[Walker]

Not sure which forum to post this under so I hope uncategorized is okay?

This issue has been going on for longer than I've owned this van, it's been doing it ever since I bought it over six months ago. When making sharp turns, there is a loud clunking/clicking noise that sounds like it's coming from the front axle area or right beneath the seats. I took a video of it and posted it to youtube to show you:

The video only shows me making left turns, but it happens when turning both directions. From inside the cab it sounds more like a loud thud or clunk than a click. It shakes/lurches the whole van.
From what research I've done, it seems like it could be: cv joints, tie rods, power steering pump (I think mine is going bad for other reasons but this could be related), front differential problem, or the transfer case. Possibly something else. I took a thorough look under the van with a flashlight and nothing seems out of place or broken... other than the leaky rear main seal spraying oil all over everything.

If anyone else has had the same or similar issue, what was the fix? What can I do to pinpoint the problem?

 

[vangogo]

I think I saw your lower A-arm moving in the vid...how do those bushing look?

 

[Mmusicman]

I once had clunking noise that sounded exactly like that in tight turns.
(this was a LONG time ago before I started really working on it)
While yours's could be anything... here's what mine turned out to be.. lol

Ball-joints, shocks, idlers, cv-axles, control arm bushings.. etc etc
You clearly need to do a full inspection (with wheels in air)

 

[Walker]

I think I saw your lower A-arm moving in the vid...how do those bushing look?

is the a-arm bushing is the one kind of below the cv joint bushing?

 

[Walker]

update:

I drove the van down the street to Auto Zone today. Just after pulling into the parking lot, as I was turning, there was an alarming BOOM noise. It was violent, I thought something seriously blew up for a second. Jumped out to take a look but still nothing had come loose or looked broken... Now the original noise is much worse and happens almost all the time when driving. The van is definitely not drive-able in this condition, although I was able to limp it home after this incident.

If you watch closely it almost looks like the drive shaft is struggling? With what happened earlier at Auto Zone in mind, I'm starting to believe the culprit may be the front transfer case. In the second part of the video, the front wheels are off the ground. Even when turning the wheels all the way in either direction there is no noise or grinding of any kind, very smooth turning.

If it is the transfer case then this might end up being a parts van... with all the other existing issues it has, I'm not sure how worth it it would be to fix. The engine is about the only thing I have faith in at the moment.

 

[gwd]

I my AWD van I had booming noise too last week.
Every rotation of wheel on the road made a bang.
Lifting both wheels off the ground did not make any noise at all when rotating the wheels by hand, even when turning the steering to both ends.
I decided I have to try to take out the half-shaft, on the side that made the noise, to inspect.
It turned out to be the axle half shaft from passenger side the universal were coming out of the socket on axle end even though the rubber boots were not broken.
It came apart once I pulled from the differential case shaft.
Placed new one in. Will see how it goes in a day or two.

 

[Don1806]

I just limped mine home with similar noises/symptoms that started today. Unfortunately I'm not in a position to do any work on this myself, so it will go to our trusted mechanic. Not the cheapest solution but they won't gouge me and they stand behind their work. This will be the second time for these in 24 years and about 176,000 miles if that is the issue.

 

[MechBob]

Sounds like a CV problem, but front diff is a possibility.

 

[erich.giles]

Mine is a 4x4 conversion with the s10 n233c kit, not AWD anymore, but was making the exact same sound this week if I was shifted into 4x4 and either making a near full lock turn or if the rear tires were on loose ground/ starting to slip and the front needed to engage. It didn’t make any noise otherwise. I just pulled my transfer case and it is the obvious culprit, I can make the same clunking sound by turning the front driveshaft output shaft on it by hand.

How I determined it was most likely the t case before actually pulling it out in case it helps you:

Jack front driver side wheel off ground (leave passenger on ground) and in park spin by hand. Is the front drive shaft spinning with it and is it clunking? If so have a friend spin it while you are under so you can tell where the sound is coming from. Mine seemed to be loudest at transfer case but was still hard to tell.

Then I tried this. Little dangerous so be very careful. Used a jack with wheels (not jack stands) under the rear differential and ensured both rear tires were well off the ground. Put it in drive with my foot on brake and camera placed under van so it could see drive shaft and t case. Took slight pressure off brake with foot still on it to let rear tires start to spin. I figured if the t case was working the front wheels would take over and it might roll me forward a bit and hopefully rear jack would roll with me. Turned out my t case was shot and instead of pulling forward at all it just started clanging like crazy and made me 90% sure I needed to pull it. Just telling you what I did not saying you should do the same or accepting any liability if you decide to try the same.

