Rookie buys IsuzuFTS750 8.2L. Question marks everywhere


New member
Hey everyone, my names Jack, I’m 24 and from byron bay. I’m stuck in Wollongong with all truck mechanics booked out for weeks so here I am. I’ve just purchased this Isuzu fts 750a for 32k from Sydney with plans to build a 6x2.5m slide on camper for the back.
I’m planning on using it for touring and hauling trailers to make my event company more mobile and efficient.
I know I kooked it by not getting the truck checked over before I bought it but at the time I couldn’t find an available truck mechanic and it felt like an honest sale.
I purchased the truck 1 week ago and don’t want to do the 10hr drive back home untill I know the truck is fully prepped for the drive back up north.
So I’m kinda stuck in Wollongong untill i know the truck is sweet.
It’s an ex railway truck with a 4 inch lift, cherry picker has been deleted and a new tray has been installed. It’s done 196 000kms. Everything seems healthy besides 3rd gear being annoying to change down into and a sound that I can’t seem to diagnose.

The sound only exists beyond 70km+ And gets more consistent with more speed. it’s like a wearing/grinding sound with little none vibration. The sound doesn’t change when accelerating, decelerating and when in neutral, it’s only more noticeable with speed above 70km. Some times the sound disappears for a split second when hitting turbulence.

I’ve changed the following oils, diffs, gearbox, transfer case and engine oil, in being hopeful that it might of been some sort of poor lubrication in one of those components.
That didn’t resolve the sound.
But I did find metal shards in the gearbox oil which would relate to 3rd gear being annoying to change down into.
I also noticed that the transfer case is leaking and is getting fkn hot but not sure if that heat situation is normal. There is also no metal debris in the transfer case oil.

Please tell me if I’m just being paranoid or not, Is this sound normal for a 25yr AWD truck and this is just a common running gear sound of some sort and maybe hearing this because I’m pushing it too hard as it’s top speed is supposed to be around 90kph

could the the sound be that transfer case PTO might be stuck on?
Is it one of output shaft bearings?
is your rig Full time 4wd? do you get any noticeable changes in running gear noises when you hit the highway?
Do you have any idea what’s going on, does this happen with you or anyone else that has the same rig?
What’s do you think?
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Aussie Iron

I'm going to take a big guess. You say the transfer case is getting hot - how hot. 1 second feel or 30 second feel (how long can you keep your hand on it). I'm going to say that is where the noise is coming from. They wind up and yes if it has a PTO on it and it is engaged then that is a problem because you are running straight cut gears (probably) at to fast a speed. It shouldn't be engaged at road speed.

Not much help, I know but somewhere to start looking,


New member
Thanks for the quick response Dan, I will take it for a drive tonight and check the temp. Yeah that pto light on the dash isn’t illuminating when flicking the the PTO switch on and off 🤔

Aussie Iron

I checked it after a 2hour drive and the transfer is 6 seconds untouchable
To me that is too hot. 10 sec rule is what I would consider maximum. I would remove the PTO drive of the case and make a plate up to replace it and give it another try.

Another thing is you are taking this for test drives. Throw your swag on the back and do your test drives in the direction of home. Take it slow, let it cool down often, enjoy the scenery and get it home.



The transfer case on these FUSO's is a little different than others. All the power goes through gears, even in 2WD. Other models will pass power through and the gears aren't turning. These gears will whine because of that.

I'd double check you have the front axles disconnected and are truely in 2WD, you should be able to turn the front driveshaft by hand. Maybe if it is stuck in 4WD, it would build up a lot of heat.

Cool Runnings

New member
I am Based in Wollongong Jack-Let me know if you would like me to have a look and or offer a second opinion?
Have some contacts as well, but you are right, mechanics are very busy here!

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