Thread: Journal bearing failure modes (bloody 300Tdi's...)

Interesting. Not at all reassuring though. I've already had one engine fug up over big end problems (I suppose the stock oil pressure gauge in the Land Cruiser flatlining at idle was a warning enough of impending doom.)

Would it lead you to suggest that perhaps the big ends and mains ought to be changed out every 250,000 km?

Joel, there seems to be a lot of big end wear problems with 2/300Tdi's from 150-300,000km.
You remember Clarkie's thread from a couple of years back, you were on it too.
Fred Smith tipped him off, and I've seen a stack of people report the same problems with bearing wear since, but they've been straight out wear (copper backing showing through the lead/tin overlay)
I'm not sure what the overlay is on these ones of mine, I suspect either Glyco sputter bearings or aluminium, they are too shiny for lead/tin/copper in my experience.
They have a 'G' in a square and 'Z3' in a square then FB on the back of the slippers, then the LR pt. # underneath.

I think I'll use ACL F780 bearings, I had good success with them in the past compared to Vandervell competition bearings, better wear and more concentric and consistent, unless someone warns me off overnight
.....and I'm going to be cheap and keep the mains. I popped off # 4 today and it looks OK, a little shiny at the bottom but OK. I really don't want to have to pull the engine, i need to get it back to work, I'm using the Patrol ATM and I'll get into big trouble if I use it past this weekend.

you're trying to be difficult right? were you trying to get every failure mode known to man for shell bearings in one bearing set?....

ok. my internet is being slow so I cant just download the pics and the edit and repost them to hightlight what I mean.

for starters lets look at the second picture the shell on the right hand side.

Its got.

a stress fracture (the verticalish line about 2/3 of the way across from the left)
pitting caused by contamination behind the shell

the groove pattern thats sort of like 3 distinctly different wear patterns is about normal caused by the lubrication passage of the crank.

the other shell.....

well

its got galling (where a piece of foreign metal, probabley from the other shell spots itself onto the bearing surface then gets torn off taking some of the shell metal with it)
its got gouging (that groove up the top near the center best seen in the first pic)
theres something freaky happening with the locating tabs
it appears to have been moving in the journal (both have it, look closely at the ends of the shells where they mate the finish isnt the same across the face.


any chance of flicking it over and showing the back faces?


most probable causes.

1. poorly controled conditions during installation letting crap to get in behind the shell (the pitting)
2. big end out of round (shell movement and stress fractures)
3. injection timing early (galling and fractures)
4. labouring(galling)
5. low quality oil (galling)
6. loss of oil pressure. (galling and gouging)

My Disco is a 97 SE7 300TDI with 278000Kms and has had all its services including the gearbox with no failures to date, regular maintenance is the key I recon.
Gazz

Yeah, I know the galling/gouging/erosion/smearing bit but that's been bought on by the failed overlay migrating.

Yes, there's definitely been poor seating of the shell/contamination behind the bottom shell, (possibly oil during manufacture) but I'm not sure it's a stress fracture that you can see, as there are literally hundreds of lines across the bearing at 90* to rotation, that one is just the most visible.
Poor quality oil ? Not during my tenure but there was 76,000km of NT Govt. service before I started servicing it, so who knows.....

I'll post up some pics of the backs tomorrow sometime, it's very obvious where the shells weren't seating properly, and whatever else I find in the other shells.

Originally Posted by Gazz

My Disco is a 97 SE7 300TDI with 278000Kms and has had all its services including the gearbox with no failures to date, regular maintenance is the key I recon.
Gazz

Really ?

Originally Posted by Gazz

My Disco is a 97 SE7 300TDI with 278000Kms and has had all its services including the gearbox with no failures to date, regular maintenance is the key I recon.
Gazz

Great that yours is OK Gazza.
What do your big ends look like - any wear?
Also, what sort of usage does the vehicle - onroad/offroad/towing etc and are you still running factory injection pump settings?

SteveG

Gazz, here's a few big end threads.... http://www.aulro.com/afvb/technical-...y-300-tdi.html
http://www.aulro.com/afvb/technical-...humainity.html

and from a few PM's I've had over the last six months, there are a lot more that have been replaced too.