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Projects & Parts => Garage/Tech => Topic started by: OHEARN.2012 on June 13, 2011, 06:52:13 AM

Title: School me on gear ratios
Post by: OHEARN.2012 on June 13, 2011, 06:52:13 AM
ok so i dont rely know to much about how gear ratios work with bigger tires smaller tires all the lil factors but school me on the ratios lower then 410s and up to rockwells massive 672s i know anything higher then 410s are street whimpy gears but right now i run either 410s or 373s in a gm 14 bolt ff and corp 10 front 35 inch cut boggers 327/350th/203 soon to be upgraded to a 208. but would a higher gear ratio lets say 513s would they give me a real high increase in tire speed? idk just SCHOOL me on gears dunno much bout them  ++peace
Title: Re: School me on gear ratios
Post by: betterbeaters on June 13, 2011, 10:48:27 AM
going from 4.10 to 5.13 will lose wheel speed.  the higher the number (5.13) the slower the wheels can spin... it may get the motor to rev faster but rpm to rpm the lower numbers (4.10) will spin the tires faster.. just like changing from a 203 to a 208 the 208 has more gear so the tires spin slower... hope this helps some
Title: Re: School me on gear ratios
Post by: mudbillyredneck on June 13, 2011, 11:21:49 AM
Also 5.13 has a smaller pinion head tooth count Than a 4.10 ....so some say it is a weaker gear set

Really depends on what your going to do with it ,(street use.....Boggs....truck pulls ...ect )  I suppose ?
Title: Re: School me on gear ratios
Post by: Blazin40s on June 13, 2011, 02:05:26 PM
4.10s should be good for 35s. 5.13s would be better for 38s on up to 42s or 44s
Title: Re: School me on gear ratios
Post by: Hammerlane on June 13, 2011, 02:07:37 PM
don't mean to hi-jack your thread..
how to tell what gears you have in your axle..
I grenaded the pinion carrier on the Cheep (9" Ford).. pinion gear is spent
ring gear shows signs of significant wear..
both the pinion and ring gear have "1940" on them.. (don't believe thats the year they were born.. ==doh )
do I divide the first 2 digits by the second two?? (.475) or the other way around (2.15.. nah!)
to find the ratio ???

Title: Re: School me on gear ratios
Post by: dirtydog on June 13, 2011, 02:58:49 PM
divide the number of ring gear teeth by the pinion gear teeht 11 41 is 3.727272727 so u round it to a 3.73
Title: Re: School me on gear ratios
Post by: Blazin40s on June 13, 2011, 03:00:59 PM
  What he said

