8.8 to 9"

[White90Bronco]

I have a 1990 Fullsize w/ an 8.8 rear and I want to swap in a 9". What all is involved? What could I get one out of other than a Bronco? All help is greatly appriciated.

 

[ocalabronco]

well, seeing as you have the AOD tranny, you are in luck. if you had the E4OD you'd have to install the VSS sensor. but for you, look in any bronco or f-150 from 84/85 earlier. most will have them. bascially, if you arent going to re-gear it, its a straight bolt in. you might have to change your driveshaft u-joints at the axle, but dont quote me on that

 

[White90Bronco]

ok thanks for the info

 

[mbtech2003]

i have the E4OD in my 95 bronco. how do i use the speed sensor if i get the 9 inch rear end??? :-B

 

[ocalabronco]

doing it on the 9" would be tricky. but doable. basically, you have to drill a 13/16's hole into the 3rd member right where the tone ring would sit on the lip of the carrier by the ring gear. you'll have to press the tone ring onto the ring gear lip. the one thing i can tell you is MEASURE MEASURE MEASURE. then measure some more then use washers to shim the sensor until it is just less than a milimeter away from the tone ring. you will also have to drill and tap a hole for the hold down bolt.

unless you are 100% comfortable with doing this, i would advise either not doing it, or taking it to a shop and explaining what you would like them to do

 

[mbtech2003]

will the 8.8inch ring will fit on the 9inch ring?? :-B

 

[ocalabronco]

it should.

 

[White90Bronco]

I have a couple more questions about the rear end.

In an 8.8 where are the shims located?

There's an ABS Sensor on the inside of the housing of my 8.8", do 9"'s come w/ that or will I have to transfer it from one to the other?

If I have to transfer them, how do I go about doing it?

 

[ocalabronco]

re-red post # 5. on the 8.8, the shims are outboard of the carrier bearings

 

[JrodssTexas]

My 88 had an 8.8 in it and the damn thing blew up on me. So i went to THE FIELD OF DREAMS and took one out of an 81 f-150 a 9" and tied the sensor wire up . and My brakes or electrical Is just fine.

 

[JrodssTexas]

My 88 had an 8.8 in it and the damn thing blew up on me. So i went to THE FIELD OF DREAMS and took one out of an 81 f-150 a 9" and tied the sensor wire up . and My brakes or electrical Is just fine.

 

[ocalabronco]

and as well it should with an 88, you have the AOD trans, or maybe one of the lucky ones to get a C6. so that means you trans isnt shifted electronically like the E40D is. the E40D is completely reliant on that sensor. and you also had RABS, not full 4 wheel ABS.

 

[JrodssTexas]

Correct. and yes I have an aod and rabs

but I wasnt aware that the e4od needed the sensor to shift.

But you learn something everyday.......

 

[White90Bronco]

Is there anyway to bypass the Rear ABS Sensor on an 8.8 rearend?

 

[BLADE262US]

The answer to that is no . If you unhook it in yours it will just disable your antilock brakes and the antilock brake light will come on . If you try that in a 92 or newer the tranny wont shift right and the speedometer will not work . The VSS sensor is whats called a proximity switch it sences metal . Thats why the tone ring on the differential looks like a gear when the teeth pass by the sensor it creates a voltage signal or pulse the computer then looks at this pulse or more the frequency of the pulses and determines the vehicle speed thats how the computer knows that if it was getting like lets say 1000 pulses a min and that is lets say 60 mph now you stomp on the brakes and the rear wheels lock for a second now that 1000 pulses just dropped to lets say 10 now the computer knows that this drop in speed isnt possible in the time that it took place so it assumes the rear wheels have locked so it enables the antilock brake pump to unlock the wheels and get the pulses back in an acceptable range and the vehicle supposedly under control again . These numbers arent exact by no means but thats a rough idea of how it works so in your case with the 88 worst thing thats goona happen is your ABS isnt going to work and youll have an extra light on the dash . /emoticons/[email protected] 2x" width="20" height="20" />

 

[mbtech2003]

i took my abs light bulb out from my dash. got tired of looking at it and i'm too lazy to replaced the left front wheel speed sensor /emoticons/[email protected] 2x" width="20" height="20" />