Draftshaft or Dif Grind Noise (97' FZJ80)

Joined
May 20, 2021
Messages
75
Location
MN
Visit site
Dropped the cruiser off at the dealership to help diagnose some grinding noise that has recently developed.

The dealer looked at it for a couple of hours and came back to me saying they couldn't pin down what was causing the noise. Obviously, this is pretty frustrating because chasing down noise/vibration is usually something they're good at doing. Drained and replaced front and rear diff fluid. Greased u-joints, all were within spec.

Symptoms:
Grinding noise at higher speeds ( > 45 MPH)
More noticeable while not under load or going downhill
Still mildly present while under load
Moves in and out of gears fine without any issue

It sounds like it's coming from the center/rear-center.

Here are a couple of videos of the noise. Noticeable starting at 26 seconds and again at 45 seconds:

Undercarriage video while at the dealer (Sorry for the poor quality video, just shot it really quick):

Any ideas? I'd love to take it to a shop that has experience with these but there's really not one in the area. LC4WD isn't accepting new work for the time being.
 
Joined
Nov 26, 2015
Messages
200
Location
San Diego, California
Visit site
I had some thoughts after the first video but the 2nd one completely blew them away.

You didn't mention the transfer case fluid, have you checked that for shavings? I kinda feel like something may have gone very wrong in there.

Also, at the dealership did their mechanic listen to the TC and the diff with a stethoscope while on the lift?
 
Last edited:
Joined
May 20, 2021
Messages
75
Location
MN
Visit site
I had some thoughts after the first video but the 2nd one completely blew them away.

You didn't mention the transfer case fluid, have you checked that for shavings? I kinda feel like something may have gone very wrong in there.

Also, at the dealership did their mechanic listen to the TC and the diff with a stethoscope while on the lift?
I wasn’t with them the whole time so I’m not 100% percent sure what method they were using to pinpoint the noise. I did ask about the transfer case and if I recall correctly he said it didn’t sound like it was coming from there.

I can call them up today to verify what was done specifically in the transfer case area. If they didn’t do the fluid I’ll do that and check for metal shavings and report back.
 

enox

GOLD Star
Joined
Mar 12, 2018
Messages
954
Location
Los Angeles, CA
Visit site
Was there anything that happened contributing to this noise? Were you off road and then it started? has it always been there but now getting louder? Does it go away if you lock the center diff?
 
Joined
May 20, 2021
Messages
75
Location
MN
Visit site
Was there anything that happened contributing to this noise? Were you off road and then it started? has it always been there but now getting louder? Does it go away if you lock the center diff?
There has not been one contributing event from what I can recall. Not driven off road. Shortly after purchasing the truck there was an issue with the truck fluttering between overdrive engaged/disengaged. I eventually tore down the center console and found that the wires on the overdrive switch had been pinched/frayed so I ordered a new O/D switch and replaced it. I did put a couple hundred miles on it while the overdrive was acting up as part of a move, but I wouldn't think that this truck would be hurt by that. It's possible that could have contributed to the issue though.

It doesn't appear to be getting louder or worse over time. Just mostly noticeable at higher speeds as noted above.

For testing the center diff, are there any concerns with driving (straight line) at the speeds required to test that? I'd have to get it over 50MPH to really feel out if locking that out has any impact on the noise.
 

enox

GOLD Star
Joined
Mar 12, 2018
Messages
954
Location
Los Angeles, CA
Visit site
Well I was just wondering since it does seem to be making a lot of noise, my original thought was worn u-joint or worn out slip yolk on the DS, or even ring and pinion wear, but your second video leaves me to think different.

to me it sounds like its in the t-case, i too would be curious what that fluid looks like inside along with if there are any shavings as @Woofythewolf & @Kernal mentioned.

Id check those drain plug magnets, check that fluid and then from there open the T-case, front case and rear case to have an inspection and check in there. You may not have to split the cases and check inside, but for me, id want to find that noise no matter what and not be stranded somewhere with a worse off repair..
 
Joined
Dec 4, 2020
Messages
103
Location
South Texas
Visit site
it seems to correlate from the first vijao with the drop in rpm, so your overdrive gear might have an issue?.
When you greased the U joints, I am sure you did the slip yoke(?) on the driveshaft itself?
 
Joined
May 20, 2021
Messages
75
Location
MN
Visit site
Well I was just wondering since it does seem to be making a lot of noise, my original thought was worn u-joint or worn out slip yolk on the DS, or even ring and pinion wear, but your second video leaves me to think different.

to me it sounds like its in the t-case, i too would be curious what that fluid looks like inside along with if there are any shavings as @Woofythewolf & @Kernal mentioned.

