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35's + 3 speed + 351W= 4.11 gear ratio?

kat

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Jul 22, 2015
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Bristol
As some may know I busted my third member with the stock 3.50 gears on my '76. Going to get a new set up and was thinking of going with 4.11 gears. I do mainly highway driving and currently at 2000 RPM Im around 70mph...which is about as fast as I like with the lift and short wheelbase.
I do like to hit the trails/mud sometimes and I know the lower gears will be nice. Will I like the 4.11's??? Thanks
 

langester

Contributor
MASTER OF MADNESS
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Mar 2, 2013
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2,660
Just my opinion here. I really like to run 4.11's with 33's, it feels just right to me. It puts the ratio at about the same as running 3.55's on a stock tire. If I were to run 35's , I think I would jump up to 4.56's to keep it close to the same feel. I am sure others will post up their thoughts as well. Good luck with your project!
 

Broncobowsher

Total hack
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Messages
34,835
I think you will like it. Do the rear end and go for a drive before you spend money doing the front to match.
 

Viperwolf1

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You will like them better than 3.50 gears, approximately 17% better.

According to my math you would have been around 2300 rpm with the 3.50 gears at 70mph. With 4.11 you would be about 2700 rpm. 4.30 gears would put you at 2900 rpm. 4.56 at about 3100 rpm.

If you plan on sticking with the tire size and transmission for the long term you would be fine with 4.11 or 4.30 gears. If there's a chance you may upgrade to an overdrive trans in the future you should consider 4.56 gears.
 

sanndmann3

Bronco Guru
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Jun 13, 2007
Messages
1,774
I'd go 4.56 with your 35"tires. It will get you to a final drive ration similar to stock tires and 3.5 gears. 3100 rpm @70 aint bad...
 
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kat

kat

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I think you will like it. Do the rear end and go for a drive before you spend money doing the front to match.
Well since my front axles are twisted up that is my plan. Have to save the money back up to upgrade the front end (ujoints/ball joints/axles/ bearings)

You will like them better than 3.50 gears, approximately 17% better.

According to my math you would have been around 2300 rpm with the 3.50 gears at 70mph. With 4.11 you would be about 2700 rpm. 4.30 gears would put you at 2900 rpm. 4.56 at about 3100 rpm.

If you plan on sticking with the tire size and transmission for the long term you would be fine with 4.11 or 4.30 gears. If there's a chance you may upgrade to an overdrive trans in the future you should consider 4.56 gears.
Thanks for the math...2700 rpm isn't to high for cruising is it???
 

AZ73

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Mar 28, 2012
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2700 rpm at 70 is about the norm for a 3 speed auto. My BMW with a 6 speed does 3000 at 80. I notice you're in FL(at)orida so you've been OK with 35's/3speed/2000/70 but if you ever hit even a slight hill you wouldn't make it without downshifting, then what's your RPM? If you're worried about gas mileage with the jump to 2700, you're driving the wrong vehicle.
 
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kat

kat

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2700 rpm at 70 is about the norm for a 3 speed auto. My BMW with a 6 speed does 3000 at 80. I notice you're in FL(at)orida so you've been OK with 35's/3speed/2000/70 but if you ever hit even a slight hill you wouldn't make it without downshifting, then what's your RPM? If you're worried about gas mileage with the jump to 2700, you're driving the wrong vehicle.
Forgot to mention its a 3 speed manual. And not worried about the gas mileage difference, just worried about redline on the engine.
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
34,835
Normally I would recommend more gear with 35s. But a 351 and mostly highway, I'll go with a higher then normal gear and call the 4.11 gears a good choice.

Your clutch will thank you as well.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
As some may know I busted my third member with the stock 3.50 gears on my '76. Going to get a new set up and was thinking of going with 4.11 gears. I do mainly highway driving and currently at 2000 RPM Im around 70mph...which is about as fast as I like with the lift and short wheelbase.
I do like to hit the trails/mud sometimes and I know the lower gears will be nice. Will I like the 4.11's??? Thanks

You say mainly highway?
4.11s with 35s without overdrive, look about right.
Just remember, it's not all about cruising down the highway. That three speed has a pretty high 1st and 2nd gear.
 
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kat

kat

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Normally I would recommend more gear with 35s. But a 351 and mostly highway, I'll go with a higher then normal gear and call the 4.11 gears a good choice.

Your clutch will thank you as well.
Confused.....4.11 a good choice or 'Ill go with a higher then normal gear'???

You say mainly highway?
4.11s with 35s without overdrive, look about right.
Just remember, it's not all about cruising down the highway. That three speed has a pretty high 1st and 2nd gear.
So I will have the feeling of more torque with the high 1st and 2nd gear???
 

