Rear driveshaft spins, wheels dont move?

[Harry Paratestes]

I recently bought a 03 4.7 sc sb for a good deal because the rear wheels dont turn but the driveshaft spins. Previous owner said he heard a clunk then the truck wouldnt move. The truck is not near me and when i go try to work on it id like to have an idea of what it could be. The truck makes no noise when the shaft is turning. Speedometer works but i read thats controlled off the trans. The driveshaft is connected to the rear yoke and no leaks, shaft isnt loose where it connects to pinion...
Possibilities:
Broken axle shaft(s)?
Bad spider gears?
Bad ring and pinion?
Big pin came out that holds spiders in?

Any thoughts?
Axle shaft would be not a bad job.
If its spider gears can you just put in a used set off a salvage rear end? Ive watched videos on disassembly of a 9.25 but not sure if my idea would work?

Any other advice or thoughts?

 

[Rlaf75]

If the driveshaft is turning while attached to to rear differential then clearly that's an issue with the rear differential. Could be the pinion gear stripped. For $h!t's and giggles, try to roll the truck either forward or backwards to get the ring gear moved to a different position to see if the pinion gear engages at a different spot on the ring gear.

 

[Harry Paratestes]

If the driveshaft is turning while attached to to rear differential then clearly that's an issue with the rear differential. Could be the pinion gear stripped. For $h!t's and giggles, try to roll the truck either forward or backwards to get the ring gear moved to a different position to see if the pinion gear engages at a different spot on the ring gear.

Ok will do that when i get to where the truck is stored. Its where it is in that pic so it might be hard to roll it on that ground but ill try

 

[Rlaf75]

Ok will do that when i get to where the truck is stored. Its where it is in that pic so it might be hard to roll it on that ground but ill try

Either way you cut it you're gonna have to pull the rear diff apart. The noise that was heard was more than likely a spider gear that broke and damaged the ring or pinion gear causing it to sheer teeth. Crawl under and check the diff cover. If there is an outward dent or hole in it then you're rebuilding or replacing the differential

 

[Harry Paratestes]

Either way you cut it you're gonna have to pull the rear diff apart. The noise that was heard was more than likely a spider gear that broke and damaged the ring or pinion gear causing it to sheer teeth. Crawl under and check the diff cover. If there is an outward dent or hole in it then you're rebuilding or replacing the differential

I do remember looking at the cover and there was no outward dents. Since its an open differential couldnt it be possible that an axle shaft snapped?

 

[jws123]

These trucks are a dime a dozen on FB market place you should be able to find a part out and swap the whole axle not that hard to do.

 

[Rlaf75]

I do remember looking at the cover and there was no outward dents. Since its an open differential couldnt it be possible that an axle shaft snapped?

I guess it could be possible but you'll find out when you open the differential to inspect it

 

[Harry Paratestes]

These trucks are a dime a dozen on FB market place you should be able to find a part out and swap the whole axle not that hard to do.

Theres not many at all in my area. Im in fargo nd. And the 3rd gens that do show up are usually complete, running and driving and not cheap.
A guy i know has a 9.25 with 3.92s and anti spin rear from a 3rd gen 2x4 but it has 230k on the truck. I actually used to own it but sold it to him for parts as the engine had a spun bearing. I did drive it a short distance when i owned it but never highway speeds to tell if it howled or was good. Im not too excited about putting in a rear end in with high miles and not knowing the condition. I guess if i can get it cheap enough i might go that route if i open this cover and its really bad

 

[Smokeybear01]

I had that happen to me on an older pickup and it was the teeth stripped off the axle shaft. It was a quick and easy fix by slipping in a new axle shaft. But I don't remember a loud clunk when it happened. Just a loss of movement. Good luck and keep us posted.

 

[Mojo88]

OP, you listed virtually all possibilities. Could be any of them.
And the only way to find out is: open her up for inspection.

