How-To: 6.0L Oil Pump R&R.

[jaded13640]

I just did an oil pump on an 05 Silverado 2500. Note this was NOT a 4 x 4 so it was considerably easier than a 4 x 4 would be. From what I've read, in order to get the pan dropped on a 4 x 4 you have to either drop the front axle or pull the motor enough to get the pan to drop.

 

The tab that fastens the oil pick-up tube to the pump is pretty much inaccessible with the pan in place. Had they designed the tube so that it could be spun around and use the bolt hole to the passenger side you probably wouldn't need to drop the pan. But the retainer tab won't spin so you're stuck using the inner most bolt hole.

 

The first question most seem to have, me included, was, "where the hell is the petcock on the radiator. There isn't one. It makes for a pretty messy drain process but I just set three wide drain pans under it and threw floor dry in what I missed.

 

After most of the coolant drained I removed the upper radiator hose and the upper half of the fan shroud. There are four push pins holding the two halves together and two little screws on the top of the upper half holding it to the radiator support. The air intake hose assembly has to be removed to gain access. With the upper half of the fan shroud off getting the fan off was pretty easy. Some use the spanner and wrench method. I don't. Usually by the time they get to me you'll snap the spanner and bend the wrench before the fan snaps loose from the threaded end of the water pump pulley. I use an air chisel and snap it loose that way. It threads on normally. In other words it's NOT a left hand thread. With the fan off, lift the lower half of the fan shroud out. It just rests in the slots on the radiator support.

 

Now would be a good time to remove the lower radiator hose from the water pump assembly. Have a drain pan ready, it's gonna make a mess.

 

I did the job with a hoist which made the job fairly easy, especially not having an axle in the way.

 

After getting coolant and oil drained out and the oil filter off the order of what you take off doesn't really matter. I dropped the pan before removing the timing cover assuming I'd be reusing the pan gasket and didn't want to damage it by pulling the timing cover off first. The pan and timing cover gaskets are pretty spendy as far as gaskets go so if you're going to reuse it, be careful removing it. They're the thick metallic type with an embedded O-ring so as long as you didn't destroy it, a little sealer should be fine. Even with my good discount the new oil pan gasket was about 55 bucks and the timing cover set was closer to 60. The customer wasn't concerned about parts cost and felt more comfortable using a new ones so I replaced them. The timing cover gasket was stuck to both surfaces and got ruined anyway but probably only because this motor has 275k on it. If it was my truck I would have cleaned i, inspected it and used a little sealer and reused the oil pan gasket. There's a cross-member held on with four long bolts and two nuts that has to come off. The nuts are not weld nuts so they do have to be held with a wrench. Pull them out and set the cross-member aside. There are loomed wires attached to the front of the oil pan. The lower loom can be loosened by popping open the loom retainers. There's a retainer on the passenger side of the block that holds the trans cooler lines and the wires in question. Unsnap the lines and open the wire loom retainers and remove the the retainer assembly. You'll need to have some slack in the wires to keep them out of the way. The upper loom is attached in a plastic piece that's held with one bolt and a pin into the front of the oil pan. Remove the one screw on the drivers side/front of the pan, the loom retainers with a screw driver and pull the plastic piece towards the drivers side and it'll pull off. There's a plastic pin on the passenger side front of that piece that slides out when you pull it towards the drivers side. I'm using the terms "driver's side" and "passenger side" because you're facing the front of the motor. (Using left and right might get confusing.)

 

The balancer/front pulley is a little tricky to get off. The puller that's designed for it barely reaches around enough to get the arms into the little notches in the back side of center area of the hub. If you don't get the arms all the way into those notches, it'll pop out of position every time. It took me several tries to get it just right but once I did, it came off pretty easy. The fit between the hub and crank snout isn't a very close fit. Once I got the puller on it good and got that initial snap it slid off pretty easy. The threaded hole in the crank is way in there so most pullers won't reach in far enough to pull the hub back on. I had to carefully tap it LIGHTLY all the way round for quite a while before it was on far enough for the threads of the hold main bolt to pull it on. But I'll get to that in reassembly. Once the pulley's off look to make sure it's not leaking any oil around the front main seal. This one was and I replaced it. Nothing special, just a seal, just drive it out and carefully drive the new one in.

 

There are quite a few screws in the oil pan, just make sure you don't miss any. Two of the torque converter cover bolts, (the lower most two) have to come out as they are threaded into the back of the oil pan. You'll have to remove the oil level sensor wire and it seems like there was a retainer in the way on the drivers side of the block that I removed. Note that there are two bolts to the rear that are down low on the sump somewhere. They're really skinny and long. Be careful with those. As thin as they are I can imagine them getting broken if they're in there very tight. Mine were not.

Once all the bolts are out just remove the pan and set it up to drain. If you've got a parts washer big enough to soak the pan, you'll probably want to remove the low oil level sensor. I just cleaned it up by hand.

 

You will of course also have to remove the AC belt. I always draw a picture of the routing even if it's fairly simple. You're going to have enough to remember as it is.

 

With the pan off, the hub/balancer/main pulley off you'll have to remove the water pump assembly. On this engine the water pump, the housing, tubes and pipes are one unit. After you have all the hoses disconnected there are only 6 bolts that hold the assembly to the front of the motor. I actually did this right after removing the upper shroud half, the belt and the fan. It'll dribble a lot of coolant for a long time. At this point I took a break and let it drip for a while.

