Gearing Solutions - Crawler Gear$$$$$ (1 Viewer)

[dmaddox]

So, as you all know - with one conversion comes many more. This one has me a little bent out of shape.

1. Stock four speed tranny
2. Stock four speed t-case
3. Stock 4.10 ring/pinion

With 37x12.50's if my math is correct puts me about 21.8:1 crawl in four-low.

At 2K rpm, that's about 35MPH in Four - Low. (Im exagerating - but you see my point).

1. Orion T-case - 1650+ - 50:1 area, that's a lot of coin.
2. SM465+3sp Tcase - same area, less coin, probably 800ish.
3. SM465+Orion - lots of coin - killer crawl ratio.

I am at a loss here. I wanted to be able to hang on these difficult trails and yet I am creating more problems (projects).

I guess there are no cheap solutions - which explains my frusteration. Just curious - does everyone just bend over and pay?

Thanks,

ragman

 

[Tigerstripe40]

So, as you all know - with one conversion comes many more. This one has me a little bent out of shape.

1. Stock four speed tranny
2. Stock four speed t-case
3. Stock 4.10 ring/pinion

With 37x12.50's if my math is correct puts me about 21.8:1 crawl in four-low.

At 2K rpm, that's about 35MPH in Four - Low. (Im exagerating - but you see my point).

I guess there are no cheap solutions - which explains my frusteration. Just curious - does everyone just bend over and pay?

I did my SM420 for about $600 including a new transmission.

New Old Stock SM420 $380 shopped to my front door
SM420 adapter plate (found used) $50
pilot bearing and retainer ring $25
new clutch plate $16
Bell housing and 3 spd front driveshaft ~$50
New input gear to mate the 4 speed t-case to the SM420 $80

Total gear reduction is about 56:1, which is perfect for almost everything I like to do.

I would like a LITTLE more gearing, but I don't really see it as a problem.

 

[Poser]

There are very few things that you can do to improve your vehicle without laying down real money, period. If you want to look at it as getting bent over, that is fine, but it is not the case. Install a 465, and stop your whining. After you have that installed and have used it a while, if you find that you need more gearing for on road, you will need to swap ring and pinions. Don’t waste your time with 4.56, go strait to 4:88’s, and be done with it. If you are finding that you need more gearing off road than what a three or four speed stock Toyota transfer case can provide, then yes, you are going to want a 3:1 or 4:1 Orion, or a Toybox, or Atlas, and then a new rear axle. Where you want to draw the line is completely up to you. After you get all sorts of gearing, you are going to need to upgrade that front axle, unless you like to wrench on your junk a lot. I like to pull a wrench on my junk too, just not on the trail. That is why I do not run Toyota axles.



Gearing costs money, there are no two ways around it.



Land Cruisers are not an inexpensive endeavor, and if you want to wheel your junk, on rugged ground, it will cost you even more. That is a fact.


Good luck!


-Steve

 

[dmaddox]

What size tires are you running? 35's (picking #'s from your sig).

I have an sm420, but its an olde - and has a closed driveshaft design. Not sure if that will work.

ragman

 

[Poser]

I have an sm420, but its an olde - and has a closed driveshaft design. Not sure if that will work.

ragman

Have you removed any of that junk from behind the 420? Tear into it! You will not use any of it.



You should not have any issues making that tranny work, provided it is not trashed to begin with.


Good luck!


-Steve

 

[dmaddox]

It is a good tranny - however, that closed driveshaft design will not work, it has a "bell" on it if you will......and is part of the housing. I may take a snap shot and post for kicks.

Oh, and no - I am not whining - just emphasizing how frusterating this can be.....

I appreciate the comments/ideas.....

ragman

 

[Poser]

TAKE THAT s*** OFF THE BACK OF THE TRANNY!!!!

I have used that style tranny on a few conversions, and not had any issues.


You will not be using ANY of that crap on the back of it. The rear housing on the back of the tranny needs to come off to install the adapter, no matter what design adapter you decide to purchase.


It is really not this difficult....



Get a three speed flywheel housing, an adapter for the 420, get it in your truck, and be done with it! It will be hands down one of the best mods you can do to your Land Cruiser. Saginaw steering and 4 wheel disc brakes are the other must do items.

 

[Markh]

If you already have an SM420 check with Novak Conversions about a rebuild kit. I rebuilt mine a little over three years ago and its still working fine. They have kits that include all the bearings, syncros, and gaskets. Doing that assumes that the gears are okay. Those are a bit harder to find.

http://www.novak-adapt.com/catalog/transmission_components.htm

Any way you go its going to cost a bunch. How slow do you want to go? How much money do you have?

 

[Tigerstripe40]

What size tires are you running? 35's (picking #'s from your sig).

I have an sm420, but its an olde - and has a closed driveshaft design. Not sure if that will work.

ragman

Yeah, I am running 35's.

