Driveline help....UPDATED 7/22/20

G_Raw

G_Raw

New member
7/22/20 Update:
I'm starting to think it's a driveline issue. I used my phone with a clinometer app ( I know super reliable way to measure) .

Trans output is 7.5 degrees
Drive shaft is 10.4 degrees
Pinion is 6.1 degrees

Trans angle 2.9
Pinion 4.3

I have not been successful at finding what the angles should be for runner specifically. All say you shouldn't be above 3 degrees for most vehicles though. So do these angles tell me I should start adjusting driveline angles? If so how? Long or shorter rear LCAs?

As I sat here typing I've begun to wonder. I have OME 891 ( hd springs) on the rear. I haven't added bumper and weight to it yet. Although all center hub to fender measure 22.7 to 23 inches at all 4 corners. But could the springs with no weight be enough to change driveline angles?

BELOW THIS POINT IS THE WHOLE STORY...

Vehicle is in my Sig. About 3 weeks ago driving on the freeway I got a crazy driveline vibration, violent. It settled down but became noticeable between 60 to 70mph. Like a humming vibration now.
All seemed well when I swapped my driveshaft a week later. Then I noticed a faint hum driving around town in the 30 to 40mph range. It changes in tone depending if your foot is on the gas, or if it is released. Today on freeway around 55 to 60 mph I noticed as I would release the gas I would get a buck? Jump? Type feel.

I otherwise don't notice slipping or anything like that.

Trans fluid and filter change 3 months ago. Fluid level still good and clean red.

Changed diff fluid early from regear...looks silver and glittery but I'm told that's expected while the gears settle and break in.

I'm also going through breaking in my 4.88 gears still... 330 miles into my first 500. Mostly city driving occasional freeway, not over 60mph.


Are these signs my trans is on its way out?


7/19/20 UPDATE:
So I have pulled my 4.88 third and posted photos. Still had vibrations when I put it back in obviously. I am told Trail Gear sees nothing wrong with third based on photos. I have now pulled the 4.88 third out and dropped in an OEM 3.93(?) third. Something is still off. I definitely do not "feel" a vibration with the current third. However now at 60 to 70 mph there is still a groan. It is almost like a dump grah grah grah sound that pulses at about 1 second intervals. If I push above 70mph ( which is a chore with this gear ratio) the noise stops. If I drop into the upper 50's mph it stops. I did feel like it intensified in volume on a banked right hand turn ( causing a left sided weight transfer) transitioning from freeway A to freeway B.

It maybe worth noting that when I did my 500 mile change the gear fluid was silver. 60 miles into that new gear oil is when I pulled the third to take photos. That fluid was still silver. However pulled the third to do the 3.93 swap and it was clean with about 100(ish) miles on it, although some debri on plug.

In all honesty I still feel the options are trans output shaft? drive shaft ( angles vs ujoints)? or axles ( wheel bearings, seals).

Again my axle bearings and seals were done a year ago, they still seem fine and spin smooth with no noise when I pull them to do the diff swaps.

My drive shaft has no play when on the vehicle. I also pulled it again while doing the third swap. No catches or play in either end u joints.

I don't have a tool to accurately measure driveline angles so I can't comment on that.

From what I can see of the out put shaft with driveshaft removed the teeth all look fine...

With that said in all honesty with normal music levels, windows down, and traffic noise I wouldn't notice this at all with this 3.93 gear ratio. SO this may have been happening prior to re-gear and I just didn't pick up on it. And if I hadn't re-geared I'd likely be driving with no issue.

The 4.88 definitely intensify the groan and vibration. And I definitely want to use that gear ratio but need to solve this issue...

Thoughts?
 
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Can you get to speed when it makes the vibration and put it in neutral? Does it go away when you do? That will take the drive line out of the question to help narrow down the issue. Just a thought trying help.

I also had a terrible vibration around 60mph twice. The first turned out to be terribly balanced tires (never got them right). Went away when I replaced. The second was a bad a u-joint on the drive shaft. Replaced that and the vibration also went away.
 
Sorry forgot to mention that part. Because it's a humming vibration groan it's hard to tell. The answer the the neutral could be yes and no.

Let's say I'm going 55mph and feel. If I hold that speed I hear and feel that hum. If I kick to neutral it changes tone ( much like when I let off the gas) and is still there but disappears quick. But it doesn't take much for the truck to drop from 55 to 49 in neutral....50 is where you start to feel it. So in a matter of a second or two the truck is under the speed to start to cause the vibration but also just because you throw it in neutral doesn't mean the driveshaft instantly stops spinning, it too needs to slow.

I'm hoping it's the shaft. Front DS angle is 80.1 to 80.3 depending where I set glucometer. Rear angle is 80.6 to 81.2. I think that's a big enough variant to create vibrations, and maybe a kick when force is release on u joints.

Thoughts?
 
Verify 100% that your universal are good and the driveshaft are still balanced. A failing universal can cause all of this.

Sent from my SM-J337V using Tapatalk
 
G_Raw said:
Sorry forgot to mention that part. Because it's a humming vibration groan it's hard to tell. The answer the the neutral could be yes and no.

Let's say I'm going 55mph and feel. If I hold that speed I hear and feel that hum. If I kick to neutral it changes tone ( much like when I let off the gas) and is still there but disappears quick. But it doesn't take much for the truck to drop from 55 to 49 in neutral....50 is where you start to feel it. So in a matter of a second or two the truck is under the speed to start to cause the vibration but also just because you throw it in neutral doesn't mean the driveshaft instantly stops spinning, it too needs to slow.

