Interest: Low Range T-Case Gears (1 Viewer)
- Thread starter colsoncj
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Ok, so maybe they don't fit and maybe its futile. But I'm one of the kind of people that has a blast trying to figure this kind of thing out. Even if they don't get produced, I think the excersize would be worth the time. But like I said, I'm weird like that. And all the naysayers just make me want to join in on this project. I haven't taken apart an 80 t-case and I hope I don't ever have to, but here is what I gather you are up against (on a very basic level):
-To get a higher ratio, you need an output gear with more teeth. If you keep the input gear the same, you are constrained on your tooth and helix geometry, so your output gear has to get bigger.
-You could make an entirely new gearset with smaller, stronger gears, but this would be immensely expensive, since Toyota already optimized their gears and they design them overbuilt already.
-If your gear gets bigger, it will interfere with something. I don't know what it interferes with, but if its another gear or bearing, then you are pretty much SOL on that alley. If its just the case, you might be able to cut it and design some kind of structural cap that will seal it back up so it actually fits the gear, but IMO thats just bad design (bandaid).
-When it all comes down to it, I think doing anything with the case, inside or out is not a great idea. Even if you do have the resources to somehow build some gears that will fit, they will never have the strength or longevity of toyota gears. Thats a big deal to me. (On the other hand, look at what Marlin is doing - he DOES improve on Toyota gears, and he gets them made by the same company that makes Toyots gears).
If you don't mess with the case, you still have options open to you, but you really have to get creative. For example, there is a company I saw a few years ago (I can't seem to find it online now) that makes a planetary gearpack that bolts between your t-case and your driveshaft. Obviously you would need two, one for each output. If you could design something like that that was selectable (between 1:1 and low range), which wouldn't be that hard because of how planetary systems work, you would essentialy have a doubler. I like planetary gearboxes for several reasons. They naturally have coaxial input/output, they are very small and compact for their strength, and the design naturally has very low bearing loads.
Anyway, thats my idea, but my point is that thinking outside the box, or the t-case, opens up alot more options.
-To get a higher ratio, you need an output gear with more teeth. If you keep the input gear the same, you are constrained on your tooth and helix geometry, so your output gear has to get bigger.
-You could make an entirely new gearset with smaller, stronger gears, but this would be immensely expensive, since Toyota already optimized their gears and they design them overbuilt already.
-If your gear gets bigger, it will interfere with something. I don't know what it interferes with, but if its another gear or bearing, then you are pretty much SOL on that alley. If its just the case, you might be able to cut it and design some kind of structural cap that will seal it back up so it actually fits the gear, but IMO thats just bad design (bandaid).
-When it all comes down to it, I think doing anything with the case, inside or out is not a great idea. Even if you do have the resources to somehow build some gears that will fit, they will never have the strength or longevity of toyota gears. Thats a big deal to me. (On the other hand, look at what Marlin is doing - he DOES improve on Toyota gears, and he gets them made by the same company that makes Toyots gears).
If you don't mess with the case, you still have options open to you, but you really have to get creative. For example, there is a company I saw a few years ago (I can't seem to find it online now) that makes a planetary gearpack that bolts between your t-case and your driveshaft. Obviously you would need two, one for each output. If you could design something like that that was selectable (between 1:1 and low range), which wouldn't be that hard because of how planetary systems work, you would essentialy have a doubler. I like planetary gearboxes for several reasons. They naturally have coaxial input/output, they are very small and compact for their strength, and the design naturally has very low bearing loads.
Anyway, thats my idea, but my point is that thinking outside the box, or the t-case, opens up alot more options.
lt1fire
SILVER Star
Any thing ever come of this?
x2!!!
Nothing probably.
Because "cheap"/80 series/xfer case/and engineering do not at all go together.
Not even the same game.
Because "cheap"/80 series/xfer case/and engineering do not at all go together.
Not even the same game.
Low gears would be nice.
What ratio is the stock low range??
What ratio is the stock low range??
lt1fire
SILVER Star
Low gears would be nice.
What ratio is the stock low range??
2.48:1, i'd spring for a set of 3.1's even if Marlin ever decided to mass produce them so we didn't have to pay $1200 to Marks
- Thread starter
- #48
I have to swap out transfers at the moment and get the second one disassembled again. Something went haywire in my current transfer, so I'll be using it to build.
Problem is right now I'm working on buying a chunk of land to build a big shop on, and that has to get done first before I can start tinkerin with vehicles again.
I have found a shop that can cut my gears and get them treated... so at least that parts done.
Problem is right now I'm working on buying a chunk of land to build a big shop on, and that has to get done first before I can start tinkerin with vehicles again.
I have found a shop that can cut my gears and get them treated... so at least that parts done.
4:1
I would buy a 4:1 low gear today for $600. My plan was to regear to 4:88 get marks low gear and install a A750f with a 4.7 V8 to take advantage of the low first gear in that trans. That gets you about a 53.5:1 which is almost double stock and still leaves you enough gears (in the 5speed) to run at decent speeds in low range like Christo mentioned. I think this is the way to go. Although it is going to cost me $7k. About what I paid for the truck!
What the market really needs is an adapter from a Tundra/FJ/4R/GX A750F to the HF2A case so I don't have to buy a $4500 LC/LX470 trans to bolt up to my Tcase.
Can you make me an adapter for this swap for under 1k? I think you would have a good market for these. I bet there are at least 10 people on this forum contemplating this swap right now.
I would buy a 4:1 low gear today for $600. My plan was to regear to 4:88 get marks low gear and install a A750f with a 4.7 V8 to take advantage of the low first gear in that trans. That gets you about a 53.5:1 which is almost double stock and still leaves you enough gears (in the 5speed) to run at decent speeds in low range like Christo mentioned. I think this is the way to go. Although it is going to cost me $7k. About what I paid for the truck!
What the market really needs is an adapter from a Tundra/FJ/4R/GX A750F to the HF2A case so I don't have to buy a $4500 LC/LX470 trans to bolt up to my Tcase.
Can you make me an adapter for this swap for under 1k? I think you would have a good market for these. I bet there are at least 10 people on this forum contemplating this swap right now.
I dont know what the difference in legth is but I had to shorten my front and lengthen my rear when I went from the A440f to the NV4500/AA/splitcase. To me it would make more sense to throw a toybox in the middle.
If you either had to not spend the money on lengthening/shortening shafts ($$ towards a toybox) or went longer and had better front driveline angle, you'd be better off in my eye's.
- Thread starter
- #51
any adapter can be made... but made correctly is a different story.... without having all the stuff on hand to look at, and the time involved, i dont think i could swing it right now.
I'd consider it in the future so I'll keep my eyes open on the forum. I have Marlins 4.7:1 T-Case with 4.88 R&P in my 85 4Runner and it made a world of difference. If you could make a high range reduction that would equate to a 4.56 or 4.88 R&P swap I think you would be able to sell to the lightly built Daily Driver and rock crawler. Most that would be interested in a T-Case gear reduction would likely be running at least 33's. So you could kill two birds so to speak. Issue there might be the people who have already done a R&P swap may not be able to hanlde more street gearing (so maybe a smaller bump would be good?).
i think an adapter for marlins crawl box or inchworm would be ideal. cost would be so much cheaper than marks crawl gears and crawl box.
