2001 QX4 vibration,Transfer case?

[lipewms]

Ok I just bought a QX4 2001 165,000 miles and there is a mild Vibration(Drone) in 2wd and a stiff vibration in 4wd (Auto) as well as 4wd "locked" all starts at about 40 mph through 65 mph. I had a mechanic check front axles,Bearings and installed new front and rear U-joints and balanced all tire, he thinks it may be the transfer case but also has a suspicion on the rear end, Now when I'm traveling through the neighborhood in 4wd "locked/fulltime" and come to a full stop and put it into 2wd there is a definite solid (heavy) clunk coming from what seems the middle of the bottom of the vehicle,I am wondering if anyone here has had this experience and if so what was the fix?
Thank you
Lipewms

[4xq]

I think it is more likely it is the front differential mounts. There are two of them that hold the differential to the frame. They have an anti-vibration flexible neoprene type mounting much like a control arm.

Failure of those is not common, but it does happen, and if they are bad it will cause vibrations / clunking. I would have him take a close look at those before you go after the transfer case.

Let us know how it works out!

[lipewms]

Thank you "4xq" I really didn't expect such a quick response, So Thanks again I will have my Guy check that out...Though I do have a couple general questions 1- Would anybody have a diagram of these differential mount locations (Maybe I could do the fix)
2- If I Google "Custom mud flaps for QX4" I get in Googles "Images" Tab actual pics of some Mud flaps that are taken from this site, Now when I click on the Picture it doesn't bring me to the actual post :-/ Anybody know of custom or after market mud flaps to install in place of the original running boards?
Thank you...and thanks again 4qx
lipewms

[4xq]

The parts you would need are 54730 and 54710m in the diagram here:
http://www.courtesyparts.com/pathfinder ... _4798.html

Please make sure those parts are the problem before you go and order new ones - I could be wrong ya know.

As to mud flaps, try starting a new thread on that. Some other people will have better ideas - I think there are one or two people here that have done that.

[mtnsrawsum]

So there is a lot of debate about what causes a vibration at certain speeds on this platform. Lots of speculation, I'll present the two best solutions that I found while dealing with the vibration form 40-60ish mph:
1) (The options we chose) Install manual locking hubs
2) keep trying driveshafts from the junkyard until one is smooth

The consensus for this problem is that it is a problem in the front driveshaft, replacing u-joints, rebalancing the driveshaft, etc. do not seem to work. The most prevalent solutions that results in a smooth car again are the two above. Hope yours turns out to be something else.

[lipewms]

Can anyone tell me, if I remove the front drive shaft on my QX4 am I able to still drive the vehicle? so I can start trying to diagnose this vibration issue on my own before I need to bring it in?

[Gregk604]

Yes that is safe to do, I just did it myself a few weeks ago for the same reason. I'm not sure if it matters but I would keep it in 2WD the whole time.

[lipewms]

Thank you Greg and did you find out what the problem was?

[Gregk604]

My vibration is coming from the rear and makes no difference whether i'm in 2wd or 4wd. I suspect I actually had multiple issues because everytime I make a fix the vibration become a little less.

-new poly bushings (upper and lower) - vibration became noticeable
-swapped spare with all four tires - no change
-wheels balanced - no change
-pulled front drive shaft and test drove without it - no change
-pulled rear drive shaft and inspected ujoints - they are fine
-pulled rear axles and checked/re-packed wheel bearings - they are fine
-checked front diff mounts - they are fine
-new rear shocks - big improvement
-fixed broken transmission mount - big improvement
-new front struts - no change to vibration

Still to do:
-run it on jack stands and see if I can isolate the vibration.
-rotate rear driveshaft 180 degrees so see if that makes a difference
-borrow new rims & tires - maybe I have a flat spot?

[rgk]

Typically the front wheels make more of a difference in terms of vibration. Have you tried rotating the wheels front-to-back?

Also, seeing as how replacing the rear shocks made a difference, have you considered replacing the front shocks?

Finally, don't forget your CV joints. If the car vibrates more under load than cruising, you can assume the issue is in the driveline. If it happens while cruising as well as under load, it's likely a wheel/tire issue.

[Mischi]

Guys,

I've been following this thread because I have the same issue. I get a vibration under the vehicle at around 50mph to around 80. How difficult is it to replace the differential bushings? I've gone through all the other options with no luck. Has anyone else solved their issue?

[4xq]

Mischi, have you pulled the front driveshaft off? You can run it in 2wd while you are trying to find the vibration.

