Bellhousing for sm420 to 22r

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V

Vicm

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hello,
I am thinking of making bolting an sm 420 to my 22r.
Here is what I am going to do, please give me your opinion.
No pics just diagrams (drawings).
I will use the bellhousing from 18rc/20r.
This bellhousing was mated to an L43 for 4x4 application.
I only show 4 bolt holes in the back of this bellhousing, in my sketches, but ther are 3 more bolt that are not used when bolting the L43 so I am not showing them to make it easier to ss things.
The first step is simply bore out the bellhousing hole where the input shaft seals housing fits to.
This will be bored so that the sm420 input shaft seal housing fits in the toyota bellhousing hole very snug.
This will center the input shaft from the sm420 t into the toyota bellhousing.
Then is is just drilling and taping the sm420 case .
first diagram , show the surface of the sm420 along side the that of the 20r bellhousing.
Once I bolt the bellhousing to the sm420, I can ad more support by using the original 4 holes in the sm420 case.
sm4201.webp
 
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You have an interesting notion there, and sounds like you're taking the LC approach to a driveline swap- adapter plates. Assuming the input shaft has the correct spline count, and you can find a clutch to make it all work, you could end up with a nice crawl ratio, however, I really don't think that's such a great idea, the 420 weighs as much as the whole 22R driveline, and the gears will be so painfully steep, your poor engine would have to work itself to death just to inch along.
Maybe you could explore some alternatives, like finding steeper internals for the L-series tranny, add a crawl box, or get a w- or r-series transmission.
 
If you won't ever need overdrive... gopherit!


Mechanical advantage is mechanical advantage last time I checked...

AA even has or had a 22R to NV4500 to Toyota TC... But I've got an old catalog.
 
cruiser88 said:
if you want lower gearing then get a marlin box
Click to expand...
Why is it any different with sm420?
Can you explain ?
Just from exp lower will be better for a very low speed application.
 
Vicm said:
Why is it any different with sm420?
Can you explain ?
Click to expand...

IF, you were going to put the L43 back in it, no, there is no difference. But why would anyone do that? Most ppl would put a 5 speed in it, with two crawl boxes and now you have OD.

SM420: 7.05 x 2.28 x 4:11 = 66.04
L43:.... 3.76 x 2.28 x 4:11 = 36.23...



Vicm said:
Just from exp lower will be better for a very low speed application.
Click to expand...

It doesn't "really" matter if it's a dedicated rig, but a lot of folks wanna drive their rigs... So they'd prolly opt for a crawl box... Plus, 9 outta 10 will already have the 5speed.

Where one might want to get the gearing just right for highway use, one with an overdrive could use even lower gears.

2 stock TC's = 2.28 x 2.28 = 5.19:1

SM420 1st gear stock TC......7.05 x 2.28 = 16.07:1
L43 1st gear w/ Marlin 3.76 x 2.28 x 2.28 = 19.54

SM420: 7.05 x 2.28 x 4:11 = 66.04
L43:.... 3.76 x 2.28 x 4:11 = 36.23...
 
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Hilux said:
IF, you were going to put the L43 back in it, no, there is no difference. But why would anyone do that? Most ppl would put a 5 speed in it, with two crawl boxes and now you have OD.

SM420: 7.05 x 2.28 x 4:11 = 66.04
L43:.... 3.76 x 2.28 x 4:11 = 36.23...





It doesn't "really" matter if it's a dedicated rig, but a lot of folks wanna drive their rigs... So they'd prolly opt for a crawl box... Plus, 9 outta 10 will already have the 5speed.

Where one might want to get the gearing just right for highway use, one with an overdrive could use even lower gears.

2 stock TC's = 2.28 x 2.28 = 5.19:1

SM420 1st gear stock TC......7.05 x 2.28 = 16.07:1
L43 1st gear w/ Marlin 3.76 x 2.28 x 2.28 = 19.54

SM420: 7.05 x 2.28 x 4:11 = 66.04
L43:.... 3.76 x 2.28 x 4:11 = 36.23...
Click to expand...
This has the 4sp g52 right now, with stock 2.28 case.
The rear axle ratio is 6.17:1
This means 55:1 at the end, but the 47" tires are drivig that ratio to the high side by about 1.6.
I don't need to take this and shouldn't take this on the highway.
I am aiming at top speed of no more 50-60km/hr.
I want very low speed. I not interested in going fast
whatsoever.

