Transfer case regear diagram + install notes (WIP) (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

1590429119146.png


Luckily, @Deathvalleypaul is not far away. I'm going to go pick up a new rear housing from him and try to get this all sorted.
I think perhaps I take the overlanding approach to wrenching haha...The respectful pursuit of trouble.
 
OK, got a new transfer case from @Deathvalleypaul and stripped off the rear extension. Got to fight with all the same snap rings twice in one day, yay.
At the end of a long day I have one rear housing ready to go. Will tackle the front housing later in the week--I must say the output seals F&R are about as hard as the gear job itself, I underestimated it (partially because the snap rings are tough.)
 
Extending the breathers is a step many people forget and real 4 wheelers regret it.
 
Thanks for the suggestion...ordered some 1/4" tubing! 👍
 
I'm having some trouble with my rear output bearing--after I pressed out the old bearing the new one is a bit loose--like it fell out after I pressed it in. Tried again and I can still pull it out by hand. I rebuilt the rear extension and it seems OK but there's a tiny bit of play and I'm paranoid, so I've ordered some bearing retainer based on the notes in this thread. This project timeline keeps growing but oh well, I hope once it's buttoned up I don't have to get back in there for a long time.
 
Got the front housing sorted tonight, thanks to @JeepinPete for his suggestion on making the puller work. This arrangement made it go.
1590634454573.png


Driving the shaft out took a bit more force (hammer blows) than I expected but nothing too bad.

After I pulled the seal and the bearing out, pressing the front shaft back in took a really long arrangement of tube--not sure if there's a simpler way but this worked for me.
1590634499498.png


Next up, clearancing the case.
1590634576345.png


Success! (photo is a bit blurry because the gear was spinning.)
1590634600310.png


Then I clearanced the rear section of the case, harder to test spin with that but I did fit it in and seemed ok (the mid case you have to take some "case" out, whereas the rear case just seems to be oil slinger.)
1590634658387.png
 
OK, tonight's update...
Stripped down the rear extension again and applied some Permatex Bearing Retainer to try and reduce the play. Tentatively, seems to have worked...
Got a lot faster at tearing down and yanking those snap rings (third time's a charm!)

Moved on to cleaning up the mating surfaces (someone suggested plastic razor blades, they've been awesome)
1590726942120.png


Moved on to reassembling the case and loading in the gears, not as many pictures of the steps but the OTRAMM video is quite helpful here.
1590727059696.png


My idler gear race was a bit loose so I also applied some bearing retainer to the race during fitup. I didn't see any weird wear patterns so I think it's OK...🤞

Now it's all put together (sensors, shift motor, etc) and I'm waiting on the gasket sealant to dry. Tomorrow hopefully is fit it back into the truck, connect everything, and fill her up...I also got the 1/4" fuel line so going to try and make sense of the breather extension then.
 
  • Like
Reactions: KTP
Oh also one thing that was a bit confusing across all the instructions is the diff lock motor position. You slide that little lever (edge of the clutch sleeve?) all the way back (towards the rear of the transfer case) for locked and forward for unlocked. Took me a second to sort out. Forgot to get a pic before reinstalling the center diff lock sensor/switch thing.
1590727710091.png
 
Nice work
 
Yesterday was reassembly day.
1590868152043.png

I noticed the breather hose from the diff motor over to the T was cracked so replaced both with the case still on the bench.

Getting the damn thing back in the truck was quite challenging, mainly because my transmission jack + the case was too tall to slide under the frame...as such I had to wheel it in on my creeper and then transfer the case onto the tranny jack under the truck--this was hard and not recommended (though I'm not sure how else to do it tbh.)
1590868268026.png


And I'm done! Made one stupid mistake when reassembling (forgot I had put the lever in "N" not low range when pulling the driveshafts, and as such my diff motor was clocked wrong...required me pulling it off and reindexing it, thanks to @OTRAMM for the advice via email.)

Now that I cleared that up, all is aces.

I was quite concerned with the potential gear whine, and I'm happy with where it came out...the gears are audible at highway speeds if you listen for it, but only when on the throttle and it's quite minor (my girlfriend couldn't hear it when I asked her about until I deliberately punched the gas and came off it repeatedly so she could notice the difference...it's quieter than the wind noise is on the highway so I'm not concerned.) Maybe if you have a ton of sound deadener in your rig it would be more noticeable, or maybe I got lucky with the gear mesh pattern...but for those on the fence due to noise concerns I'd say no regrets on this side (and I am pretty sensitive to sound.)

The low range gear seems fun! Going to hit up Eastern Sierras for a camping outing next weekend so hope to put the crawler gears to the test.

Thanks all for the support and advice along the way.
 
Just a final update to say I got to test both the underdrive and the crawler gears on a trip this weekend, both performed great. I was able to keep up with traffic climbing all the passes out of LA and up towards Kennedy Meadows, and once I got up to the 4x4 trails the crawler gear was fantastic. A lot more sections with no braking required than I was expecting...

First steep downhill and I was smiling like an idiot with the low range engine braking (which @Deathvalleypaul had mentioned to me as well--biggest change noticed was for downhills)
1591588487090.png


The underdrive gear whine also seems to have settled down with a few hundred miles on the gears, I really only notice any additional sound at extremely high load (think flooring it) on the highway, at general cruise and around town I have to force myself to notice anything--it *is* there but is way under the noise floor of road noise and wind at least in my truck (note I have AT's not mud tires.)
 
Where can I purchase a set of underdrive tcase gears? I've been searching for them with no luck. Would like to go 4:10 to 4:56 gear ratio.
 
hans27 said:
Where can I purchase a set of underdrive tcase gears? I've been searching for them with no luck. Would like to go 4:10 to 4:56 gear ratio.
Click to expand...

Call up Georg at Cruiser Brothers in Stockton, CA. I bought mine through them and he can set you up with everything you need for the swap.
 
Georg's parts and advice made my transfer case transform my FJ80 into a much more capable vehicle.
The gear change in low range gave it much more ability going down obstacles as well as took all the load off going up obstacles.
The high range underdrive got rid of all the up-down constant shifting and put it in a nice power range. I run 85 mph without taching over 3000 rpm and have much more passing and hill climbing power.
I am so glad he convinced me to use the better brand low range gear set and factory sealant! Thanks Georg!!
 
This is a great write up. What size wheel/tire setup are you running? Has anyone run this setup with something taller than a 35? If so what are your experiences?
 
I was wondering the same with tire size. I'm planning on running with stock diff gears and 285/75R16 tires.
 
You must log in or register to reply here.

Similar threads

Enders
Unexpected transfer case behavior
Replies
1
Views
343
ppc
ppc
maddss
Transfer Case Help - Update
2
Replies
22
Views
2K
CrabCake
CrabCake
suzuguru
Transfer Case Question
Replies
1
Views
515
suzuguru
suzuguru
DIRTBIKEUSA
Ls gear oil in transfer case?
Replies
4
Views
477
Mrtwooooo
Mrtwooooo

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)

Share this page

Back
Top Bottom