 

[Harry Paratestes]

Ok will report back when i can get to where its stored at

 

[Gary Fields]

You did not let your irresponsible adult child to drive it? This is often the cause of these types of problems. In my younger days an acquaintance broke a u-joint with over enthusiastic shifting a stick shift in his Dad's Chevy truck. When the front joint broke the drive shaft fell to the pavement (before the days of retaining braces) and caught in a hole/crack. The driveshaft was jammed back and bent the axle and broke the mounting bolts for the leaf springs. The truck ended up getting a salvage yard rear axle assembly. When the tow truck was backing into driveway with the rear axle cattywampus and hanging down on one side his father calmly asked his son "Are you alright?" "Any other people involved" and "We'll talk later". Little did I know I would need that calm restraint years down the line for some of my son's situations.

 

[Hagar1]

One of the all time best that I ever laid eyes on was back in my GM days. This local Doctor bought a new 1973 or so Chevy Station Wagon. Anyone around those days would know that the first couple of start attempts in the morning were generally a start- stall. Some people would get frustrated and put 'er to the mat.
Well, this Doctors wife put it to the mat but didn't let off before selecting reverse. When I got there with the tow truck, the driveshaft was laying at an odd angle, the pinion was still attached and it was laying in a puddle of oil. At the time GM said, "thank you for buying a Chevy" ......

 

[turkeybird56]

OP" Obvious sumthin broke in the rear diff. Gonna take a surgical look to see WTH happened.

 

[Marshall]

real simple , take the cover off , jack one wheel up and turn the jacked up tire and look at the gears.
If you take off the cover and a few bits fall on the ground, go to wrecking yards and see if there is one for sale cheap.
Hi miles don't matter that much .
the driver does,
what about your old one , is it still sitting around with the blown motor?
Putting used gears in sounds like a hit and miss deal unless you know how to set it up properly.

 

[Robert Anderson]

i would jack up the rear and give a pull on the tires toward you if axle is broken you should be able to move it

 

[Harry Paratestes]

real simple , take the cover off , jack one wheel up and turn the jacked up tire and look at the gears.
If you take off the cover and a few bits fall on the ground, go to wrecking yards and see if there is one for sale cheap.
Hi miles don't matter that much .
the driver does,
what about your old one , is it still sitting around with the blown motor?
Putting used gears in sounds like a hit and miss deal unless you know how to set it up properly.

If just the spider gears are broken i thought there isnt much or any adjustment needed with those. Just a ring and pinion need all the adjustments? And yes my old truck with the blown engine is still nearly complete but i havent asked the guy for a price yet. Just waiting for time to go take a look at my truck to see how bad it is

 

[Harry Paratestes]

You did not let your irresponsible adult child to drive it? This is often the cause of these types of problems. In my younger days an acquaintance broke a u-joint with over enthusiastic shifting a stick shift in his Dad's Chevy truck. When the front joint broke the drive shaft fell to the pavement (before the days of retaining braces) and caught in a hole/crack. The driveshaft was jammed back and bent the axle and broke the mounting bolts for the leaf springs. The truck ended up getting a salvage yard rear axle assembly. When the tow truck was backing into driveway with the rear axle cattywampus and hanging down on one side his father calmly asked his son "Are you alright?" "Any other people involved" and "We'll talk later". Little did I know I would need that calm restraint years down the line for some of my son's situations.

I bought it as is. He thought the transmission was bad but never got under to look. I found out the issue when i went to pick it up

 

[jawzs2]

I broke an axle shaft into three pieces with my Mach 1 trying to show off in the high school parking lot, dumped the clutch at about 5k RPM. (wasn't the first time). Only had it about a month. It took my friend Tony, about 250 - 275 lbs. working a slide hammer with two bricks strapped to the weight about 15- 20 whacks to finally get the broke axle out. My dad was not happy - LOL, but lesson learned.

 

[lpennock]

If just the spider gears are broken i thought there isnt much or any adjustment needed with those. Just a ring and pinion need all the adjustments? And yes my old truck with the blown engine is still nearly complete but i havent asked the guy for a price yet. Just waiting for time to go take a look at my truck to see how bad it is

Changing the spider gears requires no real adjustments. Changing the complete carrier on these AAM axles is very easy and only need a mag base dial indicator to perform. Changing the Ring and Pinion is a fair amount of work.