Vibration @ ~70Mph post Nitro 488 install annoying. Vibration at >80Mph unbearable

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smagna00

10 Year 15 Year
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Nov 28, 2007
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8
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Seeking guidance por favor:

Killed the LX's AHC system last year and opted for a Slee lift including diff drop. Thrilled!

Pulled the trigger on Nitro 488 gears over Xmas 2015.
Love the resurrected umph. Dislike the new driveline vibration that was introduced.

Land Cruiser specialty shop reinstalled rear gears, vibration didn't go. Shop took them out again, and asked a peer shop to do the reinstall, just in case. Vibration alive and well:(

Shop planning to take another run at the read diff next week. They are adamant that it is neither the front diff, nor the installation of the rear gears, nor faulty/aged u joints, nor an unbalanced drive shaft.

Nitro says not the gears. Nitro stated 100series are notorious for driveline vibrations post lift.

Anyone experience similar? Anyone had success with the slee attached pic?

thx
(BTW: Doug Thorley headers and cat back going in next week too, while at the shop. Maybe between the new exhaust and the stereo I can drown out the vibration)

Slee.webp
 
You can take the driveshafts off one at a time and lock the centre diff to try and isolate the fault, my vibration was the rear most u joint, it had no play but a bit of stiffness on one axis. When the driveshafts are removed check for stiffness as well as movement. Mine is still AHC. The vibration was severe at times.
 
I haven't had vibration issues with my 100 after being lifted. 80s are more notorious for vibrations post-lift than 100s, in my experience.
 
If you'd not said anything about gears! I'd check alignment, balance of wheel/tires (road force is best), wheel & axle bearings condition and bearing preload (higher the better).
 
My driveshaft had to be rebalanced this past year. My 4.88's were smooth as silk for many miles and I've been on them for 3 years now for reference. Rebalanced DS and right back as smooth as ever. I don't recall a plethora of threads on driveline vibrations post 4.88 install.
 
I'm having a similar issue after 4.88 and its really getting frustrating. I have replaced all u-joints with oem, I have rebalanced both drive shafts and installed ajustable rear control arms to correct pinion angle.
Mine is worst about 65mph.
Next is front axels since they are worn out any way and possibly rear output bearing, I not sure if either of those will fix it but won't hurt. Good luck! Let us know if you get it resolved and I'll do the same.
 
Julian Stead said:
You can take the driveshafts off one at a time and lock the centre diff to try and isolate the fault, my vibration was the rear most u joint, it had no play but a bit of stiffness on one axis. When the driveshafts are removed check for stiffness as well as movement. Mine is still AHC. The vibration was severe at times.
Click to expand...


Pulled the rear shaft and drove it with CDL on, on front dif power. Felt right. That's why i keep coming back to the idea it is somewhere from the trans to the rear end. I'm going to inspect the u joints again. This time for stiffness as you recommend. thanks for the suggestion
 
It's not uncommon for a vibration to make its self known after a gear change, it is spinning much faster with the 4.88s than the stock gearing. Typically replacement of u-joints or drive shaft balance will take care of it. Hopefully this is the case for you!
Find a good drive shaft shop to check the u-joints and balance the shaft, the shop that installed your gears should have a driveline shop they work with.
 
Just to check the basics you mention install of rear 4.88, but not install of front 4.88, I take it they installed 4.88s in both?
Why is your shop discounting problems with front install, a lot more can go wrong up there, reversed driveshaft, not seat CV halfshaft, etc.

smagna00 said:
Seeking guidance por favor:

Land Cruiser specialty shop reinstalled rear gears, vibration didn't go. Shop took them out again, and asked a peer shop to do the reinstall, just in case. Vibration alive and well:(

Shop planning to take another run at the read diff next week. They are adamant that it is neither the front diff, nor the installation of the rear gears, nor faulty/aged u joints, nor an unbalanced drive shaft.


View attachment 1215271
Click to expand...
 
So, did you do the lift and gears simultaneously? Or did you do the lift, drive it with now issues, then have vibration issues after installing the gears? I'm not convinced it's the gears... There are plenty of other things to inspect before suspecting gears.
 
benc said:
It's not uncommon for a vibration to make its self known after a gear change, it is spinning much faster with the 4.88s than the stock gearing. Typically replacement of u-joints or drive shaft balance will take care of it. Hopefully this is the case for you!
Find a good drive shaft shop to check the u-joints and balance the shaft, the shop that installed your gears should have a driveline shop they work with.
Click to expand...


