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Really hope someone has encountered the same problem and steer me in the right direction before i spend an absolute fortune!...
***The problem:***
I was getting a really annoying vibration/rattle between 1200rpm and 1600rpm in every gear on acceleration.
1st was hardly noticeable,
2nd was VERY noticeable,
3rd was VERY noticeable,
4th was hardly noticeable,
5th & 6th it was virtually undetectable - but i could still feel it because i knew what rev range to keep an ear out for.
When i say vibration / rattle.... the entire cab would shudder and resonate and i could hear a kind of rattle coming from under the vehicle.
it only occurs on acceleration, not when coasting or de-acceleration during this rpm window.
***Fault finding***
Changed the gearbox oil - no difference.
Checked the gearbox and engine mounts - no issues.
Checked all bolts, bushings, exhaust, suspension etc... - no issues
Checked both props and all prop UJ's - no issues.
I then removed the rear prop and ran it in HL (fwd only). The problem was noticeably worse!
Then i put the rear prop back in and removed the front prop to run it in RWD only.... Much better, "almost liveable with"! But the rattle is still there and still pretty VERY noticeable in 2nd + 3rd gear ONLY. I'd say 50% of the rattle/vibration is gone.
***Diagnosis***
So, here's my thinking and this is what i'd like as many opinions on as possible:
>I can rule out the rear diff (as the problem was worse when it wasn't connected).
>I can rule out the rear PROP (as the problem was worse when it wasn't connected).
>I can rule out the front PROP (as the problem was still there when it wasn't connected).
>I can rule out the front cv's and driveshafts (as the problem only happens on acceleration the vibration is still there when there is no power going through them).
So in my head, I'm only left with the gearbox and transfer case.
I was thinking a slack transfer chain or else a gearbox output shaft bearing.
My next step 3 steps are:
1). Remove the CV's and drive it like that, see if that changes anything (i really don't think it will).
2). Put all props back in and change the transfer case oil - see if that changes anything (i really don't think it will).
3). Remove the gearbox/transfer box and replace it with a replacement from a wreckers.
Any thoughts?
Oh and one more point to note.... when i put it in 2nd + 3rd at the same rev range with either prop disconnected but not in HL (so the gearbox spins but i get no drive), there NO vibration.
***The problem:***
I was getting a really annoying vibration/rattle between 1200rpm and 1600rpm in every gear on acceleration.
1st was hardly noticeable,
2nd was VERY noticeable,
3rd was VERY noticeable,
4th was hardly noticeable,
5th & 6th it was virtually undetectable - but i could still feel it because i knew what rev range to keep an ear out for.
When i say vibration / rattle.... the entire cab would shudder and resonate and i could hear a kind of rattle coming from under the vehicle.
it only occurs on acceleration, not when coasting or de-acceleration during this rpm window.
***Fault finding***
Changed the gearbox oil - no difference.
Checked the gearbox and engine mounts - no issues.
Checked all bolts, bushings, exhaust, suspension etc... - no issues
Checked both props and all prop UJ's - no issues.
I then removed the rear prop and ran it in HL (fwd only). The problem was noticeably worse!
Then i put the rear prop back in and removed the front prop to run it in RWD only.... Much better, "almost liveable with"! But the rattle is still there and still pretty VERY noticeable in 2nd + 3rd gear ONLY. I'd say 50% of the rattle/vibration is gone.
***Diagnosis***
So, here's my thinking and this is what i'd like as many opinions on as possible:
>I can rule out the rear diff (as the problem was worse when it wasn't connected).
>I can rule out the rear PROP (as the problem was worse when it wasn't connected).
>I can rule out the front PROP (as the problem was still there when it wasn't connected).
>I can rule out the front cv's and driveshafts (as the problem only happens on acceleration the vibration is still there when there is no power going through them).
So in my head, I'm only left with the gearbox and transfer case.
I was thinking a slack transfer chain or else a gearbox output shaft bearing.
My next step 3 steps are:
1). Remove the CV's and drive it like that, see if that changes anything (i really don't think it will).
2). Put all props back in and change the transfer case oil - see if that changes anything (i really don't think it will).
3). Remove the gearbox/transfer box and replace it with a replacement from a wreckers.
Any thoughts?
Oh and one more point to note.... when i put it in 2nd + 3rd at the same rev range with either prop disconnected but not in HL (so the gearbox spins but i get no drive), there NO vibration.