Rear Diff Swap

[Delancy]

Local kid's 07 rear pinion bearing was determined faulty and considering an 07, he ordered a completed third from ECGS.

My first on the FJC, and kid's short on cash, so be a swap only, against my recommendation we go through the entire axle.

Pretty sure I've a handle on it, but my experience is limited to 80s that I can sit up underneath and not require jack stands. Doesn't take very long to do, period.

I've learned a lot of tricks that would've otherwise gone undiscovered without seeing a few ( well, the few on Mud) of y'alls ( Puulboy's axle lasso being more memorable, having fought once without) so asking for any tips that'll speed the process up, since I've little time to take a breath and will be pushing to get this done in a few hours.

Already soaking in PB. I have red FIPG, but think ECGS supplied the gasket which kid will opt for. Had him get the fill, drain, and gaskets for, already, too.

 

[1911]

Don't disconnect the brake lines (and have to bleed them after), if you take the calipers off and take all the little clamps off that hold the hard lines to the axle, then there is enough give to move the axles out the 4" or so that is enough to clear the third member. Saves a ton of time, as long as the axle seals and o-rings are in good shape and reusable ('cause obviously you can't get new ones on without taking the axles all the way out). Ditto for the emergency brake cable. The FSM says to remove both of these, but there is no need unless you are replacing the seals and o-rings. Done this way, it's a pretty easy job.

Pay attention where the sliding cog for the e-locker is when you pull the e-locker motor off, and note the position of the little spur gear; it will make it simple to re-install the same way and not have to bother with the alignment procedure in the FSM.

 

[Delancy]

Sounds pretty straightforward, concern being discoveries "while we're in there" and e locker, more than anything.

I don't recall if the e locker has to be locked on the FJC, (downloading the FSM, again. Be another thirty minutes, I'm sure) as it does on the 80.

 

[Mtbcoach]

What Lee said, no need to deal with the brakes, I followed FSM first time, then Rick enlightened me and it was much easier the second time. I don't recall locking the rear diff or not, sorry.

Yes, the unknown is the fun part, unless you are looking at hosting the rig in your driveway for an extended period. Good luck...

 

[Delancy]

Can't seem to find any info on diff locked or not.

Important on the full float (one twisted the splines and wouldn't lock, but wasn't too bad, honestly. More on later) but don't know about semi.

Another question, backstory first.

Have a potential cure for the twisted e locked crap on an 80, being an axle shaft with the splines machined off






Being held hostage at the one, and only, machine shop with freezer in Tulsa, along with another local's R&P for 80, until a specified volume is acquired to viable cryo.

If the third gets here before Friday, I'm willing to pay the $50 to cryo, unless there's some reason not to, because I'm going to be paying the $50 anyway, to get my axle back.

Any reason not to freeze the completed third?

I know we could debate the merits of cryo'd R&PS all day, but all mine were done by Robbie Antonson, after I said "do it like you'd do you own", so basing on his expertise.

 

[1911]

I don't recall if the e locker has to be locked on the FJC, (downloading the FSM, again. Be another thirty minutes, I'm sure) as it does on the 80.

Can't seem to find any info on diff locked or not.

Important on the full float (one twisted the splines and wouldn't lock, but wasn't too bad, honestly. More on later) but don't know about semi.

No, the FJC rear does not need to be locked. Won't hurt if it is, but it does not need to be; the locker motor will pop right off regardless. When you're putting it back on after the new third is in, it's easy to slide the locker with a screwdriver so that it lines up with the shift fork, if need be.

Any reason not to freeze the completed third?

I know we could debate the merits of cryo'd R&PS all day, but all mine were done by Robbie Antonson, after I said "do it like you'd do you own", so basing on his expertise.

I feel so old-fashioned, but I have never had anything cryo'd, ever.

But Robbie's opinion/experience carries more weight with me than most, so why not try it for $50? It might help and couldn't hurt it I guess.

 

[BMThiker]

Remove the brackets holding the e-brake lines from the lower control arm and the frame in addition to the caliper hard brake lines on the axle housing. Then you only need to slide the axles out about 4" to clear the side bearings.

An empty 2.5gal water jug makes a good landing pad during the extraction.

 

[Delancy]

You must've done something wrong, because you're entirely to clean and happy.

 

[BMThiker]

Ha-Ha! This was the 3rd time the factory 3.73's broke and I was planning to go to 4.56...so that's my UPGRADE happy face.

 

[Delancy]

Haha. I don't typically get a happy face until the results are rock tested.

Waiting on kid to update with tracking info, but will probably try to tackle early next week.

 

[BirdManzFJ]

My .02 is, I also support the axle once slid out to take the weight off the seal. As you can see in that center pic. And I used a cut off wheel in a dremel to cut the top of the brake line tab, gives you a lot more room to move the caliper around once the line is out of that tab.

 

[Delancy]

About to start on this.

Glad we waited until it's 100 degrees out.

 

[BMThiker]

Kinda like waiting until September/October to get the AC fixed.

 

[Delancy]

Ok, put everything back together, thinking it went to well.

Locked, dash light shows locked, shouldn't be locked.

Pulled old unlocked, pushed fork over to unlocked, and locker slid back in perfectly in the position.

Pulled unlocked



Reinstalled unlocked, yet she's locked.

Where'd I err?

 

[Delancy]

Never mind.

I'm a dumbass.

Way too long a day for brakes and third swap, but she's done.

Want a lift. I hate jack stands.











Shavings for scrap metal.







Kids. Probably the weight of his horns that caused the diff failure.

 

[Mtbcoach]

Nice work (again) Chris, love the horns, have a plan for a set on my 80...

 

[Delancy]

Those horns are huge, can only guess how loud.

Kids will be kids, right?

Hahaha.

 

[BMThiker]

that's called getting the most out of your air compressor

 

[Delancy]

I guess.

More LEDs, be it interior or exterior, than a 747 cab.

Kid's cmw7373 on FJCF, and a good kid. Seems to have walked the straight and narrow through high school, more than I can say for myself, fabs his own stuff, and creative.

Took a day off work, normally allocated for any of the three projects I have going, to do, because of the above, since assistance was never extended to me as a kid (probably because I was the antipathy. Haha).

Oddly, we never figured out what moved, be it the shift fork when installing third, or the locker moving once we slid it in.

Oh, well. Live and learn.

Know if/when the FJC returns to wheeling duties or the rear end explodes DDing, will consider a full float for sure.

 

[Lemony]

I'm pretty sure the third/elocker won't clear the housing unless its locked. Last time I pulled mine I remember having a hard time pulling the third out untill I slid the locker fork over with a screwdriver.

If you slot the bracket on the backing plate for the brake line you can pull the clip then slip the hard line out and pull the axel without disconnecting the brake lines. I did that when I blew the stock rear in case I need to do it on the trail.

ECGS is the way to go, They regeared me to 4.56, 4yrs +, 40k ago and febuary I lost some pinion teeth and it only cost me shipping to get it fixed. So I had my spare regeared with the $$ I had planned to spend on repairs. My son was driving and had the "I don't know why its clicking in the rear now" answer. Couple weeks before I did some deep snow trail breaking, all four locked and foot on the floor for a couple hours on and off that may have helped some.