was only under acceleration.

 

Also the next time it’s in the air take one of the wheels and turn it until the opposite wheel barely begins to turn, then turn it back until you feel resistance, then turn it forward again, this time let the opposite wheel turn a few inches. Keep going this way until you turn the wheel all the way around a few times. While your doing this pay close attention for a longer distance between when your start turning the wheel in your hands and when the opposite wheel starts turning. If you get to any “hard” spots or places where it’s harder to turn, or popping, or grinding then you may need to source a new front diff(junk yard).

 

Also I think you may be able to do this same thing to investigate the transfer case by engaging 4WD(locked), placing the transmission in neutral, and follow the same steps above and instead of looking at the opposite wheel up front, look at the rear wheels.

 

Hope you don’t find anything with the above procedure..

 

Maybe it’s worn out splines in one of those locking hubs!!! That’d be nice.

 

 

Sent from my iPhone using Tapatalk

Edited by onespiritbrain
Link to comment
Share on other sites

I feel like I've read this post a dozen times and I'm still totally baffled. But, I'll throw some ideas and other questions out there anyway...

 

You changed the t-case fluid...what fluid did you use, and presumably it got filled to the bottom of the fill hole?

How are your motor mounts, or transmission mount? Are the motor mount spacers secured properly?

Do you have a missing link? If not, entertain me by carefully inspecting the subframe just above the rear LCA bushings.

How are the bushings on the front differential brackets? Might be hard to see all of them, but give them a look.

 

I had similar thoughts about the front diff as onespiritbrain. His procedure would check for broken teeth on gears, but you probably would have found bits when changing the fluids. But, still worth checking. It's easier to just lock the hub, leave in 2wd, and lift the wheel off the ground. Spin the tire very slowly and watch the front driveshaft.

 

Could also try locking the hubs, engaging 4H, unlocking the hubs, then take it for a spin. Can also engage one hub at time (i.e., 3wd) and see if anything changes.

 

As for the t-case not disengaging, that seems independent of the shakes, and more likely to be fluid dependent. System won't know if the truck is turning left or right, just needs a moment to de-couple. You can test the disengagement sensitivity by leaving the truck in 4H when the lever is in 2H and then rotating a tire (hubs locked) or the front driveshaft (hubs unlocked) and seeing how little rotation in one direction will disengage the coupling sleeve in the t-case. Couple ways to get there, but basically, put it in 4H, drive straight forward until 4wd dash light is on, come to stop, then shift into 2H (yes, normally you wouldn't do this, but make an exception). At that point, the lever is in 2H, but truck is 4H...you can shut off the truck and return to the ON position, not-started. Don't forget there's also a switch that controls that light, so might be worth checking its signal (i.e., remove and check continuity).

  • Like 1
Link to comment
Share on other sites

I feel like I've read this post a dozen times and I'm still totally baffled. But, I'll throw some ideas and other questions out there anyway...

 

You changed the t-case fluid...what fluid did you use, and presumably it got filled to the bottom of the fill hole?

How are your motor mounts, or transmission mount? Are the motor mount spacers secured properly?

Do you have a missing link? If not, entertain me by carefully inspecting the subframe just above the rear LCA bushings.

How are the bushings on the front differential brackets? Might be hard to see all of them, but give them a look.

 

I had similar thoughts about the front diff as onespiritbrain. His procedure would check for broken teeth on gears, but you probably would have found bits when changing the fluids. But, still worth checking. It's easier to just lock the hub, leave in 2wd, and lift the wheel off the ground. Spin the tire very slowly and watch the front driveshaft.

 

Could also try locking the hubs, engaging 4H, unlocking the hubs, then take it for a spin. Can also engage one hub at time (i.e., 3wd) and see if anything changes.

 

As for the t-case not disengaging, that seems independent of the shakes, and more likely to be fluid dependent. System won't know if the truck is turning left or right, just needs a moment to de-couple. You can test the disengagement sensitivity by leaving the truck in 4H when the lever is in 2H and then rotating a tire (hubs locked) or the front driveshaft (hubs unlocked) and seeing how little rotation in one direction will disengage the coupling sleeve in the t-case. Couple ways to get there, but basically, put it in 4H, drive straight forward until 4wd dash light is on, come to stop, then shift into 2H (yes, normally you wouldn't do this, but make an exception). At that point, the lever is in 2H, but truck is 4H...you can shut off the truck and return to the ON position, not-started. Don't forget there's also a switch that controls that light, so might be worth checking its signal (i.e., remove and check continuity).

