What gears?
What gears?
Post Fiend
Joined: Dec 2002
Posts: 6,245
Likes: 1
From: IL, USA
Gears out of the '02 should work in the '04......as far as I know they have the same axles still.
As for what ratio to go with, it seems like most of the PSD guys I know with gears like to go with the ratio that would be below the one that would get you back to stock......while some others like to get back to stock....and very few like to go to a lower gear (higher numerically than stock).
I ran some numbers real quick and while the numbers might not be on the dot for our truck it'll give you an idea of what the gears will do rpm wise with bigger tires.
All RPMs were given at 60 mph
Stock:
3.73 gears with 31.6" tires= 1666 rpms
lifted:
4.88 gears with 42.0" tires= 1640 rpms.
Hope this helps.
As for what ratio to go with, it seems like most of the PSD guys I know with gears like to go with the ratio that would be below the one that would get you back to stock......while some others like to get back to stock....and very few like to go to a lower gear (higher numerically than stock).
I ran some numbers real quick and while the numbers might not be on the dot for our truck it'll give you an idea of what the gears will do rpm wise with bigger tires.
All RPMs were given at 60 mph
Stock:
3.73 gears with 31.6" tires= 1666 rpms
lifted:
4.88 gears with 42.0" tires= 1640 rpms.
Hope this helps.
Last edited by DCSpecial; Jan 6, 2004 at 05:46 PM.
Elder User
Joined: Oct 2002
Posts: 873
Likes: 0
From: Roswell USA
Hirolln,
I am also researching which gears to go with. And w/ 38" tires the 5.13's would put me right in the middle of the graph for best overall performance. I would think 4.88's would be good though. I was wondering how u liked the 4.88's in your V10? Thanks!
I am also researching which gears to go with. And w/ 38" tires the 5.13's would put me right in the middle of the graph for best overall performance. I would think 4.88's would be good though. I was wondering how u liked the 4.88's in your V10? Thanks!
Posting Guru
Joined: Feb 2003
Posts: 2,153
Likes: 1
From: Roseburg OR.
02 and 04 have the same axles as far as I know so your gears should work. Usually with the lower rpm band of the diesel you don't want to go quite as low with the gears as a gasser so I think the 488's would be a good choice but the 6.0's do rev quite a bit more than the 7.3 psd's.
Posting Guru
Joined: Mar 2003
Posts: 1,943
Likes: 0
I would use 5.13's with the 42's. I just drove this same setup and it is really nice.Good on the highway and nice off the line.
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Posting Guru
Joined: Mar 2003
Posts: 1,943
Likes: 0
Tankhead, It does and doesn't matter. The optimum is to put the rpm range right where it was but say you want a higher final drive ratio then you would go with numerically higher gears. But you would still use your stock ratio as your starting point and then go up.
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Brett Foote
Elder User
Joined: Oct 2002
Posts: 873
Likes: 0
From: Roswell USA
CWB,
What do u think, 4.88's or 5.13's, would work for me? My crude calculations put it at higher than stock. 4.52, say 4.56 for arguements sake, would put it back to stock. I was thinking maybe some 5.13's might work too. Especially if I decide to do some hangers and 40-42" inch tires. Something to think about. The hangers wouldn't change the ride any? Would just need some good tires like these 38" PJ's. Thanks!
What do u think, 4.88's or 5.13's, would work for me? My crude calculations put it at higher than stock. 4.52, say 4.56 for arguements sake, would put it back to stock. I was thinking maybe some 5.13's might work too. Especially if I decide to do some hangers and 40-42" inch tires. Something to think about. The hangers wouldn't change the ride any? Would just need some good tires like these 38" PJ's. Thanks!
Posting Guru
Joined: Mar 2003
Posts: 1,943
Likes: 0
Well, I'll tell you. I have 40's and 4.56's with a psd and I wish I has done 4.88's. My final drive ratio is only 3.50 something. I had not planned on using 40's so that's where I am. I have two arb's so it would be costly for me to change it now. My buddy runs a gas with 40's and 5.13's and his truck is baaad. If you go to Interco's website and follow their calculators you can find out your final drive ratio. I would try and keep it somewhere above 3.73 and below 4.10. I left for a minute and did it for you. 5.13's will put you at a final drive of 3.79 with 42's. Thats about as perfect as you could ask for.I think 5.13's would give you the greatest flexibility for tires from 38" to 42".
Last edited by cwb; Jan 7, 2004 at 11:58 PM.
