Author Topic: 4600 XJ  (Read 256 times)

MarcW

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4600 XJ
« on: August 20, 2017, 03:30:30 PM »
Hey guys, first post, starting off strong lol. I'm not a huge forum guy so I'll try to update as much as possible, but I figured this was the easiest way to ask everyone at once.

Most of you know the FlexRock 4600 build, right now I'm starting to get some money saved for winter time where it'll get parked for the final stages to get it race ready by spring 2018. Including cage, seats, harnesses, center con/dash, figure out what to do with rockers, and figure out what to do with the tcase, other odds and ends.

Jeff and I have gone back and forth on the tcase, and while I would love to just buy an Atlas and be done with it, I got a d300 for $20 sitting in my parts washer all cleaned up ready to go. That and I have read about other 4600 cars actually finish KOH with 241's and other tcases. The Atlas I want is $2700 shipped.

With that said my first question for you guys is am I going to be able to keep this 300 alive? What upgrades, if any, should I do first? I will be keeping the stock 4.0 indefinitely(2000 flavor right now, possibly a 98 if I feel like building it), stock aw4, 4.88's in my 1/2 ton axles, pushing nothing bigger than a 35. It WILL BE FLIPPED, I have a diver drop hp44 that I don't plan to change.

I know many of you run d300's now, Wingman, Dennis, Mike I know you've had quite a few. Basically just looking for any insight if it's even possible to make this thing survive racing with what the XJ has. Leave it stock, 4:1, output upgrades, or is the case itself the big weak point. I've been doing a ton of research online and it seems most people run into trouble with big tires and 4:1 kits.

Thanks guys!

-Marc
« Last Edit: August 20, 2017, 03:36:47 PM by MarcW »

Wingman

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Re: 4600 XJ
« Reply #1 on: August 20, 2017, 04:01:47 PM »
Here's my $0.02 (worth every penny :P )

The Dana 300 is a decent case. While not the strongest, it is compact and light weight compared to other gear cases. It does have it's weak points.

Upgrade the rear output to an 32 spline HD for sure, and the front should be done too but may survive.

Make sure it is well supported and not just hanging off of the rear of the transmission.

For racing, I'd stick with the stock gearing. Don't bother with a 4:1 kit.

Flipping this case will be your biggest headache. It WILL leak. Shifters are a pain to arrange. And shifting can prove difficult.

Start saving your money for an Atlas.


If I were you, I'd leave the stock 231 in it until I could afford an Atlas. Maybe upgrade the planetary set and definitely the output.

Did I mention "Atlas"?
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TrailTamer

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Re: 4600 XJ
« Reply #2 on: August 20, 2017, 04:14:30 PM »
I want to agree with Wingman. Go aftermarket. Atlas or alike and nice shifter set up then you're solid I'd think.
Meanwhile, run the stock T case and watch for an used atlas to save some $$

Or build the NP231J with bigger chain, 6 gears.

luvmyxj

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Re: 4600 XJ
« Reply #3 on: August 20, 2017, 04:43:57 PM »
Np205 and don't look back

MarcW

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Re: 4600 XJ
« Reply #4 on: August 20, 2017, 05:01:16 PM »
I pretty much expected everyone that would reply to say go Atlas. I wouldn't be able to swing one for maybe a year/year and a half, I need to make cuts somewhere; I need a truck and trailer to even move the thing first. I've been searching Pirate since I started the build last year, knowing what my plans were, and almost every used Atlas I come across is located on the West Coast, and shipping would eat any savings, or the setup is completely different from what I need.

I do like the idea of just keeping the 231, short term, at the very least it needs a new chain as mine is on its way out. Are the planetary gears in it even a weak point? I think wider chain upgrade is from a dodge 231, and the 6 planetary from a 241 right? 

I like to plan for what can fail and try to be proactive about it, if it means pushing my deadline to complete the build I usually will (I did with my shocks) just to save the headache of replacing broken parts that should have been upgraded. I also don't like throwing money at something knowing it's getting replaced, so if the 300 isn't really an upgrade for a race rig, then I'd probably just run the 231 trail riding(using the time to test/tune) and hold off on racing until I could get an Atlas, if the general consensus is that the 300 or 231 will not survive.

MarcW

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Re: 4600 XJ
« Reply #5 on: August 20, 2017, 05:04:22 PM »
Np205 and don't look back

Will this fit nicely underneath with ZERO floor cutting/modification? I know Mike and Matt run them on their 4400 cars. I also know they're big and heavy.

Honestly haven't even thought of a 205 for my application, but if it can fit then it is a possibility.

