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Is this common? I thought all Bronco's had a LS. Here's the tag from my rear diff. I was surprised to not see L between 3 55. So now I'm thinking of converting it to Limited Slip. Maybe not as easy as adding the appropriate clutch packs but will research.
No, not all Broncos had a LS. In fact, I'd say most of them did NOT have one. Adding one involves swapping out the whole carrier and setting up the gears (backlash, preload, etc). Consider changing the gear ratio while you're at it. 3.55s are terrible in these Broncos IMO.
If the AXLE code stamped on the Rating/Warranty Plate (1959/79) or printed on the Certification Label (1980 thru today):
Begins with a letter: Limited Slip.
Begins with a number: No Limited Slip.
And be aware that the 3rd digit of the AXLE code refers to the front axle, but some 1959/79's may not have a 3rd digit, most 1980 and later don't have it.
The most common 3rd digit for 1973/79's is J = Power Steering.
No, not all Broncos had a LS. In fact, I'd say most of them did NOT have one. Adding one involves swapping out the whole carrier and setting up the gears (backlash, preload, etc). Consider changing the gear ratio while you're at it. 3.55s are terrible in these Broncos IMO.
Thank you all! Now I know. I was thinking of changing to 3.73 or even 4.10. Though I'm leaning toward 3.73. I've put on tires 1.6" larger in diameter and have learned that the 3.55 ratio is just not cutting it.
1.6" taller.
I'm guessing you went from something like a 235 75R15s to 265 75R15s? (~29" to ~30.6")?
A couple things to think about.
Gear upgrades can be expensive.
You probably won't notice too much by going from a 3.55 to a 3.73. It's a pretty small change. (About 5%).
Your tire size increased by about 5%, but they're also now a bit heavier. I went from 31" tires to 32" tires and I think it was around 7 lbs a tire, and rotational mass is what gets you.
4.10s may be more the way to go.
Another thought is your money may be better spent in some engine power upgrades.
I was doing the math over the weekend and thinking about which direction to go. Since its not my main vehicle and I want better off road performance I am going to 4.10s. I think this is the better move. I've heard people still get pretty good MPGs on the highway with OD and off road performance was great.
I bought the Bronco with 265 75R16s. I know the stock is 235 75R15s but stayed with the 265 75R16s because of the tires I wanted. Goodyear Wrangler Duratracs with the extra load rating for thicker sidewalls.
