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Diff pegging


treebloke
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I did a search but nothing came up related.

Trashed a crown wheel and pinion last saturday so will no doubt be replacing with Ashcroft ones which is a DIY job but wondered if its worth pegging the diffs while its out which most definately is not a DIY job. Not for me anyway.

£200 to peg a diff I believe.

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I have a pair of Ashcroft 4.1 CW&P 24 Spline ARBs and they were pegged by them too.

Prev I used to shear teeth from CWP, pegging has removed this weakness of the Crwonwheel to flex under load.

No, not cheap, but when a CWP lets go it does the ARB internals no good either

If you can afford it its a worthwhile beefup mod :)

Nige

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Yup - well worth it. Both of mine are pegged as I was breaking a diff per outing at one time!

Not hard to do if you've access to the necessary kit and materials, but if not I'd be paying Ashcrofts.

If you do decide to do it yourself you need to ensure you use phosphor bronze for the slipper pad.

Jon

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Am I missing something here, how can 2 M16 studs and a piece of phosphor bronze cost £200?

I know there's work required to put the plate on, drill, tap, and set the diff up, but £200?

I'm genuinely curious, there must be more to it than that... surely?

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Rakeway pegged my diffs. Very neat job. Not seen an ashcroft pegged diff to compare with though.

Cost wise you need to allow for:

materials - bit of phospour bronze, two of M16 bolts and a bit of steel to reinforce the diff housing

Time wise say 4 hours to strip diff, preheat and weld on reinforcing pad, set up in milling machine and spot face, drill and tap M16 threads, reassemble diff.

If you allow £40 hour that comes to £160.

Materials, say £10.

That leaves £30 profit.......

Your not going to make your millions on that kind of work.

Adrian

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I did a search but nothing came up related.

Trashed a crown wheel and pinion last saturday so will no doubt be replacing with Ashcroft ones which is a DIY job but wondered if its worth pegging the diffs while its out which most definately is not a DIY job. Not for me anyway.

£200 to peg a diff I believe.

Suggest you give Ashcroft a call and get a quote for replacing cwp and pegging at the same time.

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I was told by Rakeway if you use the thicker 4.7:1's (I think but i'm struggling to remember the ratio) that pegging is not then required as there is no way you can cause the thicker crown wheels to move or flex under shock away from the pinnion,

so changing the crown wheel and pinion is not really that much more expensive than pegging, which is not the be all and end all because the pegging can cause the diff casing to break under shock,

food for thought

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I was told by Rakeway if you use the thicker 4.7:1's (I think but i'm struggling to remember the ratio) that pegging is not then required as there is no way you can cause the thicker crown wheels to move or flex under shock away from the pinnion,

so changing the crown wheel and pinion is not really that much more expensive than pegging, which is not the be all and end all because the pegging can cause the diff casing to break under shock,

food for thought

I have my doubts, Ive run 4.7s on arbs, could trash them for fun, went to 3.5's and only had 2 failures with regard to R+P stripping.

2nd failure happened this weekend (along with a GKN shaft) , so the ARBs are out, and going to be pegged, but cant find any phosie bronze lying around, anythoughts on just leaving a bolt head with a thou or 2 clearance?

I figure, that for the few times it might touch, the oil in the diff will do its job?

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I was told by Rakeway if you use the thicker 4.7:1's (I think but i'm struggling to remember the ratio) that pegging is not then required as there is no way you can cause the thicker crown wheels to move or flex under shock away from the pinnion,

Other way round. The 4.7 ratio is the weakest due to its larger diameter crown wheel and more likely to flex. The 3.54 is smaller diameter and does not flex as much so there is less need for pegging. I also think the pegging stops some of the issue with crown wheel bolts coming loose/stretching. If you can I'd peg them Bob. And as Breg90 says, £200 is quite reasonable, Anyone who thinks not needs to try running a business.

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If you can I'd peg them Bob. And as Breg90 says, £200 is quite reasonable, Anyone who thinks not needs to try running a business.

Absolutely spot on!

Thought about doing it my self as I have a complete machine shop, Looked at the job properly, costed it, had a laugh and gave the job to Dave, I couldn't do it for 200 quid!!

As for correctly setup diffs not needing pegging! with standard power, surely not. But with serious grip and decent power, you 100% do! It's not just the ring gear you need to think about! I stretched cap bolts too, they are only 8.8 as standard!!!! Changed mine to 12.9s Caps and saddles flex, even the diff case will flex with enough grunt! Anything that helps will save a lot of grief in the long run.

Lara.

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Rakeway pegged my diffs. Very neat job. Not seen an ashcroft pegged diff to compare with though.