M4wdFab

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Re: 4600 XJ
« Reply #6 on: August 20, 2017, 07:50:17 PM »
205s are heavy and with that comes need mounting thought to make anything around them survive. 

i would stay away from an Atlas.  far too much expense and its not like they have a super glorified relibility majic carpet under them either. 

upgrade the 300 as been said, Erik J has been though those upgrades and should weigh in. 



i have blown up a rear 205 output, but im special :)   and all of our 205s are as found with only seal and yoke upgrades installed.  All of our cars (5 now? have all been divorced 205s also)

Wingman

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Re: 4600 XJ
« Reply #7 on: August 20, 2017, 07:57:50 PM »
The NP205 is arguably THE case for strength but weighs 2x as much as the Atlas, D300, or NP231/241 and only has a 2:1 low range. You'll never have the HP or drivetrain to demand that kind of beef.

I think any money thrown at a D300 would be better saved toward an Atlas. It's just going to be a leaky, flipped, SOB that you'll loathe until you swap it out.

As previously stated, a built NP231HD with the current ingredients you have is the best interim solution...
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mr.mindless

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Re: 4600 XJ
« Reply #8 on: August 20, 2017, 09:29:52 PM »
Is a 300 really even an upgrade from a mildly upgraded 231 or an as-is 241?

it's certainly not as quickly swapped for something junkyarded or given away as a 231/241 if it does give you issues.

I broke the 231DHD in my Dakota - but like Smike, I'm special. and it was impact issues when it broke (driveshafts in all cases if I'm not mistaken). Saves the need for driveshaft work too.

I'd run the stock case until issues are seen. Just keep a close eye for leaks since if they go dry they go boom relatively quickly, and a leak is often a crack.
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MarcW

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Re: 4600 XJ
« Reply #9 on: August 20, 2017, 10:52:01 PM »
That is the question, if the 300 is an upgrade. I have $20 plus gas(plus a couple hours cleaning) into the 300 thus far. So not to use it is not a problem; part it out on eBay or sell whole.

SMike you're pretty much the only one that's ever said not to get an Atlas, do you have any bad experiences with them, or just think they're overpriced for what they are?

Wingman I have read of people flipping the forks and building new shift setups where the inspection plate goes. Is the leaking attributed to the OEM shift rails, or it just leaks everywhere?

I'm really looking for what my end game should be, and start planning for that. I don't expect to be race ready until the middle/end of spring, but knowing which direction I want to go dictates what I dedicate time a resources to now, as this is probably the last "big ticket" part I need to figure out. Should I be looking for deals on an Atlas, should I be collecting parts for the 300. Or is the 231 (maybe stock 241?) with a few upgrades REALLY race worthy. I do understand it's racing and anything can break.

mr.mindless

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Re: 4600 XJ
« Reply #10 on: August 21, 2017, 12:34:14 AM »
Atlas cases are not as bombproof as you'd hope for the price. If I were in the market for something better than a 205, I think I'd be looking closer at the stak cases.


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Quote from: etk300ex
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TrailTamer

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Re: 4600 XJ
« Reply #11 on: August 21, 2017, 10:58:49 AM »
Atlas cases are not as bombproof as you'd hope for the price. If I were in the market for something better than a 205, I think I'd be looking closer at the stak cases.


Sent from my iPhone using Tapatalk

I don't think stak is available to buy new anymore. Some of their models are problematic with popping out of gear, though.
You may be referring to Trail Worthy Fab's Hero T-cases but they cost more than Atlas.
http://www.trailworthyfab.com/Trail-Worthy-Fab-Two-Speed-Hero-Case.html

wider chain and sprockets can be sourced from a NP231HD or NP231C I think, and 241 for the 6 pinion planetary if your wide chain transfer case donor don't have it.

mr.mindless

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Re: 4600 XJ
« Reply #12 on: August 21, 2017, 11:11:04 AM »
You're absolutely right, the Hero is what I was thinking of.
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Harrison

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Re: 4600 XJ
« Reply #13 on: August 21, 2017, 12:26:21 PM »
Another vote for run the 231, beef it up if you have to take it apart anyway. Lots of those things surviving abuse with XJs on 35s.

I have said this many times: if it was possible to do better than 2:1 gearing in a 205, my Jeep would have one. $800 for the ORD 203/205 kit, then buy a 203, then buy a 205, then make it work under an XJ... F that. I have no regrets with my Atlas. Broke a yoke and they sent me a new one for free.

Building a beefed 300 made no financial sense to me.

rejeep

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Re: 4600 XJ
« Reply #14 on: August 21, 2017, 01:52:57 PM »
built 300 is for bragging rights
keep the NP and work on the atlas..

I never wanted a red car.. always thought they were tacky and common...
I now have 4 very not common cars and they are all red.. :o