If that doesn't work, I think it is much more likely you have a rear driveshaft problem. I would have the rear shaft balanced if you have not done that yet. You need to check the u-joints with the driveshaft off the vehicle anyway so you can move them through their full range of motion and see if they have any rough / tight spots.

Differential is a pretty unlikely source of a vibration, although not impossible.

[Gregk604]

Well my vibration saga continues but I had more time to work on it.

Replaced both ujoints in my rear drive shaft - no change.

Pulled the rear drive shaft out and zap-strapped a plastic bag over the transfer case opening to stop an fluid from coming out, put it in 4-high and took it for a quick test drive. Success - vibration gone. Off to the drive line shop tomorrow for a $105 balance.

FYI, if anyone decides to do this test, keep in mind the transfer case oil pump is powered from the rear shaft. You would want to keep your test drives very brief since you loose lubrication.

[4xq]

Given all the things you have done chasing that down, I will be looking forward to hearing how it works out!

[Gregk604]

I am ready to trade my pathfinder in. I'm pretty frustrated.

It drives nice and smooth with the drive shaft out per my earlier post.

So I got the shaft balanced, straightened, ujoints regreased, even painted by a shop the does nothing but drive shafts.

Put it back in and it vibrates as bad as before. Going to call the shop again tomorrow and see what they suggest. I'm now thinking it's gotta be the rear diff. Maybe the front pinion bearing although it feels nice and tight when i try to move it by hand?

[4xq]

Darn, you have done many troubleshooting steps and fixed a couple of things, and you still have a vibration. Usually it is one item, but every once in a while you run into something that takes two or three solutions.

Your test with the rear driveshaft off the vehicle was pretty creative - did you lose much fluid during the test?

So here are my thoughts - maybe they will help when you talk to the shop.

First, there are a few things left that could be reponsible. Vibration comes from rotation:

1.Transfer case output shaft bearing bad. Stub that rear driveshaft mounts on therefore vibrates. It's just possible that the bad rear transfer case mount you replaced was damaged by the vibrations this would cause.
2. Differential driveshaft mounting flange not true. They can measure runout on this - it is in thousandths of an inch.
3. Driveshaft U-joint mounting flange not true - could be either end.
4. Brake drum out of balance.
5. Differential.
6. axles.
Since you drove with the front driveshaft only and had no vibration, there is no reason to suspect the transfer case front output shaft bearing or front driveshaft.

Transfer case rear output shaft bearing - they will need to advise you if there is too much play in the output shaft. Could be your problem.

Differential driveshaft mounting flange runout - they measure with a dial gauge - not hard to measure. The most likely problem on the differential. Thousandths of an inch.

Driveshaft U-joint flanges not true - this is like the runout above, but on the driveshaft side. Typically you totate the driveshaft 180 degrees, remount and test. See what the shop thinks on this.

Brake drum balance - could be a problem, but I think the vibration would have remained with the driveshaft out. Probably pretty low on the list.

Differential - you are basically saying something is wrong inside the differential if the runout on the mounting flange is in spec. That is not impossible, but very unlikely unless you have had previous problems or an accident. The hypoid gears are set up to within a few thousandths of an inch tolerance, and will make noise if they get out of spec. Again, I think the vibration would have still been noticable with the driveshaft out on your test drive if this was the cause.

Axles - I think the vibration would still have been noticable with the driveshaft out.

If it were my truck, I would focus on the transfer case output shaft bearing and runout checks first.

Anyway, I hope that helps you organize your thoughts when you talk to the shop.
Gonna be a nice tight truck when you are finished !

[Gregk604]

So the Pathfinder went back to the driveline shop for a test drive and visual inspection. He described it as being about as bad as harmonics can get. He says it really seems like an angle issue but visually everything looks perfect and the ride is stock height. He says it's "mysterious". #FML

Thanks for the ideas 4xq, I shared them with the guy.

He thinks if it was a bad bearing or overly worn pinion gear, it would vibrate across all speeds and not be so specific at 90km/h. It goes in on Wednesday and they will run it to speed on the hoist and try and find the problem.

On the plus side, they didn't charge me for test drive (unlike Nissan) and they even gave me a free tape measure as a gift!

[4xq]

Well, the angle idea is interesting - I think I asked earlier if you had tightened the new control arm bushings while the truck was in the air or on the ground at ride height. Maybe they need to be loosened and retightened at ride height?

Anyway, keep us posted. It will be interesting to find out what the "hidden" problem turns out to be.

