thatcabledude
GOLD Star
That is EXACTY what mine sounds like. Though unless I’m “floating” the throttle in a certain spot, it goes away after about 1 second. It happens when the drivetrain unloads.
3 Linked 80 is clattering....? (1 Viewer)
- Thread starter petwhookie
- Start date
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That is EXACTY what mine sounds like. Though unless I’m “floating” the throttle in a certain spot, it goes away after about 1 second. It happens when the drivetrain unloads.
I know you checked already but I had the same symptoms when my rear u joints were going out on the way to moab. It’s SO LOUD.
Side note, idk if anybody’s asked, does the tone increase and decrease depending on the speed? And have you tried turning off the car when it’s making the noise?
Side note, idk if anybody’s asked, does the tone increase and decrease depending on the speed? And have you tried turning off the car when it’s making the noise?
What he meant to measure is the distance from the floor up to each track bar bolt on a specific bar then calculate the difference. That number represents lift height.The rear panhard is 41.5”
Both driveshafts? Great tip
I laid under the truck for about 20 minutes and poked around. Per 4wu Brian, it might be the transfer case armor. Couldn’t find much. Argh
Your post reads like what you measured was the distance between bolts along the length of the track bar. @petwhookie
azngarage
SILVER Star
If you in the 2wd and the front hub is unlocked, the only the thing that should be moving or spinning is the wheel hubs. I would take the font hubs out and inspect the wheel bearings
- Thread starter
- #26
I laid under the truck again and went thru a few of everyone's suggestions:
Drove around. It still clatters which is throttle variable. It feel like it has to be drivetrain related. I think I might of found one possible issue... the sliders U-bolt was cut and found the top part of it barely welded on. I am wondering when I off throttle it vibrates this.
- Measured height of the rear
- Rear Panhard bolt, floor to bolt = 22" and 26"
- Axle to fender in rear = 25.75" (w/o oem fenders)
- Found one loose steering jam nut -- tightened up
- T-case armor hardware was loose -- tightened up
- Checked transmission link -- it's loose
Drove around. It still clatters which is throttle variable. It feel like it has to be drivetrain related. I think I might of found one possible issue... the sliders U-bolt was cut and found the top part of it barely welded on. I am wondering when I off throttle it vibrates this.
I have this same “grinding” or “grrr” sound when I let off the throttle around 50-55mph. It only last for a second or two. Feathering the throttle helps reduce or eliminate the sound. My initial thought is u joint or exhaust related.
When I first bought the truck 20 years ago it had a similar sound after the two hour drive home. I greased all the zirks and that fixed it then.
When I first bought the truck 20 years ago it had a similar sound after the two hour drive home. I greased all the zirks and that fixed it then.
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Why wouldn’t they have just welded the sliders on? That looks pretty janky to me. 
Cheers
Cheers
Delta VS
Supporting Vendor
4” difference between panhard bolts equates to about 3” of lift according to empirical data. Most stock rigs seem to have ~1” (average) difference in the back.
Sounds like mine did after the 3 link. Went through the same stuff...growl without front DL growl without rear DL checking everything. It was the rear driveline angle. I made new rear links and set more upward pinion angle to run broken back. I assume what is happening is that under acceleration and normal cruise your pinion is being pushed upward in an attempt to rotate backwards. This puts your driveline into a broken back configuration and under deceleration your pinion dives back down throwing it into binding angle. I know it sounds counter intuitive that the growl remains with the rear shaft removed. I have a tundra DC on my front driveline and it still made the growl with the rear removed. I don't know, maybe investigate it.
A side note, many places will tell you that you can't use a tundra DC on your front because it is friction welded and not a standard pilot end. My driveline guy though the same thing and after dissecting the tundra rear DC found it had enough material to make a pilot. Just nice confirmed info.
A side note, many places will tell you that you can't use a tundra DC on your front because it is friction welded and not a standard pilot end. My driveline guy though the same thing and after dissecting the tundra rear DC found it had enough material to make a pilot. Just nice confirmed info.
- Thread starter
- #31
Welp another weekend looking into this and not much progress.
Drove around the truck with the pinion angle adjustment via "broken back" method and it still clattered. I am not super familiar with this so please feel free to chime in.
I believe its better to have your TC & pinion angle be parallel?
- Upon further inspection, the other side of the U-bolt is welded on so it seems like fairly tight on there. I removed the nuts to the U-bolt picture above to remove the tension from the sliders. Drove around ... clatter. Put the hardware back on... clatter
- A few others were talking about rear pinion angle so I played around with it today
- Lengthen my upper links in the rear.
- 7 turns adding 3 degrees of pinion angle pointed towards the T-case
- Data points:
- Original measurements
- Driveshaft angle = 14.2*
- Rear diff pinion angle = 87* (or 3*)
- Pinion angle = 11.2*
- After adjusting measurements
- Driveshaft angle = 13.6*
- Rear diff pinion angle = 84.7* (or 5.3*)
- Pinion angle = 8.3* (7.6* to 8.6* variance)
- --> overall adding 3* pointing up to TC
- Measured TC flange zeroed; then measured pinion angle (2* to 3* from parallel)
- for reference, I used this measuring method
- Data points:
Drove around the truck with the pinion angle adjustment via "broken back" method and it still clattered. I am not super familiar with this so please feel free to chime in.
