Transfer case re-gearing

[orangefj45]

Will these gears work in the viscous couple case? HF2AV

Yes absolutely!!!! The viscous coupler doesn't affect the gear sets.

There is only one version in this Tcase "family" that's excluded; the shorty with full mechanical shifting. It features a one-piece idler gear like the split case so the low range gear set can't be installed.
But those cases are extremely uncommon here in North America. I've only seen one ever. And I've seen a few of the HFxA series cases .......

Georg @ Valley Hybrids & Cruiser Brothers

 

[Qball]

Sigh......I wish I has the power to rock that. One day!

 

[Cruzilla]

Yes absolutely!!!! The viscous coupler doesn't affect the gear sets.

There is only one version in this Tcase "family" that's excluded; the shorty with full mechanical shifting. It features a one-piece idler gear like the split case so the low range gear set can't be installed.
But those cases are extremely uncommon here in North America. I've only seen one ever. And I've seen a few of the HFxA series cases .......

Georg @ Valley Hybrids & Cruiser Brothers

OK, next question.. I already have a low range set of gears that I have not installed yet, can I just get the high range reduction gears and combine them with the Low range gears I already have?

 

[orangefj45]

OK, next question.. I already have a low range set of gears that I have not installed yet, can I just get the high range reduction gears and combine them with the Low range gears I already have?

The high range gears and low range gear sets do not affect each other. You can change just the high range, just the low range, or both.
We stock both sets and sell them separately.
The high range does not require and case mods. The low range requires some mild grinding to the rear case half to create space for the larger diameter output gear. You also have to trim the oil shields.
Hope that helps.

Georg @ Valley Hybrids & Cruiser Brothers
Shop 209-475-8808

 

[Cruzilla]

Sweet! So how much for the high range reduction get set? Im gonna do both in one fell swoop!

 

[orangefj45]

High range reduction?

Are you looking for high range Overdrive or Underdrive? We/Terrain Tamer offer both.

Georg @ Valley Hybrids & Cruiser Brothers

 

[Cruzilla]

I'm after the 1.097:1 to make my 35 inch tires run like stock 31 inch tires (10% reduction)

 

[Cruzilla]

So that would be underdrive..

 

[orangefj45]

Correct. You'd want the underdrive.
I'll send you a pm Scotty!

Georg @ Valley Hybrids & Cruiser Brothers

 

[NielsC]

Correct. You'd want the underdrive.
I'll send you a pm Scotty!

Georg @ Valley Hybrids & Cruiser Brothers

You can PM me a price aswell if you like.
Sounds like you have what I need, HI range underdrive gears to bring my HI gearing with 35s back to stock. Low range I am happy with how it is.
Mine is 1HD-FT full time 80, don't know wich TC it has?

 

[JeepinPete]

Georg, I know you have stated that the over/underdrive gears for hi range do not affect the low range gearing, but I do not see how that is possible.

If I understand this case, in high range power flow is through the three gears at the back of the case. From the factory, the input and output gear have to be the same tooth count to achieve a 1:1 ratio. The idler gear may or may not be the same tooth count, but it doesn't effect the ratio either way.

In order to achieve an over drive, the input gear has to have more teeth than the output gear respectively. The idler gear will have to be smaller than the input gear in order to accommodate the increase in size of the input gear. The net effect is a numerical decrease in low range gearing. This may not be much, but it is something.

Conversely, the input gear on a under drive gear set has to be smaller that the output gear, and the idler will have to be larger to accommodate the smaller input gear. The net effect is a numerical increase in low range gearing.

I took a look at the Japanese site, and the five gear under drive set seems to prove this point with a high range of 1.097 and a low range of 3.317. Everything I have read states 3.1:1 is a low a gear set that will physically fit in the transfer case.

 

[nukegoat]

Georg, I know you have stated that the over/underdrive gears for hi range do not affect the low range gearing, but I do not see how that is possible.

If I understand this case, in high range power flow is through the three gears at the back of the case. From the factory, the input and output gear have to be the same tooth count to achieve a 1:1 ratio. The idler gear may or may not be the same tooth count, but it doesn't effect the ratio either way.