Id check those drain plug magnets, check that fluid and then from there open the T-case, front case and rear case to have an inspection and check in there. You may not have to split the cases and check inside, but for me, id want to find that noise no matter what and not be stranded somewhere with a worse off repair..
My first thoughts were similar to yours. Really thought it was a u-joint gone bad. I'll see what I can do to look at the transfer case fluid and check for shavings. I don't intend on taking it anywhere soon but yes will 100% want this resolved before I do.

it seems to correlate from the first vijao with the drop in rpm, so your overdrive gear might have an issue?.
When you greased the U joints, I am sure you did the slip yoke(?) on the driveshaft itself?

I imagine if I wanted to eliminate the overdrive gear I could just disable overdrive and try to recreate the noise with that disengaged? As for the grease; I had the dealer do it since they were under there and were giving me nothing on the diag. I can't say for sure if they did them but I can try to give that a go and see how that works. I did stumble upon this video talking about driveshaft noise and thudding which I could look into:
 
Joined
Nov 26, 2015
Messages
200
Location
San Diego, California
Visit site
My first thoughts were similar to yours. Really thought it was a u-joint gone bad. I'll see what I can do to look at the transfer case fluid and check for shavings. I don't intend on taking it anywhere soon but yes will 100% want this resolved before I do.



I imagine if I wanted to eliminate the overdrive gear I could just disable overdrive and try to recreate the noise with that disengaged? As for the grease; I had the dealer do it since they were under there and were giving me nothing on the diag. I can't say for sure if they did them but I can try to give that a go and see how that works. I did stumble upon this video talking about driveshaft noise and thudding which I could look into:

I like the idea of an ultra-thick lube to hide the clunk, maybe a moly fortified NLGI number 3 or 4 is more easily available. Mine clunks pretty bad, and has a lot of play in the slip yoke, but because it's an involute spline it self centers whenever there is the tiniest bit of load so it's not an issue. It's as smooth as can be.
edit: NLGI #4 is nearly unobtanium and most greases aren't even available as a 3 or 4.

On another note, "he says "the rear driveshaft is actually supposed to be out of phase" even though his marking shows it as in-phase and when he installs it, he puts it in phase. I think he's a bit confused.
 
Last edited:
Joined
May 20, 2021
Messages
75
Location
MN
Visit site
I like the idea of an ultra-thick lube to hide the clunk, maybe a moly fortified NLGI number 3 or 4 is more easily available. Mine clunks pretty bad, and has a lot of play in the slip yoke, but because it's an involute spline it self centers whenever there is the tiniest bit of load so it's not an issue. It's as smooth as can be.
edit: NLGI #4 is nearly unobtanium and most greases aren't even available as a 3 or 4.

On another note, "he says "the rear driveshaft is actually supposed to be out of phase" even though his marking shows it as in-phase and when he installs it, he puts it in phase. I think he's a bit confused.
He actually addresses that in the comments on that video if you scroll there.

That said, I thought I've since read in various posts here that Toyota changed the guidance that they should be in phase? I'm more leaning towards my issue being in the TC honestly, which isn't ideal. Will see once I do some more work to isolate it.
 
Joined
Nov 26, 2015
Messages
200
Location
San Diego, California
Visit site
I just watched it on here, ih8mud makes it so convenient so it's hard to not take advantage of it.

Knowing what I know about the sinusoidal oscillations caused by U-joints, there are some rare cases where you want to take advantage of them, but a driveshaft is not one of them (and never will in the reasonable future, because the moment of inertia of a driveshaft will always be less than the moment of inertia of its powerplant, and you want to minimize the oscillations of the item with the greatest moment of inertia).

Cases where it COULD be useful:
Variable rate steering for a gokart or some other device where you only turn the wheel 90 degrees each way, but want increased or decreased sensitivity at the center or extremes of its motion.
variable angular displacement of a cam throughout its travel (such as the hyundai CVVD system, but this would do the whole cam so it's not that useful except on single cylinder engines), where bulk isn't a major concern. In this case you would do 1 ujoint and 1 CV joint such as a CV joint or a geared connection at the other end.

Perhaps you read the thread about Toyota changing the clocking of the bushings in the front radius arms?
 
Joined
May 20, 2021
Messages
75
Location
MN
Visit site
I just watched it on here, ih8mud makes it so convenient so it's hard to not take advantage of it.

Knowing what I know about the sinusoidal oscillations caused by U-joints, there are some rare cases where you want to take advantage of them, but a driveshaft is not one of them (and never will in the reasonable future, because the moment of inertia of a driveshaft will always be less than the moment of inertia of its powerplant, and you want to minimize the oscillations of the item with the greatest moment of inertia).

