ARB locker (model RD90) install questions

[gavinpears]

Cheers Gents & thanks for the welcome.

I generally only use it on roads but when i get the chance I take it offroad. Hopefully when I have the cash i will install a front ARB locker. I think the rear factory fit locker is good enough.

Can anybody explain what a 3rd member is & why do I require one to get an ARB locker at the front (or rear)? The costs involved for this '3rd member' make it extremely expensive modification.

[TEPUI]

Originally Posted by gavinpears

Can anybody explain what a 3rd member is & why do I require one to get an ARB locker at the front (or rear)? The costs involved for this '3rd member' make it extremely expensive modification.

Hello Gavin, and welcome to mud!

You already have a third member, it's the mechanism sits in the middle of the axle, and houses the differential, the gears -ring & pinion- and all related bearings.)

[gavinpears]

Thanks for the welcome & info. Does that mean that if i buy an ARB from locking diff & air compressor it will slot right into the front diff housing without having to buy anything else?

I was told by 2 offroad 4x4 part companies in the UK that I would require a 3rd member or a different one as the ARB locker RD90 would not go straight in. I wrote to ARB in Australia & they couldn't tell me either.

[TEPUI]

Originally Posted by gavinpears

Thanks for the welcome & info. Does that mean that if i buy an ARB from locking diff & air compressor it will slot right into the front diff housing without having to buy anything else?

It should fit right in your front diff without having to buy anything additional.

Originally Posted by gavinpears

I was told by 2 offroad 4x4 part companies in the UK that I would require a 3rd member or a different one as the ARB locker RD90 would not go straight in. I wrote to ARB in Australia & they couldn't tell me either.

Are they authorized ARB dealers? ARB specifies the RD90 for many IFS Toyota models (mostly 96-03), and they clearly state that it fits all gear ratios. What are they claiming to be wrong with your current 3rd member?

[gavinpears]

Tepui,

They are claiming that they don't have any experience with my model & are not sure what mods are required to fit an RD90 with regards to a 3rd member. Unbelieveable!!!

Thanks for the info though. I may try to get it fitted next time home.

[TEPUI]

Look at the link below. The author is Steve Schaefer, he has plenty of experience with 3rd gen 4runners, which share the same diff with the 90 series Prado. If your rig is full time 4WD there might be some minor differences, but I don't think they affect the ARB install at all.

http://www.sonoransteel.com/front_locker.html

Steve is a member here on ih8mud, and he's always very helpful. You may want to try contacting him directly through his website. (sonoransteel.com)

Also, you may find additional information on www.yotatech.com. I've seen a few threads there about the RD90.

[TEPUI]

More info here: http://www.sonoransteel.com/ARB_RD90.pdf

Hope it helps you!

[gavinpears]

Thanks Tepui,

Great links. I will have a look in more detail.

[ringpinion.biz]

You have the clamshell style 7.5 reverse frontend. They use the rd 90 diff.