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| Grenadier Member Since: 23 Jul 2014 Location: The foot of Mont Blanc... Posts: 5829   
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Was watching a YpuTube video by a well-known classic Defender specialist ,on various mods they do to their uograded/improved Defs. Recent episode included a very nice axle set, including new diffs and some nice BB calipers.
So it led me down the rabbit hole of Differentials and it made me wonder what the differences or advantages of one over the other are. OEM, LSD, 4-pin, Pegged etc. To keep things simple, rather than going over all the various set-ups and their positives and negatives, I'm offering a hypothesis based around my Def and its usge. Puma 2.4 110 DCPU Stage II Remap Standard Gearbox 18" Bowler Wheels Single Piece Half Shafts (Eventually) Gwyn Lewis propshaft 99% Road Use - mainly mountain A-roads, 3rd/4th gear, lots of gear changes Daily driver Occasional towing Of all the types of Diff available, whether stock or upgrade, which would be best suited for the Def I have, what's been done to it? Just wondering.....  Monsieur Le Grenadier
I've not been everywhere, but it's on my list..... 2011 Puma 110DC - Corris Grey |
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2nd Aug 2023 10:18am |
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| Grenadier Member Since: 23 Jul 2014 Location: The foot of Mont Blanc... Posts: 5829
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Thanks Chicken Drumstick (yum
 )
Basically, as per the OP, my driving is mainly road and mainly mountains. So a lot of bends, dropping down a gear, accelerating away, back up a gear.....and repeat. With it being remapped, a 110 and my type of driving, at most you'd think a 4-pin would be the one to upgrade to, if indeed any at all? Monsieur Le Grenadier I've not been everywhere, but it's on my list..... 2011 Puma 110DC - Corris Grey |
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2nd Aug 2023 10:32am |
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| geobloke Member Since: 06 Nov 2012 Location: Nottinghamshire Posts: 4410 
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Hi Grenedier.
From my experience the standard front 2 pin Rover diff is fundamentally flawed on a TD5 or Puma era Defender. I have now been through two of them in my time with Miffy and both times it has been the diff centres that have fallen apart. The replacement this time is an Ashcroft ATB and that is due to reported strength and driving benefits associated with the torsion style diff. The latter is important to me as Miffy does not have ABS or TC so the additional traction aide on and off road will be appreciated. As for the rear P38 diff that falls squarely into some of the posts I have been making this past month. In particular the P38 rear diff poll https://www.defender2.net/forum/topic88673.html?highlight=p38 The same applies to the back as the front, I have managed to get my hands on an ATB for their too and will be installing it shortly. The P38 is reputedly a weak diff, compared to its predecessor the salisbury, however the poll doesn't bear witness to that and I suspect if all P38 Defender owners were to vote the stats would just widen further. When investigating options for both diffs a few months back and speaking to Ashcroft and others, they recommended either the ATB or the 4 pin diff centres for my application which is a bit of everything, all the time. As for pegging of diffs, I believe and I may be proved wrong here, that this is utterly belts and braces and not necessary for the general use owner. Unless you have significantly larger tyres fitted of the 35" ilk then the additional ring gear support might be overkill. On the topic of bigger tyres it is worth noting that with every inch of taller tyre the ATB behaves approximately 3% less efficiently, so a standard 32" tyres will get more benefit from an ATB than the taller 35" tyre by approximately 10%. What that means in practice I do not know as Miffy is still up on axle stands, but 10% could be significant. I decided not to renew my CVs or half shafts or flanges because IMHO these are the fail safe for the diff. If they break during use that is OK, they owe me nothing being close to 250k miles old. Plus it is worth knowing that the upgraded CVs from Ashcroft require a new pair of swivel balls and hubs to accommodate the larger proportions of the CV. If and when one of those components gives up the ghost, I will be replacing with standard items. Hope that helps. |
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2nd Aug 2023 10:45am |
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| Chicken Drumstick Member Since: 17 Aug 2020 Location: Near MK Posts: 751
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Do you find you ever get any wheel scrabble at all on the tight bends (probably the inner front wheel if you do)? And do you drive in slippery conditions such as snow and ice? The 2 pin diff at the front is weaker, but I'm not sure many have failed with normal road use. It is off road and using the traction control that was breaking them as a rule. Likewise with the rear, the age of your 110 should have the p38 based short nose diff. Which I think will be a 4 pin already. It is a 4 pin in the rear of a 4.6 p38, but never checked for a 110. I'd be most surprised if it caused an issue on road for you. Limited slip diffs, such as ATBs would work well on snow and slippery surfaces. But unless you are getting wheel scrabble and spin I think the gains would be very minimal on road. If you drive hard enough to see plough on understeer, a front LSD might help prevent this a bit. But you do need to be driving it like a Subaru Impreza or hot hatch to really reap the benefits. |
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2nd Aug 2023 11:07am |
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| geobloke Member Since: 06 Nov 2012 Location: Nottinghamshire Posts: 4410
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Not in my case. Two 2-pin front diffs and mostly road and touring. I am incredibly mechanically sympathetic when driving on or off road. These diffs are just too weak for the more powerful Defender. |
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2nd Aug 2023 11:11am |
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| Oldowner Member Since: 26 Dec 2018 Location: South west Posts: 625 
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Personally I would be fitting an Ashcroft 4 pin front (doesn’t need pinning etc) and leaving the rest as is as the standard 4 pin 110 rear is plenty good enough for your usage.