Cases where it COULD be useful:
Variable rate steering for a gokart or some other device where you only turn the wheel 90 degrees each way, but want increased or decreased sensitivity at the center or extremes of its motion.
variable angular displacement of a cam throughout its travel (such as the hyundai CVVD system, but this would do the whole cam so it's not that useful except on single cylinder engines), where bulk isn't a major concern. In this case you would do 1 ujoint and 1 CV joint such as a CV joint or a geared connection at the other end.

Perhaps you read the thread about Toyota changing the clocking of the bushings in the front radius arms?
I think this is the post that was on my mind when I mentioned it:
 
Joined
Nov 26, 2015
Messages
200
Location
San Diego, California
Visit site
It looks like the newest version is installing them out of phase, and Toyota has inverted terminology.

DylanICON brought up a good point, in that if the flange angles don't match even when completely stock then maybe this is something to alleviate problems from it?
It seems like rather poor engineering to do that...

Maybe inverting them spreads out the displacements to reduce the maximum amplitude in the above scenario?

I know my mom had a LOT of issues with blowouts when mine was brand new, ended up going to a different tire brand than the factory Michelins to fix it after a couple of them, and that fixed it. Maybe that's why they made this change to putting it out of phase?

Edit:
Mine is stock height, maybe in the next week or so I will borrow a magnetic angle finder and see what my flanges are at.
Also, mine are in phase (real in phase, not Toyota's in phase), always have been, and the first set of u-joints lasted well over 300k miles.
 
Last edited:

Box Rocket

SILVER Star
Joined
Jan 2, 2003
Messages
4,990
Location
Syracuse, Utah
Visit site
This is a common noise on many 80's. There are lots of threads that describe the noise and vibration exactly like yours. I've been chasing the noise in my own 80 for 5 years now. Here's a list of possible causes of the noise from the research I've done.
-Dry front Spindle bushing
-worn driveshaft ujoints
-worn driveshaft slipyoke/splines
-improper driveshaft phasing
-driveshaft flanges not parallel
-ujoint angles too steep
-worn transfercase output bearing

I have checked and confirmed everything on that list is in good shape and working properly with the exception of the t-case output bearing. That's the last thing I have to check and address. I think the output bearing could be the common cause for many.
 
Joined
May 20, 2021
Messages
75
Location
MN
Visit site
This is a common noise on many 80's. There are lots of threads that describe the noise and vibration exactly like yours. I've been chasing the noise in my own 80 for 5 years now. Here's a list of possible causes of the noise from the research I've done.
-Dry front Spindle bushing
-worn driveshaft ujoints
-worn driveshaft slipyoke/splines
-improper driveshaft phasing
-driveshaft flanges not parallel
-ujoint angles too steep
-worn transfercase output bearing

I have checked and confirmed everything on that list is in good shape and working properly with the exception of the t-case output bearing. That's the last thing I have to check and address. I think the output bearing could be the common cause for many.
Thanks for the exhaustive list to run through here. The truck has been lifted for years and run on these tires for a few years as well, so I think angles may be the least likely. Since its more recent, I feel like it could be one of the items here related to wear.

Plan is to take a closer look at the t-case this weekend. If I don't see much else I'm going to have a shop start pulling parts of the shaft out to isolate it at least.
 
Joined
Jul 7, 2020
Messages
9
Location
Minnesota
Visit site
I've been trying to tackle the same problem for a couple months now. I also had some issues with my overdrive wires being frayed... However my first thoughts were to correct the pinion angle. @Box Rocket has some good points. This makes me think a double cardan shaft might be worth looking into.
 

Pierce

SILVER Star
Joined
Jun 10, 2016
Messages
285
Location
San Antonio
Visit site
Been chasing the same noise under the same circumstances for 2 years now. All rear axle bearings and u-joints have been replaced with little improvement. Had the rear drive shaft rebuilt and balanced at the same time. I’m fearing that I’ll need a transfer case rebuild. Also wondering if the driveshaft shop did quality work after learning that one of the u-joints was installed backwards (ungreasable) and they blamed it on me.

Looking forward to seeing your results.
 

Squash

SILVER Star
Joined
Dec 8, 2006
Messages
1,599
Location
Sudbury, Ont. CA
Visit site
Do yourselves a favour and pull the spline zerk for rear D/S. Spray some brake cleaner into the fitting and test drive. You could also have a chbby friend bounce the body while you watch the spline for movement while rocking the rear end.
If there is movement then replace the zerk and lightly regrease.

When greasing splines watch for movement or grease ejection from zerk this is not good. Movement will increase d/s length thus applying force between the T/C and diff...force equals growl!!!
An overgreased spline will act like a hydraulic ram preventing your driveshaft from floating.
Those of you who run tracked equipment will be familiar with how grease is used to tighten tracks.
 

Users who are viewing this thread

Top Bottom