3rd member swap

[scott]

i trashed an axle and exploded the spiders on my rear axle. i'm looking at a couple of 3rd members out of a range rover classic that look pretty much like the iia's. they use the same gasket which says the bolt pattern is the same. if the distance from the drive flange to the gasket suface is the same and the distance from the gasket surface to the center of the gear that fits the axle is the same, can anyone think of why they couldn't be swapped?

[Leslie]

You can put RRC/Disco/Def 3rd's into a Series. Been done before many times.

Thing is, your Series has 4.7 gears, the RRC is a 3.54.... so, while you might do better at cruising speeds, it'll be harder for the 2.25 to get you there, and off-road, you won't have the lower gearing.....

FWIW...

[a109]

You can put RRC/Disco/Def 3rd's into a Series. Been done before many times.

Thing is, your Series has 4.7 gears, the RRC is a 3.54.... so, while you might do better at cruising speeds, it'll be harder for the 2.25 to get you there, and off-road, you won't have the lower gearing.....

FWIW...

You also will have to replace both diffs as the ratios would otherwise be different.
John

[yorker]

you can swap the RR diffs in, if they are 24 spline you can get upgraded series shafts for them too from Jim at Series trek. If you want to use 4.7 ring and pinion you should be able to swap those in to the RR diffs. Later RR diffs use different bearings (metric vs imperial)than series diffs but if you swap it all together it should work. This is a common swap in the UK. You might need a spacer for the ring gear to make it fit the 3.54 RR carrier because the 3.54 is thicker than the 4.7 ring gear. Those spacers are like $10 or so IIRC GBR has them.

[scott]

thanks all. yes i bought 2 knowing i might have to do the front. i was hoping to swap the ring & pinon so i coud keep the low end. can any of you guys id the critical measurement, how exact will i have to shim the 4.7 serries iia ring when i replace the rrc 3.5. for me the best part of owning a rove is nothing is exact, just get it close and it'll run

[yorker]

I have one of those spacers I can measure for you. I think it was like .1" but that is just a guess, I'll get back to youy tomorrow or tonight

BTW You can buy those spacers from ashcroft too.
http://www.ashcroft-transmissions.co.uk/part_7.html

also BP has them:http://www.britishpacific.com/landro...RBlockers.html

AB:
http://www.roverparts.com/Parts_Acce...ferentials.cfm


The real way to go would be to get 24 spline 3rd members from a 94 disco and do the swap with a set of the HD 24 spline axles. Later you could get a truetrac or detroit as well.

[scott]

oh yea! that who be a sweet set up and is it's what i want eventually, but i'm getting these 2 rrc 3rd mbrs delivered for less that $150. a bud gave me his spare 10 splines. not too bad, 2 hrs of fun in the dirt and it only cost me $150 (plus another after the holidays to replace the borrowed axles) and about three hrs of knuckle bang'n. are you sayig that there's only one size shim, 0.1 in?

[yorker]

Yeah there is only one size shim, any of those spacers from the above sources should work. Might need longer bolts too depending on the age of the RR diffs you got.

[a109]

thanks all. yes i bought 2 knowing i might have to do the front. i was hoping to swap the ring & pinon so i coud keep the low end. can any of you guys id the critical measurement, how exact will i have to shim the 4.7 serries iia ring when i replace the rrc 3.5. for me the best part of owning a rove is nothing is exact, just get it close and it'll run

You'll only need to shim for pinion height since the ring is freely adjustable side to side.

John

[scott]

you're scar'n me now. i was thinking of using my oringinal 3rd member leaving the pinion gear where it is. i was going to pull and swap the spider gears and the thing that holds 'em. i figured all i'd have to do is pull the ring gear off the rrc's and put my iia ring gear with the 0.1" spacer i just ordered and drop it back into my original 3rd mbr housing. am i not on track here?