Need help with transmission and transfer case options in an already 350 swapped fj40 with the original 3 speed. (1 Viewer)

Seoirse

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Right now my 40 has a SBC and the original 3 speed and transfer case. I have been talking to some people in a local facebook group but I think I need some more opinions.

One guy said a fj60 4speed and split case will fit directly where my 3 speed goes no issue, and it is a superior transfer case.

Another person said the 3speed transfer case is both stronger and lower geared so it is better for off road anywas.

I already have my hands on a split case from a 60 series, so would that only bolt to a 60 series 4 speed? Would a 40 series 4speed work here as well? Is one better than the other? Are there any other transmission options I should be looking at that are easily swapped in place on the3 speed?

I am very knew to 40s overall so any help is appreciated. Thank you
 

reddingcruiser

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The split case isn't going to bolt to your 3 speed and 4 speed trans isn't going to bolt to a GM bell housing with a 3 speed adapter. The FJ60 4 speed and split case is a good choice. At the end of the day all this will only get you 1:1 in high gear.

You need a 4 speed adapter bell housing along with the correct flywheel and clutch, and you can use the FJ60 transmission and split case.
 
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Easy is a relative term.

When I decided to replace the 3 speed in my FJ 40 that had been converted to a SBC years ago I went with the NV4500. It gave me overdrive that other conversions did do. The V8 was left where it was originally placed during the conversion following Downey instructions and parts. The NV4500 conversion via Advance Adapters put the shift lever back into the original 3 SPD location. I kept the 3 SPD one piece transfer case but added reinforcement pieces. The parking brake cleared the rear frame cross member, just barely.

You can go with which ever transmission you like, it just changes how much of your drive train is Chevrolet and how much is Toyota. Mine is all Chevy engine, bellhousing, clutch, transmission connected via AA to the Toyota transfer case and Toyota drive line.

The choice is yours.
 

Seoirse

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The split case isn't going to bolt to your 3 speed and 4 speed trans isn't going to bolt to a GM bell housing with a 3 speed adapter. The FJ60 4 speed and split case is a good choice. At the end of the day all this will only get you 1:1 in high gear.

You need a 4 speed adapter bell housing along with the correct flywheel and clutch, and you can use the FJ60 transmission and split case.
Is there anything specifically great about the split case that would make it better than a 3 speed case? I pulled one from a junkyard but I’m not worried about not using it.

Are there any differences in the bolt patterns or gearing between an FJ40 and fj60 4spees?
 

Seoirse

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Easy is a relative term.

When I decided to replace the 3 speed in my FJ 40 that had been converted to a SBC years ago I went with the NV4500. It gave me overdrive that other conversions did do. The V8 was left where it was originally placed during the conversion following Downey instructions and parts. The NV4500 conversion via Advance Adapters put the shift lever back into the original 3 SPD location. I kept the 3 SPD one piece transfer case but added reinforcement pieces. The parking brake cleared the rear frame cross member, just barely.

You can go with which ever transmission you like, it just changes how much of your drive train is Chevrolet and how much is Toyota. Mine is all Chevy engine, bellhousing, clutch, transmission connected via AA to the Toyota transfer case and Toyota drive line.

The choice is yours.
This may be a stupid question but if I’m looking for an NV4500 should I limit it solely to Chevy transmissions? Dodges would widen that search.
Thanks for the help
 

reddingcruiser

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Is there anything specifically great about the split case that would make it better than a 3 speed case? I pulled one from a junkyard but I’m not worried about not using it.

Are there any differences in the bolt patterns or gearing between an FJ40 and fj60 4spees?
The one thing you can do with a split case that you can't do with the one piece case is upgrade the low range gear set to 4:1 gears.
 
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And then there is changing drive shaft lengths, and matching up drive shaft bolt patterns when switching from 3 speed to anything else.
 

Lil'John

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The case on the split case is much much stronger than 3/4 speed tcases. The split case isn't known to crack in half nor shred the front output housing.

I have a club member that converted his FJ40 to a split case. He needed to buy new flanges for his differentials. No big deal. I forget how much he paid. On my project, I already had Dana 60 to Toyota flanges so I had the pattern :p

Driveshaft adjustment is also not a big deal. I did that on my FJ55 when I converted from 1 piece to split case. I don't recall the price off the top of my head... I've done it twice. Basically, one gets shortened and one gets lengthened.

I like the quietness of the split case in my FJ55 and I have no concerns of running it behind a 6.0L ls engine.

Dodge NV4500 is a challenge to search for because of different versions. If you get a diesel version, it has the unusable input gear(1 1/4" vs 1 1/8") that isn't swappable... the input hole in the main case is also a different size. Yes, I fell into that trap. If you get a gas one, you need to swap the input gear(shorter GM) and I forget if the input bearing retainer has to get swapped. In all honesty, I'd recommend just getting a rebuilt unit whether from AA or otherwise. I am a small fortune into my "cheap" junkyard NV4500 because of numerous issues found(OD shaft wears badly where it goes from case into housing)
 

Living in the Past

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Has anyone mentioned the hand brake will not be on US split cases. The split case also had lower gearing than the one piece that bolted to the four speed. There were slightly different gear ratios in different markets. No H41 offered here so ours was a little lower geared.
 

Lil'John

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IIRC there's a parking brake setup for the split case, if you're interested. Give Georg a call at Valley Hybrids or @orangefj45
Yes there is. Output housing and drum specific to split case, while the rest is FJ40. Not a cheap option though. My wallet is still hurting ;)

The advice from FB is often not accurate, unless it comes from someone also here on Mud. Glad you came here for help.
Being from here doesn't provide any guarantee of accuracy especially if it is the same 20+ year parroted "you will kill nuns and orphans if you don't do this mod" that still are around.
 

Living in the Past

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If you don't already have a a split case and not looking to spend a fortune on a new one can buy a used 10/82+ case from a BJ45/FJ45/HJ47 those will have the hand brake and are set up for the H55F five speed. These will have the 34 MM idler shaft not the later 38 MM shaft.
 

Seoirse

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Damn a lot of good information here. I too am glad I didn't do anything else besides pull a split case before I came on here. I think I might try to wheel the 3 speed for a bit before I make any decisions. I am looking at swapping the 3 speed for a nv4500 mated to a fj60 split case. And since I will rebuild it while I bolt it on I might as well try and change some of the gears in it while I'm at it.
 
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This may be a stupid question but if I’m looking for an NV4500 should I limit it solely to Chevy transmissions? Dodges would widen that search.
Thanks for the help
Yes, it saves a lot of headaches. A lot of folks here prefer the Toyota external clutch slave because it is easier to change or work on in the field, I chose to go with the Chevy internal and simply upgraded the clutch master to a larger diameter for full travel.
 
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When I was faced with the same situation I went with a Toyota 4 speed transmission and kept my 3 speed TC. It wasn’t too expensive and It’s been working for me for ten plus years plus I got to keep it mostly Toyota. You gotta love a V8 and a four speed!
 

Seoirse

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