4.11's or 4.56's????

[highgravity]

I've got a mechanically sound 1980 FJ40 with factory 3.70 gears. I am running 33's and do not have enough acceleration. I want to gain acceleration while maintaining the ability to run near 75 mph without turning too high of an rpm. Has anyone run a similar setup with either 4.11's or 4.56's? Which ratio worked best for you?

thanks

 

[2badfjs]

4.11's are prolly what you want if you want to go 75 mph

 

[Poser]

4.11's are prolly what you want if you want to go 75 mph

X2.

 

[thsorens]

Are you ever going to take it off road? I know that I would DEFINATLY go with the 4.56's, but I have 35 inch tires, and dont' care how fast it goes. If you are going to buy new gears, the 4.56's are the same price. However, you could get used 4.11's pretty easy since alot of them came that way.... Just depends if you are ever going off road.... 4.56's are not really that low with a 33" tire....

 

[highgravity]

I do plenty of four wheeling, but I want to be able to drive long distances as well. Does anyone drive in the mountains with the 4.11's? Do the 4.11's seem adequate with oversize tires?

Thanks for the feedback, I'm leaning toward the 4.11's

 

[2badfjs]

i've got 4.11's in my 69 40 right now.
runnin a built 2f with a sm465 and my 3spd t-case.
havent had it on the road yet.
but when i had the 3spd trans in it, it would run in the mountians pretty well. maybe just a bit of a bog down but not much with the built 2f

jim

 

[spike6901]

Unfortunatly you can't have a low craw ratio and a good highway gear at the same time with your situation. It depends on whether you can live with more clutch use and not a slow enough crawl speed with the 4:11 when wheelin' and still be able to run 75 without the engine exploding. Or, would you rather be able to crawl like a rockstar but run like a granny on the highway with 4.56?

Tough call. If you don't do a lot of really slow crawling and want to drive the rig there, I would probalby go with the 4.11. If you can tow the rig there, then definatly the 4.56. Running 4.56 = committed trail rig with 33's and some slower crusing about.

I have the same delima. I have 35's and 3.70's and it sucks at crawl speed but is great on the highway. It is my daily driver so it sees a heck of a lot more highway than offroad use. Once I buy a tow rig someday, I will probably drop 4.56's in her.

 

[bull]

4.11s for your 33s youd be fine. If you go up in tire size you will want 4.56 or 4.88

You need to figure out what you are going to use the rig for and plan accordingly.

 

[Roswell Rat]

FWIW, my mechanically sound 76 FJ40 has 4.11 gears and 33" tires. I would have to rev it to the moon to see 75mph. If you want a highway cruiser, you are better off with the 3.70 gears and suffer through the poor acceleration.

 

[2badfjs]

FWIW, my mechanically sound 76 FJ40 has 4.11 gears and 33" tires. I would have to rev it to the moon to see 75mph. If you want a highway cruiser, you are better off with the 3.70 gears and suffer through the poor acceleration.

cool old school "BONES" avitar.....

 

[Roswell Rat]

Thanks 2badfjs....

Everyone should check this out. Very informative.

http://www.4wheelparts.com/4wp/ORS/gear_calculator.asp

 

[FJ40fiji]

See if you can find a used diff . You could probably get one with factory 4.11's to stick in the rear in an afternoon. Then drive around IN TWO WHEEL DRIVE for a week and decide if you are happy. Around here I can find one for $50-$100. Lots cheaper than a new ring and pinion and set up kit. If it is a daily driver for you then you will have one already out if you do decide to go 4.56. Set it up, switch it in, set up the other, switch it in viola'. Sell the extra or gear it too just in case.

 

[highgravity]

Excellent advice FJ40fiji

 

[bikinnotdykin]

I have 4:10's in my blazer with a 36" tire and a sm465 and a 205 and I can crawl pretty damn good even for moab!!