[Gregk604]

So the shop found quite a bit of play and a clicking noise where my front drive shaft enters the transfer case so they suspect a bad front output shaft bearing. They recommend I replace the transfer case with a used one from the auto wreckers. They can't explain why it drives smooth on the front shaft but not the rear but says it needs to be fixed, so might as well do that to see if that fixes the vibration as well. I had tried a drive with the front shaft removed and the vibration was still there.

Local wrecker has one for $350 which has 179km and a 6 month warranty. Anyone swapped out a ATX14A? How involved is it? I have read the FSM but would appreciate feedback from anyone who has actually done this.

[lipewms]

Hello Gregk604...just getting curious as to any news on the transfer case?
thanks
lipewms

[Gregk604]

I took it to another drive line shop for a second opinion and they are saying for sure it is a problem with the rear drive shaft. They say there is a harmonic balancer within the shaft which "dries out" and can cause the issue. I'm not sure I believe that any more than my front transfer case bearing would cause a rear vibration which disappears when I take the rear shaft off. They are putting on a used drive shaft tomorrow for $195 plus 1 hour labour and say if that doesn't fix the issue I can return the part for a refund. I'll know more tomorrow and will definitely post.

[rgk]

I too have a vibration which recently started around 48-52 mph in 2wd and 60 mph in auto.

I replaced my transfer case fluid, it was dark brown. This made it a little better, but the vibration is still there. Only about 2 quarts came out, and I was only able to put about 2.5 back in. The capacity on the ATX14 is about 3.25 quarts.

I had to add fluid until it started spilling out, drive the car around the parking lot, and return to add more fluid. I did this about five times. I will try to add more today. Hopefully if I get 3 quarts in it the vibration will cease.

I recently ran the car in 'auto' at about 70 mph for a few hours and wonder if that was OK to do.

[Gregk604]

Success!

I have been chasing this vibration issue since January. Putting another rear drive shaft completely solved the issue. I'm gonna cut the old driveshaft in half and see if there is a harmonic balancer inside.

[rgk]

Congrats!! Must feel GREAT!

I just checked my shafts and notice that the front shaft, transfer case u-joint has play, so hopefully that is my issue.

Thanks for keeping us up to date. I'm curious about the balancer myself.

Here is to not having to replace the TC!

[Gregk604]

You can safely drive the truck with the front shaft off if you want to test it out. If it's never been taken off the bolts are really tight and you can only get a 14mm wrench on them - not a socket or impact. I ended up using a big screw driver through the knuckle to lock the rotation and then had to kick the wrench to break them free.

[rgk]

I replaced my front shaft u-joints, and that did not solve the issue.

Next up I will try driving the car with the front shaft out.

I'm a little scared to pull the rear shaft, since that is what powers the fluid pump, and since I have to drive four miles to get up to vibration speed.

4xq had mentioned that the transfer case output shaft should have some play in it. How much/what kind of play? When I press up on mine it clunks and moves a bit, then drops back down into place. It's a stiff action and seems unhealthy.

Greg, did you ever get a chance to cut your old shaft in half?

[Gregk604]

Yes I cut my shaft in half, there's nothing inside as I expected. Seems the first shop just did a poor job on the balancing.

I was a little nervous driving with the rear shaft out for that exact same reason. There is an electric pump in the transfer case that activates in certain situations, one of them being in neutreal and low speed or in park. You could always drive a mile, idle in park for a minute, repeat. From the FSM:

The transfer motor drives the sub-oil pump to provide proper lubrication and oil pressure control when the
vehicle is at standstill, during low-speed operations or is being driven in reverse.

The main oil pump is operated by the driving force of the mainshaft. In other words, sufficient oil pressure
buildup does not occur when the vehicle is at standstill or during low-speed operations. While the vehicle
is being driven in reverse, the main oil pump rotates in the reverse direction. Therefore the main oil pump
does not discharge oil pressure. During any of the above vehicle operations, the transfer motor drives the
sub-oil pump to compensate for insufficient oil pressure.

[rgk]

Great, good to know. Thanks.

[4xq]

Glad to see you got it fixed! Would be nice to know what happened to the original driveshaft that caused the vibration - but sometimes it remains a mystery.

[rgk]

I removed my front shaft, took it for a drive, no vibration. So I was thinking transfer case or shaft. I could rule out front end, differential, rear shaft, etc.

I spun the transfer case output by hand and, even though I did hear some rolling noise, I could not feel any dead spots in the bearings.

I examined the shaft closely and noticed uneven wear in the greased portion, where one half meets the other.

I decided to install the shaft turned 180 degrees (shaft differential side to transfer case) and what do you know? No vibration.

My only questions are whether it's OK to drive with the shaft backwards, and whether I should expect the vibration to return.