Clunking on acceleration

[westyss]

I have just entered Mexico and am south of San Filipe and have just started hearing a clunking sound when accelerating in second gear, maybe three or four clunks, then maybe one or two in third gear but once moving along it goes away.
It seemed to be more when leaning to the left but that may be uncertain.
No sounds before that all the way from BC Canada! Wondering if anyone else has had something similar or can make a suggestion as to what it might be or where and how to look?

I have jacked up the rear axle and rotated the drive shaft and also heaved on the driveshaft to see if anything is loose, particularly the ujoints and shocks. I do have a bit of slop when turning the driveshaft to turn the wheels forward then backwards but it seemed to have the same amount since new, about 1/2” of play.
Truck is a 2007 Fuso FG

 

[westyss]

Also has a bit over 180,000kms if that makes any difference.

 

[SkiFreak]

I'm no mechanic, but I have read, on more than a few occasions, that there is a nut on the mainshaft of the transfer case that can come undone.
That may be a red herring, but it's possibly something to consider.

 

[westyss]

Ok thanks Owen, I’ll look into that, I’m guessing it would be ahead of the parking brake drum ?

 

[westyss]

Sitting here thinking about it I did stall the engine in second gear going up a sand hill this morning, thinking that might have something to do with it.?

 

[SkiFreak]

As I am sure you know, these boxes are not known for being all that robust.
A simple sanity check might be to drop your gearbox oil and confirm that there are no metal bits in there.
If you use a nice clean container, you just put the same oil back in if no contaminates are found (hopefully).

 

[westyss]

As I am sure you know, these boxes are not known for being all that robust.
A simple sanity check might be to drop your gearbox oil and confirm that there are no metal bits in there.
If you use a nice clean container, you just put the same oil back in if no contaminates are found (hopefully).

That is my plan tomorrow, pitch black out now, but I will try to do the Tranny and rear diff oil, thanks.

 

[SkiFreak]

Contrary to the gearbox/transfer, the rear diff on these trucks is pretty bulletproof.
If there was an issue with the diff, I would expect that you would hear noises in more than one gear.

 

[westyss]

Contrary to the gearbox/transfer, the rear diff on these trucks is pretty bulletproof.
If there was an issue with the diff, I would expect that you would hear noises in more than one gear.

Yeah you have a point there, I’ll focus on the transmission, thinking about the clutch plate too, original and a few miles on it!

 

[Joe917]

Check your mounts.

 

[westyss]

Yup, checked the mounts and other things but it’s the transmission. So far the mechanic thinks it’s the bearing in the tranny but obviously we haven’t gotten into it yet, seeing about parts.

 

[westyss]

Managed to limp back into the States and am busy finding a reliable towing company to probably get me to Kearny Mesa Truck Centre as it’s the closest one from me, definitely getting worse and don’t want to drive it!
So far one company came back with $2000 US to go 160kms!

 

[SkiFreak]

Did anything metallic come out of the gearbox/transfer when you dropped the oil?

 

[kerry]

Managed to limp back into the States and am busy finding a reliable towing company to probably get me to Kearny Mesa Truck Centre as it’s the closest one from me, definitely getting worse and don’t want to drive it!
So far one company came back with $2000 US to go 160kms!

Won't help right now, but we use CoachNet for road service towing. Will tow to the nearest dealer for the truck. Once towed our Wanderlodge (36' about 35k lbs) about 120 miles to a nearest Caterpillar dealer. Cost--$0 for us.

 

[kerouac]

Could it be CV joints? Does it happen when cornering too?