ruined rear end

[jim-bob]

What all can happen mechanically (I specify mechanically so you won't include getting your gun) when your truck is driven with out lube in the rear end?..what parts will be affected?..do you think the axles will be effected?.. how far do you think it will travel before it stops? and will it make a loud noise? Please give serious answers..Thanks!

[truckster]

Burned up bearings (inner, outer, and pinion), torn seals, broken gears, parts going through the housing... depends on how hard it's run and how long it's dry. If you have posi, the clutches are likely toast.

[sick472]

Here's my speculation (assuming NO fluid at all)...

The gears and the bearings will be effected first along with the seals. However, the seals won't leak anything since there's no fluid in it.

The gear tooth faces will get stupid hot and start to spall. This is kinda like getting hot enough that the metal starts to weld together at the gear mesh surfaces which starts to pit one face (pulling the spot weld from one face), but may leave raised pimples on the other surface (the spot weld and the pit pulled from the other face). Since gears don't often share the same tooth mesh upon every rotation...the problem amplifies as the pimples on the next revolution now hit a fresh tooth where no pits reside. This reduces any clearances you originally had and further increases the heat that is developing which increases the spalling which increases the heat...and so on. Once this starts, it's Goodnight Irene! If the lack of clearances don't take it out, the heat will.

Not to mention that the start of the heat-up causes the gears to swell (or grow). This also contributes to the reduction in the original clearances which adds to the heat-up of the unit.

The real question is...Do the bearings seize first or the gears? That may depend on how it's being driven. Driven real hard like drag racing and I think the gears will give first...the slow drive to grandma's and I'd put money on the bearings melting down first.

If the bearings sieze first...the gears could be right behnd it. You'd hear a tire lock up and squall, then the gears granade.

If the gears went first by locking up, you might have both tires squalling you to a stop OR if they bust up...you get a shattering noise followed by no forward acceleration.

Fun question!

[Bigdav160]

Pinion bearings quit first they are turning 3-4x faster

[cdub2010]

Mine went 2 miles on the freeway. It was real noisy and started to lose power and get sluggish like a sticking brake caliper. The truck wouldn't move once stopped. I got it towed home, it groaned and howled wildly all the way. The next day I was able to remove the axles easily. The spider gears and shims were in bad shape. The ring gear is pictured with the carrier and a partial shot of the pinion. Never tried to reuse as I had a spare axle.

[JMac11]

Got a leaf spring builder if you are close to Tallahassee. No Charge

[maverickmk]

Heat will be the biggest problem. Cook the bearings and it's all over except for the crying.

*Edit: I'm sure someone who "does" or "used to" own a shop or "has worked in these trucks for over X years" will chime in and say I'm wrong, so take my opinion with a grain of salt.

[A1971Blazer]

I saw one once where the pinion gear welded itself to the ring gear....after it was parked and had sat all day.....would not move

[special-K]

If you run with no lube the only thing it hurts is all the moving parts.

Sad but true. That doesn't mean all will be hurt, but check for heat damage. Just bluing is a bad sign, time to replace

[JMac11]

Saw an Impala at the Dirt Track Races that the center section was glowing red, after it sat it had to be loaded with the wrecker. Assume the innards welded together.

[Sheepdip]

Many Moons ago a guy I was working on the same jobsite in Nevada with had a square body blazer, him and his girlfriend were both killed after being ejected in a roll over, (I believe she was to drop him off).

They were traveling about 80 mph across the Nevada desert when the rear end locked up and sent them off the highway to their deaths.

[jim-bob]

...much obliged for all the replies and explanations.. the repair guy was in line with most of your answers.. I also asked if the axles would be affected.. can someone comment on the axles..please and thank you

[BCOWANWHEELS]

Its junk now................find another rear

[truckster]

There's a story here you're not telling. Come on, inquiring minds want to know...

[davischevy]

If you discovered the low grease situation with no noise, fill it and don't worry about it.

If you discovered the situation with noise, replace the rear, or rebuild it, end to end.

[HO455]

Yes it is probable the axles would be affected. The splines should be checked for excessive wear, an axle bearing may have spun and gauled an axle (that might be repairable with a speedy sleeve). And worst case the carrier got so hot to cause the heat treating of the axles to be affected, but that would be a long shot, and that would be pretty apparent throughout the inside of the rear end.
Personally I would find another axle and start anew.