3.1:1 T-case gears ARE available!

[-Spike-]

http://www.marks4wd.com/products/gearmaster/lc-80-100-extra-low-tc-gears.htm

Credit to RavenTai for finding this. It's been buried in another thread, so now it's out here for all to see.

-Spike

 

[Nay]

Yea, I'm responding to all those other threads . 3.15:1 sounds about perfect for an 80 on 35's as you don't get too low for those trails that have distance between obstacles, but you have better gearing than stock in low range even with 35's. No other mods required (presumably).

The site says that AA is selling this as a distributor but I couldn't find it. I don't have the coin right now, but this is first on my list.

Man I need to go to bed

Nay

 

[landtank]

NAY, the site doesn't mention the HF2AV as being a candidate for these gears.

 

[GXO]

That is some pretty substantial coin for some additional engine braking...going forward I get my AT crawler action...any other reason for this?

I have 4.88s and 35s

 

[TCH2FLY]

We will need Christo to chime in...I was at the shop and asked Ben about these a month or 2 ago and he said they would not fit in my 94 (obviously a HF2AV so I assumed that was the difference)

 

[Nay]

That is some pretty substantial coin for some additional engine braking...going forward I get my AT crawler action...any other reason for this?

I have 4.88s and 35s

Sure, you get the low range for major uphill rock crawling obstacles without having to regear your diffs.

You can get the benefits of 4.88 gears on the highway with OD Off, but that doesn't help you offroad and the ungearing is a serious issue on climbs like the picture below (you wouldn't like the noise you hear from what I presume is the torque converter).

This solution would let you keep the strength of the stock gears and for around the same $$$ provide a major offroad upgrade.

But now we hear they don't fit, despite Marks website saying they are for our application

Nay

 

[landtank]

But now we hear they don't fit, despite Marks website saying they are for our application

Nay

The site clearly states it's for the HF2A transfer case. You have the HF2AV case.

 

[Doc]

What years had the HF2A then?

 

[extremetoy1]

91-92 I beleive, someone correct me if I am wrong

 

[RavenTai]

91&92, 98 to current in the US,

not sure about in Aus where the author of that parge would be.

externally the HF2a and HF2Av look very similar I thought diffeering only in the output housings, I thought the rest of the two was the same but I do not know that for sure,

 

[cruiserdan]

What years had the HF2A then?

91-92, all and 93-94 W/O ABS and W/semi-float rear axle.

 

[TiredIronGRB]

Sweet...

 

[landtank]

It would be interesting to identify which gears are getting swapped out and confirm it won't fit the HF2AV. As Raventai pointed out, the VC is in the rear extension housing and maybe that is all that is different. Since they are out of Australia maybe they never got the HF2AV transfer case.

 

[cruiserdan]

The stock low speed gear and low speed idler gear show to be the same part numbers for both cases.

 

[Vitesse_6]

91-92, all and 93-94 W/O ABS and W/semi-float rear axle.

WOOO HOOOOOO, Oddballs rule!

 

[-Spike-]

The stock low speed gear and low speed idler gear show to be the same part numbers for both cases.

That sounds good, now we need to confirm that there's enough clearance in the case. I assume it's a different case?

-Spike

 

[Slomo]

This solution would let you keep the strength of the stock gears and for around the same $$$ provide a major offroad upgrade.
Nay

I understand that the higher numerically (lower) a gear set is the weaker it is, all other things being equal. I know the 5.29's can be iffy depending on usage but I have not heard of the 4.88's being problematic. Is the increase in ring and pinion strength between the 4.10's and the 4.88's that critical for 35" tires for medium-core usage in the 80 series? The 80 is alot heavier but, I ran 4.88's in a SAS 4runner with 35's for many years on medium to hard core trails with only one ring and pinion failure which I attribute to driver error. I am only planning on medium-core use with the 80 as I am over beating the crap out of my rig for fun but I do need to tow occasionally. Ideally I would like lower t-case gears and lower axle gears but I don't want to introduce an inherent weakness.


Not very cost effective but is swapping in an HF2A possible? Or would the part time conversion and removal of the viscous coupler from the HF2Av make the difference in fitment of the gears if the cases are indeed the same?

 

[Nay]

I understand that the higher numerically (lower) a gear set is the weaker it is, all other things being equal. I know the 5.29's can be iffy depending on usage but I have not heard of the 4.88's being problematic. Is the increase in ring and pinion strength between the 4.10's and the 4.88's that critical for 35" tires for medium-core usage in the 80 series? The 80 is alot heavier but, I ran 4.88's in a SAS 4runner with 35's for many years on medium to hard core trails with only one ring and pinion failure which I attribute to driver error. I am only planning on medium-core use with the 80 as I am over beating the crap out of my rig for fun but I do need to tow occasionally. Ideally I would like lower t-case gears and lower axle gears but I don't want to introduce an inherent weakness.


Not very cost effective but is swapping in an HF2A possible? Or would the part time conversion and removal of the viscous coupler from the HF2Av make the difference in fitment of the gears if the cases are indeed the same?

I doubt I would ever bust a set of 4.88's in my usage. Gear swaps can have other complications, such as increased gear noise. It's one of those things that if you can leave it alone, it's worth leaving alone. I'd just so much rather have Toyota 4.10 gears than Yukon 4.88's.

Nay

 

[baxter650]

At one time i priced out those gears from AA at $1395.oo.
A used HF2A was priced out at $1000.oo + shipping but can't remember from where right now.

 

[GXO]

Lose the VC and you have the "A" version of the t-case. I believe that is the only difference. Wouldn't that get you the room for this swap?