ltwt1981 Posted August 30, 2005 Share Posted August 30, 2005 Is it a relatively simple job to change a locker from 3.54 to 4.7 ratio. With the big tyres etc mine is now overgeared and 4.7 could be the answer. Quote Link to comment Share on other sites More sharing options...
LR90 Posted August 30, 2005 Share Posted August 30, 2005 Nige, sort of simple. That's what I had with my ARB, just put a 4.7 R&P on it with a spacer ring behind the ring and swapping out the pinion. but... the stock R&P didn't even last two punches!! 4.7 seems fine with an open diff, I've been running them with my Simex for over a year no bother, but lockers just let you get more torque to the wheels and stress the components far more. By all means try it but I'm now running that stock diff (thanks) while I save for a set of 4.75 R&Ps Quote Link to comment Share on other sites More sharing options...
jules Posted August 31, 2005 Share Posted August 31, 2005 There is amasive improvement on your control and reduced clutch wear. Quote Link to comment Share on other sites More sharing options...
LR90 Posted August 31, 2005 Share Posted August 31, 2005 Agreed the lower gearing is great. Changing R&Ps is one route with crawler gears and crawler boxes being others. The R&Ps are still the cheapest option and I could always add a crawler box later Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted August 31, 2005 Share Posted August 31, 2005 DONT DO IT! I have just bitten the bullet and gone up to 3.5's after a year of running 4.7's (rear Detroit, front ARB), I have got so fed up with breaking diffs - around 14 of them! I agree totally with the low gearlow speed theory though, so, in desperation to keep the drive ratio's right, I am also fitting an LT77 to bring the 3.54 back into line. Roger Quote Link to comment Share on other sites More sharing options...
LR90 Posted August 31, 2005 Share Posted August 31, 2005 Did you try any of the aftermarket (KAM, Great Basin) 4.75 R&Ps though? Reads90, Tonk and several others on here have been running these for a while now with no bother. IIRC shearing the bolts that hold the ring on is the next point of weakness they have found Quote Link to comment Share on other sites More sharing options...
ltwt1981 Posted August 31, 2005 Author Share Posted August 31, 2005 Many thanks I must now give it some thought, I'm in a series 3 with 2.25 petrol so not overpowered. Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted September 1, 2005 Share Posted September 1, 2005 Did you try any of the aftermarket (KAM, Great Basin) 4.75 R&Ps though? I am the original "off- roader on a budget" - Im sad to say Quote Link to comment Share on other sites More sharing options...
LR90 Posted September 1, 2005 Share Posted September 1, 2005 I thought I was I'll still be running 4.7 on an open diff in the front for a while yet so its only one gearset for the back but yes it is more money than I'd intended spending just yet. Still a lot cheaper than some of the other alternatives though. Quote Link to comment Share on other sites More sharing options...
Adrian Turner Posted September 1, 2005 Share Posted September 1, 2005 Hi all Just to add my bit, I tried 4.7 diff's in my v8 hi-brid with 35'' simex's, both had arb's installed, They only lasted one outing damm thing's went back to 3.54's for now but will change to 4.11's in time Regards Adrian, Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted September 1, 2005 Share Posted September 1, 2005 Nige. Few points : 1. The lower the gearing (3.54 - 4.7) means lower then the more stress is in the unit, and most 4.7s are old and tired.. 2. The 4.7 casings and 3.54 casings are different there are about 4 sets, sometimes you just need different carrier bearings, sometimes you may need to grind away the inside of the casing to clear your (bigger) centre / locker 3. You have series gearing 4 speed, so very differeenrt to Lt77 / LT85 etc...so yes it makes a huge amount of difernce. 4. 35 inch simesx, and 2.25 Petrol + 235 85 16 Grizzlys are a world aprt, fret yee not too much ! 5. There are HD ring and pinions maybe worth looking at..... ? Nige Quote Link to comment Share on other sites More sharing options...
dirtydiesel Posted September 2, 2005 Share Posted September 2, 2005 4.75 : 1 kam R&Ps still break!! Quote Link to comment Share on other sites More sharing options...
ltwt1981 Posted September 2, 2005 Author Share Posted September 2, 2005 Thanks all, I know it will cost money, first half shafts cos they break regularly, then diffs. Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 2, 2005 Share Posted September 2, 2005 Yes - just need the spacer ring and longer bolts. I'm running stock series 4.7's on arbs front and rear on my series, with a V8 and the biggest grizzlies and havnt broken one yet. In fact the only 4.7 diffs I've ever broken were stock ones! It all seems to depend on how you set them up, although I fully admit that they're not the strongest. I've swapped a 4.7 into a 3.54 case before now so it can all be done. Cheers Jon Quote Link to comment Share on other sites More sharing options...
ltwt1981 Posted September 2, 2005 Author Share Posted September 2, 2005 Jon I have some 4.7 diffs in the garage, will the detroit guts fit in these or do I have to use the 3.54's I have in the LR at present. Quote Link to comment Share on other sites More sharing options...
istruggle2gate11 Posted September 2, 2005 Share Posted September 2, 2005 The detroit diff should fit in a 4.7 case no problems, as Jon said, sometimes you might have a clearence issue, I had one with my arb in a 3.5 case (I had to grind away about 2mm off the inside of the bearing cap) but a couple of mins with a grinder will sort that. If you are using 4.7's (imperial cases) you will need bearing sleeves and spacer plates, available from Ashcroft, or if you can wait a couple of weeks, I have 2 x spacer plates and 1 pair of bearing adaptors. (I had to use the 2nd pair of bearing sleeves on one of my 3.5 diffs as it was still an imperial case, but didnt require the spacer plate due to the larger pinion) Spacers are £18 each + VAT from Ashcroft Bearing Sleeves are £20/pair + VAT from Ashcroft + Delivery If you can wait a couple of weeks (I need to prove my conversion to 3.5's first) then you can have my spacers and 1 pair of sleeves for £30 + Postage. Let me know if you want them. Rog Quote Link to comment Share on other sites More sharing options...
Jon White Posted September 2, 2005 Share Posted September 2, 2005 Yes - should do - you'll just need the spacer rings and longer bolts as I said. If the detroits are 10 spline, then they'll drop straight in. If they're 24 spline you'll need the bearing adaptors. Spacer rings can be had from Kam over in godalming for a few quid (he does deals for cash). You'll need to check the threads for the longer bolts however as some diffs are BSF and some are UNF. Cheers Jon Quote Link to comment Share on other sites More sharing options...
LR90 Posted September 2, 2005 Share Posted September 2, 2005 Fitting it to the 4.7s is simpler (though as stated above you will need the bearing carriers) as you won't need to mess with the pinion. I got so far trying to fit my ARB with 4.7s in a metric case and had to pass it to Tonk in the end. Quote Link to comment Share on other sites More sharing options...
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