Cost wise you need to allow for:

materials - bit of phospour bronze, two of M16 bolts and a bit of steel to reinforce the diff housing

Time wise say 4 hours to strip diff, preheat and weld on reinforcing pad, set up in milling machine and spot face, drill and tap M16 threads, reassemble diff.

If you allow £40 hour that comes to £160.

Materials, say £10.

That leaves £30 profit.......

Your not going to make your millions on that kind of work.

Adrian

Thanks Adrian, makes a bit more sense now :)

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Agree - I did my own and I reckon the machining and welding alone took me more than 4 hours. Add some time in for stripping and re-building the diff and you're into an awful lot for your money!

Bear in mind phosphor bronze aint cheap either! The slipper pad is also quite an awkward little chape to make and theres a fair amount of machining in making that alone!

I dont agree with whoever says properly set up diffs dont break. I broke so many ring and pinions before pegging, and after pegging havnt had a single breakage. I had my diffs set up by the guy who does Jez's Volvo ones, so you're not telling me that they werent set up right - they're just not strong enough! I broke one on 7.50 muds on a standard 2.25 petrol engine for gawds sake!

Jon

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Other way round. The 4.7 ratio is the weakest due to its larger diameter crown wheel and more likely to flex. The 3.54 is smaller diameter and does not flex as much so there is less need for pegging. I also think the pegging stops some of the issue with crown wheel bolts coming loose/stretching. If you can I'd peg them Bob. And as Breg90 says, £200 is quite reasonable, Anyone who thinks not needs to try running a business.

True Steve but also the 3.54 has a very thin crownwheel so pegging should do quite a bit. Apart from helping stop crownwheel flex it takes some of the load off the crownwheel bolts and stiffens up the housing which can flex resulting in poor ring and pinion mesh (increasing chance of failure).

Some say pegging isn't necessary and in many cases it isn't but, like Lara, if you are using Rover diffs in high stress applications then its a wise move. £200 isn't a lot of money considering the work - it all adds up. Ashcrofts strip, clean, weld up (the sticks to do this are very expensive as you're welding steel to cast iron), supply parts, tap the new plate, repaint housing, reassemble. For £200 its a very small price to pay for increased durability.

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2nd failure happened this weekend (along with a GKN shaft) , so the ARBs are out, and going to be pegged, but cant find any phosie bronze lying around, anythoughts on just leaving a bolt head with a thou or 2 clearance?

I figure, that for the few times it might touch, the oil in the diff will do its job?

Erm :blink:

Phosp bronze is used due to it properties of slide, and it will in effect polish the crownwheel face on contact.

Having a bolt head or two will give you absolute "Feedback" as to them meshing :ph34r: and will act like a lathe tool over time, as it will pick up on the face with heat and friction, untimately I think "Mr F Me ThatwereaBang" will revisit you

Jon IIRC bought a lump off ebay :lol:, as others have said its a load of work, with the ashcroft 4.1s the arb centres have to be popped in a lathe to machine a bit as the CW is so much thicker.

The strength of LR diffs varies between CW&P those that have many teeth on a small pinion are weakest, some (as a la Ashcroft) the pinion is much bigger and the teeath less so bigger etc, and the Crownwheel thicker - but pegged as well ended my chipping teeth away on a regaulr basis :)

Worth every penny, the casting welding is a REAL PITA and requires skill, and then there the machining etc and building, not a DIY mit drill n hammer job :)

or bolts for pad :P...oh and <cough> Degrease tank pleeeeeeeeeeeeeeeeeeeeeeease Rog :) ??)

Nige

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Sorry

I take it all back

This below proves that you can peg your diff yourself at home, you just need

a hobby welder, hammer, B&D Drill ('near enough straight' model) a bent screwdriver few bits of loose change and a couple of nice long bolts

Enjoy; http://forums.lr4x4.com/index.php?s=&s...st&p=103799 :rofl:

Nige

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Obviously I understand the benefits of using Phosie, but.......

Be warned, it takes an age to load

Just bearing in mind, mines a mud plugger, never sees the road!

oh and <cough> Degrease tank pleeeeeeeeeeeeeeeeeeeeeeease Rog :) ??)

Nige

Mate, in Bristol next Thursday, could swoop your way and collect then?

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Sorry

I take it all back

This below proves that you can peg your diff yourself at home, you just need

a hobby welder, hammer, B&D Drill ('near enough straight' model) a bent screwdriver few bits of loose change and a couple of nice long bolts

Enjoy; http://forums.lr4x4.com/index.php?s=&s...st&p=103799 :rofl:

Nige

I don't remember welding Jon's diff for him.... :ph34r:

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