I believe its better to have your TC & pinion angle be parallel?
- Thread starter
- #32
Did a few more test and to simplfy my above posted. I played around with my rear pinion angle without the front driveshaft. I believe this noise isn't due to pinion angle.
Measured TC flange, zeroed in. Then measured rear pinion flange angle:
I think I need to bring this truck back to my fab guys...
Measured TC flange, zeroed in. Then measured rear pinion flange angle:
- Parallel with about 0.5* degree variance .... clatter
- Pointed rear pinion angle up 3*..... clatter
- Pointed rear pinion angle up 1.5*.... clatter
- Pointed rear pinion angle down 1.5*... clatter
I think I need to bring this truck back to my fab guys...
Will, I know that you said that the rear drive shaft is new, but have you checked the slip joint ?
I was having the same noise and that's what it ended up being.
Good luck
I was having the same noise and that's what it ended up being.
Good luck
- Thread starter
- #34
I've been playing around with the pinion angle more in the rear. Adjusted a few degrees down and I notice the clatter changes.
With about 1.5* to 2.5* degrees, the clatter noise has calmed down more but its still there at half throttle. The off throttle noise is gone which is a plus.
At first, I thought I found my issue. The rear sway bar rubbing against the lower control arm bolt. I moved it slightly and drove it around... clatter. But, I think I need to remove my sway bar to fully confirm this. If you can see by the picture, it looks like it was vibrating off it quiet a bit. I really hop its this.... I'll keep you guys posted.
I need to bust out my old GoPro 4 next..
With about 1.5* to 2.5* degrees, the clatter noise has calmed down more but its still there at half throttle. The off throttle noise is gone which is a plus.
At first, I thought I found my issue. The rear sway bar rubbing against the lower control arm bolt. I moved it slightly and drove it around... clatter. But, I think I need to remove my sway bar to fully confirm this. If you can see by the picture, it looks like it was vibrating off it quiet a bit. I really hop its this.... I'll keep you guys posted.
I need to bust out my old GoPro 4 next..
That picture doesn't look a whole lot like there is and real wear. Usually if that were vibrating causing that kind of noise it would sound like metal slapping...kind of like a spring board type noise. Also, the vibration would wear the paint or powder coat off and shine the area up as well. I'm still thinking its the driveline.
- Thread starter
- #36
I did a little more testing and drove with the sway bar off. To me, it seemed like it’s still there. Maybe less clatter. Hard to tell now (I’m going crazy)
The good news is that the clatter is a little harder to “find”. It use to always happen when I had no pressure on the throttle (off throttle). Now it only happens at half throttle and not all the time. I have to sorta hunt for the half throttle clatter. When I throw it in neutral going 65+, it clatters fairly loud.
I also found some missed welds. I’m sending the truck back to my fab guys for them to help.
The good news is that the clatter is a little harder to “find”. It use to always happen when I had no pressure on the throttle (off throttle). Now it only happens at half throttle and not all the time. I have to sorta hunt for the half throttle clatter. When I throw it in neutral going 65+, it clatters fairly loud.
I also found some missed welds. I’m sending the truck back to my fab guys for them to help.
Might be worth it to invest in something like this. Not sure about this one specifically I just used it as a reference. Should help pinpoint any noise.
Chassis Ears Automotive Electronic Stethoscope 6 Channel Car Engine Noise Finder Sound Detector Tester Tool Set, Adjustable Sensitivity Mechanic Stethoscope https://a.co/d/gErewV0
Chassis Ears Automotive Electronic Stethoscope 6 Channel Car Engine Noise Finder Sound Detector Tester Tool Set, Adjustable Sensitivity Mechanic Stethoscope https://a.co/d/gErewV0
@petwhookie consensus says it's the rear driveline. I want you to do me a favor. Very carefully inspect the inner edges of the yokes of the rear driveline and the companion flanges. I was able to find wear there on mine which is what led me to the cause. If I remember correctly I added quite a bit of an angle to the rear pinion before it stopped. I ended up lengthening my rear links and sleeving them in .250" wall DOM which required re-setting the angle but I haven't had issue's since the initial adjustment. You may need to band-aid it with a DC but many of us haven't and my initial lift was 7" TJM this solution worked on the 6" Slee and is still working down to the 5" Dobinsons Heavy.
Take that rear driveline off and give it another good inspection at the yokes and companions...you should find some indicator of wear. Or maybe on of your spiders is grinding due to lost/damaged needles.
Take that rear driveline off and give it another good inspection at the yokes and companions...you should find some indicator of wear. Or maybe on of your spiders is grinding due to lost/damaged needles.
