03 LB7 Dually ass end issues

[Big Block 88]

Our 03 FatBack is having issue in the rear, we pull a 48 foot 6 horse slant full living quarter and about 100 gallons of water dark/ and tap. Last time it hit the scales fully decked it ran alittle 35K pounds. The truck is all stock except a small tune.

My sister was pulling to Nevada and while going over the mountains she called me while she was pulled over saying the truck was struggleing on the mountains, she walked the trailer and found it was pulling a locked up flat tire so she was dragging it that way for about an hour she thinks. While talking smoke started pouring out from under rear of the truck, and she said it smelled real bad so I figured gear oil. She did finish the trip with its issues when it got home it had blown a hole in the pumpkin where the axle tube slides in, front seal dripping anyway it was toast so we grabbed a new/used 1150, also inspected spring to find 3 broken leafs on one side and 2 on the other.

She was in full load again pulling to Wisconsin and she called saying the truck would not stop smokeing by the axle, I figured dragging brake but the wheels aren't hot and no dragging sounds.

Any ideas what could be getting that hot? Truck made it back to town again but it leaves for Carolina next weekend, like to figure it out soon.

 

[james13]

hows the oil look ,are the duals touching win it's loaded

 

[Big Block 88]

I never even thought to check and see if the tires are tiouching under full load that is definatley possible, thanks man the oil is fine it just had set number 5 of injectors so it's not motor related.


any other ideas I haven't thought of yet

 

[Leadfoot]

She was in full load again pulling to Wisconsin and she called saying the truck would not stop smokeing by the axle,

Not sure on the rest, but when my fairly recently replaced axle seal went out, I had smoke coming from the rear axle when towing my trailer. Hubs were not any warmer than usual, but axle oil leaking out and vaporizing as the brakes heated up. Something to check anyway.....

 

[james13]

i was talking about diff oil not motor

 

[Big Block 88]

I kinda figured I wasn't positive what oil you were talking about. Everyone who looks at it always says it's an LB7 you probably have an exhaust leak and it is really the injectors smoking, definatley not the case.

As for the diff oil it got a fresh batch of 90 weight when we through the new/used axle in. It had about 60k miles on it I believe. And we replaced the pinion seal, are there outer seals too? I know it is a full floater I wasn't sure if they had outer seals, when we slid the axles back in we used hightemp silicone to seal it up.

 

[Sledhead]

IIRC the outer seals need to be replaced if you pull the axles.

 

[jlawles2]

From what I remember when pulling my axle apart. There are a total of 6 seals in the axle. One on the pinion. One on the pan. One on each shaft end (two total) and it is paper. One on each hub assembly (two total).

If pulling just the axle, then replacing hub seals is not necessary. I removed and reinstalled the axles twice on mine when doing the hub seals and have not changed the axle shaft seals yet. I do have marks on the axle ends to ensure that they are put back in the same as they were removed.

When pulling the hub seals, make certain you get all of the pieces. The factory and replacement seals are 3 pieces (or more) and one of the pieces actually looks like part of the hub. The hub seal has it's own stationary ring that the lip seal rides on for sealing. That is the piece that is easily missed as it looks like part of the hub seal.

 

[Big Block 88]

Thanks for the ideas guys I'll check it out when the truck gets back

 

[scratchrob13]

If its rubbing on the fenders you need some bags!

 

[Big Block 88]

The tires don't rub anywhere but it does make the springs go completely flat.

 

[scratchrob13]

The tires don't rub anywhere but it does make the springs go completely flat.

I have bags on mine. I went with the air ride auto style, set it at the level you want it at, and anytime you are loaded it gives the 5000# bags a shot of air to keep it level via the included compressor. I will never go back now, bags are the way to go.

You can ask Ben (DURAtotheMAX) how well they work when I was hauling his truck back the other night. I had probably 16000# behind me and the truck was leveled right out. (Obviously it wasn't all tongue weight)

 

[Big Block 88]

We will be putting the manual bags on the back and just leave them pumped up, the truck only unhooks from the horse trailer to switch to the other horse trailer.

The trucks days are numbered right now, it is about to be retired for an LML

 

[scratchrob13]

Good plan then. And the LML's give me a hardon.