Both my 90’s have the Ashcroft 4 pin front, one has Trutrac rear, other has Ashcroft ATB rear, however these were to replace the rubbish 2 pin rears that the 90’s have. |
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4th Aug 2023 6:14am |
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| Grenadier Member Since: 23 Jul 2014 Location: The foot of Mont Blanc... Posts: 5829
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I do occasionally drive it like a Subaru but not often enough to warrant changing up to a LSD. Similarly, no noticeable slippage etc. The question was more aorund slop/slack and strength. Monsieur Le Grenadier I've not been everywhere, but it's on my list..... 2011 Puma 110DC - Corris Grey |
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4th Aug 2023 8:00am |
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| MercianRover Member Since: 07 Apr 2022 Location: Culworth Posts: 141 
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I found that with a Quaife ATB in the rear of my 100" cornering radius under power was tightened.
Now the same car has LSD front and rear the effect is more noticeable, especially in wet weather. More predictable handling with variable grip. Both these cases the centre differential lock was open. |
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4th Aug 2023 8:43am |
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| landy andy Member Since: 15 Feb 2009 Location: Ware, Herts Posts: 5726 
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Reads to me that a standard four pin would be good for you. Far stronger that the two pin, which I have broken a few of. Can’t see that you require anything higher ability than that. You can probably pick up a unit that been removed by someone upgrading diff, so will be a cheap upgrade if you are currently running a two pin.
Why do you want GL props? From your written description of use aren’t they overkill? |
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4th Aug 2023 9:21am |
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| Grenadier Member Since: 23 Jul 2014 Location: The foot of Mont Blanc... Posts: 5829
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Continued thanks to all.
LA, for the props, merely because it will eventually be stage 2 tuned, because it's a Puma (so the geabox/TC/prop angle thing), and because I think my UJs take a beating because of the number of occasions I have to head into a hairpoin bend, drop down from 4th to 3rd or even 2nd, then accelerate out of the bend and up the next straight to the next bend or hairpin bend just a few hundred metres away. And on many of these roads that can be 'and repeat' for 10, 20 even 30kms. I think when stage 2 tuned it will only take more of a kicking. Oh, and I like the blue of the GL versions. But on all of the above I stand to be corrected. Monsieur Le Grenadier I've not been everywhere, but it's on my list..... 2011 Puma 110DC - Corris Grey |
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4th Aug 2023 11:16am |
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| Grenadier Member Since: 23 Jul 2014 Location: The foot of Mont Blanc... Posts: 5829
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LSD is interesting as I do drive on snow, on ice, on cold wet roads throughout through late autumn to spring, and as mentioned elsewhere on this thread, negotiate many hairpins on certain roads, which will undoubtedly create different wheel speeds between inside and outside of each bend. So might be worth considering? Here's an example of just one road I have to use fairly frequently:  Click image to enlarge Monsieur Le Grenadier I've not been everywhere, but it's on my list..... 2011 Puma 110DC - Corris Grey |
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4th Aug 2023 11:49am |
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| MercianRover Member Since: 07 Apr 2022 Location: Culworth Posts: 141
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Twisty.
I prefer the ATB because there are no friction parts to wear. The only reason I changed from ATB was that the axles I fitted were built up with the rare KAM locker / LSD centres, otherwise I would have fitted an ATB in the front too. |
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4th Aug 2023 12:07pm |
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| Grenadier Member Since: 23 Jul 2014 Location: The foot of Mont Blanc... Posts: 5829
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Monsieur Le Grenadier
I've not been everywhere, but it's on my list..... 2011 Puma 110DC - Corris Grey |
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4th Aug 2023 12:24pm |
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