Low noise from what seems the front diff. Sounds like a dishwasher. (1 Viewer)

[OffRoadScott]

The rear is definitely out of phase it needs to be IN phase.

Front appears to be IN phase and it should be 90 degrees out of phase.

Also, both DS should have the slip yoke to the FRONT of the truck. That mean the rear should be on the transfer case and the front should be on the front diff.

Not saying you are wrong but why would he want the front out of phase? I have heard if you are getting a hum from the front it could be multiple things, u joints in the front driveshaft, sometimes having the ears on the driveshaft lined up cures some of those issues, but it could be other things as well related to your knuckles/bearings, etc.

 

[BILT4ME]

Not saying you are wrong but why would he want the front out of phase? I have heard if you are getting a hum from the front it could be multiple things, u joints in the front driveshaft, sometimes having the ears on the driveshaft lined up cures some of those issues, but it could be other things as well related to your knuckles/bearings, etc.

This is why:

@cruiserdan and @beno both concur that the FRONT shafts on ALL years are SUPPOSED to be 90° out of phase.
These two are THE most knowledgeable about these trucks. Period.

In phase or out of phase?

1992 FJ80 - I'm getting conflicting info here. Most of the stuff I read says that the front driveshaft should have the u-joints 90 degrees out of phase... But, then a coupld of guys chimed in and said that's only for FZJ80's - FJ80's are supposed to have them IN PHASE. Which is right?

forum.ih8mud.com

 

[Tools R Us]

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View attachment 1929734

The rear is installed backwards, the slip should be at the transfer. Likely not your problem, but the slip is better protected that way.

On the front, the early ones were shipped and the FSM shows conventional in phase, about the start of the 1FZ it was switched to out of phase. This is unique to the 80 series, if unique is important to you? Have never seen it on any other vehicle, drive shaft books and shops say it wont work, but it does, in stock configuration. When lifted, sometimes they run smoother in the conventional in phase configuration. When chasing drive line vibration, changing phase is one of the first tests that we do, in some cases, has solved the problem.

It looks like those were randomly put together? Restoring phase may help, when doing it the grease zerks should be in line, makes greasing them easier.

 

[Qball]

I have a little bit of vibration and been reading this thread, finally got some time so crawled under the 80 and I installed the front driveshaft slip yoke up and in phase. So I reinstalled the drive shaft out of phase and slip yoke forward. Test drive it and it helped a little I think but still have vibration so guess I need to dive into the front axle in a few weeks.

 

[Tools R Us]

I have a little bit of vibration and been reading his thread, finally got some time so crawled under the 80 and I installed the feint drive shaft slip yoke up and in phase. So I reinstalled the drive shaft out of phase and slip yoke forward. Test drive it and it helped a little I think but still have vibration so guess I need to dive into the front axle in a few weeks.

How much moly grease is in the knuckles?

 

[Qball]

How much moly grease is in the knuckles?

The zip tie method says it's almost to the top and the grease line method says that too. I'll try again with a stick, I'll also try the wheel wiggle to make sure the bearings are tight.

 

[REKCUT]

On the front, the early ones were shipped and the FSM shows conventional in phase, about the start of the 1FZ it was switched to out of phase. This is unique to the 80 series,

My thoughts would be that if it changed with the 1fz and is unique to this vehicle then toyota was most likely chasing an issue with something on these trucks that they felt benefited from moving the front shaft out of phase. I personally would try to put it that way but if you have no issues with it the other way then just leave it.

 

[OffRoadScott]

This is why:

@cruiserdan and @beno both concur that the FRONT shafts on ALL years are SUPPOSED to be 90° out of phase.
These two are THE most knowledgeable about these trucks. Period.

In phase or out of phase?

1992 FJ80 - I'm getting conflicting info here. Most of the stuff I read says that the front driveshaft should have the u-joints 90 degrees out of phase... But, then a coupld of guys chimed in and said that's only for FZJ80's - FJ80's are supposed to have them IN PHASE. Which is right?

forum.ih8mud.com

Okay, but people have tried other ways and found it works better. I in no way are saying they are wrong.

 

[MoJ]

The FSM is clear on the phase orientation.

 

[surfinjoel]

The zip tie method says it's almost to the top and the grease line method says that too. I'll try again with a stick, I'll also try the wheel wiggle to make sure the bearings are tight.

I use the zip tie method too. It’s the best

 

[surfinjoel]

If it turns out that my diff is bad and I have to replace. I want to re gear them both. What is the best gearing for 33inch tires?

 

[shocktower]

If it turns out that my diff is bad and I have to replace. I want to re gear them both. What is the best gearing for 33inch tires?

4:10

 

[surfinjoel]

4:10

Would 4.56 be too much if I want to leave the option of going with larger tires open?

 

[shocktower]

Would 4.56 be too much if I want to leave the option of going with larger tires open?

4.88 are your next common gears

 

[chap79]

If you want to run 35’s in the future regear to 4:88.

 

[surfinjoel]

I’m on the Slee website looking at 4.56 4.88 and 5.29

 

[shocktower]

I did not realise they have 4.56 go with the 4.88

 

[MoJ]

I’ve never tried 4.56 first hand but have always heard it’s not enough difference from stock to justify the expense. I’d suggest jumping to 4.88 with 315’s. I wouldn’t suggest anything smaller than 315’s with 4.88 if you like to cruise at or above 80 mph.

 

[REKCUT]

I also have always hear that you need to jump 2 sizes to really tell a difference.

 

[surfinjoel]

I’ve never tried 4.56 first hand but have always heard it’s not enough difference from stock to justify the expense. I’d suggest jumping to 4.88 with 315’s. I wouldn’t suggest anything smaller than 315’s with 4.88 if you like to cruise at or above 80 mph.

I don’t need to go 80. I’d just like to be able to do 65/70 without being in 3rd gear. Ha