SYE??

[Jesse J]

Ok so I am planning on running a 231/231 setup behind my ax15 and I am doing six gear planeterys on both and a wide chain and I am wondering if I should go with an SYE I know its popular but my current driveshaft is 4' long and with the doubler it will probably turn out to be ~3.5' long which is way to long to worry about driveshaft length like a cherokee. is it worth upgrading? is it even an upgrade? 

[ghetdjc320]

It’s an upgrade for sure. Stronger main shaft and a sealed-off yoke are worth it imho. May i ask though, why a doubler? That will give you an extreme granny gear but do you have an actual use for it? That’s usually something that full size trucks on 40+” tires use when they have a couple of extra NP205’s laying around. 

[Jesse J]

2 hours ago, ghetdjc320 said:

It’s an upgrade for sure. Stronger main shaft and a sealed-off yoke are worth it imho. May i ask though, why a doubler? That will give you an extreme granny gear but do you have an actual use for it? That’s usually something that full size trucks on 40+” tires use when they have a couple of extra NP205’s laying around. 

I already have a 231 laying around doin nothing. Also it being an ax15 I’d rather not be stuck on something steep trying to clutch out and all that jazz. The kits already on its way so no one can stop me *maniacal laighter*

 

So it’s definitely worth getting one? 

[ghetdjc320]

Ok, I’d recommend you get some input from others here also. The sye is a great upgrade. Get the one from JB conversions, best I’ve ever used.
 

I’ll throw this out there for whatever it’s worth, that doubler is going to cost you a lot of headache and expense. Sell the extra 231, run 4:1 teralow gears, a 241OR from a rubicon or deeper gearing. All will be a lot less trouble than running that doubler. You will likely be just fine running  the stock 2.7:1 ratio and your ax15. I drove that combo on 4.56’s and 35’s all over the wheeling world stateside with no issues and never wanted a lower gear. With a doubler you may find the low gear miserably low. Also, the 4.0 does good at low rpm. A doubler can also really increase the torque going into that D44 rear and easily exceed the input torque rating. Again, just my $.02 and maybe worth even less 

[Pete M]

an SYE is a good upgrade in both strength of the t-case, but also strength of the new rear driveshaft.   

 

but it's not all that necessary. 

[Jesse J]

1 hour ago, ghetdjc320 said:

Ok, I’d recommend you get some input from others here also. The sye is a great upgrade. Get the one from JB conversions, best I’ve ever used.
 

I’ll throw this out there for whatever it’s worth, that doubler is going to cost you a lot of headache and expense. Sell the extra 231, run 4:1 teralow gears, a 241OR from a rubicon or deeper gearing. All will be a lot less trouble than running that doubler. You will likely be just fine running  the stock 2.7:1 ratio and your ax15. I drove that combo on 4.56’s and 35’s all over the wheeling world stateside with no issues and never wanted a lower gear. With a doubler you may find the low gear miserably low. Also, the 4.0 does good at low rpm. A doubler can also really increase the torque going into that D44 rear and easily exceed the input torque rating. Again, just my $.02 and maybe worth even less 

Thanks for the input!

 

1 hour ago, Pete M said:

an SYE is a good upgrade in both strength of the t-case, but also strength of the new rear driveshaft.   

 

but it's not all that necessary. 

What do people usually do for the rear shaft?

[DirtyComanche]

Personally I'd find a NP241DLD or something like that for the rear tcase.  But the SYE for it will be more money, if you can get one without making it yourself.  I just don't think the 231 is strong enough for that use.  However, lots of people have done it and all that, so eh, what do I know.  If I was to do it I would absolutely run a SYE.  I'm running a NP205 as the rear case in my XJ personally, and while I like it I don't know if I would do it again.

 

Doublers are awesome unless you just run mud, sand, or easy trails.

 

For a rear driveshaft I'd just call Tom Woods or High Angle or JE Reel or whatever.  They all build good stuff for minimal money, and this would definitely be the preferred option as they will do it right the first time.  Or, I'd lengthen (honestly you might not even need to, there might be one that long) an XJ front shaft because I'm really cheap, and then be upset when it failed and took out a bunch of other stuff.  For the front shaft I'm not really sure, I don't recall what I'm using in the front of my XJ, but the 205 keeps the front shaft a lot shorter, so it might well just be another XJ or other Jeep shaft.  Sorry to give you a useless answer.

[ghetdjc320]

I ran both Tom woods (4xshaft.com) and adams driveshaft. Both are top notch

[Jesse J]

I’m running a lengthened stock rn. Might search for a 205 at the pick n pull. Would it bolt up to the back of my first 232? (Froehlich kit if that makes a difference)

[DirtyComanche]

1 hour ago, Jesse J said:

Might search for a 205 at the pick n pull. Would it bolt up to the back of my first 232? (Froehlich kit if that makes a difference)

 

I don't think so, at the very least you need an output shaft for the 31 spline Ford input.  I'm running a NWF Ecobox, and it's meant for the 205.  I wasn't really suggesting you do it, it's a stout setup but very heavy and big.  Plus you have to cut part of the case off the 205 and weld a plate in it.  And make shifters, an extra mount (the weight issue) and it uses a different style speedo gear/drive, etc, so there's lots of things about it that aren't exactly ideal.  That said, it does have fixed yokes from the factory, no SYE required.

[ghetdjc320]

I ran a t18 with np205. Cranking heavy combo. Your going to need to sort out a stouter crossmember just trying to double a 231 which ways considerably less. Just something to consider. I would assume you’ll also need to rework the trans tunnel a bit or else clock it down a ways.  You’ll also need to extend the front driveshaft or get a new one and work out shifter linkages. It also makes it more difficult to brake as you’re multiplying the torque significantly and low speed braking is used heavily while crawling. 
 

