Difference between non-split and split t-case (2 Viewers)

[yoda'stoy]

Perhaps a stupid question but here goes. (I did look in the FAQ)
What is the difference between a split t-case and a non-split t-case?
I understand that the split t-case is supposed to be stronger, but what makes it stronger? What year did Toyota change from non-split to split?
I was thinking of upgrading to an H41 for the lower gears. I thought that it was a direct swap. On cruiserparts.net there are two types of H41's?, one for a non-split case and one for a split case.
My truck is a 76FJ40...so I believe I have the non-split case, but I would not know by looking at it.
How can I tell the difference? I did not find any info in my manuals.
Where might I find pictures and/or more info?
Is there anyone that has made this swapped and H41 for their H42 that can give me some feedback?
Thanks in advance for your help.
Sincerely,
Bill L.

 

[peesalot]

split case = better aluminum case with higher low range . It actually is a bolt together halves.
Non-split = a 1 piece aluminum case with lower low range and is prone to cracking in some situations.

 

[lcruzrlvr]

split case = better aluminum case with higher low range . It actually is a bolt together halves.
Non-split = a 1 piece aluminum case with lower low range and is prone to cracking in some situations.

Split case has additional gearing options available.

Depending on what you are doing with the truck:
A) SM420 / 3 speed transfer
B) H41 / RockBox or ToyBox / 4 speed transfer
C) SM465 / 3 speed transfer

Troy

 

[Tigerstripe40]

Split case has additional gearing options available.

Depending on what you are doing with the truck:
A) SM420 / 3 speed transfer
B) H41 / RockBox or ToyBox / 4 speed transfer
C) SM465 / 3 speed transfer

Troy

You can also run the 4 Speed transfer with an SM420 and an SM465.
The gearset in the 4 speed t-case has a wider surface area than the gearset in the 3speed case. Sure you give up some gearing but you gain a slightly stronger case, and a stornger gearset than the 3 speed.

OVerall, I have been EXTREMELY happy with my SM420-4Speed t-case setip, but I do feel that I need just a TOUCH more gearing.

4.88's here I come!

 

[Josie'sLandCruiser]

Hi All:

The "split" t-case arrived on the US market in 1980 Land Cruisers (40 and 60 Series.) It is an inherently stronger design than the earlier, one-piece t-cases used in 1960s and 70s production Land Cruisers.

The caveat of using a "split" t-case is that the versions used on USA-spec vehicles were not set-up for the t-case parking brake; the parking brake was placed on the rear axle assembly. One can source geniune OE Toyota parts to mount a drive shaft parking brake on the rear output of a "split case," but is is not cheap and the rear drive shaft on your FJ40 is already short enough!

There is no advantage to the typical FJ40 owner to switch to the "split type t-case; just bolt-up that H41 onto the regular "four speed" t-case like I did!

Regards,

Alan

 

[Vortec_Cruiser]

The gearset in the 4 speed t-case has a wider surface area than the gearset in the 3speed case. Sure you give up some gearing but you gain a slightly stronger case, and a stornger gearset than the 3 speed.

I see no advantage to using the thicker 4-spd gears, since I have never heard of anyone breaking the 3-spd gears. The best setup is to use the stronger 4-spd case with the lower 3-spd gears.

 

[Rusty79]

I think the h55 transmission (toyota 5 speed) mated to a split t-case...

 

[cruiser_guy]

I think the h55 transmission (toyota 5 speed) mated to a split t-case...

The H55 can ONLY be mated to a split case as far as I know but the H41 is the same gearing as an H55 only without the overdrive.

I've got an H41 mated to a 3 speed single piece transfer case behind the 3B diesel in my '67 FJ45LV. This is how the tranny/transfer combo look. The red object is a transfer case saver designed to avoid breakage in the most common area. It's an aftermarket item.

Here is also a picture of the split case behind the H55 and 3B in my '82 BJ60 when I swapped the frame. Not the best picture but it's all I have.

 

[rick_d]

too much information...

H41's
there was once a 5.3:1 first gear four speed (late 1960's FJ55 non import)
the one piece case 4 speed has 4.9(+):1 first gear
the split case 4 speed HAS THE SAME RATIO AS the H55, they are also always short (no extension).

bandierante "H55's" use a cast iron one piece case (the basis for the AA 4:1 gear case). They also have an adapter that allows this one piece case to bolt essentially to a split case tranny.
(another note, the bandierante 5 speed transmissions have a cast iron top plate vs aluminum toyota types)

Split cases are Aug 1980 and later. Placed on R type and Heavy duty cast iron transmission lc's until 1999.
10/1985 toyota introduced the 38mm idler shaft (vs the 34mm) which ran from 1985-1999 essentially untouched. I was told that 34 mm gear sets could be pushed "sideways" in candian mining operations, the 38's never had that problem.

Gear ranges from 1:99/1 to 2.4/1 (high calculated by a machinist friend of icky's). To the best of my knowledge, all H55 applications got a 1.99:1, Auto transmissions got reverse cut gears and 1.99:1 (all 1.99 using a 38 tooth low range output gear)

 

[PabloCruise]

rick-d,

Any comments on when you can find the 2.4:1 in the split case?

Good info - thanks!

