Topic: T-case gears: Something about halfway between 2.28 and 4.0?

[Winch]

Does anyone know if it is possible to find and swap T-case gears somewhere between a 2.57 - 3.00:1 ratio for stock 2.28 gears into a gear driven Toyota T-case?

OK, that's the end of my question, but incase anyone is interested in wondering why I would want such a ratio, here is a bit of an explanation:   I have a 2002 Tacoma Doublecab with the 3.4L V6 and a 5speed R150F tranny with dual T-cases using the Marlin adapters and 2.28 gears in both.  I think my truck weighs just over 5000 lbs. I did not post this in the Tacoma section, because I felt it is more relevant here since I am using 1980-83 T-cases.

I find the T case ratios of 2.28 and 5.2 just enough for most terrain.  My buddy has 2.28 in the first T-case and 4.0 in the second and I find the 4.0 too low for the type of non-competitive wheeling that we do.  My buddy is always either falling behind because he runs out of gears, or has to stop to shift the T-case in Hi. 

I think it would be great to convert my low range back to a stock configuration of around 2.57.  I don't really have any problems with power on the V6, but my main issue is with hill descends.  Whereas I think the 2.28 will slow down a lighter vehicle, it is not enough reduction to slow down my 5000 lbs Tacoma, while the stock 2.57 gears did that.  I miss having the downhill control I had before.

Descending steep hills with only one T-case in low is not enough, and putting both in low is too low.  Having both T-cases in low and the tranny in second gear, is slightly lower than having one T-case in low and the tranny in first, but still not quite enough.

My prefernce would be to have a ratio of about 2.57 - 3.00 in my second case.  As far as I understand, I cannot swap the 2.57 gears from my old Taco T-case because they are a planetary design, and I am unaware of anyone making gears in that ratio for a Toyota.  So do I have any options?  Will a machine shop be able to make me a set of gears in the ratio I want, or are there perhaps other vehicle T-case gears that will swap in with such a ratio?

Thanks
Gary

[REG535]

Am not sure why you having problems with this setup? To me going slow is more important than going fast down a hill, a hill can either flop you or roll, which is why going as slow is possible helps.
There are no such gears for the gear-driven cases. If you wanted to you could use the t-case that first came with R150F and put it back in along with the adapter from chain-driven that bolts to gear-driven t-case,,instead of using two gear-driven t-cases.
 

[BLACKDOG]

the MC10 is the adapter that places a 2.28 gear driven crawl box in front of a 2.57 chain drive case.  That is what I have in my truck.  Love it.

[79coyotefrg]

um  i find  i run 2.28+ 2.28 +3rd gear in tranny alot,  i dont understand why people think they have to shift the tcase to high range before they use 3rd or 4th gear

[Winch [OP]]

No, I need both T-cases to be gear driven because I need my front driveshaft passenger side to match the FJ80 axle.  I think 2.28 is fine for a lighter truck, i.e. mini truck or 4Runner, but with the weight of my truck it doesn't matter waht configuration I use (2.28 plus 1st gear, or 2.28 plus 2.28 plus 2nd gear), I either go too slow or too fast down steep hills.  In my opinion a ratio of 2.57:1 to 3.0:1 would have been ideal for a Tacoma like mine.  So, I take it from your responses that there simply is no such option???

[jimbo74]

No, I need both T-cases to be gear driven because I need my front driveshaft passenger side to match the FJ80 axle.  I think 2.28 is fine for a lighter truck, i.e. mini truck or 4Runner, but with the weight of my truck it doesn't matter waht configuration I use (2.28 plus 1st gear, or 2.28 plus 2.28 plus 2nd gear), I either go too slow or too fast down steep hills.  In my opinion a ratio of 2.57:1 to 3.0:1 would have been ideal for a Tacoma like mine.  So, I take it from your responses that there simply is no such option???

you have 2 choices,

learn to live with it, and shift to another gear,

or learn to make your own gears

[BLACKDOG]

No, I need both T-cases to be gear driven because I need my front driveshaft passenger side to match the FJ80 axle.  I think 2.28 is fine for a lighter truck, i.e. mini truck or 4Runner, but with the weight of my truck it doesn't matter waht configuration I use (2.28 plus 1st gear, or 2.28 plus 2.28 plus 2nd gear), I either go too slow or too fast down steep hills.  In my opinion a ratio of 2.57:1 to 3.0:1 would have been ideal for a Tacoma like mine.  So, I take it from your responses that there simply is no such option???

no you don't the t-case from the 3.0 trucks is also chain drive, but passenger drop.  It has the same ratio (2.57:1)  It would work fine for what you want.

[OOPS]

no you don't the t-case from the 3.0 trucks is also chain drive, but passenger drop.  It has the same ratio (2.57:1)  It would work fine for what you want.

I have one I will give you, if you want to come to Roseville, CA and pick it up. Only has about 72,000 miles on it.

[Winch [OP]]

no you don't the t-case from the 3.0 trucks is also chain drive, but passenger drop.  It has the same ratio (2.57:1)  It would work fine for what you want.

Ok thanks, but back in the day when I did my research on going dual cases, I read that the 3.0 chain driven cases were the weakest of the three.  If I remember correctly, most of the opinions were that the new Taco T-case was the strongest because the chain is almost twice as wide as the 3.0 L chain, but could still stretch over time, the old gear driven cases were next, and the 3.0 Liter T-cases were considered the weakest, especially since they would be used behind the first T-case.  Other thing is I already have a custom crossmember attaching to the gear driven case, driveshafts, ect. so I would prefer to keep the two gear driven cases, and was hoping that someone made a ratio about halfway between the two extremes (2.28 at the high end and 4.0 + at the low end)

[BLACKDOG]

Ok thanks, but back in the day when I did my research on going dual cases, I read that the 3.0 chain driven cases were the weakest of the three.  If I remember correctly, most of the opinions were that the new Taco T-case was the strongest because the chain is almost twice as wide as the 3.0 L chain, but could still stretch over time, the old gear driven cases were next, and the 3.0 Liter T-cases were considered the weakest, especially since they would be used behind the first T-case.  Other thing is I already have a custom crossmember attaching to the gear driven case, driveshafts, ect. so I would prefer to keep the two gear driven cases, and was hoping that someone made a ratio about halfway between the two extremes (2.28 at the high end and 4.0 + at the low end)

That was why Marlin didn't try to produce an adapter for a long time, but then through testing, he discovered that the 3.0 t-case is in fact strong enough to handle the stress.  The taco case is probably stronger, but IIRC, marlin discovered that the 3.0 chain drive t-case is of similar strength as the gear driven t-case.

It probably wouldn't be too hard to adapt that crossmember either.  I made a chain drive t-case mount by cutting of one side of the mounting tab,and welding it on at a different angle. 

I think you're SOL as far as a gearset in the range you're looking for.