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inquiring_mind2 10-15-2009 12:09 AM

needing some advice on gearing for my jeep
I have a 75 CJ5 that I use for mudd bogg competitions. I have it set up with a BBC and a turbo 350 tranny and the dana 300 transfer case. My question is I want to run different gears in the front to make the tires spin faster. right now I am runing 410 in the front and rear. I am also using 35 boggers. I was wondering if I could leave the 410's in the front and maybe use like a 373 gear in the back??? Remember this will only see mudd NO pavement. If need be I can shift it into 2 wheel drive to get to the starting line. But still that will be on dirt NOT pavement. Or if anyone has any suggestions on which gears I should put either the front or the back any help would be appreciated. Right now with the 410's in it I can turn 7000 in second gear and 5700 in drive. So I am open to anything that will help out

M&M CUSTOM 10-15-2009 03:54 PM

Your question of the 4.10s in the front and 3.73s in the rear would let you float the front up on top of more mud like I am assuming you want to do.

Have you seen trucks with much more aggressive tread cutting done on the front tires? this also helps out in keeping the front end up like you want it to be in the mud drags.

I am also wondering what you are doing for traction aiding differentials, you are certainly using something there, gearing differences between the front and rear like you are asking about will act like a locker or spool in a single axle on a turn, you will have to get used to the handling differences coming into and out of the lanes, but once you get lined up and slam on the go pedal, your Jeep will want to follow those front tires no matter what you do, just like you want.

inquiring_mind2 10-15-2009 07:34 PM

for my class they won't let me cut on the tires I wish they would though. What doyou mean by (I am also wondering what you are doing for traction aiding differentials). BUt from what you are saying it can be done with out any harm??? Can I leave it in for wheel drive to get to the line or should I drive it in t2 wheel. Its on the dirt never any pavement

M&M CUSTOM 10-16-2009 10:28 AM

If you still have 2WD available to use, use it off the mud and where you need to make sharp low speed turns like the pits and such, wherever you don't have the mud or loose dirt to help the tires slip, shift into 2.

I also just got done looking at your album, it looks like you are running Boggers, you shouldn't have a problem on harder surfaces with them slipping a little I have TSL's and they will break loose pretty easily with a little right foot.

At the RPM's you are running- traction aiding differentials are pretty much necessary, you didn't state that, I was thinking in type. I'm just curious on what axles you are running under the Jeep.

inquiring_mind2 10-16-2009 11:22 AM

I have J10 jeep truck axles underneath. They are the dana 44.

wildman1932 10-16-2009 11:52 AM

If you want the fronts to spin faster, the 3:73's go in the front, not the rear

Daves Hot rod Shop KC Mo.

inquiring_mind2 10-16-2009 12:08 PM

OH ok thanks. I just figured since the 373 were a higher gear they would go in the back and the 410 would go in the front

M&M CUSTOM 10-16-2009 10:49 PM

UH, yeah- brain fart on my part, the faster spinning axle should be the front axle, and 3.73 times per revolution IS faster than 4.10.

inquiring_mind2 10-17-2009 12:30 AM

ok so know you hve me confused LOL. The 410 in front and 373 in back???

M&M CUSTOM 10-17-2009 02:22 PM

You want the front tires to spin faster, with 4.10's in the rear axle and 3.73's in the front axle you will be spinning the front faster like you would want.

At just 1000 RPM's and a direct 1 to 1 transmission drive ratio, the rear tires with 4.10 gears would be spinning 243.90 RPM's, and the front tires with 3.73 gears would be spinning at 268.09 RPM's.

At 6000 RPM's your 35 inch tires would be spinning at 167.5 MPH with 3.73 gears and 152.4 MPH with 4.10 gears.

with faster spinning tires on the rear it will be next to impossible to control as the rear will want to come around on you all the time, the faster spinning tires on the front will want to drag the rear straight behind it at all times.

inquiring_mind2 10-17-2009 03:56 PM

ok I gotcha thanks alot. I really appreciate it. Just trying to figure what to do this winter to make it better for next season

old76c10 10-17-2009 04:33 PM

might try running boggers on back and tsl's on front

inquiring_mind2 10-17-2009 06:22 PM

I have tried that and no luck

old76c10 10-18-2009 10:47 AM

but you havent tried it with the gear swap.just say you do the swap and run 373s in the front with the boggers when they bite spinning faster that the rear what you reckon is going to happen? run the more aggressive tires on the slower spinning wheels and tsl's on the faster wheels...also what type of mud are yall running in up there? looks like red clay but i really cant tell maybe more sandy than the clay?

inquiring_mind2 10-18-2009 11:54 AM

I have gone to a new place this year and its more mud than anything. Maybe a little bit of clay but more dirt than anything else. If the bite I better hold on to my rearend cause I am going to go for a ride LOL

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