  • I did change, and flush the TCase fluid, using ATF as specified by the manufacturer recommendations. I'm a tech and parts retailer, so thankfully that's a simple thing for me.
  • ​Motor mounts and transmission mounts were replaced when the SFD was done, for security, since it's oh-so-fun to get those off. Torqued to spec according to FSM.
  • ​I do have the missing link, which was installed recently, no change before and after it was installed other than the other benefits of having it.
  • ​I just removed every subframe bolt one by one and properly installed some washers on both sides of the blocks, as the bolts were going without washers. Torqued to spec as according to Fastenal.com. No change from before, or after, other than having eliminated creaking in the subframe when turning.
  • The differential bushings are actually my next thing to check. A NORAC (Nissan Offroad Association of Colorado) member on Facebook messaged me with the solution to a similar problem, and gave me the links to the parts to order. Funny enough, when I was double checking the driveshaft U-Joints, I was putting the driveshaft back on and tightening the bolts, and as I was tightening it, the differential could move up and down quite easily. Essentially, it rotated toward the front of the vehicle. My thoughts are, that if there is that much play in those bushings, it's possible that under load, the rotation of the CVs on both sides, along with the driveshaft rotation, causes harmonics between those bushings. Then, the differential flops back and forth rapidly.
  • Thankfully, differential gears are spotless, and everything's turning great. When hubs are unlocked, and the vehicle is in 4Hi, I can drive around easily at any speeds, and I tested up to 45mph, with no vibrations. This is also nice to know since that means the driveshaft and CVs are rotating at their angles naturally, and not binding or having any balance issues.
  • I didn't think about the switch, but then again, when it's in 4WD, I do know because of the vibrations and inability to go any faster than 25mph without fear of damage. I have found, however, that it disengages when the lever is in 2WD when I take tight turns, either right or left. It just doesn't like to switch when I'm driving straight.

     

    ​As always, Everyone's advice and expertise is so greatly appreciated! I never feel like I'm tackling these problems alone.

Link to comment
Share on other sites

I think you should check the splines inside your wheel hubs.

 

Also my wife’s MDX had a bad cv axel and it would shake the vehicle to pieces from 35-55mph. However if it was cold outside it wouldn’t shake at all. Also the moment you let off the gas the shaking would cease. So the shaking in our MDX was only under acceleration.

 

Also the next time it’s in the air take one of the wheels and turn it until the opposite wheel barely begins to turn, then turn it back until you feel resistance, then turn it forward again, this time let the opposite wheel turn a few inches. Keep going this way until you turn the wheel all the way around a few times. While your doing this pay close attention for a longer distance between when your start turning the wheel in your hands and when the opposite wheel starts turning. If you get to any “hard” spots or places where it’s harder to turn, or popping, or grinding then you may need to source a new front diff(junk yard).

 

Also I think you may be able to do this same thing to investigate the transfer case by engaging 4WD(locked), placing the transmission in neutral, and follow the same steps above and instead of looking at the opposite wheel up front, look at the rear wheels.

 

Hope you don’t find anything with the above procedure..

 

Maybe it’s worn out splines in one of those locking hubs!!! That’d be nice.

 

 

Sent from my iPhone using Tapatalk

  • I pulled the hubs and cleaned the grease out, and cleaned them good. No metal shavings, and no damage to splines in the hubs. Still locking and disengaging great!
  • I decided to put the GoPro on my bumper to watch my suspension and CVs, just to check their angles and see if there's anything noticeable. Thankfully, no. I did have some small suspicion with the Driver's side CV, which was just replaced a couple months ago. I decided to warranty it and swap it just to be safe. While the subtle clunk of the CV is gone, probably just defective from the factory, the problem still exists. With the SFD, The CVs will rotate still under full flex, but of course I have to be very slow if they're maxed out. At the angles during normal driving, including 4WD, they don't exceed operating angles that they're designed to operate under.
  • Thankfully, the gears are all good. Everything rotates smooth, whether its by rotating the driveshaft, or the wheels. I describe the rest of that in the reply to Hawarish, just to not sound like a broken record.

     

    ​Would have been nice if it were the hubs or something!

    Thankfully, I was smart and stored the old drive flanges away in case I needed them later, so I threw them back on instead of the manual hubs, and the problem still exists. But, like all things, that's troubleshooting. At least it's getting narrowed down, slowly but surely!

Link to comment
Share on other sites

I am planning on placing my GoPro on the transmission crossmember to watch the differential at high FPS. My hopes are to slow down the video playback on my PC and see if I can see the differential moving. I'll likely try that before work tomorrow.

