jai_landrover

Well-Known Member
Hi there how many people have broken their diffs in p38's etc just trying to get some numbers and ideally a couple of examples especially if they re the 4 pin centre type want to inspect them closly of poss.

Might have some some beer money if people are willing to provide samples.

Cheers
Jai
 
My front diff in my 2000 4.0 thor was completly shot at 120k, the planet gear pin wore in the crownwheel carrier and was moving around about 10mm where it had worn a huge slot, pinion bearings were completly gone too but that could have been swarf from the carrier wearing, in 30 years as a mechanic never seen anything like it...?
 
thats interesting was that a 4 pin?

i know LR have modded the oil ways in the pins for added lube but if its that bad this would be an emergency measure to slow it down and not fix the problem.
 
My rear diff went at about 130,000 miles - not sure what it was, the local LR specialist fixed it, it didn't lock up or anything, just lots of vibration and they traced it to there.
 
my front 2 pin locked solid in slow traffic on M4 at ~160k. It locked so quickly that I didn't even have time to get across to the hard shoulder. Police couldn't shift it an inch with their 4x4. The RAC guy came and undid the propshafts (thinking it was the gearbox) - of course it still didn't move. Took a seriously big commercial winch to drag it onto a low loader
 
extra lube holes etc isnt important it runs in oil the brg closet to flange wears first ,it puts crownwheel and pinion out eventually to failure,usually caused by not changing oil regulary
 
extra lube holes etc isnt important it runs in oil the brg closet to flange wears first ,it puts crownwheel and pinion out eventually to failure,usually caused by not changing oil regulary


I could be wrong but I believed that the later diffs had larger bearings?

The above crownwheel and pinion misalignment wouldn't cause the centre pin to wear in the carrier it would cause missing teeth on the crownwheel/pinion. It would be good to get an example of a damaged carrier I'll keep my eyes peeled.
 
I guess its possible that the cross pin (in a single pin diff) has picked up welded itself to one of the two gears and the other end spins in the carrier wearing a groove at that end. I know early diffs the gears can pick up the pin weld itself to it and snap in half but I've never seen one wear a grove in the carrier. Many a broken carrier/gears but never elongated a hole in the carrier.
 
I've had two front diffs go in my 1993 classic, the first one ground the sun and planet gears almost bald before I really felt something horrible happening to the steering, the only telltale for weeks before was an occasional "clonk" on full lock. You wouldn't have believed the mess when I took the diff out!
The second snapped the cross shaft and locked up solid. I stopped immediately and stripped it out, it had made a nasty mess of the diff carrier, but the gears themselves were ok.
 
its more likely that viscous stiffening is putting pressure on diff shaft and gears as is more of a problem on rr
 
Viscous stiffening? I've not heard of that one before but it sounds very interesting. What is the reasoning behind how it happens?
 
the viscous coupling in front of t/box output housing eventually sieze putting strain on system especially diff gears
 
James, thanks for the tip, sadly you were quite right, the coupling has seized solid and has caused me numerous problems with other bits of the transmission in the recent past. I wish I had checked it out earlier; still you live and learn. It's my next job to replace the coupling, in the meantime front prop is now removed to save me any more broken bits!
 
mate pulled a tooth off diff towing a stuck 7.5 ton lorry
 

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