 

[cruiser_guy]

rick-d,

Any comments on when you can find the 2.4:1 in the split case?

Good info - thanks!

Marks makes the low range gear sets but you probably won't like the price!

 

[rick_d]

the gearset calc'd at 2.4:1 was a 34mm. I was sold it in 2002 as a 38mm, which I traded off to a friend who is using it now (I was shipped it and always thought it was 38)

marks gearsets are $1,400 US or so with freight. Upgrading a 1.99 to 2.27 with oem gears will cost near that.

 

[hi50phd]

Split Case

As mentioned above, you need to be careful if you use a split case. The TC that was attached to my H55 had the 1.96 Low Range. Not the best for off-roading.

I imported a Marks low range (3.05: 1 low and 1.05:1 high) directly from: http://www.mannellmotors.com.au/. Four years ago, it was about 800USD including freight and tariff.

If you go with the Marks conversion, you will need to determine whether your TC has a 34mm or 38mm gear, I think. Don't remember the details, but I recall the TC had to be disassembled before ordering th gear set.

 

[Cruiserdrew]

I'm pretty sure the 38mm idler shaft started with 4/86 production, not 10/85.

It's pretty easy to figure out what size your idler shaft is with no disassembly-it sticks out the rear of your transfer case so you can just measure it, though it is slightly beveled so it won't be quite 38mm.

The gear ratios in low are a matter of some speculation. For sure, the 87 (38mm idler) case I am using is 2.26:1. The 34mm idler shaft cases are either 1.99:1 or 2.26:1. I have an 84 t-case with the 34mm shaft that I will eventually disassemble and answer that question. FJ40Jim who should know, says even the earlier cases in the USA are 2:26:1. If true, that's a good thing! I have a spare one that may find it's way into my FJ40.

As to what makes a split case stronger than a non-split case, the answer is; everything. The case is thicker, the gears, shafts and bearings are all bigger, the output bearings are better supported. There is more reinforcement webbing cast into the sides of the case. Even the clutch engagement teeth on the output shaft are bigger and thicker. The output splines are fine spline.

 

[yoda'stoy]

Thanks for all who posted and thanks to Cruiser_guy for the pics. I found the info very interesting and something to consider for future mods. The near future for me will include a rebulit and (broken in) 2F and the H41. I'm excited about the change as my truck has been in need of improvements for several years.
I'll post pics when the changes take place.
Sincerely,
Bill L.

 

[PabloCruise]

Thanks for all who posted and thanks to Cruiser_guy for the pics. I found the info very interesting and something to consider for future mods. The near future for me will include a rebulit and (broken in) 2F and the H41. I'm excited about the change as my truck has been in need of improvements for several years.
I'll post pics when the changes take place.
Sincerely,
Bill L.

See you soon Bill!

 

[rick_d]

andrew et al-

38mm idlers began in world production in october, 1985. US trucks (60 series) seemed to have gotten leftovers and 4/86 they showed up here.

A 10/85 HJ60 CDN spec will have a 38, as will similar BJ70.

 

[Cruiserdrew]

andrew et al-

38mm idlers began in world production in october, 1985. US trucks (60 series) seemed to have gotten leftovers and 4/86 they showed up here.

A 10/85 HJ60 CDN spec will have a 38, as will similar BJ70.

That makes some sense. Thanks for the info. When I was installing an H55, I made sure I had an 87 case to rebuild before I started the swap.

I have never even heard of a broken 34mm split case, though it must occur. I wish there was an easy way to adapt an SM420 to a split case, as that combo would rock, and be tough as nails. A later H41/split case with Mark's gears would be a nice combo too in an FJ40. In a wagon, with the longer wheelbase, it's easier to consider a Toybox, or similar.

 

[Jerry G]

I have a 72 FJ40 with a 350 Chevy conversion. It currently has the original 3 speed and one piece T case. Would love some recommendations as to 4 or 5 speed and any other necessary conversion. This is more of a driver than off road so I do need the extra gears to make the 350 lope but do occasionally use it in the Rocky Mountains.

 

[Tigerstripe40]

I have a 72 FJ40 with a 350 Chevy conversion. It currently has the original 3 speed and one piece T case. Would love some recommendations as to 4 or 5 speed and any other necessary conversion. This is more of a driver than off road so I do need the extra gears to make the 350 lope but do occasionally use it in the Rocky Mountains.

The go-to 5 speeds are the NV4500 and the Toyota H55f. Another option is the Ranger Overdrive.

NV4500 has adapters to go to the 1 piece transfer case and you retain your parking brake.
These are no longer available new, but can be found rebuilt.
The transmission is long, and you lose quite a bit of rear driveshaft.

The H55f will require a split case and a parking brake option.
The factory parts to put the parking brake on the output of the split case are really hard to come by.
You can get a parking brake disk brake from a few different places, I think TSM still makes one.

The Ranger Overdrive would install between your 350 and your stock 3 speed and essentially split each gear. You will loose driveshaft length,

For consideration, the Ranger Overdrive (7.5") + J30 transmission (8.5") is shorter than the NV4500 (12.735") + t-case adapter (6.375"). (15.5 inches vs 19.11 or 22.125 vs 28.75). The H55 is 15.5" and Split case is 9" so 24.4"