Crunching some number here: ax15, 4.56, np231 (2.72:1) running 33’s puts you at a crawl ratio of 47.50:1. Running (2) np231’s puts you at 129:1

Stock was about 32:1. 

For comparison, a stock TJ Rubicon was about 63:1. 
 

It should be noted also that the np205 only has a 1.96:1 low range. 
 

If your goal is to not stall off-road then you might consider a hand throttle mounted to the shifter. That’s what many rock rigs run. That and/or an automatic tranny. I love driving manual but automatics are great fun off-road also. The torque converter acts as an almost infinitely variable first gear. 
 

 

[Jesse J]

38 minutes ago, ghetdjc320 said:

I ran a t18 with np205. Cranking heavy combo. Your going to need to sort out a stouter crossmember just trying to double a 231 which ways considerably less. Just something to consider. I would assume you’ll also need to rework the trans tunnel a bit or else clock it down a ways.  You’ll also need to extend the front driveshaft or get a new one and work out shifter linkages. It also makes it more difficult to brake as you’re multiplying the torque significantly and low speed braking is used heavily while crawling. 
 

Crunching some number here: ax15, 4.56, np231 (2.72:1) running 33’s puts you at a crawl ratio of 47.50:1. Running (2) np231’s puts you at 129:1

Stock was about 32:1. 

For comparison, a stock TJ Rubicon was about 63:1. 
 

It should be noted also that the np205 only has a 1.96:1 low range. 
 

If your goal is to not stall off-road then you might consider a hand throttle mounted to the shifter. That’s what many rock rigs run. That and/or an automatic tranny. I love driving manual but automatics are great fun off-road also. The torque converter acts as an almost infinitely variable first gear. 
 

 

I have it all planed out for the x member (thinking even another one behind the doubler and definitely driveshafts will be made and is actually a huge upside to it because I am slightly running into front shaft angle issues.

 

2 hours ago, DirtyComanche said:

 

I don't think so, at the very least you need an output shaft for the 31 spline Ford input.  I'm running a NWF Ecobox, and it's meant for the 205.  I wasn't really suggesting you do it, it's a stout setup but very heavy and big.  Plus you have to cut part of the case off the 205 and weld a plate in it.  And make shifters, an extra mount (the weight issue) and it uses a different style speedo gear/drive, etc, so there's lots of things about it that aren't exactly ideal.  That said, it does have fixed yokes from the factory, no SYE required.

I see I see. I think I might stick with 2 built 231 if they are good enough for full size dodges they are good enough for me

[ghetdjc320]

9 minutes ago, Jesse J said:

I have it all planed out for the x member (thinking even another one behind the doubler and definitely driveshafts will be made and is actually a huge upside to it because I am slightly running into front shaft angle issues.

 

I see I see. I think I might stick with 2 built 231 if they are good enough for full size dodges they are good enough for me

Those that run on a dodge have wide chains, sprockets/gears and 6 pinion planetaries. Are you going to run the Chevy or dodge versions or the Jeep version? 

[Jesse J]

7 hours ago, ghetdjc320 said:

Those that run on a dodge have wide chains, sprockets/gears and 6 pinion planetaries. Are you going to run the Chevy or dodge versions or the Jeep version? 

Jeep with the 6 planetary and wide chain so technically it won't be as beefy as a 231 HD but pretty close and better than stock

[Oizarod115]

I think SYE is worth it just because it allows you to lift the pinion up a few inches to set the proper angle getting you extra clearance at the driveshaft/pinion

[DirtyComanche]

13 hours ago, Jesse J said:

Jeep with the 6 planetary and wide chain so technically it won't be as beefy as a 231 HD but pretty close and better than stock

 

The front output is the weak link.

[Jesse J]

12 minutes ago, DirtyComanche said:

 

The front output is the weak link.

would a chain and sprocket not help with that I was under the impression they where stronger

[DirtyComanche]

Just now, Jesse J said:

would a chain and sprocket not help with that I was under the impression they where stronger

 

It's the same 27 splines regardless.

[Jesse J]

1 minute ago, DirtyComanche said:

 

It's the same 27 splines regardless.

I see. 

 

 

 

[Pete M]

remember, not matter what you do, there will always be a weakest link.  the question is whether or not it's weak enough to ever be an issue.  most people break something else first.  ujoints for example.   

[ghetdjc320]

Very true, I’ve popped many a u joint out on the trail. Better that than the ring and pinion though! It’s good to have a “fuse”

[DirtyComanche]

1 hour ago, Pete M said:

remember, not matter what you do, there will always be a weakest link.  the question is whether or not it's weak enough to ever be an issue.  most people break something else first.  ujoints for example.   

 

True, if he has a D30 he will break everything in it first.

 

I personally don't subscribe to the "fuse" concept.  I'd rather not break.  But that's me, running one tons and 37s in an underpowered slug.

[ghetdjc320]

4 minutes ago, DirtyComanche said:

 

True, if he has a D30 he will break everything in it first.

 

I personally don't subscribe to the "fuse" concept.  I'd rather not break.  But that's me, running one tons and 37s in an underpowered slug.

He’s running a LP D44 waggy front iirc. 

[Jesse J]

6 hours ago, ghetdjc320 said:

He’s running a LP D44 waggy front iirc. 

thats the setup. 

[Jesse J]

do I need a cv or a non cv yoke? as far as I can tell the only difference is between the bolts in the back or the front of the yoke. also 1350 or 1310?