B2 Stock gears

OCD4B2 · Post by **OCD4B2** » Mon Oct 11, 2004 7:44 pm

OK, i have to replace my rear ring and pinion do to a loss of traction and a hard grinding noise....nope doesn't sound good. But I need to know what the stock gears are so i can replace them, i'd also like to know what the stock differentials are, such as an 8.8 or a dana 28 (I'm not shure what the stock differentials are called!

). I have a 1990 B2, eddie bauer, should be the same as n e other bronco II. Thanx please post me some help

Post by **Nobody** » Mon Oct 11, 2004 7:53 pm

Front axle is a Dana 28. Rear axle is a ford 7.5 inch.

Stock gear ratios are 3.45, 3.73, and 4.10. I believe 3.73's were the most common.

You need to look for the data tag on axles to find out what gears you have. Post up what info you find. It should be bolted to one of the diff cover bolts.

Front and rear gear ratios MUST match.

You can also see if the data label is present in the drivers side door jam. Post up the axle code.

Despite what the data tags say, it's still possible that someone in the past has changed out the gears. The best way is to count the number ring gear teeth, and divide by the number of pinion teeth

For example, the ring gear has 41 teeth, and pinion has 10 teeth

41/10 = 4.10

DBrown · Post by **DBrown** » Mon Oct 11, 2004 8:12 pm

if you look on the rear tag the first 3 numbers of the bottom row is the gear ratio.

i.e. 3 73 = 3.73 open
3L73 = 3.73 limited slip

the next two numbers on the botom row is the axle size

i.e. 88 = 8.8
75 = 7.5

as for the front I think you do have the D28 but if you can post a pic I can tell you what it is. the 28 and the 35 look similar but the 3rd member is larger on the 35. also they made a hybrid 35 housing with 28 internals but I can't remember what years they did it. I agree with Nobody......you should pull the gears and count. I swaped in the 4.10's and you would never know unless you drove it or I told you.

OCD4B2 · Post by **OCD4B2** » Mon Oct 11, 2004 9:58 pm

OK, here it is
(TOP)
S604H
(BOTTOM)
73 75 9M18
I'm pretty shure is a 3.73 on a 7.5, Thanx ill make shure to count after a buy a new ring and pinion set.

DBrown · Post by **DBrown** » Tue Oct 12, 2004 5:16 am

yeah, you have a 3.73 in a 7.5 rear
I did the same thing, the first number is under the bolt.
you do know that the 4.10's came in the rangers stock right? I think I paid $225 for mine front and back used. that was getting the 3rd member for the front and just the R&P for the rear. it was one of the best upgrades I did to mine before I took it apart again.

plowboy · Post by **plowboy** » Tue Oct 12, 2004 7:01 am

DBrown, My ranger has 3.73' L/S. Was that an option? Wish it had 4.10s. Oh well at least my BII has 4.10 L/S

Post by **Nobody** » Tue Oct 12, 2004 7:39 am

ooops... I forgot about the Dana 35. I don't believe any bronco II's had they hybrids.

I agree, I wouldn't pay to have gears setup in your axles. I would try to find a set of 4.10 axles and swap in the entire axles. 4.10's came in BII's stock too.

DBrown · Post by **DBrown** » Tue Oct 12, 2004 9:03 am

yeah, like Nobody said 3.45, 3.73, and 4.10's were the options. the 3.73 seems to be the most common. you can even pull gears from mustangs. they got the 7.5 also.

I wasn't sure if they came in the BII so I didn't say anything about that. the gears I got came from a ranger.

Ranger Dave · Post by **Ranger Dave** » Tue Oct 12, 2004 4:36 pm

a friend of mine has a 90 B2 with a D35 in it. He needed a hub for it and i had a spare from a D28 and it didnt fit

OCD4B2 · Post by **OCD4B2** » Wed Oct 13, 2004 11:23 am

I did the math on my 9" its only 3.00 so i'm gonna have to get rid of those gears and get 4.11, i wanna get a posi or a detroit locker for it. Its money but well worth it