T-Case Options/Doubler

[Pile of parts]

Seems I just can't leave things alone. For 98% of my wheeling, I love the options of gear/crawl ratios I currently have. However, the other 2% would be nice with even lower gears. Simple solution that most would say is, "Go to an auto trans." For whatever reason, I just prefer my manual. Here is what I have and some of the options to consider. I would appreciate any input. Let me mention again, I really want to keep my current, or close to, gearing and have the option of even lower.

350 TBI
Dana 60 / 14 Bolt, 5.38 - Detroits
T-18 (6.32 1st gear)
'80 Scout Dana 300 (2.62 low range)
This set up was originally intended for a CJ5 so it needed to be short. It ended up in a CJ 7/Wrangler stretched to 106" Wheelbase so I have some extra room now.

Options
Stak 3 speed - Not sure of the quality - Even more importantly - I'm sure I don't have the money. Size is small and choices of gearing are nice.
Atlas 4 speed - Yeah, right. See the part about money above.
Behemoth Strong Box (shorty version) I like this idea. Still compact. Overall cost can be spread out. Good gearing options. What's the word on these? Still a pretty good chunk of money when all is said and done. Am I better off saving for the Stak or Atlas?

OK. There you have it. Let the opinions fly.
BTW, if you have a T-18 to Dana 300 (Jeep) adapter and possibly the Dana 300 as well, I might be interested.

 

[RockChucker]

Holler at Lifelong Jeeper. He is running a Stak Replace a case D300 (so it is driver drop for his ZJ) with the strong box shorty. It seems to work quite well, and that 7.xx:1 is stupid low. Especially with an auto.

I would stay away from the Stak 3 speed. Stak is no longer around. It would be difficult to get replacement parts should you need them.

 

[1993yj]

Personally, I would save for the Atlas (that's what I'm doing). And as mentioned, Stak is not really an option as the company doesn't exist anymore.

 

[Pile of parts]

Holler at Lifelong Jeeper. He is running a Stak Replace a case D300 (so it is driver drop for his ZJ) with the strong box shorty. It seems to work quite well, and that 7.xx:1 is stupid low. Especially with an auto.

Rockchucker,
I saw the thread for Lifelong Jeeper. I'll get in touch with him. 7.xx:1 is way lower than I need, but with the manual transmission, I have options - already created a spreadsheet with crawl ratios in each gear to see what I would have and where they would cross over.

Personally, I would save for the Atlas (that's what I'm doing).

1993yj,
What are you currently running? Give me some of your thoughts as to why you would just save for the Atlas. Is it a matter of strength in the gears or case? Or, is it a matter of money - what a person would spend to upgrade the 300 to Atlas level? I already have a 300 HD output shaft for the rear. Always appreciate a different perspective.

I did not know Stak was out of business. I still see them on line but have not even gotten close enough to being serious about contacting them. - Good to know!

My understanding on the Atlas 4 speed is that it is basically the 2 speed with a planetary gear set in front - just like the strong box concept.

 

[gertsch]

I'd go atlas or twf hero case. Niether are jeep but they are sweet!

 

[1993yj]

I am currently still running the 231. I was originally thinking a 300, but once I priced out buying one and then building it up, the price was within a few hundred of just buying an Atlas 2 speed. And at that point the Atlas is still stronger than a 300. I personally don't have a need for the 4 speed (or even a 3 speed case). Plus, comparing a 3 or 4 speed case to a 300 is apples to oranges.

 

[thenag]

My old rig I had full size bronco with a efi 460, np 435, np 203/205 doubler, and 4.10's in the axles. With the granny gear and without OD the setup worked great, sometimes I would have liked to have a little lower gear but it worked well enough that when I built the jeep I NEEDED dual t-case. I love love love having low range and double low range, especially with a manual transmission.

In the jeep I have a 4.0l ax15, np231 doubler, d300, and 5.13's in the diffs. (still with 37's)

Pretty much when I air down I put the np231 into low and leave it there until we air back up. I leave the d300 in RWD High for most driving on the trail, I put the d300 in 4wd L for obstacles, and even WITHOUT a good low first gear I am often in 2nd on obstacles.

I guess what I am saying is if you can do some kind of range box go that route.

Allegedly Duffy Machine still makes stuff, that is who made mine. It is not nearly as short or as pretty as the behemoth box, but it is cheaper. (my father in law is putting together a behemoth shorty and a d300 soon)

Of course by the time you pick up an adapter for a np231 to a t18, get the doubler kit, and a JY np231, you will probably be in the ball park of a 4:1 gear set for your d300.

It took my father in law, and liflongjeeper damn near a year to get their behemoths, hopefully he has cleared his back orders but who knows. (Duffy has had similar issues, If you try to deal with Duffy do so on the phone, leave messages, etc)

I have some pics on my build thread, end of page 2 beginning of page 3, and page 4
http://www.rme4x4.com/showthread.php?83436-Nathan-and-Tanja-s-99-XJ-Build-up/page2

Nathan

 

[Pile of parts]

I was originally thinking a 300, but once I priced out buying one and then building it up, the price was within a few hundred of just buying an Atlas 2 speed. And at that point the Atlas is still stronger than a 300. I personally don't have a need for the 4 speed (or even a 3 speed case). Plus, comparing a 3 or 4 speed case to a 300 is apples to oranges

.

I agree, to build a 300 to atlas specs wouldn't really be worth it. But that's comparing it to a two speed atlas. As mentioned, I'm looking for additional gearing options due to the fact that I like what I have now but would like the occasional, lower gearing.

Nathan, nice build thread and it was fun running Moab Rim with you guys last fall. I appreciate your input on this. If I had know you were running this set up and that I would be leaning this way back then, I would have spent some time under your jeep.

Allegedly Duffy Machine still makes stuff, that is who made mine. It is not nearly as short or as pretty as the behemoth box, but it is cheaper. (my father in law is putting together a behemoth shorty and a d300 soon)

I've looked at both the Duffy stuff and Behemoth. Behemoth is shorter, cleaner and a little more expensive but I don't weld aluminum and figure by the time I pay someone to do it the cost vs. benefits is negligible.

Of course by the time you pick up an adapter for a np231 to a t18, get the doubler kit, and a JY np231, you will probably be in the ball park of a 4:1 gear set for your d300.

Found a good deal on the adapter - actually with the transmission too even though I already have that. 4:1 gear set limits me to just that - I want more.

It took my father in law, and liflongjeeper damn near a year to get their behemoths, hopefully he has cleared his back orders but who knows. (Duffy has had similar issues, If you try to deal with Duffy do so on the phone, leave messages, etc)

This seems to be the only complaint on this option. Everyone says he seems to be an honest guy in all but his promised delivery time.

 

[thenag]

.


Nathan, nice build thread and it was fun running Moab Rim with you guys last fall. I appreciate your input on this. If I had know you were running this set up and that I would be leaning this way back then, I would have spent some time under your jeep.

I didn't even realize that was you. I was really tempted to try to get a behemoth just for the cleaner install and less chance of leaks. (I know I can sell my duffy box) But as it sits my front and rear drive shaft are identical, so the behemoth would change that. (I only carry one spare shaft, I can break two shafts and still have RWD assuming the shaft is the only thing that breaks) Plus I think I finally got my duffy box to seal so that makes it less annoying.

I think it is tough to beat a behemoth shorty on a d300, very cost effective, compact, strong, easy to get parts, streetable, easy to swap in (even running the d300 up-side-down is easy)

Nathan