HJ75 Grinding Noise

[Brizcruza]

Hey all,

Got an 88 HJ75 with aftermarket turbo. I have looked on here but all the threads only have some of my symptoms,, not all.

Very unusual grinding noise coming from front half of truck, not sure if it engine, gearbox or transfer??? Happens regardless of 2WD, 4H or 4L. Putting any load through the drive train (ie hill starts, taking off to hard, not to mention - any kind of 4WDing is out of the question). Clutch is not slipping but I lose a great deal of power when this noise is going.

Only in first gear - most torque - fine at any speed over 15-20km.

Any ideas?

 

[Clint79]

Broken engine mount and fan hitting rad shroud?

 

[roscoFJ73]

Hey all,

Got an 88 HJ75 with aftermarket turbo. I have looked on here but all the threads only have some of my symptoms,, not all.

Very unusual grinding noise coming from front half of truck, not sure if it engine, gearbox or transfer??? Happens regardless of 2WD, 4H or 4L. Putting any load through the drive train (ie hill starts, taking off to hard, not to mention - any kind of 4WDing is out of the question). Clutch is not slipping but I lose a great deal of power when this noise is going.

Only in first gear - most torque - fine at any speed over 15-20km.

Any ideas?

Did it come on suddenly or slowly get worse? As Clint suggested ,I would check all the mounts.
Realistically ,only 2 things can rob you of power,lack of fuel/air or the clutch

 

[Brizcruza]

Had a look tonight - nothing as far as the fan shroud goes. But the one of the gearbox mounts is leaking fluids, possible compression when I put torque through the drivetrain

 

[roscoFJ73]

Had a look tonight - nothing as far as the fan shroud goes. But the one of the gearbox mounts is leaking fluids, possible compression when I put torque through the drivetrain

Gearbox mounts dont contain fluids,its most likely gear oil which softens the rubber.
Get a lever and and lift the gearbox/t/case or put a jack under it,if there is a split that will open it up.
Broken mounts can often be felt through the gearstick as you let the clutch out etc
It still wouldnt explain the loss of power while its making the noise.

 

[Brizcruza]

Hi guys,

I have found that if I am taking off and I push the gear lever against the natural movement of the GB as torque is transmitted through the drive-train - the grinding does not occur. I have got a feeling that the input shaft for the GB is breaking contact due to excessive movement in the GB from the faulty mount.

I will advise after i have replaced the mounts.

Even if it isnt the mounts - i will be able to eliminate them from the equation and will be one step closer to solving this problem.

 

[lshobie]

Check the harmonic balancer - it can make a grinding noise.

 

[Brizcruza]

I have replaced the gearbox mounts and problem solved. The old mount was completely separated. Now I just need to fix the 4WD engaging problem mentioned in a previous thread.