300 M rear axles and flanges

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105 hubs are quite a bit beefier.

Bolt PCD for axle flange studs went from something like 94mm PCD to 106mm. Not certain of measurements, is a long time since I measured all this.

One thing that might be a fly in the ointment is the amount of material left on an 80series hub.
If a blank 80series hub was available to machine to suit 105series flange and hardware, there may not be enough meat at the outer diameter to capture the hardware due to greater diameter PCD and thicker hardware


Wheel centre hole is larger on 105 rims to cope with the bigger hubs

Someone needs to do some measuring
Think @mudgudgeon and @cruiseroutfit, right

Measured 43422-60070 and 43422-60040, rear axle hub gaskets for the 105/7x and 80, respectively.

Overlaid on top of each other, you can tell they don't quite match up.

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So, is everybody still happy with their RCV 300M rear axles? Was checking my rear bearings today and saw that the long side rear shaft was twisted and chewed up. These are OEM. Guess it's time to upgrade? Not going with Nitro that's for sure.

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Not sure how much you want to mess with it, but you could use a 100 series rear 3rd and see if RCV would make you 32 spline axles as an upgrade for the 30 spline. That is my plan.

Gearing is limited to 4.88s though, right? That's a big downside. Can't see myself giving up the 5.29s
 
So, is everybody still happy with their RCV 300M rear axles?
Cruiser Outfitters steered me away from the 300m axles after hearing that I drive a significant distance, 4 hours, to the trail. They said the 300m axles wear fast on the road.

I asked about RCV 4340 rear axles and they said RCV doesn’t make them since the stock axles are so strong. Read a post yesterday that said RCV does make 4340 rear axles, but doesn’t advertise the fact. I find that hard to believe, but might be worth a call to RCV if you’re concern about road wear on the 300m axles.
 
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Cruiser Outfitters steered me away from the 300m axles after hearing that I drive a significant distance, 4 hours, to the trail. They said the 300m axles wear fast on the road.

I asked about RCV 4340 rear axles and they said RCV doesn’t make them since the stock axles are so strong. Read a post yesterday that said RCV does make 4340 rear axles, but doesn’t advertise the fact. I find that hard to believe, but might be worth a call if you’re concern about road wear on the 300m axles.
I’d be asking RCV about their products.
 
So, is everybody still happy with their RCV 300M rear axles? Was checking my rear bearings today and saw that the long side rear shaft was twisted and chewed up. These are OEM. Guess it's time to upgrade? Not going with Nitro that's for sure.

you remind me I need to pull my Nitros and see if the twist they had last I saw has increased. May be time for me to RCV.
 
Front but I will just leave this here.

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Yup that is five lug as well. Both 105’s and 78/79’s run beefier hubs and both are also beefier lug studs and five lug.

Cheers
 
Cruiser Outfitters steered me away from the 300m axles after hearing that I drive a significant distance, 4 hours, to the trail. They said the 300m axles wear fast on the road.

I asked about RCV 4340 rear axles and they said RCV doesn’t make them since the stock axles are so strong. Read a post yesterday that said RCV does make 4340 rear axles, but doesn’t advertise the fact. I find that hard to believe, but might be worth a call to RCV if you’re concern about road wear on the 300m axles.

RCV will make custom axle sets but it's not one they've had as a stock/shippable item unless something changed. We have them make us custom hub gears for example, call and ask them and they will tell others they don't make it :D

Clarification: We generally recommend customers consider the miles they will be encountering when considering front axle kits, not necessarily the rear. RCV and others don't warranty clicking axles and they can/will click. We've heard from many customers frustrated by this over the years and want to make sure future customers are aware or this on front axle kits.
 
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Gearing is limited to 4.88s though, right? That's a big downside. Can't see myself giving up the 5.29s

What carrier are you running? 5.29's are possible with 32 spline side gears, just not using the 100 R&P, use the 8x R&P in a converter carrier.
 
Pulled my rears recently to have a look, not a lot of road miles but plenty of time in the rocks. JV, Sand hollow, the Sierras, excetera
1618149153760.png

Everything looks good, I'm running 39s and like the hard lines
1618149224686.png

So yes I'm happy with my RCVs front & rear
 
I’m building a truck for rock crawling the Sierras, mainly the Tahoe area. My goal is to prevent breakage before it happens by strengthening the weak areas.

Cruiser outfitters just explained that RCV makes drive flanges with 6 dowel pins. No longer any need for larger hub studs. Ordered
For what it's worth, I left the stock drive flanges in the front (two pins only ) as a fuse. I would rather break that then gears, axles or birfields 🤷‍♂️
I do run ARP hardware.
On the Rear RCVs I only added 2 pins, so a total of 4 for the same reason.


Looking foreword to meeting you, I see you are singed up for the wagon run ;)
 
For what it's worth, I left the stock drive flanges in the front (two pins only ) as a fuse. I would rather break that then gears, axles or birfields 🤷‍♂️
I do run ARP hardware.
On the Rear RCVs I only added 2 pins, so a total of 4 for the same reason.


Looking foreword to meeting you, I see you are singed up for the wagon run ;)
Great point @Broski. I've been wondering where to leave the weak point in the system. I'll bring trail spare flanges and go with less pins.

Look forward to meeting you too. It will be my first time in the Con. Can't wait !!
I'll have a cold adult beverage waiting as thanks for sharing your knowledge with the community. Appreciated !
 
What carrier are you running? 5.29's are possible with 32 spline side gears, just not using the 100 R&P, use the 8x R&P in a converter carrier.

For now I'm still running the factory FZJ80 elocker. This was a nice unwelcome surprise as I was working on my brakes/bearings.

Pulled my rears recently to have a look, not a lot of road miles but plenty of time in the rocks. JV, Sand hollow, the Sierras, excetera
View attachment 2641859
Everything looks good, I'm running 39s and like the hard lines
View attachment 2641861
So yes I'm happy with my RCVs front & rear

Thanks for pics, those sure do like pretty. This seems like the next logical step. Just sucks about having to pull the hub again to get it machined. If I do, might just go straight to the bigger ARP bolts and ditch the studs/cone washers.
 
For now I'm still running the factory FZJ80 elocker. This was a nice unwelcome surprise as I was working on my brakes/bearings.



Thanks for pics, those sure do like pretty. This seems like the next logical step. Just sucks about having to pull the hub again to get it machined. If I do, might just go straight to the bigger ARP bolts and ditch the studs/cone washers.
Worse then that for me, is now I need spare rear hub to go with my stock spare axles.
Other wise you need RCV replacements if something go south!!
 
Brian @ Front Range Offroad and Fabrication had a rear RCV set made for me before they were for sale in the US. I had asked him because I saw that they were available in AU but couldn't find a source here. (Needed something stronger, 1HDT with 30 pounds of boost and everything highflowed.)
I would ask him about custom stuff as he owns Diamond Axle. He is a great guy and basically owns his own machine shop. I didn't get anywhere when I called RCV.

He also has done custom drive flanges
 

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