Bit of a drive problem??

[OVOXO]

Driving along today, and then herd the truck was making a clanging noise.

It only happens on load, If i clutch in, and then clutch out again, it won't make the noise until I gas on again..

If I put it into 4wd, and turn hub locks on, and do a tight circle, the front doesn't skip like it used to.


I do have welded front and rear diffs, and I'm thinking the front diff is fucked? But it doesn't make sense because it only happens when theres drive/load.

(Truck is a KZJ78)


Opinions??

[rangimotors]

does it do it in 2wd as well as 4wd? with welded diffs chances are you've broken something. Diffs often only make noise when they have load on them but obviously you've shagged something in the driveline so its going to be a process of elimanition to work out what it is.

[OVOXO]

Maybe transfer case? I'll have to jack it up to see?

[T-Boon]

Do a jump and see if it fixes it Joe

Yeah trial and elimination is your best (and also trickiest) bet.

[pruggerdore]

if your driving on tarseal with 2 welded diffs every thing will b e broken

[OVOXO]

Haha yeah, sorry long day of thinking.


Front isn't locked.
Wasn't in 4wd - Rules out transfer case?
Defiantly louder than if it were the hubs.

I'm thinking either gearbox or diff?

Need to get the silvia running so I can have some more axle stands handy
As you can tell I know next to nothing about 4wds

[pruggerdore]

back diff. welding diffs on road is a no no IMO

[OVOXO]

Ok, I took rear driveshaft out, put it in 4wd, tried to drive away (should be front wheel drive??) and nothing happened.

So put it back in, and then took out front driveshaft. Still made the noise.

Transfer case? I didn't think it could be transfer case, because It wasn't in 4WD when the noise started.

Gearbox? I don't think so, as no matter what gear I'm in (even reverse) it makes the noise regardless.


It's running quite a bit more power than factory, so driveline/axle related?
Any help is greatly appreciated.

[meatc]

Jack the back up and try the gears. If it has blown a CV it wont drivne in FWD only but will still make noise as you go down the road, even with unlocked hubs there could be bits touching the moving stuff enough to make a fair bit of noise.

[kbushnz]

Sounds like transfer case, either the output bearing it on its way out or the idler shaft bearings. These run all the time....And is a common area of wear / noise when they start to go....

Have you jacked it up and felt the diffs while rotating with no drive shafts
Check front with hubs on....
This eliminates the diffs....And what meatc said....
With the rear shaft off, and the transfercase in N, turn the output drive flange...Should feel smooth...not wiggly...

Drop the fluids and check for metal....

[OVOXO]

Yeah, I really wanted to put the thing on axle stands and get underneath it with a stethoscope, But My axle stands aren't big enough, so I'll have to buy some from work and try things throughout the week. Checked the rear diff fluid (through the filler hole) and the oil looks clean as. Haven't checked the front as of yet.

[tomsoffroad]

Checked the rear diff fluid (through the filler hole) and the oil looks clean as.

Pull the drain bung and check the magnet on it. The metal filings (if any) will be at the bottom

[T-Boon]

I have a pair of big ones, so just get 2 and borrow mine, Any further into the diagnosis ?

[OVOXO]

I'll text during the week Boon, I'll probably take your offer up.


I can't do much else till i get it spinning on the axle stands