CJ7 Auto Transmission

[Hog Head]

Hi friends. I'm currently running a T-18 behind a 4.0L with a Dana 300 Transfer Case . I do primarily rock crawling and would like to change to an automatic Transmission . I was told by some of my crawling buddies that the AW4 was a good one to go with. But after reading Novak's take on it, which wasn't to stellar, I'm having second thoughts. Could anyone recommend another automatic for consideration? I do drive on the street some, and it would be nice to make highway speeds if need be. Here's some additional info on my rig.
4.0L HO out of a 93 cherokee
T-18 short tale
Dana 300 transfer
Dana 30 chromoly axles
AMC20 chromoly one piece axles
4.56 gears
Spartan lockers front and rear
35x12.5x15 mud tires
Thanks in advance for your input.

 

[Lumpy Grits]

Biggest issue you have to address with any 'juice-box', is the heat they will create. Heat is 'cancer', to all automatic transmissions.
Also-the engine braking isn't that good.
LG

 

[Hog Head]

Thanks LG. Any suggestions on another Transmission ?



Sent from my iPad using Tapatalk

 

[Lumpy Grits]

IMHO-Stay with that T-18 .
Put a 4:1 kit in the t'case and enjoy the rocks.
LG

 

[Hog Head]

Thanks LG, what is a 4:1 for my Dana 300 ?


Sent from my iPad using Tapatalk

 

[hole]

Your 300 has 2.6... to 1 for low range in stock form. The 4-1 makes a huge difference in rocks! I personally went with Lomax when I did mine, but TerraLow makes a set as well.

 

[Hog Head]

Thanks for your input hole. Got it. For now I have a granny first gear in the T-18 while in 4 low sometimes need to shift into second on the side of a hill, or just start out in second. And on occasion when everyone stops on the side of a steep rocky hill, the guy behind me pulls right up on my bumper. And then knowing I’m gonna have to dump this clutch to not roll back into him. Anyway if I can find a good match, I’m going automatic, hopefully one with an Overdrive .


Sent from my iPad using Tapatalk

 

[Lumpy Grits]

Going to an auto-You will need that 4:1 kit in the t'case.
Love the 4:1 I put in mine-
LG

 

[hole]

While I love an auto for a DD and in my other toy (Bronco), I do love the T19 in my 8 for offroad. All my wheeling buddies have autos (2 XJ's and 1 CJ7 ) and I cant help but notice they ride the fat pedal a lot, especially down hills. Have watched all of them more than once start to slide towards the edge of a loose rock shelf road because they had to brake to keep speed down while I barely break a sweat because I have no need to touch that pedal (providing I've chosen the correct gear ) If I'm doing the math right, based on what spec's you've already stated, your crawl ratio is currently 75-1 and would be 115-1 just by adding a 4-1 gear set to your Transfer Case . Most autos that I'm aware of have a mid-high 3-1 to low 4-1 first gear ratios and would lower your crawl ratio to about 50-1 if you keep the stock 300 gear set and back to mid 70-1 range with 4-1 gear set.

 

[Posi]

Re: CJ7 Auto Transmissiong

A couple “slush”box options is the 350 and 4L60E.
The 350 is short, the 4L60E is on the long side but best Transmission IMO

 

[Hog Head]

Yes sir I understand, all my Jeep buddies except one wrangler are running autos and yes I do see a lot of brake lights going up and down hill while I’m just letting the engine do the braking. I’m pretty new to jeeping, only in it a little over a year now. So gear and Transfer Case selection is a learning process I’m still in. With the help of my jeeping friends (and this forum), I feel like I’ve finally got my rig to where I thought I needed to be for crawling. The spartan lockers were chosen for cost savings, but now wishing I had a selectable on the front because of the diminished turning ratio. Not sure, but with my twin stick set up, I’d like to be able to shift the front axle in and out of low as needed, and help with the turning issue. That said, I may save the money for the auto tranny and put it into a selectable front locker. This last weekend I broke a front axle u joint that boogered up the axle so now I’m changing front axles to chromoly with larger u joints. Keeps me in my shop, if I wasn’t there I’d probably be out into some trouble somewhere lol.


Sent from my iPad using Tapatalk

 

[Hog Head]

Thanks posi I was just reading about both those on Novak’s website. Looks like the 350 will fit fine but curious about the 4L60 being a little to long.


Sent from my iPad using Tapatalk

 

[hole]

For just that reason I generally run around in 2 low and shift in the front as needed. My buddy with the 7 has a selectable up front but at least twice in the last 5-6 trips he's had one thing or another cause issues leaving him with only 2wd.

 

[Hog Head]

I’ll have to experiment with my twin stick, hoping I can go from two low to four low only shifting the front axle in and out.


Sent from my iPad using Tapatalk

 

[Hog Head]

Haha I know about getting stuck with only two wheel drive. When I broke the front u joint last weekend, I was at the palo duro challenge and had to climb outa the canyon (about 800 ft up), in two wheel high. Twice the rear end tried to pass the front end and got kinda sideways. Pucker factor went high lol.


Sent from my iPad using Tapatalk

 

[Lumpy Grits]

HH-What R&P ratio, and carrier types are you run'n in the diffs?
LG

 

[Hog Head]

4.56 r&p not sure about the carriers


Sent from my iPad using Tapatalk

 

[Lumpy Grits]

I would think with 4:56 gears, you will want an OD in the tranny you pick.

LG

 

[Hog Head]

LG
The lockers are spartan, I’m not sure what LSD is


Sent from my iPad using Tapatalk

 

[Posi]

LSD= Limited slip differential
Obviously you don’t have a LSD if you have the auto locker Spartan.