 

[Mmusicman]

I've done the "rear wheels jacked" with my AWD to see if it would "pull" me.. which mine did. I only went about a foot forward.. I didn't want to press my luck too much with floor jack which did roll along... lol. It should be noted it kind of jerks into action, as the AWD becomes engaged (seeing the rear wheels up in air spinning)

This obviously should NOT be attempted by MOST people, unless you CLEARLY understand what you are doing, and the risks. With proper care however, it's pretty simple.

Spinning the one front wheel by hand (with opposite side on ground) will spin front drive-shaft and might certainly be enough to reveal a possible issue. Great suggestion.

Eventually (even though my AWD case worked fine).. I switched it out to the manual 233C.

 

[Walker]

Mine is a 4x4 conversion with the s10 n233c kit, not AWD anymore, but was making the exact same sound this week if I was shifted into 4x4 and either making a near full lock turn or if the rear tires were on loose ground/ starting to slip and the front needed to engage. It didn’t make any noise otherwise. I just pulled my transfer case and it is the obvious culprit, I can make the same clunking sound by turning the front driveshaft output shaft on it by hand.

How I determined it was most likely the t case before actually pulling it out in case it helps you:

Jack front driver side wheel off ground (leave passenger on ground) and in park spin by hand. Is the front drive shaft spinning with it and is it clunking? If so have a friend spin it while you are under so you can tell where the sound is coming from. Mine seemed to be loudest at transfer case but was still hard to tell.

Then I tried this. Little dangerous so be very careful. Used a jack with wheels (not jack stands) under the rear differential and ensured both rear tires were well off the ground. Put it in drive with my foot on brake and camera placed under van so it could see drive shaft and t case. Took slight pressure off brake with foot still on it to let rear tires start to spin. I figured if the t case was working the front wheels would take over and it might roll me forward a bit and hopefully rear jack would roll with me. Turned out my t case was shot and instead of pulling forward at all it just started clanging like crazy and made me 90% sure I needed to pull it. Just telling you what I did not saying you should do the same or accepting any liability if you decide to try the same.

Thanks for the suggestions, I like your idea of getting the drivers side wheel of the ground and giving it a spin to see what happens. I think I'll try that soon. Jacking up the rear diff and taking the whole van for a drive sounds a bit too risky to me haha. Sounds like a good way to get to the bottom of it however I'm already like 90% sure the problem is the transfer case...

I read on different post that you aren't supposed to take the front drive shaft out and drive around like that because it's bad for the transfer case. But if my t case is already toast would it really matter if I did that?

 

[erich.giles]

Hmmm, I’m no expert on the awd t case so don’t want to steer you the wrong way, sure there are others on here that may know better. Have you tried opening the t case oil fill plug, sticking you finger in and seeing if it has the correct blue all trac fluid in it? I will say that I know not having that correct blue fluid in and having like atf instead will screw things up, but sometimes you can correct it by draining the wrong fluid, putting all trac fluid in for 100 miles then changing it again to new all trac fluid.

I don’t know if the awd case is chain or gear driven. The 4x4 np233c case is chain driven and when I took mine apart I noticed that my chain that engages the front driveshaft was so loose it was starting to wear a hole in the actual case and was about to start dumping all the oil out if I let it keep going even though I was just driving it in 2wd and the front shaft shouldn’t have been engaging.

I was a little intimidated before pulling mine out, but if you do end up needing to replace it you just need to take the 4 bolts off the rear drive shaft u joint and slide that out of the transfer case and then it is only 5 bolts that hold the transfer case to the transmission, 1 is hidden behind the tranny mount. And some wires. I bet you could pick one up at a junk yard/ pick and pull cheap enough, they are $215 near me if you can find an awd to pull one from. If you go on the Journeys Off Road how to page they have a good write up on how to pull it.

 

[erich.giles]

Scratch the stuff about all trac if you have a ‘91. Was reading this article Astro-Safari-Info - AWD Transfer Cases

And it sounds like yours was supposed to use ATF and did have a chain driven t case

 

[Translations]

like others have said I would check the fluid on the AWD transfer case. I had a clicking as well only in sharp turns and I ended up putting the most current recommended fluid in and the clicking went away immediately.