I'm hoping it's the shaft. Front DS angle is 80.1 to 80.3 depending where I set glucometer. Rear angle is 80.6 to 81.2. I think that's a big enough variant to create vibrations, and maybe a kick when force is release on u joints.

Thoughts?
Click to expand...
Sounds like rear diff noise to me. I would try removing the rear drive shaft and driving it in 4wd (front wheel drive at that point) and seeing if the noise is still there and if it changes tone between accelerating and coasting in gear and coasting in neutral.
 
Bad Luck said:
Sounds like rear diff noise to me. I would try removing the rear drive shaft and driving it in 4wd (front wheel drive at that point) and seeing if the noise is still there and if it changes tone between accelerating and coasting in gear and coasting in neutral.
Click to expand...

I am also of the opinion that something may be up with the rear diff, especially since the rear diff got replaced. What was in there and what did you replace it with? Same gears? Did you add a locker or limited slip? Where did you get the third member from?
 
NJ-4Runner said:
I am also of the opinion that something may be up with the rear diff, especially since the rear diff got replaced. What was in there and what did you replace it with? Same gears? Did you add a locker or limited slip? Where did you get the third member from?
Click to expand...

I drove yesterday and now agree that it's the diff. I got long groaning sounds while in neutral for a decent time. It was a third member swap from low range. It was whatever stock gears were to 4.88 with arb air locker.

I still get that bump, jump, buck type feel occasionally when letting off the gas. It seems to only happen when I'm closer to that 60 mph zone...Would the diff do that as well?

Could that be from the slip in the drive shaft moving? I disconnect the drive shaft yesterday to inspect u joints better, which still seem fine to me. But I did notice the slip could move about an inch before it bottomed out...should I throw a .75 inch spacer on to see if that corrects the jump? How far in should the slip yoke be? Is that inch normal?
 
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G_Raw said:
I drove yesterday and now agree that it's the diff. I got long groaning sounds while in neutral for a decent time. It was a third member swap from low range. It was whatever stock gears were to 4.88 with arb air locker.

I still get that bump, jump, buck type feel occasionally when letting off the gas. It seems to only happen when I'm closer to that 60 mph zone...Would the diff do that as well?
That sounds like the gears aren't set up correctly to me. Too much back lash can cause a very similar feeling.

Could that be from the slip in the drive shaft moving? I disconnect the drive shaft yesterday to inspect u joints better, which still seem fine to me. But I did notice the slip could move about an inch before it bottomed out...should I throw a .75 inch spacer on to see if that corrects the jump? How far in should the slip yoke be? Is that inch normal?
If I'm understanding you correctly (it's early for me) then that's normal. The driveshaft needs to be able to collapse/slip in for whenever the rear axle compresses upward.
Click to expand...

My thoughts in bold.
 
G_Raw said:
I drove yesterday and now agree that it's the diff. I got long groaning sounds while in neutral for a decent time. It was a third member swap from low range. It was whatever stock gears were to 4.88 with arb air locker.

I still get that bump, jump, buck type feel occasionally when letting off the gas. It seems to only happen when I'm closer to that 60 mph zone...Would the diff do that as well?

Could that be from the slip in the drive shaft moving? I disconnect the drive shaft yesterday to inspect u joints better, which still seem fine to me. But I did notice the slip could move about an inch before it bottomed out...should I throw a .75 inch spacer on to see if that corrects the jump? How far in should the slip yoke be? Is that inch normal?
Click to expand...

I read one of your other posts from your diff install and saw that you had some issues with clearances when installing the 3rd member. You had to shave the third member to fit it in the axle. Is it possible that you installed it a little sideways...and by a little i mean a couple tenths or hundredths of an inch. I realize you clearanced it and it slid into the housing but it may be possible that it wasn't clearanced enough to bottom out properly in the cradle. When you slid the axles back in did the axles slide right back into the third member super easy or did they fight you a little bit?
 
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Jack up the rear axle off the ground and put the 4R in neutral. Then spin the tires by hand. Do they spin freely with some drag or do you hear/feel any catching or binding? Disconnect the driveshaft if needed to isolate the third member. A bad third is easier to feel by hand because we do not have the same power going to it as a motor/trans put to it.
 
tx_shooter said:
Jack up the rear axle off the ground and put the 4R in neutral. Then spin the tires by hand. Do they spin freely with some drag or do you hear/feel any catching or binding? Disconnect the driveshaft if needed to isolate the third member. A bad third is easier to feel by hand because we do not have the same power going to it as a motor/trans put to it.
Click to expand...


Noise... 30mph with rear end up on stands...
YouTube
 
Well I guess the 4runner is going to be sitting on jack stands with all 4 wheels off the pavement for a bit. I gotta pull the third and send it in for the to inspect and hopefully warranty. I don't have a covered garage so while the runner is up with rear end disassembled I guess just tape bags at each end of axle and saran wrap the diff opening to keep debris from getting in?

Can I stash the rear axles in the truck or should I keep them upright so I don't mess up the bearings and seals?
 
MStudt said:
I think you found the issue. I'd really check that 3rd member out to make sure your gears have a good mesh. Low Range isn't known for the best quality of work.

Mike
Click to expand...

:frusty:Awesome...better taking it to a driveline and gear shop in the area and biting the bullet cost wise for them to repair vs sending back for them to either repair/ send new third?

I know nothing about setting ring and pinions, black lash, etc...
 
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