Link to comment
Share on other sites

The differential bushings are actually my next thing to check. A NORAC (Nissan Offroad Association of Colorado) member on Facebook messaged me with the solution to a similar problem, and gave me the links to the parts to order. Funny enough, when I was double checking the driveshaft U-Joints, I was putting the driveshaft back on and tightening the bolts, and as I was tightening it, the differential could move up and down quite easily. Essentially, it rotated toward the front of the vehicle. My thoughts are, that if there is that much play in those bushings, it's possible that under load, the rotation of the CVs on both sides, along with the driveshaft rotation, causes harmonics between those bushings. Then, the differential flops back and forth rapidly.

 

Thanks for addressing all the questions! This seems to make the most sense at this point, and it's the "under load" part that's key, when small vibrations are locked to the rest of the truck.

Link to comment
Share on other sites

Damn. Mine felt soft a while ago when I did my Lokka but didnt have a frame of reference for how they should feel. I have my front end apart now so Im going to hit these. Are you replacing with OEM spec or is there a polyurethane option for the diff mounts?

 

Link to comment
Share on other sites

Damn. Mine felt soft a while ago when I did my Lokka but didnt have a frame of reference for how they should feel. I have my front end apart now so Im going to hit these. Are you replacing with OEM spec or is there a polyurethane option for the diff mounts?

Quite honestly, I can't find them anywhere in-store near me, but I found them on Amazon for $20 a bushing. I searched all over online, can't find polyurethane at all, which would have been awesome.

 

Here's the link to the amazon ones, but if anyone can find better ones, please let me know!

https://www.amazon.com/547300W002-Bushing-Differential-Nissan-Febest/dp/B00DMA7WJM

Link to comment
Share on other sites

Nissan sells them as a unit, with bushings installed for 75 a pop, and there is a driver/passenger side. I bet there is a poly alternative. I'll yank mine and pop the bushings out. If We can get the measurements im sure Energy Suspension or another vendor has something that will work.

 

NnWkCOk.png

 

B4PW7Fc.png

Link to comment
Share on other sites

Wow! Yeah, that's not supposed to do that. Smart deal with the Go-pro. Years ago I made a ghetto mount for a Flip camera that bolted on where my tow hook was to watch the front end and see if I could spot what was loose in my suspension, but it didn't give me a smoking gun like that.

Link to comment
Share on other sites

Nissan sells them as a unit, with bushings installed for 75 a pop, and there is a driver/passenger side. I bet there is a poly alternative. I'll yank mine and pop the bushings out. If We can get the measurements im sure Energy Suspension or another vendor has something that will work.

If I can just pop the bushings out and replace them, I don't mind saving a few dollars instead of getting the whole mounts. The mounts are fine, just need new bushings is all. But the ply alternatives would be awesome, let us know what you find! Probably a good thing going here anyways, because I'm sure having better bushings would make things just that more secure on tougher trails.

Link to comment
Share on other sites

Wow! Yeah, that's not supposed to do that. Smart deal with the Go-pro. Years ago I made a ghetto mount for a Flip camera that bolted on where my tow hook was to watch the front end and see if I could spot what was loose in my suspension, but it didn't give me a smoking gun like that.

I got lucky! Thankfully the GoPro has high frame rate options to really track things like that down. I always tie a string to the GoPro just to be safe in case it comes off of wherever it's mounted. The Control Arm mount areas on the subframe had just enough of a flat edge that I could clip the camera onto it and get a great view of the diff. The little guy's saved me in more situations than I know.

Link to comment
Share on other sites

That’s wild! Very good detective work! I am thoroughly impressed. This is great stuff. Great info for the community man, good job!

 

I actually had no idea that piece was secured by bushings and I was all up in there for my engine. I stripped the scrap out of one of the bolts that secures the diff to that piece. It’s nice knowing that whole piece can be replaced!!! Thank you!

 

 

Sent from my iPhone using Tapatalk

Edited by onespiritbrain
  • Like 1
Link to comment
Share on other sites

If I can just pop the bushings out and replace them, I don't mind saving a few dollars instead of getting the whole mounts. The mounts are fine, just need new bushings is all. But the ply alternatives would be awesome, let us know what you find! Probably a good thing going here anyways, because I'm sure having better bushings would make things just that more secure on tougher trails.

I agree with you. Was just sharing the nissan OEM for reference.

 

Im in the middle of replacing a just about all my suspension bushings with poly and would love to tackle this as well since I got everything apart. Should have it out tonight and be able to come back with nubers for a possible poly replacement.

  • Like 3
Link to comment
Share on other sites

I actually had no idea that piece was secured by bushings and I was all up in there for my engine. I stripped the scrap out of one of the bolts that secures the diff to that piece. It’s nice knowing that whole piece can be replaced!!! Thank you!

 

 

Sent from my iPhone using Tapatalk

Me either, I always thought it just bolted to the subframe. Guess it makes sense, since something has to balance the harmonics of the cvs and driveshaft

 

 

Sent from my iPhone using Tapatalk

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...