Anyone know what the options were? I'm trying to figure out what ratio the Bronco has, as well as my truck. I've heard the Bronco probably has either 2.73s or somewhere right around a 3.00. My truck, using online calculators, I've gotten 3.55 as the ratio.

Either that, or I'm sure there's a tag somewhere I can find this all out at?

Thanks!

 

Nevermind...I searched even deeper and found a page listing everything out. I'll have to see if I can read the door tag, if not, under the truck I go.

 

Good Lord! 2.75s in the truck and a LS w/2.75s in the Bronco. No wonder those things are dogs on acceleration...

 

That doesn't sound right, my kid's 85 Full size Bronco had 3.55. I think the code was H-9 but not sure.

There should be a tag on the diff also-post your door code and diff tag # and I'm sure someone can verify.

 

Standard rear axle under an 86 Bronco was an 8.8" with 3.55 gears. My Bronco, a 91, has a 5.0 w/3.55, 9" rear gears and is a land slug. But like any slug, it'll go any where it wants. As I've often said, the Bronco is not a truck, it's a piece of equipment.

 

I've seen them with 2.73's - it was for EPA gas mileage numbers.

 

Bronco door tag read H3 and my truck is 16. Both 1986 and both 4x4. Bronco has a 5.0 and the OD transmission (AOD?) and the truck has the 5.8L HO and a C6, if that's needed.

This is where I found the code descriptions (I can't get the link to un-link, just in case it's against the rules...sorry!): http://www.ford-trucks.com/forums/sh...69&postcount=2

 

Don't think that link is right, it doesn't have 8.8 diff's at all, and I know my kid's Bronco had the 8.8. I think his axle code was B6 or B9 can't remember exactally.

 

Both of mine have the 9" as far as I know...

I did find this list too: http://www.fullsizebronco.com/forum/...9&postcount=49
According to that though, the Bronco has an 8.8" with LS and 4.11 gears (no way in hell) and my truck: 9" with 3.50 gears. The F150 gear ratio makes sense since the take off is MUCH better than the Bronco, and can go faster than ~25MPH up a hill at max RPM. The Bronco has wide, 33" A/T tires vs. my truck with "normal" width ~31" tires (285/75/16).

 

The 9" third member comes out the front, I think. The 8.8 has an inspection cover on the back (of the rear one) that un-bolts and the third member comes out the back.

I'm not an "expert" but I don't think they have used the 9" in the trucks since they became F150's from F100.

Somebody sharper than me can chime in on that one.

 

I thought the 9" rears were used until the late 80s in the F150/Bronco? Neither have covers like the 8.8" rears do (I have an 8.8" on my Mustang). They are the big, round looking rears, on the trucks. Both have a Dana 44-IF, is it, on the fronts.

 

Wow! I know my kid's 85 Bronco was for sure an 8.8, I thought that was all they used on the Bronco.
Yea I think the front was a Dana. The rear was an 8.8

Maybe it was a tow package or something, or like GLC said an EPA special. I don't know, but I'm gonna watch and learn!

Good luck. Jim

 

The whole reason for me asking, besides out of curiosity about what my truck had, is the Bronco is a dog. I live in the mountains, and it simply cannot pull itself up the hills. My friends V6 Toyota that was running on 5 cylinders at the time with a plugged cat still did much better than the Bronco will. I have been over on FSB, and everyone has pretty much suggested either 4.11 or 4.56 gears. I just couldn't believe they would have a 2.7X gear ratio! I mean, both have dual, beefy looking springs up front on the suspension, and I've yet to see a diagram showing this. Odd CA trucks maybe, lol?

 

Stop screwing around with code lists and MEASURE the ratio yourself.

With an open diff:
Make a chalk mark on the driveshaft. Put the tranny in neutral. Jack up one rear wheel. Turn the raised wheel by hand through two complete revolutions and count the rotations of the driveshaft. The number of rotations is the ratio, e.g. 2-3/4 rotations is a 2.75 ratio.

With a Trac-Loc LSD:
Make a chalk mark on the driveshaft. Put the tranny in neutral. Jack up both rear wheels. Turn the raised wheel by hand through one complete revolution and count the rotations of the driveshaft. The number of rotations is the ratio, e.g. 2-3/4 rotations is a 2.75 ratio.

If you have 9" diffs the bolting flange is on the front of the rear diff housing and the carrier and all the guts of the diff drop out the front; with an 8.8 the flange is on the back and everything drops out the back

 

Thought so-maybe they were changed out.