Why do Disco diffs go bad?
#1
#2
I was told traction control puts a beating on the 2 pin carrier design.
the nature of how the traction control is sending a pulsing drive transferred thru the ring/pinion wears.
i was even given a theoretical amount of traction control uses before the carrier would see its limit! (Aprox 100x)
now I’m sure there is plenty of first hand experience here to conflict that.. Off-road use and on. Mine had roughly 165k on them. And 40k of the last included some good off roading.
I did notice as I serviced my rear the front was in similar condition on its way out.
the nature of how the traction control is sending a pulsing drive transferred thru the ring/pinion wears.
i was even given a theoretical amount of traction control uses before the carrier would see its limit! (Aprox 100x)
now I’m sure there is plenty of first hand experience here to conflict that.. Off-road use and on. Mine had roughly 165k on them. And 40k of the last included some good off roading.
I did notice as I serviced my rear the front was in similar condition on its way out.
#3
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Jetfiremuck (02-16-2020)
#4
#5
@redwhitekat That is largely because they do go but usually with higher mileage. One of the issues is as alluded to by @SundayFunday is traction control but there is little more to it.
Used as intended by the designers traction control does not really load up the diff very much, the intended use is:
If that type of usage is common your diff is going to fail sooner rather than later, go on to a forum where the the 4x4 guys are primarily mudders lots of killed diffs. All from way to much throttle when spinning them something catches it puts a lot pf stress on the internals.
Poor maintenance is another issue, but 20000 miles is long time for fluid changes in a diff for a truck used off road a lot. I do mine every 2nd year or about 6000 miles, but it is a second vehicle and I go through a lot of water.
Gear oil matters too heavy is bad as it too light it is a splash lubrication system so need to stay with in sort of an ideal band
Used as intended by the designers traction control does not really load up the diff very much, the intended use is:
- Slow speed
- Low revs
- Very light throttle increasing gradually
If that type of usage is common your diff is going to fail sooner rather than later, go on to a forum where the the 4x4 guys are primarily mudders lots of killed diffs. All from way to much throttle when spinning them something catches it puts a lot pf stress on the internals.
Poor maintenance is another issue, but 20000 miles is long time for fluid changes in a diff for a truck used off road a lot. I do mine every 2nd year or about 6000 miles, but it is a second vehicle and I go through a lot of water.
Gear oil matters too heavy is bad as it too light it is a splash lubrication system so need to stay with in sort of an ideal band
#6
This is from the Ashcroft site:
A standard 2 pin diff centre, as fitted to all Discoveries, Defender 90's and Defender 110/130 front diffs can be a weak point in the drive train as the single cross pin can either friction weld to one of the planet gears which then spins and wears the casing hole or they can just shear, either way the 2 pin stock diff will not take much off road abuse before failing. They also wear prematurely if the traction control is used excessively ie in sand etc.
https://www.ashcroft-transmissions.c...ff-centre.html
My rear diff went out last year when off-roading. I replaced it with this Ashcroft 4-pin rebuilt diff.
I hear the 4-pin reverse-cut gears for the front diff is the way to go for reliability.
A standard 2 pin diff centre, as fitted to all Discoveries, Defender 90's and Defender 110/130 front diffs can be a weak point in the drive train as the single cross pin can either friction weld to one of the planet gears which then spins and wears the casing hole or they can just shear, either way the 2 pin stock diff will not take much off road abuse before failing. They also wear prematurely if the traction control is used excessively ie in sand etc.
https://www.ashcroft-transmissions.c...ff-centre.html
My rear diff went out last year when off-roading. I replaced it with this Ashcroft 4-pin rebuilt diff.
I hear the 4-pin reverse-cut gears for the front diff is the way to go for reliability.
Last edited by acg; 02-08-2020 at 04:40 PM.
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Discorama (02-09-2020)
#7
This is from the Ashcroft site:
A standard 2 pin diff centre, as fitted to all Discoveries, Defender 90's and Defender 110/130 front diffs can be a weak point in the drive train as the single cross pin can either friction weld to one of the planet gears which then spins and wears the casing hole or they can just shear, either way the 2 pin stock diff will not take much off road abuse before failing. They also wear prematurely if the traction control is used excessively ie in sand etc.
https://www.ashcroft-transmissions.c...ff-centre.html
My rear diff went out last year when off-roading. I replaced it with this Ashcroft 4-pin rebuilt diff.
bbbvvbbbbbvvbbbbbbb
I hear the 4-pin reverse-cut gears for the front diff is the way to go for reliability.
A standard 2 pin diff centre, as fitted to all Discoveries, Defender 90's and Defender 110/130 front diffs can be a weak point in the drive train as the single cross pin can either friction weld to one of the planet gears which then spins and wears the casing hole or they can just shear, either way the 2 pin stock diff will not take much off road abuse before failing. They also wear prematurely if the traction control is used excessively ie in sand etc.
https://www.ashcroft-transmissions.c...ff-centre.html
My rear diff went out last year when off-roading. I replaced it with this Ashcroft 4-pin rebuilt diff.
bbbvvbbbbbvvbbbbbbb
I hear the 4-pin reverse-cut gears for the front diff is the way to go for reliability.
I found a super nice used one on eBay from a dead Disco for $100.
#8
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Brandon318 (02-10-2020)
#10
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