Debating on going to 4.88's or putting in a Toybox... I like my high speed on the freeway with the 35's and 4.11s (can do 75-80).

Unfortunatly, I have exhausted all of the 'cheap' tricks that can be done to the 'cruiser, and anthing else I do gearing wise is going to cost MUCHO $$$.

Perhaps I should just leave it well enough alone for a whiles....

But I LOVE to tinker with my truck.

 

[bustanutley]

Listen to Steve! All sm420s will work, they are all 10 spline, and they were all set up in a 2wd application (bell on back). Take those six bolts out and boot that POS in the trash, bolt on a plate style adapter and mount-er-up. You are looking at around $100 for the conversion gear to use your 4 speed case with the 420, or whatever you can get a 3peed case for. As little as $50 for a used adapter. Mine new was $300 and included everything needed for the conversion to the t-case. If you are running a 2F you need a special pilot bearing, a Chevy clutch disc, a sleeve where the throw-out bearing rides and a special indexing ring. There are also custom nose cones made that are very trick, and if I had more $$ at the time I would have gotten one of those.

Oh yeah, you need 3 speed bell housing

My 420 costs were

$300 adapter included indexing ring
$175 Tranny
$10 clutch disk
$80 pilot bearing adapter and sleeve (if I knew how to use a lathe at the time I would have made this myself, I was young and dumb )

So yeah ~ $600

I love my 420! I still think it is the best thing I have done to my cruiser. Most the time it is low enough for me. Pretty much everyone on the trail that I talk to or run with mentions how low my gears are which tells me they don't see many trucks go that slow, of coarse my engine will run at 200rpm

Oh and 35's for the time being, but very very soon at least 37's maybe 38's

 

[Poser]

Not all 420's came with an enclosed driveline...I have a couple that are just the yoke, and nothing else, and then have one with a parking brake drum and lever on it...

 

[green40]

Can someone explain to me why there isn't the option of different gearing available for the stock transfer case?
Just a rookie trying to think!
Lane

 

[AlaskanWheeler]

MarksOffRoad and Man-A-Fre come to mind when changing stock T-case gearing for later models

 

[dmaddox]

yeah, just got home - upon further investigation I can pull all that crap off. I don't think the tranny needs a rebuild. It came off my dad's rig - bought new, very low miles. I shifted through all the gears very smooth, everything spins smoothly, etc...

I am going to take it to a shop to verify.....

Other than that - I may get the tranny/tcase done - found a guy who will rebuild my 4 speed t-case with all 3 speed components. I'll have him mount it to the sm420 and go from there.

Hopefully this will solve the crawl gearing issue.....sm420 to lc 3speed tcase gears....

thanks for the ideas.....

ragman

 

[madoc1]

Can someone explain to me why there isn't the option of different gearing available for the stock transfer case?
Just a rookie trying to think!
Lane

orion-google it. i never have but it might be fun.

 

[bustanutley]

Not all 420's came with an enclosed driveline...I have a couple that are just the yoke, and nothing else, and then have one with a parking brake drum and lever on it...

Zapped!

Oh at least I do know that all are 10 spline

 

[Poser]

Hopefully this will solve the crawl gearing issue.....sm420 to lc 3speed tcase gears....QUOTE]



Worked 11 years for me, running 33's, 35's, 38's, 38.5's, and 42's(with 4:88 r/p with the last two) Been all over out west, other than Kalifornia



Switched to a 4.3 Atlas this spring...I did not want to be the first guy to blow up an Orion, but was anyhow...



https://forum.ih8mud.com/showthread.php?t=21385&highlight=Orion



Good luck!


-Steve

 

[dmaddox]

I am uncertain on the years of this closed driveshaft deal - however I know that this SM420 came off of a 1952 Chevy. When working on my 1950 GMC I seem to remember the 1954 time frame - when chevy went to that different front end - that they then switched to the open driveshaft.

Ragman

 

[Josie'sLandCruiser]

Hi All:

I swapped-in an H41 four spedd tranny as a replacement for the H42 a few years ago. It has helped off-set the 33 inch tires, but for $500 plus clutch parts I'm sure I could have done the SM420 swap and netted lower off-road gearing, though admittly the "street manners" of the '420 are poor in comparison to the H42.

I feel that the SM420 swap is the best "bang for the buck" in gear reduction for a 40/45/55 Series TLC.

Good luck with your rig!

Alan
Seattle

 

[green73]

This past year, I did the H41/Orion swap. The main reason, was for retaining my already lengthened driveshafts (flipped springs/SOA). Before the end of the year, I'll be going to 4.88's in the diff's too. The only complaint I have is 4wd low is often too low (East coast rig) and I have to pay more attention to what gear I am in in certian situations, but over-all am pleased with this option in gearing. I know, changing to 4.88's will further lower the crawl ratio, but oh well...