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4.10\'s???

I have a 82 cj-7 with a 258, t-5 5 spd, and a dana 300 transfer case. I am running 31x10.5x15 tires now with 2.73 gears and it pulls ok, but it has no pickup and it's hard to use 5th gear. I was thinking I would need to swap to 3.54 or 3.73 to run a 33" tire without it bogging the engine and get pretty good pickup, but a guy at tarheel 4wd in Charlotte told me to go ahead with 4.10 since I had the overdrive tranny and it would pull the best. What should I do? Thanks
 

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Re: 4.10\'s???

go 4.10
i had a t-5 with 35 bfg mt's and 4.56 gears.. it was perfect
4.10's with 33's would be very nice
it costs a ton of $$$ to have gears swapped for you, and it's a good time to throw a locker or posi in..more $$$$...
then you look at the dana 30 front axle...is it worth putting all this into?? no not really...now you are looking at a dana 44.. and as long as you are putting a custom axle in, might as well do a spring-over...now that you have a spring over, you have plenty of room for those 35's that look so nice.. hmm now you could use those 4.56's......uh-oh.. the 4.56's broke that t-5.. now you need to get either a t-18 or an automatic.. both of which will cause your RPM to be too great on the road.. have to change back to 4.10 or maybe 3.73....now it just doesn't crawl like it used to.. you need the 4 to 1 transfer case kit... did you remeber to put 1 piece axles in the AMC 20 rear?.. i am rambling, but my point is to get the gears you want forever.. it's too expensive to do it again

~~Elusive~~
it's sort of still a cj thingy....
 
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Re: 4.10\'s???

East,
I am running 32's with 4.10 gears. Its about perfect....on the freeway I use 5th. 2.73 Gears with anything over 29" tires is going to be tough.

John......southern CA
84CJ7, 3"lift, 32"BFG, 4.10's, ARB Locker, Solid Axle's, Durabak
 
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Re: 4.10\'s???

You might want to try hitting junkyards for a 1980 and up 4 cyl. CJ, some of them had 4.10 gears. I found a set of 3.73's to replace my 3.08's that way.

Grant
60 CJ5
80 CJ5
 

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Re: 4.10\'s???

whos got the math handy?

I plan to run 33 inch tires with 4.56, and 1:1 T18 tranny

whats my Rpm at 65 MPH?

OzarkJeep
77 CJ5, in a bunch of sanded and primered pieces
 

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Re: 4.10\'s???

RPM = MPH x gear ratio x 336 divided by tire diameter in inches.

65 x 4.56 x 336 / 33 = 3017.89 RPM
 

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Re: 4.10\'s???

cool, Ive been plugging numbers, is gonna crawl nicely, but I wont be doing many trips down I40 in this rig!

thanks guys!

OzarkJeep
77 CJ5, in a bunch of sanded and primered pieces
 
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Re: 4.10\'s???

You might want to measure the height of your tires if you want an (fairly) accurate number as a 33" tire will probably only be about 31.5" tall. Might sound nitpicky, but at 60 that's a 133 rpm difference. At 70 it's 154 rpm's.

Darren (Mr. Nitpicky)
 

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Re: 4.10\'s???

My Scrambler has a T-5 tranny sitting behind a 304. I have the 4.10 gears and was running 32" BFG's. Ran great with lots of torque, heck, I could burn 'em thru 3rd gear. When I went to 35" tires I thought the gearing may be a problem, but it still has plenty of power on and off road. I cruise at 60mph and turn 2000 rpm's.
For 33's the 4.10 gears are perfect, but I'd recommend 4.56's for anything larger. -Just my 2 cents worth.

Keep on Jeepin'
Scott
 
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