In order to achieve an over drive, the input gear has to have more teeth than the output gear respectively. The idler gear will have to be smaller than the input gear in order to accommodate the increase in size of the input gear. The net effect is a numerical decrease in low range gearing. This may not be much, but it is something.

Conversely, the input gear on a under drive gear set has to be smaller that the output gear, and the idler will have to be larger to accommodate the smaller input gear. The net effect is a numerical increase in low range gearing.

I took a look at the Japanese site, and the five gear under drive set seems to prove this point with a high range of 1.097 and a low range of 3.317. Everything I have read states 3.1:1 is a low a gear set that will physically fit in the transfer case.

Yeah i am confused too about this

 

[half k cruiser]

You should probably tag him if you want an answer, @orangefj45 can you comment on post #71 above ?

 

[half k cruiser]

I guess not !

 

[Dragos80]

Georg, I know you have stated that the over/underdrive gears for hi range do not affect the low range gearing, but I do not see how that is possible.

If I understand this case, in high range power flow is through the three gears at the back of the case. From the factory, the input and output gear have to be the same tooth count to achieve a 1:1 ratio. The idler gear may or may not be the same tooth count, but it doesn't effect the ratio either way.

In order to achieve an over drive, the input gear has to have more teeth than the output gear respectively. The idler gear will have to be smaller than the input gear in order to accommodate the increase in size of the input gear. The net effect is a numerical decrease in low range gearing. This may not be much, but it is something.

Conversely, the input gear on a under drive gear set has to be smaller that the output gear, and the idler will have to be larger to accommodate the smaller input gear. The net effect is a numerical increase in low range gearing.

I took a look at the Japanese site, and the five gear under drive set seems to prove this point with a high range of 1.097 and a low range of 3.317. Everything I have read states 3.1:1 is a low a gear set that will physically fit in the transfer case.

The low range gear set; usually 3.15:1 is a two gear set.
It includes the smaller gear on the idler shaft/cluster and the larger gear on the output shaft/cluster.

The high range OD or UD gear set replaces the input gear as well as the smaller gear on the output shaft/cluster.

Georg @ Valley Hybrids & Cruiser Brothers

I guess not !

Maybe Georg's quote from the 1st page would clear some issues. Hope it helps.

 

[Dragos80]

I am not the mechanical engineer here, nor do I pretend to be one, but... I think there is a wrong approach, by my count, to JeepinPete's post.

In order to achieve an over drive, the input gear has to have more teeth than the output gear respectively. The idler gear will have to be smaller than the input gear in order to accommodate the increase in size of the input gear.

I think it is the other way around.

A larger gear with more teeth would provide under drive capabilities. It would just spin less and slower for each one turn of the input shaft. At the same time an overdrive gear would have to be smaller and have less teeth as well and it will spin faster than the input shaft, therefore what comes out of it will go at a higher speed rate than what you put in.


In case we are talking about different things, I apologize in advance for my post here. We may not be on the same page with this theoretical issue.

 

[orangefj45]

@JeepinPete your correct other than that the high range gears are the front 3-gear-set, the two rear gears make up the low range.

Both the OD and UD gear sets retain the same tooth count idler gear.

I'll get tooth counts for every setup ( high range stock, UD & OD ) tomorrow when I'm back at work. We have all these gear sets in stock currently.
And I'll post the tooth counts for stock and 3.1:1 low range gears as well.

Then we can do some simple math and figure out the exact gear ratios for each application ........... I think you're on the right track in assuming that low range will be affected by the UD & OD high range gears, even if it's just slightly. But today my mind is far from Tcases and gear ratios.

Hope everybody is celebrating Independance Day properly!!!!

Happy 4th!!!!

Georg @ Valley Hybrids & Cruiser Brothers

 

[JeepinPete]

Dragos80, we are saying the same thing. Overdrive, input is larger than output. Underdrive, input is smaller than output.

Georg, I am very curious to see the results.

 

[Tapage]

There is only one version in this Tcase "family" that's excluded; the shorty with full mechanical shifting. It features a one-piece idler gear like the split case so the low range gear set can't be installed.

like this one ..?

which it's the correct model for this one ..?

 

[orangefj45]

Yes! That's the "shorty"!
I've only worked on one of these since they're not very common in the USA.

Georg @ Valley Hybrids & Cruiser Brothers