Quote from: dirtydog on June 13, 2011, 02:58:49 PM
divide the number of ring gear teeth by the pinion gear teeht 11 41 is 3.727272727 so u round it to a 3.73
Title: Re: School me on gear ratios
Post by: ProGrade on June 13, 2011, 03:41:30 PM
Quote from: OHEARN.2012 on June 13, 2011, 06:52:13 AM
ok so i dont rely know to much about how gear ratios work with bigger tires smaller tires all the lil factors but school me on the ratios lower then 410s and up to rockwells massive 672s i know anything higher then 410s are street whimpy gears but right now i run either 410s or 373s in a gm 14 bolt ff and corp 10 front 35 inch cut boggers 327/350th/203 soon to be upgraded to a 208. but would a higher gear ratio lets say 513s would they give me a real high increase in tire speed? idk just SCHOOL me on gears dunno much bout them  ++peace
a gear ratio is the number of times the driveshaft revolves to one revolution of the axle shaft.  so for a 4.10:1 the driveshaft turns 4.1 times to turn the axle 1 time.  (this is in a posi or locked state)  so a higher ratio means lower wheel speed, it also means higher torque.  if your torque at the rear output shaft of the t-case is 300ft-lb (its probably much higher)  if you are in 2wd, a 4:10:1 will give you 1230 ft-lb through the axle where as a 3.73:1 will give you 1119ft-lb through the axle.  if you are in 4wd the torque from the t-case is cut in half because half is sent up front.  With 35" tires Blazin40s is right, 4:10's are plenty for a trail/mud rig.  Since a higher ratio results in more torque in the axle shaft and at the wheel, there is a greater chance of snapping an axle when gassing the truck.  If you are going from a 203 to a 208 case, you will lower your wheel speed an increase your torque in low range.  hi range will remain constant.  hope this helps.
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on June 13, 2011, 04:34:42 PM
is your 10 bolt beefed up with any goodies.. cut boggers even 35's will tear it up if ur not carefull. try to keep front tires on ground, if they happen to leave dnt stay in throttle to much when u come dwn
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on June 13, 2011, 08:24:52 PM
no just stock i do believe
Title: Re: School me on gear ratios
Post by: Blazin40s on June 13, 2011, 08:27:19 PM
Boggers will snap those shafts.....may wanna trade someone with tsls 2 of yer tires and run tsl up front and bogger in rear
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on June 13, 2011, 08:33:47 PM
just dnt cut the fronts, u should be ok. i got a corp 10 front 410 gears new lockouts and calipers shaved to fit 15 in rims was told its beefed up a lil what ever that means if u need it for a spare i want to sell it. i ran it last year with 35 boggers and had no problems. i upgraded to a d60.
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on June 13, 2011, 08:38:35 PM
i want a 60s and some 40+ tires
but finds are tight
Title: Re: School me on gear ratios
Post by: ProGrade on June 14, 2011, 02:24:52 AM
Quote from: OHEARN.2012 on June 13, 2011, 08:38:35 PM
i want a 60s and some 40+ tires
but finds are tight
10 bolt front will be fine, usually when you break up front its cuz you are in it and turn, or have a bad u-joint.  if you are really worried about it beef up your u-joints, thats probably what 85 heavymetalbogger is referring to.  I know a lot of guys with big power that run 10 bolt fronts without a problem.
Title: Re: School me on gear ratios
Post by: Blazin40s on June 14, 2011, 04:35:00 PM
I kept breaking my 10 bolt shafts, and I babied it with the 10 bolt.  But I was runnin 39.5s........dang u joints snapped and broke both shafts
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 27, 2011, 08:15:45 PM
so im thinking about upgrading to a 39.5 tire this winter wat would you guys suggest for a step up in gears?
Title: Re: School me on gear ratios
Post by: Blazin40s on July 27, 2011, 08:17:39 PM
4.88s or 5.13s
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 27, 2011, 08:20:54 PM
well with running a 208 wat would match better with its gearing?
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 27, 2011, 08:25:23 PM
how much power u gonna have to turn em? I like my 410's
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 27, 2011, 08:31:39 PM
idk yet decision on an engine is up in air leaning towards smc but if price is good on a running bbc prolly go with it.
still got that axle?
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 27, 2011, 08:36:38 PM
yes sir
Title: Re: School me on gear ratios
Post by: Blazin40s on July 27, 2011, 08:37:33 PM
Id say if its a straight bogger, go 5.13s, I run 39.5 and 4.10s with a 208 and about 400hp......it does good, but I would be happier with taller gears.  I'm going 5.38s when I do mine.......but I'm gonna go to 44s prob
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 27, 2011, 08:48:31 PM
str8 up bogger nuin else maybe pull some trees out lmao
Title: Re: School me on gear ratios
Post by: homewrecker john on July 27, 2011, 09:11:07 PM
Quote from: Blazin40s on June 13, 2011, 08:27:19 PM
Boggers will snap those shafts.....may wanna trade someone with tsls 2 of yer tires and run tsl up front and bogger in rear

I ran 44 bogs on the jeep with a 10 bolt open diff and never had a problem... 5:38 gears with 600hp +
Title: Re: School me on gear ratios
Post by: homewrecker john on July 27, 2011, 09:16:12 PM
If you plan on running 40 with a 208 you should go with 5:13's....your tranny has more than one forward gear right? Plus if you go with a 5:13's you could run a bigger tires later without changing gears again.

