Need help troubleshooting

[1loehoe_tony]

What I understand... Engine revs, truck doesn't move. Need a few more details. I know you lifted up the rear end but not for sure exactly what all you tested there...

Here's a few questions.

1. Check to see if your shifter linkage is working. Place your cell phone camera on record on ground under the linkage as you operate it in truck. The linkage has a big black rubber boot on it... It's on the driver side of the transmission housing just above the service pan, and above the exhaust. Broken shifter linkage will result in no codes, always in park (at least in your case), the dash will show gear change, but it'll remain in park and behave as it's in park.

2. Did it roll when they put on tow truck or did they have to drag it up on flatbed?

3. Did you try to spin wheels in neutral? Or just in gear with rear diff raised? I assume both tires were off the ground when you tried to spin a tire? To fully check the rear end you need both tires off the ground. I think you know this... but wasn't sure by your post.

4. Any engine codes?

5. What kind of rear end does the truck have? G80, limited slip, or open diff? If open diff with both wheels off the ground the wheels should still spin by hand even in gear (with a properly functioning rear end). Take a picture of your options sticker in glove box. It shows what the rear diff is.

6. State of transmission fluid would be very helpful were you able to check the stick for smell / dark fluid?

Trying to help you isolate problem to rear diff or transmission. Won't be brakes if you select a gear and engine still revs freely.

1. I checked that and it looks all good there seems to not be messed up any
2.they used a truck that picked it up by the rear wheels so the fronts rolled.
3.i tried spinning them in all gears with both sides off the ground and it Didn’t want to move any.
4. Still none have popped up.
5.im not too sure as I bought it built how it is all I was told is “it has 4:10 gears with a locker” in it
6.transmission fluid looks good but can’t really tell in the pic but the build only has 30k miles on it look at pic for detail of fluid.

 

[1loehoe_tony]

Obviously a broken piece here, when these trucks are lowered its good to install an offset arm like this https://djmsuspension.com/product/2...r-sway-bar-end-links-for-lowered-suspensions/
When you put the truck in “gear” did you try to spin the wheels while it was in neutral?

Yes I did

 

[1loehoe_tony]

The broken part in the pic is not at all related to why your vehicle won't move. The sway bar link is for nothing more than vehicle sway, side to side, like while cornering. You could likely have snapped your sway bar link while you were sliding around in the rain. It's at the incorrect angle to do its job properly. Your vehicle is lowered and that looks like a stock sway bar link. The sway bar should be parallel to the ground, not at an angle downward.

When you go from park to any gear, do you feel the trans shift?

When you step on the throttle in gear, does it feel like the vehicle wants to move at all, like lurches, jerks, etc? Or does it feel just like you're revving the engine in park/neutral?

When you move the shifter, does it just fall, or do you feel the detents of each gear?

I can feel it shift and the revs change as if it went from park to drive.
Just like I’m revving the car does not jerk it lurch.
I feel the dents in each gear

 

[15burban]

I'd take the driveshaft off. See if the tires will spin then. If they still don't then pop the rear end cover off and see what's broken/locked up.

If they do spin with the driveshaft removed then you most likely have a transmission problem.

 

[Matthew Jeschke]

1. I checked that and it looks all good there seems to not be messed up any
2.they used a truck that picked it up by the rear wheels so the fronts rolled.
3.i tried spinning them in all gears with both sides off the ground and it Didn’t want to move any.
4. Still none have popped up.
5.im not too sure as I bought it built how it is all I was told is “it has 4:10 gears with a locker” in it
6.transmission fluid looks good but can’t really tell in the pic but the build only has 30k miles on it look at pic for detail of fluid.

Fluid pic looks good. That's reassuring. Not to say there's nothing in bottom of pan, but at least you aren't seeing clutch material in the fluid.

#5 Sounds like you have an aftermarket locker. I always suspect other people's work. Depending on failure mode it could create symptoms you are describing. Mine went out years ago. I just went down to the junkyard and bought another one for $300. Was really easy to swap out too.

I can feel it shift and the revs change as if it went from park to drive.
Just like I’m revving the car does not jerk it lurch.
I feel the dents in each gear

That's even better news. Sounds like the transmission is shifting but something in driveline is bound up.

I'd take the driveshaft off. See if the tires will spin then. If they still don't then pop the rear end cover off and see what's broken/locked up.

If they do spin with the driveshaft removed then you most likely have a transmission problem.

100% with @15burban on this one. To fully isolate which part is broken you can remove the driveshaft. It's SUPER easy. Just be VERY VERY VERY careful under the truck. I'm sure you know but I've know people killed getting under vehicles. Preferably do with emergancy brake on, tires chucked both ways on all four tires and NOT lifted off ground. If you have to raise it up make sure you have on flat surface and jack stands under axle on both sides of rear end. Then I STILL put stuff under truck incase it falls. Like the Jack, a tire (if it's off) etc. etc. etc. Sorry for parent rant there...

I believe it's two 11 or 13mm bolts on each side of yoke where driveshaft meets rear end... tightened to 19ftlbs. Undo those straps on the universal joint. Then push shaft forward to release it from the yoke. Afterwards it will slide off output shaft of transmission. When you put it back on clean the splines where it mates to transmission and reapply some silicone grease / lubricant (stuff you lube ball joints and whatnot with).

You SHOULD be able to with some effort (maybe have to put driveshaft on transmission but off rear end to get enough leverage to turn output shaft) turn the transmission when in neutral with the truck OFF. NOTE: if you start the truck and put it in gear then you'll have to go to neutral to stop shaft from spinning before you go from forward to reverse. Otherwise, the shaft will be spinning wrong way. DO NOT put it in park until engine is off. If you forget it'll be a bit ******* transmission / can bind things.

Rear wheels should now spin freely as well with the driveshaft off.

Otherwise, you could remove the inspection cover from the rear diff and see what's going on inside there. That'll tell you a LOT.