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Well i finally got the locking lugs off (the key was missing). If anyone needs tips on how to get those off, send me a message.
The differential is toast! It's clear someone was already in there trying to fix it. Oh well...buyer beware. I knew with a 43 year old truck there would be work to do.
So, I need to either rebuild it or replace it. I'm leaning toward replacing. My door tag says the axle code is 16, which I think translates to a 3.50 ratio from this site: 1973-1979 Ford Truck VIN Tag Codes (Rear Axle) - FORDification.net
How do I tell if it is a 9" or 8.5" (I can use a ruler, but I don't know what to measure).
Thanks for all of your help and insight! Wish it had been an axle...but it will work out.
Hold on there not so fast.
First I dont think they put anything but 9 inch in trucks before the mid 80's but you would need to measure the ring gear as that is what tells if a 8.5 or 9"
Now I am not seeing anything wrong with the center section but I cant see the pinion gear or the rest of the ring gear if it has any missing teeth.
I am going to guess all the teeth are in place, if they were not it would be making any noise unless the pinion had no teeth.
I am also going to guess both axles were good from wheel mounts to the splines that fit into the center section?
Now that center section looks to be a track lock I think Ford calls it or limited slip / posi as it is also called.
I have not seen one where the clutches were that bad it would not drive the axles but guess it could happen?
What do others think? Could be rebuilt or just replace with say a gear locker?
Dave ----
Thanks!
Pretty sure it's a 9 inch.
Both axles appear to be good.
Here's 2 more photos of the gear.
Not sure what you mean by lockout, but I like the sound of it. As is apparent, I know very little about differentials. I'm not sure what to look for to fix it. I'm guessing:
9" Ford rest with 3.50 gear ratio.
I'd that all or am I missing something?
Thanks!
Bolts from the ring gear to the differential are missing? Or did you remove them. I see one in there loose and space between the differential and ring gear.?
Edit correction I see 2 bolts holding ring gear but definitely a gap between there.
If so the differential is likely shot from loose bolts beating up the holes and will require a complete rebuild. Reuse the housing. Or buy a complete built drop in 9" center section.
I removed them...I figured it was shot, pieces came out.
On the great news side, I think I found a donor truck, but I have 2 problems. I need to go get it tomorrow and his door decal has been painted over. How in the world do I tell what rear is in there without that code? He didn't seem to know. Same year, same engine...I'm just hoping same rear. I don't need much from it, so I will have a lot of parts to share.
Hey Fuzzie,
I believe I would check the Gear Ratio on your front axle just to be sure you are installing the same ratio. Most times there will be a tag on one of the diff cover bolts.
I have heard of rigs that someone replaced the ring and pinion and had the wrong ratio. If you are lucky you end up with what you have now
if not it will destroy the TF Case.
With these old rigs you never know what someone has done or the KNOWLEDGE they had while doing it,,LOL
With these old rigs you never know what someone has done or the KNOWLEDGE they had while doing it,,LOL
I resemble that remark!
Thanks for the tip. He can't figure out what's in there. It's only 5 hours away, and the interior looks perfect. Worse case, I can't find matching front and rear between the two, I still have parts. I'll probably installed the extra brake pedal on the passenger side to give me something to press while I'm teaching him how to drive a stick! He'll probably think it's operational just like he thought he had to change his blinker fluid.
Gear ratio is how many time a pinion turns to cause the ring gear to turn once. If you are trying to find the ratio in your front axle, put the transfer case in neutral, jack up one front wheel, leave hubs locked, turn the jacked up wheel two full turns exactly (due to the fact you are just turning one wheel loosing motion in spider gears) ... and carefully count exactly how many times the front driveshaft turns. Use chalk, do it a couple times if not sure. Example ... if it turns 3-1/2 turns as near as you can tell, it's a 3.50:1 ratio.
When you get the replacement pumpkin, simply count teeth on the ring gear and on the pinion gear, the devide the ring gear count by the pinion gear count.
Thats a nice donor truck.
did we figurecout whats wrong with rear axle and can i have that donorvwhen your done with it
Thanks! With traffic, road closures, and wrecks, my 5 hour trip was 8 hours each way.
The rear is toast. Just going to swap out the donor. Donor might be worth restoring too...stopped running when rusted (inside) bed was removed. Might just be a ground.
What do you need?
Is it better (or easier for the clueless) to switch the whole rear or just the gears? I've never done either, so I bound to mess it up.
I would say the whole rear.
Undo the Ebrake cables, brake line, drive shaft, ublots holdinh axle to springs and it is ready to come out.
Gears are a PITA to setup and if not done right will make noise and trash the gears.
Dave. ----