DirtDonk

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Confused.....4.11 a good choice or 'Ill go with a higher then normal gear'???

I think he was referring to the 4.11's as the higher than normal gear. Where he'd normally recommend "more gear" such as a 4.56 or 4.88 instead (biased more for off-road and acceleration).

Paul
 
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DirtDonk

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Right now you're running closer to 2400-2500 with 3.50's and a typical 35" tire.
So as someone said, either your tach is off, your speedo is off, or your gears have been changed from the 3.50's to something more like a 2.92 or so.

Personally I think you would be very happy with the 4.11's overall compared to the 3.50's. You can benefit greatly off-road of course, and maybe even more if you go with an even lower gear like a 4.56.
On the highway I would think that keeping engine speed below 3200 rpm at 70 is a good thing. That would be 4.56 so yeah, the 4.11's should make a nice difference.

Probably help the next rear end live longer too!;D

Good luck.

Paul
 
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kat

kat

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I think he was referring to the 4.11's as the higher than normal gear. Where he'd normally recommend "more gear" such as a 4.56 or 4.88 instead.

Paul
I also forget on here that there are a lot of rock/trail riders....I see 4.11 as a low gear when others say its high
 
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kat

kat

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Right now you're running closer to 2400-2500 with 3.50's and a typical 35" tire.
So as someone said, either your tach is off, your speedo is off, or your gears have been changed from the 3.50's to something more like a 2.92 or so.

Personally I think you would be very happy with the 4.11's overall compared to the 3.50's. You can benefit greatly off-road of course, and maybe even more if you go with an even lower gear like a 4.56.
On the highway I would think that keeping engine speed below 3200 rpm at 70 is a good thing. That would be 4.56 so yeah, the 4.11's should make a nice difference.

Probably help the next rear end live longer too!;D

Good luck.


Paul

Well...Speedo quit working after a couple weeks of owning it....Its actually bounces around 90mph...I had someone follow me and tell me over the phone how fast I was running at 2 grand. The 'busted' gears in it now are 3.50..I checked...But, I am ordering 4.11's in the morning....thanks for all the feedback.
 

DirtDonk

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Fronts too?
Usually yes, but this is one of those perfect times to experiment. Since you must change the 9" you can try the ratio-of-choice now and make sure you like it as much as we think you will.
If you do, then great. Go ahead and swap the fronts after that.

But if you really feel like you should have gone taller (3.73) or shorter (4.56) then you're only out one relatively inexpensive set and setup.
Lots of us do it that way when we're not lucky enough to live next to a Bronco buddy that has a spare 9" laying around for us to try!

Paul
 

camodown

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Sep 23, 2016
Messages
51
Give us some feedback when you do. I've been wondering the same thing. I feel like the 2,300-2,400 rpm is already pushing it for long drives so I'm kind of weary changing the gearing and running 2,700+ range.
 
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kat

kat

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Jul 22, 2015
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Fronts too?
Usually yes, but this is one of those perfect times to experiment. Since you must change the 9" you can try the ratio-of-choice now and make sure you like it as much as we think you will.
If you do, then great. Go ahead and swap the fronts after that.

But if you really feel like you should have gone taller (3.73) or shorter (4.56) then you're only out one relatively inexpensive set and setup.
Lots of us do it that way when we're not lucky enough to live next to a Bronco buddy that has a spare 9" laying around for us to try!

Paul
Yes I know I will have to change the fronts but that will be in a month or so when I can save the money back up (busted axle)...Not understanding you Paul....Try it and see if I like it??...and if I don't like it I have to change the ring and pinion...not that 'inexpensive'

Give us some feedback when you do. I've been wondering the same thing. I feel like the 2,300-2,400 rpm is already pushing it for long drives so I'm kind of weary changing the gearing and running 2,700+ range.
I will.....what engine are you running??? You have 35's??
 

blubuckaroo

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Jun 11, 2007
Messages
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Confused.....4.11 a good choice or 'Ill go with a higher then normal gear'???


So I will have the feeling of more torque with the high 1st and 2nd gear???

No. You loose torque and it's hard on the clutch.
When referring to gearing in both the tranny and differential, "higher" means a lower numeric ratio.
Confusing, I know, but that's how it works.
 

DirtDonk

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Yes I know I will have to change the fronts but that will be in a month or so when I can save the money back up (busted axle)...Not understanding you Paul....Try it and see if I like it??...and if I don't like it I have to change the ring and pinion...not that 'inexpensive'

It's not that expensive when you compare it to doing both the rear and the front. Re-doing one is much cheaper.
That's only an issue if you find that you don't like the choice you made.

Sounds like you're already going to do just the rear anyway until the budget catches up, so you're already there. If you have the time to drive it much before re-gearing the front to match you will have your answer.

Paul
 
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