OME Light/Medium 2.5" Lift and driveline vibrations (2 Viewers)

[AutaviaFJ40]

Just replaced clutch and installed new OME Springs. also rebuilt front and rear wheel bearings.

I was having an issue with driveline vibration starting at 35mph so added a 4 degree shim which eliminated the vibration...but now I have a noise that sounds like its directly under 4WD shifter. It sounds like the gears aren't fully disengaged and the teeth are just barely touching...could be completely unrelated, but that is what it sounds like.

Its most noticeable at higher speeds when coasting in neutral or when clutch is engaged at above 35mph. I can occasionally hear it at lower speeds...but mostly when coming to a red-light or stop and shifting out of gear.

any ideas?

UPDATE IN POST 15 BELOW

 

[Michael Hanson]

Hi, Sure you did the clutch right? Did you use Toyota parts? Mike

 

[AutaviaFJ40]

all Toyota Parts. I had my local shop do it, im starting to wonder the same

 

[AutaviaFJ40]

But the clutch shifts as smooth as butter, no obvious clutch issues

 

[Mark Jennings]

Does your rig have locking hubs. Or is the front end flanged. If flanged, the front differential and drive shaft will rotate full time.

If that’s the case then your 4 degree shims are a bit to much and has changed the front differential angle, kinda like offsetting the front driveshaft universals. The noise will be more of a rumble then a rattle.

2 degree shims are all you should need if no extended front shackles and a simple 2.5” spring kit. 4 degree shims on a 2.5” lift with stock shackles is way to much.

I use a skyjacker 2.5 inch spring set...with stock shackle length. The caster angle on and alignment stand was -.2 and -.4....2 degree shims brought it back to just slightly positive +1.0 both sides. The stock caster is 0 to +1.0....this gives the correct front differential alignment for the u-joints and the correct caster for drivability.

 

[AutaviaFJ40]

Thanks Mark,
yes locking hubs- but ive tried both locked in 4h and unlocked 2h and no difference

I guess I could remove the front drive shaft and see if the noise goes away first

 

[Mark Jennings]

If the drive shaft isn’t rotating, hubs unlocked and transfer case in 2H, then there should be no noise. If the transmission/t-case were removed, are you sure the t-case is fully disengaging. Did the service tech that replaced the clutch mis-adjust the manual linkage or is the vacuum shifter working correctly (older rigs)?

 

[AutaviaFJ40]

If the drive shaft isn’t rotating, hubs unlocked and transfer case in 2H, then there should be no noise. If the transmission/t-case were removed, are you sure the t-case is fully disengaging. Did the service tech that replaced the clutch mis-adjust the manual linkage or is the vacuum shifter working correctly (older rigs)?

hmmm...this might explain some other vibrations. I'll check in morning.
I just assumed it was disengaged

 

[AutaviaFJ40]

well, you got me excited there as that would be an easy fix.
the locks are working correctly and are disengaged.

BTW its an '81 FJ40 so 4 speed

 

[Mark Jennings]

Mines a 68....and sometimes the vacuum shift leaks by...makes all kinds of wonky noise if the front differential is engaged without locking the hubs....then again it’s an FJ40....there’s always a wonky noise.

 

[cbmontgo]

Push forward slightly on the t case lever and see if the noise goes away.

 

[AutaviaFJ40]

Push forward slightly on the t case lever and see if the noise goes away.

Doesn’t seem to help at all

 

[AutaviaFJ40]

It’s definitely in the transfer case. Only when rolling in neutral

 

[DangerNoodle]

Bearing going out? Those cases are cheap to rebuild before something grenades.

 

[AutaviaFJ40]

I changed the thread topic to reflect this update:

The 4 degree shim was swapped w/ 2 degree shim and the issue described in post one is gone. Very strange as it sounded like it was coming from transfer case.

But now I have a driveline vibration at about 28-35 mph and again above 50mph. Drive shaft is at a 14.5 degree angle, which seems extreme for such a short driveshaft.

 

[SuperDuperCruizer]

Check your rear driveshaft for play at the output flange of the transfer case. Do you see any movement when you push on the drive shaft? If your transfer case hasn’t been rebuilt it’s probably time. Is there any oil leaking at the output flange? Do you have a split transfer case or a one piece case?

 

[AutaviaFJ40]

Check your rear driveshaft for play at the output flange of the transfer case. If your transfer case hasn’t been rebuilt it’s probably time. Is there any oil leaking at the output flange? Do you have a split transfer case or a one piece case?

Its 81 w/ split transfer case, has 150,000 miles...just checked again, no play at all...we replaced rear output seal when it was pulled to replace clutch and rebuilt rear drive shaft at same time.

 

[Mark Jennings]

Make sure the u-joint yokes are at a 90 degree orientation.....from each other. Both drive shafts. Also look and verify the universal caps are tight in the yokes. And make sure that you’re yoke flange bolts are tight.

On the 68, I've had the rear drive shaft t-case end flange bolts come loose....made all kinds of rumbling noises. Above and beyond the normal FJ40 wonky noises. It’s now a routine check every 1500 miles or so.

 

[AutaviaFJ40]

rear drive shaft is in phase, but nipple is facing me on transfer case side and away from me on rear axle side...is that ok?

 

[Mark Jennings]

Did you use extended shackles in the rear? If so how long?