Yes, i think this is exactly path i will take this week. I was trying to capture as many symptoms as possible this weekend. I found that at ~70Mph+, just as i let off the accelerator, there is a low pitched hum for about 3/4 of a second. Time after time after time. Very easy to replicate. Very consistent. I will do some research on that too.
 
Stumpalama said:
So, did you do the lift and gears simultaneously? Or did you do the lift, drive it with now issues, then have vibration issues after installing the gears? I'm not convinced it's the gears... There are plenty of other things to inspect before suspecting gears.
Click to expand...

The Slee lift and dif drop were installed over a year ago. All went well. Shortly after the lift i went from Michelin 275/70 on the OEM 16" wheel, to 285/70 17" on aftermarket Momo wheels. Even though the tires were more aggressive than stock, and even though i had to add spacers, the ride was pretty smooth with the original drive train set up of 410s.

The 488s went in about a year later (Dec 2015). I had the 285s balanced right before the 488 install, since i had the shop put in a new steering rack at the same time. the steering rack is genuine toyota, and not aftermarket. Again, all rolls like a dream when CDL is locked and the rear drive shaft is removed.

Based on all of your guys' feedback, i feel it must be a bad u joint, and unbalanced drive shaft, or a wonky gear install. I can't image the gears are flawed. I guess (i hope) we'll know this week.
 
Skidoo said:
Just to check the basics you mention install of rear 4.88, but not install of front 4.88, I take it they installed 4.88s in both?
Why is your shop discounting problems with front install, a lot more can go wrong up there, reversed driveshaft, not seat CV halfshaft, etc.
Click to expand...


Yes, did the 410 to 488 front and back upgrade together. I didn't do lockers. I hope i don't regret thato_O. I have requested the shop to do the moral equivalent of a full physical this week. I'll keep you guys posted.
 
BTW this is me at Granite Hills Wash in Cave Creek, AZ on Pres Day. The "Chute" is a little tight for anything bigger than a Jeep JK, but thanks to a good spotter, made it through unscathed.
DSC_0219.webp
DSC_0223.webp
DSC_0279.webp
 
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Gears do not (or should not) vibrate. A driveshaft vibration is more evident post gear install because of the increased speed. It may have been there before, just not as noticeable. Going from 4.10 to 4.88 is going to significantly speed up the driveshaft rotation. The 100 series is extremely sensitive to vibrations. The higher you lift it, the more noticeable a vibration could be without the proper pinion angle.

Rebalancing the driveshaft doesn’t necessarily do anything because it is usually more of an angle issue than a balance issue.
 
smagna00 said:
Seeking guidance por favor:

Killed the LX's AHC system last year and opted for a Slee lift including diff drop. Thrilled!

Pulled the trigger on Nitro 488 gears over Xmas 2015.
Love the resurrected umph. Dislike the new driveline vibration that was introduced.

Land Cruiser specialty shop reinstalled rear gears, vibration didn't go. Shop took them out again, and asked a peer shop to do the reinstall, just in case. Vibration alive and well:(

Shop planning to take another run at the read diff next week. They are adamant that it is neither the front diff, nor the installation of the rear gears, nor faulty/aged u joints, nor an unbalanced drive shaft.

Nitro says not the gears. Nitro stated 100series are notorious for driveline vibrations post lift.

Anyone experience similar? Anyone had success with the slee attached pic?

thx
(BTW: Doug Thorley headers and cat back going in next week too, while at the shop. Maybe between the new exhaust and the stereo I can drown out the vibration)

View attachment 1215271
Click to expand...


I don't know if it's a "thing" on the LandCruisers, but is it possible that the shop who installed the gears messed up the phasing of the rear driveshaft when they reinstalled it? I know that most shops put a small index mark to note the location where the two halves come together at the slip joint and the entire assembly is balanced in that specific orientation.... maybe there's a chance that someone was careless when bolting the driveshaft back up to the rear pinion...????


-G
 
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