DWEINBERG01

I was thinking about gettin some 4.7:1 t-case gears from marlin, but don't want to buy a gear driven case and adapter. Does anyone know if you can put the 4.7 gears into a chaindriven case? If so, how hard is it and does anyone have a how-to for it? Thanks

4Crawler

iTrader: (3)

I think if you could, every place would list them for sale and there would be no need for the gear drive adapters

tc

No, you can't change the ratio in a chain driven case, and the auto t-case is an animal unto its own.

If you want a better crawl ratio with an automatic, you're stuck with the Inchworm adapter.

phildelfino

I thought Dirtco did it in his red turbo build up thread.
Don't know about how much of a pain it would be though.
Might want to PM him and ask.

https://www.yotatech.com/f191/dirtco...thread-155840/

tc

DirtCO used the inchworm adapter to put a gear drive case behind the auto transmission.

phildelfino

Thanks for the clarification. I must have missed something when reading his thread.

FredTJ

Mmmm, why ?
What, specifically, are you trying to solve ?




Fred

tc

It was easy to miss ... after 12 pages, I was just about to give up when I saw it...

dropzone

iTrader: (6)

He probably wants to be able to crawl over big rocks...i used 3 combinations today: 2.28, 4.7 and the 2.28*4.7 on some big rocks.

It's not a problem, it is a want to be able to do it

FredTJ

With the auto tranny that he has it would not be a problem crawling over big rocks. Not need at all for that deep of an xfer case (assume that his diffs are geared correctly for the tire size).
That's one of the many beauties of an auto tranny, an almost infinitely variable "crawl ratio" or amount of torque to the wheels. Because of this, gearing too low
will make the vehicle such that it can over run it's brakes.




Fred

DWEINBERG01

I was on TTORA a couple of months ago and saw one of the guys from yotaranch did it. I just couldn't get enough detail to be able to do it myself.

I do know that dual's will overpower the brakes, but I think the 4.7 set alonewould be okay.

BTW, I have 4.88's waiting to get the money for locked 5.29's.

FredTJ

What, specifically, are you trying to solve here ?



Fred

DWEINBERG01

Not really trying to solve anything at this point. I just know that duals (2.28-4.7) will be too low and will overpower my brakes. I do want a lower crawl ratio than what is currently in my t-case to make it crawl better.

tc

Let me repeat - there is NO way to regear the automatic transmission tcase. This transfer case is "siamesed" to the transmission - it's basically a 2 speed automatic behind the regular transmission and using the same fluid, pumped by the torque converter in the trannt.

If you want a deeper crawl ratio than stock, you MUST swap to a different tcase. As near as I can tell, there are no aftermarket tcases that will attach to the preTaco automatic.

You have two options:
- the Inchworm adapter at $550
http://www.inchwormgear.com/store/pr...products_id=86

- swap in a newer model transmission, and use one of the adapters for it (TacoBox, etc) (Actually, I'm guessing this could be done, never seen a writeup on how to deal with the ECU)

FredTJ

Well, the 5.29's will solve your problem, assuming you're wheeling the auto correctly.
Actually you shouldn't have that much, if any, of a problem "crawling" with the 4.88's, other than keeping the tranny cool, again, assuming that you're wheeling the auto tranny correctly.
You do have an aux tranny cooler, right ?




Fred

Hayes

DirtCo says the 4.7s overpower the brakes. I have stock t-case( auto trans) and 5.71 gears in the diffs and I overpower the brakes.

I call BS on the yotaranch guy doing it. Unless I see proof, it isn't feasible to swap the gearsets in a planetary gear controlled t-case.

FredTJ

Yup.
There is simply no need to use an ubber low geared xfer case in an auto tranny vehicle, as long as the diff is geared correct.
Many yeople simply don't understand how the auto tranny works, the almost infinitely variable torque/crawl ratio that it supplies nor how to wheel with an auto tranny.

As we say here in the land of the big 'ole rocks;
"The manual tranny guys make easy obstacles look hard and the auto tranny guys make hard obstacles look easy".

I friend of mine finally, after 8 ~ 9 year of very, very tough wheeling, finally did the manual to auto swap and when I saw him last, about 6 months ago he said that now (after the swap) "everyone thinks that I really know how to drive these insane trails"




Fred

DWEINBERG01

I would like to apologize to the yotatech nation. I finally got in touch with the guy who did it. Basically, auto tranny to inchworm adapter to gear driven case. I just couldn't tell by the original pics that the case had been changed.

SOOOOOO to all of the above


Geeeeze. It's like you guys have researched this and worked on these things before. Ya'll

dropzone

iTrader: (6)

one problem though with the auto is that at an extreme angle sometimes the fluild will drain from the converter.

Hayes

you can solve that by overfilling by a quart or so.