Been jammin
Member
- Joined
- Jan 5, 2009
- Location
- granite falls
I've been told doubling 231/300 aren't so great. Is busting on the 231 side common.
231/300
- Thread starter Been jammin
- Start date
- Joined
- Apr 18, 2005
- Location
- Greensboro, NC
I think a lot of that is going to depend on several things. I just fisished putting a 231 krawl box in my XJ. Haven't had a chance to test it yet, however...........
Chip, uonover on this board, has a 231 krawl box/D300 setup in his rig. He is a VERY large CJ, stretched with tons, 44s, V8, and LOTS of tools. Needless to say he's heavy. He has had a couple of problems but nothing that couldn't be fixed. He did crack a case when the whole weight of his rig came down on it but that's to be expected! I think his issues relate to weight and use of skinny pedal.
Austin, SPOA87YJ on this board, is running a 231 krawl box/231 combo in a 4.0L YJ, tons and 38" TSLs. He has had a couple of shifter issues but no actual breakage.
I don't know who told you "doubling 231/300 aren't so great" but I would bet it's not someone thats running the como in their rig. IMO the front half of the 231, which is what you are using with the krawl box, is plenty stout enough to stand up to 6 cylinder power and 38"ish tires. 'Course I'll have more concrete data after I beat mine some
FWIW there's a 231/300 doubler expert right there in Granite Falls. 3DCRAWLER here on this board, he runs Minton's Automotive and he knows his stuff!
Chip, uonover on this board, has a 231 krawl box/D300 setup in his rig. He is a VERY large CJ, stretched with tons, 44s, V8, and LOTS of tools. Needless to say he's heavy. He has had a couple of problems but nothing that couldn't be fixed. He did crack a case when the whole weight of his rig came down on it but that's to be expected! I think his issues relate to weight and use of skinny pedal.
Austin, SPOA87YJ on this board, is running a 231 krawl box/231 combo in a 4.0L YJ, tons and 38" TSLs. He has had a couple of shifter issues but no actual breakage.
I don't know who told you "doubling 231/300 aren't so great" but I would bet it's not someone thats running the como in their rig. IMO the front half of the 231, which is what you are using with the krawl box, is plenty stout enough to stand up to 6 cylinder power and 38"ish tires. 'Course I'll have more concrete data after I beat mine some
FWIW there's a 231/300 doubler expert right there in Granite Falls. 3DCRAWLER here on this board, he runs Minton's Automotive and he knows his stuff!
- Joined
- Mar 20, 2005
- Location
- Morganton NC
As John said, I run the 231/300 set up. I have the gearing selection of an Atlas 4 speed.
1:1
2.72:1
4:1
10.88:1
I have broke my box twice. Both times it was torque that broke it. IF you can harness the torque, I don't think you will have any issues. I'll Explain.......
The Torque of the engine, multiplied by the gearing has to be controlled. If the torque is allowed to escape anywhere but at the front and rear outputs of the 300, you will have issues like I did. Where I was loosing the torque was with my engine mounts. I have some heavy duty leaf spring type mounts for the transmission, and the crawl box. The transmission mount is center of the tranny, and to the frame. With the mount so close to center, it's easy for it to act as a pivot. The engine mounts being stock, have a good amount of flex. therefore what happens when I break the 231 box is that the rear of the drive line is staying put, the transmission was allowing some pivot, and the engine was moving in essence twisting the crawl box and breaking it. The fix is to hard mount everything with ploy bushings allowing minimal movement. I haven't done it yet, but the engine will soon have similar mounts as the tranny and crawl box. I think I will at the same time hard mount the 300 to prevent it from being able to move
So am I happy with it? Yes. It's all in your design. I found out the hard way.
ANd YEs, David is an expert now LOL he got to practice a lot on mine.
1:1
2.72:1
4:1
10.88:1
I have broke my box twice. Both times it was torque that broke it. IF you can harness the torque, I don't think you will have any issues. I'll Explain.......
The Torque of the engine, multiplied by the gearing has to be controlled. If the torque is allowed to escape anywhere but at the front and rear outputs of the 300, you will have issues like I did. Where I was loosing the torque was with my engine mounts. I have some heavy duty leaf spring type mounts for the transmission, and the crawl box. The transmission mount is center of the tranny, and to the frame. With the mount so close to center, it's easy for it to act as a pivot. The engine mounts being stock, have a good amount of flex. therefore what happens when I break the 231 box is that the rear of the drive line is staying put, the transmission was allowing some pivot, and the engine was moving in essence twisting the crawl box and breaking it. The fix is to hard mount everything with ploy bushings allowing minimal movement. I haven't done it yet, but the engine will soon have similar mounts as the tranny and crawl box. I think I will at the same time hard mount the 300 to prevent it from being able to move
So am I happy with it? Yes. It's all in your design. I found out the hard way.
ANd YEs, David is an expert now LOL he got to practice a lot on mine.
Been jammin
Member
- Joined
- Jan 5, 2009
- Location
- granite falls
Thanks for all the input. I know David, didn't know he was so experienced in this application.
I'm interested in how you're going to mount the D300, please continue...
- Joined
- Mar 20, 2005
- Location
- Morganton NC
I have my crawl box mounted via the two bottom holes of the kit plate. I am going to come off of that to tie the 300 in with that mount. nothing fancy. Just going to give the unsupported part of the 300 some support.
jlshermanjr
Member
- Joined
- Mar 10, 2007
- Location
- brevard nc
I'm running the 231/300 combo, 350tbi/700r4, 5.38's, 42's.
The only problem that i've had is oil leaking. I used RTV at the assy., but it still leaks. Take the time and make you some good gaskets. I'm running the stock gears in the 300. I haven't had any problems so far. I love all the gear possibilities. I built a "cradle" for a lack of better words, for the 300 to set in, seems to work well.
The only problem that i've had is oil leaking. I used RTV at the assy., but it still leaks. Take the time and make you some good gaskets. I'm running the stock gears in the 300. I haven't had any problems so far. I love all the gear possibilities. I built a "cradle" for a lack of better words, for the 300 to set in, seems to work well.