I want it to be simple ,like 2 shifter , one for the transmission and one for hi,lo and I have to keep it short also..
It is too fast in hi range right now and with the 420 I might make use of first and second in hi range. That is about it.
Thanks for the info Helix and evrybody.
Just think of tractors and you will understand what gearing I need..
 
Cool build. You know about the adapters at OTT right? Ever thought of stacking two trannies together? I've seen SM465s back-to-back to gain the gear reduction, but guy who did that is a machinist. It was going behind a Cummins 4BT and the whole shebang into a ... well, don't wanna ruin it for him. Anyway, if you get the 420 up to the 22R, how about 4.7:1 or 5:1 gears in a mini case? Why did you ditch the 2F? It's easier to use a three speed bellhousing with minor mods with an SM420, no?
 
Thanks to all you guys.
I typed for 1/ hr then I lost it all when I hit the wrong botton.
The easiest and cheapest way is to buy the doubler and keep the Toyota trany, but I can make some of the adapters so I want the 420 for the low gear the tuoghness and the pto.
The 2F was not in my initial plan, but to explain it is a long story.
It is better room and better allignment with 22r.
The 2F is hrd to come by around here.
The 22r will keep my options open for a diesel later on.
Believe me through this build , I must have learned more about evrything than I care to, but I forgot most of it.
It is even harder when you want to kkep it very low cost.
I will post pics of how the bellhousing bolts to the sm420 , incase someone else wants to do it.
I have no idea yet how I will go about adapting the case to the 420, but I have few options, as you know.
OTT are great bunch to deal with ,from what I read, but I am trying to save money as much as I could for the things that I can't make.
Just to give a short list of what went into this build ,
Front axle from fj40.
rear axle from a 52 2 ton international.
Power steering sginaw from a 1/2 ton chev.
Steering column an steering wheel . mix from 71 fj40, 82 bj20 and 84 toy truck.
All my 4 peddals are from the fj40.
2 clutch master cyl from fj40 and one from a bj60.
sending unit for temp and for oil pressure from fj40.
The gauge cluster is and will be from fj40.
rear fender from a ford 8N or so.
rear tires and rims are made from MF and international rims.
It is not even have done yet so who know what else I will use..
 
Updat:
I got the 18RC/20R bellhousing bored and bolted to the sm420 case.It is bolted with 4 ,12mx125 bolts.
Later I will add another plate which will be bolted to 4 original sm bolt holes and the remaining 4 bolt holes in the bellhousing.
That should be easy to do since it will external to the housing.
Now I am going to look for a pilot bearing and a clutch.
The 22R pilot bearing is
32 mm OD,
12 mm ID ,
.3937" wide.
The pilot bearing I will need will have to have 32 mm OD
0.754" ID
The clutch will have to be 10 splined bore and about 9" OD.
I will clean up some stuff then take few pics..
I hope it will all fit together and :steer: once everything is in..........:cheers:
 
Looking forward to seeing more pics. I assume you're going to use a Toy pressure plate and hydraulic master/slave setup. I'm wondering where you'll get a 10 splined clutch plate that will fit the Toy flywheel. I'm pretty sure you can get them custom made, but that defeats your purpose. Keep at it!
 
2ndGenToyotaFan said:
Just get a 10 spline clutch and stick it on a lathe and turn it down to the right diameter for the Toyota stuff.... :D
Click to expand...
I was thinking the same thing too.
Anyway the closest clutch I can order around here is the one used on 83 jeep cj7 with 4cyl.
It has the right splines and OD 9 1/8" ,where the 22r calls for a 8 7/8" OD.
I will get the clutch on monday .
I am going to get the input shaft tip of the sm420 also turned down to fit in the 22r pilot bearing.
I just want to stop looking for parts and move on with it.
Thanks,,,,,,,,,,,,,,
 
Here are some pics of the sm420 to the toyota bellhousing.
sm1.webp
sm2.webp
 
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