Whining coming from front area.

[atijerino]

Hi,
I have a 94 LC that I got it about two months ago. I took it on my first long trip this weekend. I noticed that it makes a whining noise when I push the accelerator when moving, when I take my foot off the accelerator and let it coast the noise stops but as soon as I push the accelerator the noise is back again. The whinning noise starts at around 20mph and it gets a little less noticeable at around 70mph, there is also a sweet spot even during accelerations when the sound is not noticeable.
Could this be a bad u-joint or an out of balance drive shaft?
I did the birf job a week after I got the truck, Could I have done anything wrong in the process?
However I do remember it had this sound before I did the job, but I did not do much freeway driving until this weekend.
Any pointers at to what could it be?
How do I actually pin-point the source of the problem?

Thanks,

__________________
Antonio
1994 FZJ80

 

[wob]

Wife?

 

[NorCalDoug]

Non-OEM belts? Does it whine when you're in PARK or NEUTRAL and rev the engine?

 

[Kalawang]

How old are your tires and are they worn ?


Kalawang

 

[Bear80]

Could it just be the exhaust whistle? I thought it was the intake for the longest time until I rode back in the jump seats and read here on the board that it was the exhaust.

 

[zipastro]

I have a 94 that does the same thing. I only notice it at 45-75mph while keeping a constant speed. It goes away if you accelerate hard or coast. It was a dead issue on the 80s cool board with no fix. The best explanation being that parts somewhere in the driveline were in harmonic tune?

I myself think it has something to do with how power is split between frt and rear wheels? It also sounds like a 5sp sounds in 5th gear when you coast at a high speed.

 

[Aseif007]

I too have this problem with my 97' FZJ. I keep thinking it is a u-joint, or bearing. My whining is comming from the back though. I will probably change them all and hope it fixes the problem. My tiires are new and the noise was there with the old tires.

 

[cc93cruiser]

Check Your Fluids (all Drivetrain)!

 

[atijerino]

Check Your Fluids (all Drivetrain)!

The tires are newer Michelin LTX M/S type of tires. Fluids are ok all around, I jsut recently did the birf job and the front diff got a treatment of brand new gear oil.

Thanks,

Antonio
1994 FZJ80

 

[rbsheppard]

I had a similar problem with my 94 LC. If the wining is present when you have torque on the drive shaft (ie. pressing the pedal) it is probably your pinion bearing. I had just bought my LC and the previous owner had allowed the oil in the front differential to leak out. The pinion bearing in the front differential is the first part of the differential to lose oil. It will overheat and then damage the bearing.

 

[atijerino]

I had a similar problem with my 94 LC. If the wining is present when you have torque on the drive shaft (ie. pressing the pedal) it is probably your pinion bearing. I had just bought my LC and the previous owner had allowed the oil in the front differential to leak out. The pinion bearing in the front differential is the first part of the differential to lose oil. It will overheat and then damage the bearing.

How do you actually pinpoint the whinne to the pinion bearing?
According to your description; yes the whinne is present only when ther is torque on the driver shaft. Then it could be the pinion bearing.
How hard is it for a DIY (2 1/2 bananas) to change this bearing? Any write-up about this job in the forum? Is is spell out in the FSM?

Thanks,

________________
Antonio
1994 FZJ80

 

[Aseif007]

rbsheppard,
I will check that when I can, thanks for the info.

 

[alia176]

I have induced a similar whine in my drivetrain from when the R&P (4:56)were changed. If you want to change the mondo Pinion bearing and the smaller bearing, then it's a difficult DIY job. If you want to replace just the smaller pinion bearing then it's much easier and can be done in situ.

 

[neowulf]

I had a similar whining on my LC, I changed the oil in my front dif. to a synthetic type and it stopped.

the whining was only there when I had a slight pressure on the throttle. (somewhere in-between accelerating slightly and holding the same speed.)


i would gues that it's the difs. Pinion bearing

 

[zipastro]

I had a similar whining on my LC, I changed the oil in my front dif. to a synthetic type and it stopped.

the whining was only there when I had a slight pressure on the throttle. (somewhere in-between accelerating slightly and holding the same speed.)


i would gues that it's the difs. Pinion bearing

How long has the noise been gone? My comes and goes and come to think of it tends to be more noticeable in summer\warmer weather? I guess I should have went syn when I did my last fill.

 

[atijerino]

I had a similar whining on my LC, I changed the oil in my front dif. to a synthetic type and it stopped.

the whining was only there when I had a slight pressure on the throttle. (somewhere in-between accelerating slightly and holding the same speed.)


i would gues that it's the difs. Pinion bearing

Tried the advice of neowulf and changed the gear oil in the front diff from regular oil to Syntetic Mobil 75-09W oil. I drove the truck this morning and it feels a little less whinny and I hope that this will help. I guess eventually I will have to check the pinion bearing, u-joints and drive shaft. This will have to wait, spring is almost here and I promissed the wife to get the garden area ready for her to plant her gardent his year.

Thanks for you tips and help. Glad I was able to find this site.

____________________________
Antonio
1994 FZJ80

 

[atijerino]

Sorry, but I am reviving this thread again.
I replaced the two front u-joints in the front this weekend (next weekend will do the rear) and the whinne still persists. I noticed that when I pulled out the slip yoke from the shaft it had some surface rust and was rust pitted on some other areas. I guess water got in. I cleaned with some 3M pads and greased the heck out it. The "thunk/clunck" in the front diff area persists. I am going to open the birfs again soon when I replaced the rotors and inspect the area, it looks like noise is coming from that area, it could be that either put too much grease or not enough.

Thanks for your ideas.

_____________________
Antonio
1994 FJZ80

 

[IdahoDoug]

Did you get grease on the inner spindle bushing when you repacked? This is a bronze bushing inside the spindles, through which the axles protrude.

DougM

 

[atijerino]

I can't remember if I did, would that cause the thump/clunk noises? At first the noises were sporadic, but now they are more consistent. I guess since I will need to replace the rotors soon; (down to 27mm) I guess sooner than later; I will get the spindles out while there anyways.
What kind of damage would be present if the bushings did not get enough grease?

Thanks,

_________________________
Antonio
1994 FJZ80

 

[Pitbull]

Non-OEM belts? Does it whine when you're in PARK or NEUTRAL and rev the engine?

Mine did the same whine when I changed to gates belts. Changed back to OEM and it was gone. I guess Antonio has ruled this out since he is doing other changes??