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vesparex

Lower diff gearing

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Good afternoon,

Took my 81 GL out on trails over the weekend here in Colorado. Did ok but with 15" wheels and 27" tires, she could really benefit from lower gears. I've read about Foresters having a 4.44:1 ratio gear set. Are these swappable into the GL's trans and rear diff?

Duane 

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Edited by vesparex

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As GD said ^ But...

Only way around this and keeping the low range is to find an RXII coupe AWD gearbox. 

This box has the locking centre diff - you’ll want to find one that’s not flogged out from running different front and rear diff ratios or from dickheads doing rear wheel burnouts using the front hand brake. 

From here you can cut and shut the pinion shaft to have the 4.44 ratio diff. The crown wheel needs to be shaved to clear the low range gears too. 

The good L series low range of 1.59:1 will drop in once the crown wheel is shaved to clear. 

Then you’ve got basically the ultimate package - best low range, 4.44 diff ratio, locked centre for 4wdn and AWD on the road - especially good if you’re running the EJ22. 

Downer on this box is that it’s a custom build with few spare parts available these days. Over here I have the advantage of EJ AWD dual range gearboxes for the drive gears at the very least. It’s the centre diff that will have this as toast if it dies (I lock it whenever I’m on dirt to avoid wear). 

Not a simple task, and in the eyes of GD, not cost effective, go get a truck :p (sorry GD, couldn’t help myself!).

Cheers 

Bennie

Edited by el_freddo

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Over here, we used to swap in Nissan transfer cases as part of an 8" to 10" sub-frame lift. Such as my hatch has. Has 20 forward gears and all the crawl ratio you could ever want. Alas the parts to reliably wheel it just don't exist and if I take it out I'll just break stuff I can't replace so it's just a nice ornament at my shop that people occasionally offer to buy. 


And yes. In any case my 1984 K5 Jimmy with 35's and 350 HP will wheel circles around any Subaru including my hatch and you can get ANY part you want for it including any gear ratio. Not that I need it with 350 HP and an auto....'

So yes - buy a truck. You'll just break that poor EA81 and you can't get any parts to fix them anymore. Sadly it's a dead platform. 

GD

Edited by GeneralDisorder
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Thanks guys. I realize what I have. My wife and I own a New Jeep Cherokee and a 1968 Bronco. So I'm not trying to replace something. I just love these little buggers and am curious what there are for options. 

Maybe I'll just concentrate on a little more power (ie engine swap or fuel injection bolt on) and building a more compliant suspension. Sunday was our first time out on trails with the little GL. Performance was actually surprising. But holy hell does she ride rough. 

I was just curious if we had any option to gain a little more torque that was lost in the 27" tire upgrade. 

Duane .

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11 hours ago, GeneralDisorder said:

Over here, we used to swap in Nissan transfer cases as part of an 8" to 10" sub-frame lift. Such as my hatch has. Has 20 forward gears and all the crawl ratio you could ever want. Alas the parts to reliably wheel it just don't exist and if I take it out I'll just break stuff I can't replace so it's just a nice ornament at my shop that people occasionally offer to buy. 


And yes. In any case my 1984 K5 Jimmy with 35's and 350 HP will wheel circles around any Subaru including my hatch and you can get ANY part you want for it including any gear ratio. Not that I need it with 350 HP and an auto....'

So yes - buy a truck. You'll just break that poor EA81 and you can't get any parts to fix them anymore. Sadly it's a dead platform. 

GD

GD, 

I saw in a search you mention a Toyota trans swap. Is there info on this out there anywhere? 

Duane

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Maybe instead of worrying about gears, I concentrate on an EJ22 swap. Make up for lost torque in the tire size with a bigger engine!

D

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50 minutes ago, vesparex said:

Thanks guys. I realize what I have. My wife and I own a New Jeep Cherokee and a 1968 Bronco. So I'm not trying to replace something. I just love these little buggers and am curious what there are for options. 

Maybe I'll just concentrate on a little more power (ie engine swap or fuel injection bolt on) and building a more compliant suspension. Sunday was our first time out on trails with the little GL. Performance was actually surprising. But holy hell does she ride rough. 

I was just curious if we had any option to gain a little more torque that was lost in the 27" tire upgrade. 

Duane .

Fuel injection wont make any more power. Weber swap has better throttle response than the EA82 SPFI. 

More power will just destroy the 4 speed. You would have to go to a 5 speed dual range for an EJ22. Parts are getting difficult to go this route. Mostly clutches, etc. 

The suspension is not up to the task of more power either. Doesn't have enough dampening and if you go fast with a lot of power (because no gearing) you will bend the front struts. Don't ask how several of us know that. And front EA struts are a difficult item to find. 

GD

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46 minutes ago, vesparex said:

GD, 

I saw in a search you mention a Toyota trans swap. Is there info on this out there anywhere? 

Duane

https://www.billsautofab.com/

It's for the EJ engines. And it requires a LOT of fab work. It is essentially the replacement for my Nissan t-case swap. With the toy trans you need a rear diff in the front and a complete 8"+ sub frame to accommodate it. The Subaru rear diffs don't last well when run in reverse 100% of the time up front, and the power, gearing, tires are much more than the suspension, gearing, steering etc can handle for long. That's why I don't wheel my hatch - it eats steering racks, front diffs, 5 speed transfer gears, ball joints, struts, shocks, etc, etc. It's a parts whore. 

GD

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As mentioned. The 4.444 front pinion shaft can only be paired with an EJ AWD center differential. Not ideal, and modifying it for anything else is even less ideal.

I started building one of those transmissions to go in my Brat. Encountered a speed bump about the time I got my 4Runner working, and haven't touched the Brat project. I'm no longer interested in dealing with a clutch pedal on an offroad vehicle unless it has at least 100:1 crawl ratio (best combination in a Subaru is about 25:1).

 

Yea, Bill's bellhousing with an EJ22 and a Toyota transmission is probably the next best option. That ~150:1 crawl ratio becomes possible (you'll have to refinance your home to do it). But, yea, you have to have enough lift in it to make room for an extra front diff. The r160 isn't really up to the abuse, there are other options, but require custom axles, etc. The steering isn't up to the abuse. Before you know it, you'll have $20k into it...and it still won't be as capable as an XJ.

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5 hours ago, Numbchux said:

I'm no longer interested in dealing with a clutch pedal on an offroad vehicle unless it has at least 100:1 crawl ratio.

Exactly. The automatic is THE answer. The best answer. It's right there in the name. "Torque Converter". Couple that with a low range and some V8 power and you have the answer for crawling. Thus why my K5 is a built 700R4. Excellent freeway manners with TC lock and overdrive, and really low 1st gear with a 4WD low range t-case. And 350 HP to turn 35's. Plus you can get parts at ANY parts store in the middle of nowhere because if they carry anything at all - they carry Chevy Small Block parts. Scooter and his cousin Skillet have to be able to get parts for their farm trucks

Crawl ratio on my Nissan t-case hatch is about 46:1 and that's just about enough for the 30's it runs. It could use more, but it's pretty ok. It struggles to do even 60-65 on flat and level freeway though. 40-45 on mountain passes is all it can manage. In comparison my K5 will do 80+ up.... well anything pretty much. Though the suspension is pretty squirrelly. 

GD

Edited by GeneralDisorder

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