If you change the gears before you change the case you could run 35s...if you change the gears and case you will NOT have a lot of tire speed.....
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 27, 2011, 09:19:12 PM
would i be better off with a 205?
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 27, 2011, 09:20:42 PM
Quote from: 85cHeavyMetalBogger on July 27, 2011, 08:36:38 PM
yes sir
looking for any trades?
Title: Re: School me on gear ratios
Post by: homewrecker john on July 27, 2011, 09:28:33 PM
203 and 205 have the same gear ratio which is 1.96:1 and the 208 is 2.73:1

205 are tuff but harder to find
208 is 1/4 the weight, plentiful, and has a much better gearing....

I think your best setup for your truck is as follows

35" tires, 5:13s with 203 ( since you have mentioned that funds are tight

40" 5:13's and 208 ( wont need high hp to run this setup and then you could run bigger tires up to 44"

All this is IMO...that is what i would do if i was in your shoes....

Here is a link with 44 bogs, 208 and 5:38s and stock motor ;) !

http://www.youtube.com/watch?v=8LvM-vaC9Kc# (http://www.youtube.com/watch?v=8LvM-vaC9Kc#)




Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 27, 2011, 10:09:25 PM
Quote from: OHEARN.2012 on July 27, 2011, 09:20:42 PM
Quote from: 85cHeavyMetalBogger on July 27, 2011, 08:36:38 PM
yes sir
looking for any trades?
i dnt knw, what u got
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 28, 2011, 02:19:29 AM
Quote from: 85cHeavyMetalBogger on July 27, 2011, 10:09:25 PM
Quote from: OHEARN.2012 on July 27, 2011, 09:20:42 PM
Quote from: 85cHeavyMetalBogger on July 27, 2011, 08:36:38 PM
yes sir
looking for any trades?
i dnt knw, what u got
i got some canned goods and cereal lmao watcha need
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 28, 2011, 02:20:24 AM
hmm john im liking that setup im building it over this winter so i just have to budget for it
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 28, 2011, 04:46:29 PM
got captain crunch/crunch berries?jk.. i dnt knw that i need anything, got any guns? 100 buks takes it, well worth it.
Quote from: OHEARN.2012 on July 28, 2011, 02:19:29 AM
Quote from: 85cHeavyMetalBogger on July 27, 2011, 10:09:25 PM
Quote from: OHEARN.2012 on July 27, 2011, 09:20:42 PM
Quote from: 85cHeavyMetalBogger on July 27, 2011, 08:36:38 PM
yes sir
looking for any trades?
i dnt knw, what u got
i got some canned goods and cereal lmao watcha need

Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 28, 2011, 04:51:46 PM
u dont know how bad i want it man that is a steal and i need one with brakes and urs has brakes
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 28, 2011, 06:29:01 PM
new brakes, calipers, warn lockouts.. calipers shaved if ur runnin 15 in rims
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 28, 2011, 06:34:04 PM
u got 100 buks its yours..
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on July 28, 2011, 09:17:39 PM
u rely shud save it for me man id buy it here in a month or 2
Title: Re: School me on gear ratios
Post by: 85cHeavyMetalBogger on July 29, 2011, 07:35:29 AM
cant pass on a sell if you dnt end up getn it u knw
Title: Re: School me on gear ratios
Post by: 390JOE on July 29, 2011, 08:51:26 AM
we may missing a key question here; what is best tire speed or torque?
Title: Re: School me on gear ratios
Post by: betterbeaters on July 29, 2011, 12:41:33 PM
Quote from: 390JOE on July 29, 2011, 08:51:26 AM
we may missing a key question here; what is best tire speed or torque?



wheel speed is king!!! keep them tires clean!! the faster the wheels spin the faster you go!!!
Title: Re: School me on gear ratios
Post by: MuddIce on August 10, 2011, 11:45:30 PM
thanks for the lesson... lots of good info here.. I am getting ready to change out my 1/2 ton to 3/4 ton and was just ondering what gear ratios to go with.. Thanks

MudIce
BackYard Mudders!
Title: Re: School me on gear ratios
Post by: OHEARN.2012 on August 11, 2011, 02:27:34 AM
Quote from: MuddIce on August 10, 2011, 11:45:30 PM
thanks for the lesson... lots of good info here.. I am getting ready to change out my 1/2 ton to 3/4 ton and was just ondering what gear ratios to go with.. Thanks

MudIce
BackYard Mudders!
wat kinda tires u running?