Gearing and transfer options (1 Viewer)

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Cruiserdrew

On the way there
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This may be a hypothetical thread but maybe not. I have a 76 FJ40, I've wheeled it a lot, traversed the Rubicon many times. I have an SM420 and a 3 speed transfercase. I'm happy with the low gear but lower would be good.

I currently have a spare split transfer case, and would like to run that in place of the 3speed case, but there are other options. Assume for the purposes of this discussion that cost is not a major consideration. I'm looking for bullet-proof, and permanent..

Option 1-Run the current set up, with the risk of a case fracture like Texican recently.

Option 2-Sm420 plus split case using the AA adapter kit-looks complex

Option 3-H41 19 spline tranny (from SOR) + split case + Mark's gears-tempting all Toyota setup.

Option 4-Sm4320 + Orion + Warden's nosecone if I can get one, and forget split case

Obviously anything but #1 will involve time and $. Any and all advice appreciated, especially if you have experience with one of the options. I don't want a longer driveline, which rules out a Toybox. I am leaning in the Option 3 direction and do not care about additional gear noise-the SM420 makes that a non-issue.

Appreciate any and all advice.
 
" cost is not a major consideration "



420 and an Atlas, and be done with it.


Not even on the list... :rolleyes:






" Warden's nosecone "


Where ya going to find one of these? ;)


420 and an Orion would be a decent combo. Provided that you do not bind up your front driveshaft, you *should* not have an issue with the nose cone... Order late model one-piece case main and front output shafts from Marv, those would be the strongest... Fine spline front output...



" Option 3-H41 19 spline tranny (from SOR) + split case + Mark's gears-tempting all Toyota setup. "

Just completed an H41 install into a 1983-40 series...I had already installed the Marks gears a couple years ago....pretty sweet set up, rolls out really nice, and crawls well too. These are the under-drive/over-drive set, not the under-drive/under-drive. You still need to sand down the inside of the tcase to make them clear....no biggie.





Good luck!


-Steve
 
Hi All:

It seems that the SM420 mated to the Orion t-case would be the simplest, and cheapest option for you. I have a buddy with the H41 and the Orion and 4.88 diffs that has 90 to 1 or so crawl ratio - the SM420 would back the crawl even lower.

If you follow the various Orion threads, the bugs are getting worked-out on this beast. My bud was all concerned with the Orion popping out of gear, so after reading all the threads he went through it and tightened everything well and after a trail run last weekend reports no more problems.

Good luck!

BTW - how much do you want for your three speed t-case and adaptor?? ;)

Regards,

Alan
Seattle
 
adapter from 420 to split case = toybox

but like poser said, atlas is the shizzy, should go center rear axle though
 
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Thanks guys (especially Poser) just the type of info I'm looking for. I am Jonesing to use my extra split case since I know it's good, and I just rebuilt another! SM420 + toybox + split case would be very low-I saw on the other thread that Tornado is running this in an FJ40. That rear driveline would be very short though. It may be my best option taking $ into account, since I have all of the parts except the Toybox.

I may call Danny and see if he has a nosecone in his stash-that might send me in that direction, but the guts of the split case are so much beefier and heavy duty.
 
The AA adapter that connects the 420 to split case is the same or close to the same length as the toybox as the mating link
 

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