I have a 1983 ford bronco 4x4 can anyone tell me what size rear end came in that year. i mean like a 9 in. or what i know it cant be an 8.8 thats what my step dad has in his 95 stang. so could someone let me know please thanks...

 

A quick way to tell:

If the bolts to open up the differential are on the front (the side with the driveshaft coming in), it's a 9".



If the bolts and access plate are on the rear towards the tailgate, it's an 8.8".




They started using the 8.8 around 82 - 84 (can't remember exactly, my 84 has an 8.8"), so it's possible you could have either.

 

Hopefully your's look like one of the ones pictured, if not post a picture, maybe a previous owner swapped in something odd.

 

I actually have a 83 ford bronco with a 8.5 rear end. the research shows it has the unique pinion flange that you cant use 8.8 parts. So I need to know what vehicles can i steel the axle out of that will bolt right up. The rear end i have now has missing teeth and no parts avaliable. So im looking for a axle i can refresh and bolt in. thanks in advance guys

 

The only 8.5 Ford differential was produced for a very limited time. I only know of its use in 1979-82 on the first of the "downsized" Crown Vic's. It DOES use the same carrier and gear sets as the 8.8 though. The Bronco was only equipped from the factory with the 9' or the 8.8. So, if you truly have an 8.5 which is a WER-E differential, then someone swapped it in. The gears and carriers for an 8.8 will swap in though. If the pinion flange is different, you should be able to swap to the pinion flange from an 8.8 to make everything work.

 

The axle tag is WDR-D. According to everything ive found this came in the 83 bronco, 83 F100 and F150 with a 3.55 ratio, The axle is identical to a 8.8 every where but the pinion which is a smaller diamiter. Cant get parts for it so i need to know what years and vehicle types i can get a axle out of to bolt straight up to the 83 bronco. this way also if it ever craps again i can just get the parts needed. Thanks again for the info and help guys.

 

You should be able to find 9" rears pretty easily, with 3.55 gears as they seem to be the most common in Broncos. 78 & up thru early 80s Broncos & 73? thru early 80s F150 should bolt right in. An 8.8 would work also, but the 9" is considered better by most guys. Only experience I've had with 8.8 was my son's 92 Bronco. It started making clunking noises, then locked up a few days later. We replaced it with another 8.8 from the JY.

 

Dude this is what i was trying to figure out. Thank you so much.I would like it if anyone can confirm that the year ranges will fit. That be extra awesome. Im going to start cruzing the JY's and Craigs list now. Thanks again guys.

Edit. Does the more splines mean stronger axles??

 

Those year ranges sound good to me. More splines generally means stronger. But i wouldn't worry too much about them.

 

IIRC, the Bronco 9" came with 35 spline axles & F150 with 31 splines.