I have a 2000 Chevrolet Silverado in “work truck” trim, which is 2WD with a 5.3L engine and automatic transmission. This truck is rarely driven, but I want to keep it in excellent condition.
Recently, I have noticed that the differential, which is at the center of the rear axle is leaking a lot of oil. I am concerned about the loss of this oil, and also don’t like having leaks.
Online research indicates that there are fiberboard or rubber gaskets available, and that the oil is pumped in through a fill hole on the side.
For me to get under this truck and change the gasket and fluid, I would need to jack up the rear, and place a spare wheel (laying flat) under each rear tire. This means that the differential will be level from right to left, but not front to back. I assume that will not be a problem for refilling?
Which gasket would you use? Fiberboard or rubber? If fiberboard, would you put any additional sealant, such as clear or black silicone?
What fluid is best to use? Online research indicates that people are using AC Delco Synthetic Axle Lubricant SAE 75W-90, p/n 88900401. Is this the correct differential fluid for my truck? This comes in a 32 oz. bottle, and online research indicates that the fluid capacity is “approximately” 2.2 qts, so I’d need two bottles.
Any recommendation for the pump to use for refilling the lubricant?
You could also raise the front wheels the same amount and then the truck would be flat. Do you have jack stands? They’re pretty cheap. You could get 4 for $100 or less that would work unless you consider your work load heavy. 3 to 4 ton load limit is plenty.
There may be more than one gasket that could leak, pinion seal, case seal etc, so make sure the replace the correct one. My Ford 9 incher tends to spring leaks where the removable carrier bolts to the case. It is indeed an awkward job to pour the fluid in. (Even harder to get it out … lol … ) I use a short plastic bottle and small funnel, repeat, until filled . The fluid pump idea mentioned above seems easier. Use a product meeting the manufacturer’s specs. An additive might also be required.
75W90 regular or synthetic is fine. Valvoline sells a synthetic in a squeeze pack that makes filling super easy. I have used only black rtv to seal and it works fine. It helps to hang the rear axle so place the frame on jackstands.
All the cover bolts are English.
Don’t over think the fill. It is far from critical. Slight overfill is better than under.
Just remember if you have a limited slip differential to make sure you add the additive for it… I don’t think you have it but just incase, check for it…
Sometimes you can get lucky and have plenty of room to add the gear oil straight from the standard bottle… I had put half a quart using the proper tool in my RR rear diff before I thought WTH am I doing, I have plenty of room to add gear oil with the standard bottle… lol
Really? I have an 01 Silverado 1500 2wd and I can and have laid on the ground to do that. I’m 6 foot 265 lbs so probably bigger than you are. It’s not comfortable but it’s easily done and I imagine you get yourself into tight quarters in your HVAC work.
As for resealing that Chevy 10 bolt, I would use a Fel Pro paper type gasket. Be sure the surfaces are clean and that the cover didn’t get bent prying it off. I assume you’ve looked and confirmed the pinion seal isn’t the source of the leak.
I just wanted to post an update here. I finally had time to look at my truck, and it appears the seals for the half-shafts are leaking. Also, the suspension is worn out and needs help. I drove the truck recently, and it rides like it has at least 300,000 hard miles. It actually has about 213,000 miles but was used as a landscape contractor’s work truck for 209,000 of those miles.
I do not feel that I can safely replace the shocks, etc on this truck at home with a floor jack and jack stands, so I will have to take this to a professional shop. Any ideas on how much I should budget for this type of work? Obviously, I want OEM quality parts used, not cheap AutoZone/O’Reilly garbage parts.
Half shafts? Your truck uses a live rear axle. Half shafts (CV shafts) would be for independent rear suspension or the front of a 4WD truck.
Just replacing shocks shouldn’t break the bank, but a thorough suspension inspection will probably reveal many worn and aged steering and suspension components. If we start talking ball joints, etc. the bill goes up rapidly. When I left the retail world at the end of 2021 our labor rate was $144/hr. Same shop is now $174.
For the 1/2 ton version of Chevy 1500 5.3 L 2WD truck, I’m seeing about $300 each for the rear shocks, and generally less than an hour’s labor to replace both (depends on spring & RTD configuration) . Surprisingly the shock part price for the 3/4 ton version of the truck is significantly less expensive. Go figure.
Half shaft seals leaking? Maybe OP is referring to the rear axle seals located near the hubs. Each rear axle shaft for this truck as far as I can tell is enclosed within the rear axle ass’y almost all the way to the wheel. But each could be called a “half-shaft” I suppose. I’d guess around 3 hours labor to replace both rear axle shaft seals.
hmm … well, you’re the pro so in better position than I to know. $50 is definitely a much more reasonable price. The $300 shock price tag seemed to apply only to the 1/2 ton model of the truck, and the 3/4 ton model was considerably less. Maybe OP will tell us which model they have.
