Occasional Whining Sound While Off-Road (1 Viewer)

[ScratchedFJ]

I bought my 1993 80 series late last month and the last few weeks I've been working through "baselining" the truck. Yesterday, the wife and I took it out for a shakedown run at Hollister Hills OHV and a few things came up.

1. tow hitch had to get removed
2. Spare tire got moved from underneath to the trunk (until a rear bumper is purchased)
3. A check engine light came on (still need to pull codes)
4. A whine occurred a few times

The whine only occurred in specific conditions. The condition where whine occurred are: 4Lo engaged, the suspension is extending (going over a bump with the front end and the front suspension droops out), and medium to high throttle input. The one fluid I have not changed is the transfer case fluid. So I'm doing that this week. Are there any other ideas on what to check?

I think I'm going to put the whole vehicles on jack stands so that the tires are off the ground, put it in 4Lo, and ensure the suspension is drooped out. Then put it in drive and give it some gas to try to recreate the sound.

 

[enox]

We're you perhaps going at a higher speed in 4lo?

 

[ScratchedFJ]

We're you perhaps going at a higher speed in 4lo?

Since my speedometer is broken, I'd only be able to estimate something in the range of 5-10 MPH. Is there a known speed related whining/grinding sound with these vehicles? The way I described the sound to my friend was "two stripped plastic gears rotating against each other at high speed". I'll have to get a video of the sound the next time I'm in this specific scenario.

 

[enox]

Would be good to service your driveshafts, I think 5-10mph is fine

 

[Shipwreck]

Since my speedometer is broken... 'snip' ...The way I described the sound to my friend was "two stripped plastic gears rotating against each other at high speed".

Have you looked into the Speedo problem? There is a plastic gear at the transfer case.

 

[enox]

Have you looked into the Speedo problem? There is a plastic gear at the transfer case.

Oh wow, good point

 

[Grandlooser]

Is it from a passenger?

 

[ScratchedFJ]

Have you looked into the Speedo problem? There is a plastic gear at the transfer case.

Not 100%. From what I've read if my cruiser control works (which is does) than more than likely there is a burnt electrical trace on the instrument cluster. I pulled my cluster and briefly looked for one while changing bulbs but did not find a burnt trace (maybe it is under the blue layer)

Is it from a passenger?

That would be the easy solution for this one