im pretty sure thats what the guy i bought my bronco said it was..he liked the truck alot and did alot to it, like headers...fiberglass tank so it wouldnt rust through....etc etc... and when he put in the new 4x4 system is when i understand he changed the gearing of it
r
does 5:3 gear ratio seem resonable? i dont think it would be 5.3:10 or w/e it is stock..because he traveled alot and im sur ehe wanted some more gas mileage (from CO to LA for special forces training)

 

That doesn't make sense to me at all. Chances are that if the gears are stock, they are 3.54:1 if it's an 8.8 rear. It may be a 3.50:1 if it's a 9 inch. Depends on the year of your truck.

 

these ARENT stock gears, he payed like 200 dollars to get the rear diff changed out (records show it on them), and he loved his truck..had it for a LONG time, put alot of money into it, and it is a NICE vehicle, thanks though..im pretty sure when i test drove it he said that it was a 5:3, and it DOES get better gasmileage compared to my friends dad with a 91 or so bronco and a 302, this one 13 and his 11, and mines an 87 btw

 

Ok they're not stock gears, you've established that. With any research on the subject, you'll find a "stock" set of gears will run you $200. To get the rear "changed out," will be close to $200. A change out is strictly the labor involved, not the parts. I am also assuming it is using the stock rear axle unit and not a retrofit, as that would have cost quite a bit more. To get anybody to machine you a custom set of gears will be in the several thousands of dollars, before labor which may be higher since it is now a custom application.

My point is: if this 5:3 rear you speak of only cost the guy $200, something was left out in the explanation. If I had poor morals, I could tell anybody how much I love a truck just to get them to buy it. Don't believe everything your told, research the subject well. I have been guilty of that myself.

A 5:3 rear would put you at 1.67:1 final rear ratio. I doubt any vehicle would respond well to that kind of a ratio. Especially one with a 302 and a 4 spd (even the NP435 and T18 with a granny low). The gas mileage point is moot. My parents had an '84 Bronco with the 4 spd and a carbed 302 and could get 13 mpg with the stock 3.50:1 rear. Mileage really depends on driving habits and condition of drive train. If the rear is in fact a 5:3 you should be better gas mileage than 13mpg.

Just jack the rear of the Bronco up, put it in nuetral, mark the drive shaft and tire with a piece of chalk or paint marker, turn the tire and see how many rotations of the drive shaft you get to turn the tire once. The ratio will be the number of turns of the driveshaft per turns of the tire. This will give you a ball park as to what the ratio is. Try it a couple of times to make sure you get the numbers correctly.

-Kerry

 

haha..so u know..the guy that i bought it from is a Capt in the special forces ..and his dad that actually did the businees (son lives in CO right now), is a counsler at my school..and his wife was my first grade teacher that i do stuff with her classes everyyear..if i can trust anyone, i think it would be them..and it could ahve been the 5.3..he said those numbers, and i do have teh papers that say rear torque change and its around 200 dolalrs i believe, work done in NC i think..and yea i'll try the rotation thing

 

the ratio is 5.38 to 1. very common in the rock crawling world. a common set-up is 5.43 to 1 in a front dana 44 and 5.38 to 1 in the ford 9". it's all about the crawl ratio.
shon

 

[updated:LAST EDITED ON 07-Oct-02 AT 00:18 AM (EST)]5.38:1 ...Not a great gas mileage saving gear ratio. I know of the existance of this, but the original was posted as a 5:3 ratio. Perhaps it was a 5.3:1 Joe? They like to bog in North Carolina, and they do have a fair amount of 4 by trials. It would make sense about the "torque conversion."

Colorado, eh... If you take a look at the bottom of the page I linked below you'll see I have a fair amount of history in Colorado myself... https://www.ford-trucks.com/dcforum/DCForumID56/5.html

-Kerry

 

[updated:LAST EDITED ON 07-Oct-02 AT 00:56 AM (EST)]i was'nt ripping on your info. i just thought i could offer some info. those are the ratios i'll have in my little crawler. just got an 88 5.0 . i have a 435 and d20 set-up. i swapped a solid 44 and 9 into my bronco ll.
here's a pic...http://shons99ranger.homestead.com/files/39side.jpg
shon
hope to be rolling by spring.

 

maybe post your engine ,tranny, and tire size. if you got a 300 I-6 and say... 36-38's it may take the 5.38's to stay in the power curve of the motor. i had to run 5.13's in my old ranger with a 2.9 and 5 speed just to use 5th. i had 35-14.5-15 boggers.
but as kspilkinton stated.. 5.38's are'nt mileage gears with say a 351-c-6 and 32's. youd be at like 4 grand at 60.(not an exact, just an approximation)
shon

 

[updated:LAST EDITED ON 07-Oct-02 AT 07:33 PM (EST)]when i test drove it he said it had been changed to what it sounded like 5:3, Im going to get the specifics soon, i have a 5.0 liter v8, headers (gonna check on the brand also), the tires are (Kelly Safari SUV, and hte markings on it P255/70R15 w/ also 108 S on there**excuse my ignorance i havent been into cars a whole lot for very long, i do believe these are the stock tire size? ..and i dont think he did much 4x4, not very aggresive tire treads on these? better than our van's 115 dollar all weather ones but, not much better haha, next time i get tires thier gonna be oversized and a more aggressive tread for offroad**

i dont know any other specifics on it, my uncle that lives about na hour east of here knows alot about cars and does alot of work himself, and i have a 2nd cousina dn great uncle that works here at a garage for a car dealership in town that do work on cars, so when i get a tune-up/check on everything i'll ask them the specifics of everything

*btw thanks guys for all ur help, im just sorta learning now, and hopefully will get in some automechanic classes as a jr and sr as a pud class that wont have alot of hw and i can do my own work on my truck, save money, and have a fun hobby*

 

[updated:LAST EDITED ON 07-Oct-02 AT 10:04 PM (EST)]The stock tire size should be 235/75R15..pretty close to the 255/70R15. Can't be much more than a 1/4" height difference with a little wider look. The actual stock tire size should be posted on your driver's door jamb...if the build sticker is still there. It's the one with the VIN, and codes for interior, axle...etc.

-Kerry

 

yea..haha i guess i knew that one, my uncle said that was probably close to stock, so yea pretty close, i'll try to get the info at school tomorrow

 

from the info given i would have to guess 3.50 gears. 5.38's would hardly be streetable. it may have had 3.08's factory. best thing for you to do is invest 15 bucks in a chiltons manual. it gives you a breakdown of the vin code. chilton's or haynes. either one will help you to become familiar with your rig.
i'm new to this board but i frequent a few others. i can probably speak for most of the people on the board when i say" we will do everything in our power to answer your questions"
shon