Changing rear diff gears for towing
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Changing rear diff gears for towing
I have a 95 F250 4wd 351 ci with 3.55 rear end . I have a couple of car trailers
I tow and would like a little more power when doing it . Can I go to a set
of 4.1 gears and be ok ? Is this difficult and exspensive ? Thanks in advance .
I tow and would like a little more power when doing it . Can I go to a set
of 4.1 gears and be ok ? Is this difficult and exspensive ? Thanks in advance .
Hotshot
Joined: Jul 2003
Posts: 12,177
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From: Newport, WA
And remember that if you swap the rear gears you also have to swap the front gears...
IMO if you want more towing power, you need to put the 351 to bed and upgrade to something with a bigger motor.
IMO if you want more towing power, you need to put the 351 to bed and upgrade to something with a bigger motor.
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Thanks Bill . the thing is I priced out a new F350 with V10 and decided I
didn't want to spend that much , so I thought if I could change gears I
could get the job done with less money . You make a good point about the 351 , although a good engine it is probably up against it when towing .
I guess I will just keep buying lottery tickets and who knows .
Dan
didn't want to spend that much , so I thought if I could change gears I
could get the job done with less money . You make a good point about the 351 , although a good engine it is probably up against it when towing .
I guess I will just keep buying lottery tickets and who knows .
Dan
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
Thanks Bill . the thing is I priced out a new F350 with V10 and decided I
didn't want to spend that much , so I thought if I could change gears I
could get the job done with less money . You make a good point about the 351 , although a good engine it is probably up against it when towing .
I guess I will just keep buying lottery tickets and who knows .
Dan
didn't want to spend that much , so I thought if I could change gears I
could get the job done with less money . You make a good point about the 351 , although a good engine it is probably up against it when towing .
I guess I will just keep buying lottery tickets and who knows .
Dan
Sit. Stay.
Joined: Oct 2001
Posts: 18,308
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From: Washington State
What size tires you running? Smaller diameter tires (of the correct load range) will help lower your effective ratio, too.
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Post Fiend
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From: Central Florida
Assuming you have 0.74:1 Overdrive,
3.55 gears on 31" tires 70mph at 2000rpms
4.11 gears on 31" tires 61mph at 2000rpms
4.56 gears on 31" tires 55mph at 2000rpms
now if you're running 35" tires
3.55 gears, 79mph at 2000rpms
4.11 gears, 68mph at 2000rpms
4.56 gears, 62mph at 2000rpms
an engine has a sweet spot somewhere between 1700 and 2500rpms. This is where you will most likely want your cruise speed to be.
3.55 gears on 31" tires 70mph at 2000rpms
4.11 gears on 31" tires 61mph at 2000rpms
4.56 gears on 31" tires 55mph at 2000rpms
now if you're running 35" tires
3.55 gears, 79mph at 2000rpms
4.11 gears, 68mph at 2000rpms
4.56 gears, 62mph at 2000rpms
an engine has a sweet spot somewhere between 1700 and 2500rpms. This is where you will most likely want your cruise speed to be.
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I think for now I am going to stay with what I have . I am about to put new rotors and pads on . What wheel nut socket do I need ? I think
OTC # 7158 but not that sure . I don't know what axle I have , I do have
4 inch diameter hubs if that helps . Thanks in advance .
OTC # 7158 but not that sure . I don't know what axle I have , I do have
4 inch diameter hubs if that helps . Thanks in advance .
Post Fiend
Joined: May 2006
Posts: 10,007
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From: Central Florida
I'd suspect a 10.5/10.25 in the rear and a dana 60 upfront in some variation. If it's 4wd, you shouldn't have to pull the hubs to get the rotors off, the ones I've messed with were a top hat like rear rotors. If it's 2wd It's probably got a castle cover over a big regular hex nut.
Thanks.
Thanks.
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
I'd suspect a 10.5/10.25 in the rear and a dana 60 upfront in some variation. If it's 4wd, you shouldn't have to pull the hubs to get the rotors off, the ones I've messed with were a top hat like rear rotors. If it's 2wd It's probably got a castle cover over a big regular hex nut.
Thanks.
Thanks.