FJ60 rear FF & SF 3rd members

[abosely]

Is there a difference between a FJ60 FF 3rd member and a SF 3rd?

Strength wise, when in installing a 3rd member from a SF axel on a FF axel.

Allen

 

[Tinker]

IIRC the SF diff is weaker because of the machining for the clips that hold the axles in. FF rear diff is the same as any 60/62 front.

 

[abosely]

Ah, so I could just source a front 3rd member and use it on the new FF rear axle assembly.

Allen

 

[Spike Strip]

Yes. Probably your cheapest option -- What about a locker since you've got the 3rd out ?

Incidentally, if you're thinking about replacing the pinion seal on the new diff, be aware it will change the bearing preload when you remove the nut -- But some have said if you count the threads or measure the torque needed to remove the nut, and replace as such, it should be ok.

I found this out the hard way and had to send the diffs out for proper set up when I installed my FF rear.

 

[abosely]

Most likely will be going with ARB front & rear.

Allen

 

[Spike Strip]

Check out THIS LINK

That's Ken (ZUK) Francisco doing my diffs -- He's one of the best and it's a great write up on how to do it right.

I also had him use Solid Collars instead of the crush type - So when I need to replace the pinion seals, I won't *!#& it up again!

 

[Spike Strip]

Also, if you're going with a FF rear and ARB locker, use the RD33 - it's for a FF and is stronger than the SF version.

 

[weak-link]

Only difference is a little lip cut into the spider gears. I highly doubt it would make any difference in strength.

 

[Randy88FJ62]

Also, if you're going with a FF rear and ARB locker, use the RD33 - it's for a FF and is stronger than the SF version.

What does RD33 mean? I am going to be putting a stock FJ60 FF in my 62 when going SOA. I have an extra front third member. Is it worth using that for the rear? Can you explain how the front third differs from the rear third and why it is marginally stronger?

 

[Spike Strip]

Randy, if I follow your question, the RD33 is the ARB locker for a FF 60-series axle (and 40's too). RD124 is for the SF. You can use a RD124 in a FF or SF, but the RD33 is ONLY for the FF

THREAD

But there is no difference btwn your front 3rd and the rear. Using it in FF is fine. Or did you mean you have a front ARB ?

 

[GLTHFJ60]

Only difference is a little lip cut into the spider gears. I highly doubt it would make any difference in strength.

I agree with weak-link that the strength difference is probably minimal.

Then again, if there is an ARB unit that's set up specifically for the FF third, then there might be a bigger difference.

 

[Randy88FJ62]

I guess I have two RD124's then. The parts truck I bought has 62 axles with ARB's in them that I will use. You answered all my questions. Thanks.

 

[Spike Strip]

Randy, is the parts truck where you're getting the FF rear from ? If yes, It may have the RD33 in both the front and rear - or the older style RD02 (not sure how to tell the difference other than older takes 45mm carrier bearings. New style take 50mm ... )

The older RD08 was for SF -- I think the change was about 5 or so years ago.. ?

 

[Randy88FJ62]

The parts rig is a standard U.S. 62. Georg has an extra FF that he is willing to trade... So I have 62 axles with ARB lockers already installed. The FF is a stock FJ60 which I will be installing the locked third member into.

 

[Spike Strip]

Ah, well good luck with it!

 

[Kynot62]

I installed a FF in my 62 this summer and changed the gears. The only difference I could find between the stock SF rear carrier and the stock FF front carrier was a spacer on the pinion shaft in the rear carrier, the spacer is not needed on a FF as there are no c-clips.

I don't have ARB's yet but everything I read says you can use a SF ARB in either axle but a FF ARB can only be used in a FF axle. Best guess is that the full float has no access for c-clips. Call ARB to confirm.