Which rear axle now?

[Greg]

You are thinking of the GM 12 bolt. I'm talking about the Isuzu modified 12 bolt. Not the same axle at all. The Isuzu axle is comparable to a D60 and has a third member. Look at the first post I made on this page, I posted the information there about it

Gotcha... 99% of the time when someone says '12 Bolt', they're talking about the POS GM axle. The Isuzu axle still sounds quite obscure, I wouldn't chance it. Do your axle upgrade right the first time.... or 3rd time, it's your money.

 

[mbryson]

You are thinking of the GM 12 bolt. I'm talking about the Isuzu modified 12 bolt. Not the same axle at all. The Isuzu axle is comparable to a D60 and has a third member. Look at the first post I made on this page, I posted the information there about it

Personally, I'd go a D60 as illustrated above by the Leaner. Leave that Izusu stuff to someone that wants to spend money making it work rather than using a tried/true solution.

My issues with the Isuzu axle. How hard are parts to come by for it? How long will you have to wait to have a pinion yoke shipped to you in Mexican Hat, Utah (insert any obscure, out of the way place you desire here)? How about axle shafts if/when they do break? How's the availability? That's why I'm not a big fan of uber-custom stuff and like off the rack type parts. Just my opinion....

 

[1995zj]

Gotcha... 99% of the time when someone says '12 Bolt', they're talking about the POS GM axle. The Isuzu axle still sounds quite obscure, I wouldn't chance it. Do your axle upgrade right the first time.... or 3rd time, it's your money.

2nd time

Personally, I'd go a D60 as illustrated above by the Leaner. Leave that Izusu stuff to someone that wants to spend money making it work rather than using a tried/true solution.

My issues with the Isuzu axle. How hard are parts to come by for it? How long will you have to wait to have a pinion yoke shipped to you in Mexican Hat, Utah (insert any obscure, out of the way place you desire here)? How about axle shafts if/when they do break? How's the availability? That's why I'm not a big fan of uber-custom stuff and like off the rack type parts. Just my opinion....

Yeah, I'll have to check around and see if parts are scarce (most likely they are). I just figured for the price of the axle, I could pick up a few spare shafts at pick-and-pull. There seemed to be ~2-3 of these axles per yard I called. Western Sandy Metal actually had 6 of them on hand.

 

[ichi-san]

The only other thing would be gearing. I could regear the front to 4.27's, but is that close enough to not cause problems? I remember a thread about that recently but I couldn't find it searching.

I was just reading in some 4x4 mag - can't remember which - that a 1% variance in gear ratios is acceptable

4.27/4.30 = 1.007 = 0.7% is less than 1%

Richard

 

[1995zj]

I was just reading in some 4x4 mag - can't remember which - that a 1% variance in gear ratios is acceptable

4.27/4.30 = 1.007 = 0.7% is less than 1%

Richard

Ah good information, thanks!

 

[Cody]

1500 for a 9"?
I think I was into mine about $500

 

[1995zj]

1500 for a 9"?
I think I was into mine about $500

I'm thinking $150 for the axle, $450 for 35 spline 6-lug shafts, $150 for disc conversion, $150 spool, $250 gears....plus whatever else comes up.

 

[ichi-san]

The only other thing would be gearing. I could regear the front to 4.27's, but is that close enough to not cause problems? I remember a thread about that recently but I couldn't find it searching.

Found it -

"As long as the front and rear ratios are within 1%, the vehicle works just fine on the road, and can be as different as 2 percent for off-road use with no side effects."

4Wheel Drive & Sport Utility Magazine, June 2009, pg 98, Gear Talk by Randy Lyman and Kevin Wiebusch

 

[1995zj]

Found it -

"As long as the front and rear ratios are within 1%, the vehicle works just fine on the road, and can be as different as 2 percent for off-road use with no side effects."

4Wheel Drive & Sport Utility Magazine, June 2009, pg 98, Gear Talk by Randy Lyman and Kevin Wiebusch

Sweet

 

[Kiel]

As far as splines go, I was just reading about the spline pitch on 14 bolts 30 spline versus 35 spline dana of 9 inch splines. It came back was the pitch of the 14 bolts was noticably stronger due to the pressure being less on each spline. But I have really never seen stripped splines except on toyota stuff, usually the shaft just breaks, so it would not matter. I like the idea of using common axle parts. If you break 1541, you can get 4130, 4340, 300m etc etc . Room to grow. Izuzu isn't going to have anything.

 

[Gravy]

yes 9" would be ideal, but more expensive to fab it to your exact wants.

but those isuzu axles are literally all over the place, no one uses them. you could have stacks of spares and it doesn't seem that anyone has a huge history of breaking them.

If you cant live without 6 lug, 4.56 gears, discs and correct width
for a cheap swap it cant be beat.

Seriously read up on a few of the zuzu builds on pirate. quite a few guys running front 60's and rear zu axles with big tires and no problems.

I'd try it. if you blow it up, throw new shafts and a new third member in and your set. or sell it to someone less abusive and build an uber axle.

I personally like the oddball beefy cheap and creative stuff. someday I will build an eaton front axle with 60 or spidertrax outers.

 

[1993yj]

You know my vote. If you go D60 you can go bigger tires in the future with minor changes, rather than installing your 4th axle.

 

[1995zj]

If you cant live without 6 lug, 4.56 gears, discs and correct width
for a cheap swap it cant be beat.

Well if I go the Isuzu modified Corp. 12 bolt (98+ Trooper) then I have to live without 4.56's. 4.30's are the only thing offered for it. I doubt I'd notice the loss of gearing though.

 

[1995zj]

You know my vote. If you go D60 you can go bigger tires in the future with minor changes, rather than installing your 4th axle.

Where is everyone getting these 3rd and 4th axle swaps from? This will be the 2nd axle to go in there. Also bigger tires for this thing are out of the question.

You gonna pay to get the D60 machined out and the 35 spline shafts?

 

[jevyguy]

You say that you have an isuzu 44 in the rear now? That your 2nd axle.. Now if you put the isuzu 12 bolt in that's the 3rd. What people are refering to is when you end up pulling the 12 bolt out (if you ever have to) because you keep breaking it to install your 4th axle.

 

[dstrbd1]

D60 or 14-bolt. I went with a semi float D60 with 35 spline chromos. With conversion to semi float custom shafts gears disk brakes and locker I was less than $2000. Tough simple setup.

 

[1995zj]

You say that you have an isuzu 44 in the rear now? That your 2nd axle.. Now if you put the isuzu 12 bolt in that's the 3rd. What people are refering to is when you end up pulling the 12 bolt out (if you ever have to) because you keep breaking it to install your 4th axle.

The way Greg said it "3rd time" would mean my 4th axle. Yes this is my 3rd axle so it would be my 2nd time swapping. I understand where people are coming from, 1993yj (my brother) was just being a smart ass so I was being one back

 

[00harpdawg]

I'd say go simple and cheap and do the izuzu axle weld it up and just hammer on it if it breaks then do your 9 in but if it last do your arb just my 2 cents

 

[Greg]

The way Greg said it "3rd time" would mean my 4th axle. Yes this is my 3rd axle so it would be my 2nd time swapping. I understand where people are coming from, 1993yj (my brother) was just being a smart ass so I was being one back

1st swap was the Dana 44, 2nd swap will be this uber-bitchen Isuzu axle and when you get tired of breaking that, the 3rd swap will be the final Dana 60.

 

[Cody]

I tihnk you should drop it down to 35's, make it street legal again so you can do long range overland type trails, and build a buggy.