8.8 to 9inch

[George Coleman]

I have a 96 Bronco XLT and will need to replace the rearend soon. Is there a 9 inch setup that can be bolted in to the stock Bronco with out major refit? Is this a good idea as with my old 79 Bronco the rearend repair was a lot easier!! Thanks George

 

[Yardape]

That's a popular swap, shouldn't be too hard. 3 problems I can pick of the top of my head are your 8.8 has a pinion ******' the 9 inch has a yoke. The 9 has no abs so your rear abs light will stay on. The 9 inch should have 3.50 and you front d44 should have 3.54, that may be close enough of a ratio to use but I would definatly ask someone that knows for sure. Those gear ratios aren't 100 percent but in my experience they are most common

 

[Miss Kitten]

you bring up good points yardape however you have missed the single most important reason as to why that swap will NOT work

you have a vehicle speed sensor on the top of your 8.8 diff that sends electronic pulses to your E4OD transmission that tells it when to shift and what gear to be in

without that sensor your truck will run like a bag of ****. it won't know what gear it's in, it won't downshift when you need it to, you may get stuck in first gear. there's endless possibilities of what can happen and none of it good

the only way to avoid this is i've heard rumours of a vss relocator kit, but they are pricey. i'm not sure where to get them or if they are available so you may have to ask someone else about that

the other two options are ditching out the E4OD and putting a ZF and then you can use any diff your little heart desires or finding a sterling 10.25 from an f250 as it has the same vss sensor on it

 

[love_my_bronco]

i have an 84 that i want to swap the rear axles too. 8.8 to a 9. the question i'm wondering is would i have the same problem.. theres really not much going to the housiing just brake lines that i see. i know i need to watch ratio's but other than that anything on us early 80's?

 

[Yardape]

Nope I'm pretty sure its a direct bolt in for you, are you sure you don't already have a 9 inch? 84 should have it

 

[love_my_bronco]

Yea it's the 8.8 limited slip i wish i had a 9 in. i can get one for $200 but my front gears are 3:54 and a 9 in is 3:50 will it hurt anything??

 

[love_my_bronco]

i was given a link that told me something very valuable here is what i read i hope that it helps everyone else out there.

"The gear ratio in the front of a four wheel drive has to be different from the rear so the front wheels will pull more.

There have been many different ratio combinations used in four-wheel drive vehicles, but not so that the front will pull more. Gear manufactures use different ratios for many different reasons. Some of those reasons are: strength, gear life, noise (or lack of it), geometric constraints, or simply because of the tooling they have available. I have seen Ford use a 3.50 ratio in the rear with a 3.54 in the front, or a 4.11 in the rear with a 4.09 in the front. As long as the front and rear ratios are within 1%, the vehicle works just fine on the road, and can even be as different as 2% for off-road use with no side effects.

1 point difference in ratio is equal to 1%.

To find the percentage difference in ratios it is necessary to divide, not subtract. In order to find the difference, divide one ratio by the other and look at the numbers to the right of the decimal point to see how far they vary from 1.00. For example: 3.54

 

[Seabronc]

i was given a link that told me something very valuable here is what i read i hope that it helps everyone else out there.


"Myth - The gear ratio in the front of a four wheel drive has to be different from the rear so the front wheels will pull more.

Fact

There have been many different ratio combinations used in four-wheel drive vehicles, but not so that the front will pull more. Gear manufactures use different ratios for many different reasons. Some of those reasons are: strength, gear life, noise (or lack of it), geometric constraints, or simply because of the tooling they have available. I have seen Ford use a 3.50 ratio in the rear with a 3.54 in the front, or a 4.11 in the rear with a 4.09 in the front. As long as the front and rear ratios are within 1%, the vehicle works just fine on the road, and can even be as different as 2% for off-road use with no side effects.

Myth- 1 point difference in ratio is equal to 1%.

Fact

To find the percentage difference in ratios it is necessary to divide, not subtract. In order to find the difference, divide one ratio by the other and look at the numbers to the right of the decimal point to see how far they vary from 1.00. For example: 3.54

 

[miesk5]

FYI,

Superlift Speed Sensor Recalibrator Info for 92-93 Bronco, all exc. w/4 wheel ABS, 92-03 F Series; Does NOT fit 1994-96 Bronco with 4 wheel ABS

Source: by Jeff's Bronco Graveyard

But you can go with a DANA 60 w/VSS

 

[wileec]

With stock or close to stock tires the dana 60 or ford 10.25 will **** the clearance under the diff.

 

[love_my_bronco]

Thanks Sea Bronc kinda let that fact slip my mind. here's another question did the 9" come as a limited slip or is that something i can install?