 

 

 

With the water pump assembly off you have to remove the timing cover. Most of the 8 or so screws in the front of accessible with a socket but one sits slightly behind the AC compressor bracket. The AC compressor bracket is kind of a pain to remove as the compressor appears to have to come off first, then the bracket so I just took that one bolt out with a wrench. It wasn't a big deal and there's plenty of clearance to get it out with the AC compressor and bracket still on the motor. If you're going to soak the timing cover you'll probably want to replace the front main seal regardless if it's good or bad. Removing it to soak the cover and re installing it may cause you a leak down the road. The seals aren't that expensive so I'd replace it no matter what.

 

Before pulling the oil pump off you'll have to remove the oil pick up tube. There are two nuts that hold it to the oil deflector (windage tray) and one screw that holds it into the oil pump. With the timing cover, oil pan and the two retaining nuts off the oil pick up tube you'll now have access to the attaching bolt that holds the pick up tube to the oil pump. (The whole reason you have to pull the pan in the first place.) Remove the two nuts and one bolt and remove the oil pick up tube. There's an O-ring on the pick up tube, mine was very dried out and brittle. I didn't notice any cracks in it at the time but it's possible. I didn't expect it to be that brittle and actually broke it in two when I tried to roll it off the end of the tube. If there's a crack in that O-ring, that could be the cause of lost oil pressure and could possibly have been the cause on this one. At this point I had it this far apart, the pump was already purchased. It wouldn't have been a good idea to just put a new O-ring on and hope for the best.

 

There are only four bolts holding the oil pump to the front of the block. There are no gaskets or O-rings, other than the one on the pick up tube. The pump is driven my notches on the inside diameter of the drive gear that engages with corresponding notches on the lower timing gear. It'll only go on one way so don't worry about putting it on wrong. If it fits over the snout, it's right.

 

Install the new oil pump using the four bolts. I didn't have handy access to torque specs for those bolts. Just use common sense, they need to be tight but you don't have to put 80 ft lbs of torque on them either. I'm guessing 35 45 ft lbs of torque would have been the spec. I just snugged them all, went around and around snugging a little more until they were good and tight.

 

Put the timing cover back on next and then the oil pan. It doesn't matter if you put the water pump back on next or the main pulley. My timing cover gasket set came with both paper water pump gaskets and metal ones with embedded O-rings. I think the O-ring type is far superior and chose those. Don't forget to put a little oil on the front main seal before putting the main pulley back on. Smearing a little oil on the hub where it engages the seal would probably do just as well, I do a little of both. Again, I had to tap the pulley on far enough to get the threads to engage and used the hold bolt to drive it on. I oil up the inside face of the bolt and a little on the bore to make sure it slides easily. Oil will take up clearance so maybe a little WD would be better as a lubricant just to get the hub to slide over the snout. In this case it's a pretty loose fit so it probably doesn't matter what you use. After the Pulley was all the way on I ran the bolt back out, cleaned it up and applied a little BLUE loc-tite to the threads and ran it back in. I don't know what the torque spec is on that but it's gotta be tight! I ran it in as tight as my beefy impact would take it. I'd be a little concerned about doing that part with hand tools. Without a way to hold the motor it would be tricky getting that bolt tight enough. I guess you'd have to remove the torque converter cover and hold the ring gear teeth with a pry bar while cranking it tight. Whatever method you use, make sure it's good and tight.

 

Now put the oil pan back on, again, not sure of the torque, remember those two skinny bolts, be careful not to snap them. I'm a bit anal about going around and around and around snugging just a little at a time. The pan is aluminum and would be fairly easy to crack if you tightened one area too much at once. Just be patient and do it evenly and work your way around. Torque specs are far less important than evenness. Of course they do have to be tight enough just don't over tighten them. Replace the wire retainer in the front and on the passenger side. Replace the cross member or rock guard or whatever that is.

 

Next comes the water pump assembly, 6 bolts, tighten them evenly, good and snug. Feel free to go by torque specs if you want, I just make sure they're good and tight but not over tightened. As long as I've been doing this I can usually come within two ft lbs of the torque wrench anyway. I often only use it on critical stuff like head bolts, rod bolts, main bolts etc. Some plastic intakes need to be very evenly torqued and are only about 15 inch pounds. That's one exception there but most of the time I'm fine with just going by feel.

 

After the water pump is back on set the lower half of the fan shroud back in and put the belts back on (or vise versa), spin the fan back on and tighten it by whatever method you choose. I use the air chisel method. I don't use loc-tite on fans but I make damn sure they're on there really tight with the air chisel. If you're doing it by hand you probably want to use loc-tite. Now put the upper half of the fan shroud back on.

 

Replace all your hoses and refill your fluids. Unless you're starting with a freshly rebuilt engine I don't see a need in pre-oiling. You've really done little more than an oil change in that regard. Replace your air intake hose, belts etc. At this point you're just putting stuff back on till you run out of parts. Put on your new oil filter, fill it up with oil first of course, add the rest of that quart and 4 more and after fire up you'll need to add yet one more. Total of 6 on this engine. I assume the 4 x 4 models use the same oil pan so the capacity should be the same but double check.

 

Heat cycle it a few times to let air burp out of the cooling system and you should be good to go.

 

It's been a long time since I've done one of these write ups so feel free to let me know if I've forgotten anything. I didn't take any pictures along the way as I I really wasn't planning on doing a how-to write up. Now I wish I had.

 

Good luck,

 

Wayne

[txab]

[GPGuy]

Good write up.

[jaded13640]

Thank you, to you both.

 

I hope it's useful but I'm afraid that since so many of these trucks are 4 x 4 it will only be of limited usefulness.

I'm glad this one wasn't. If it was I don't know that I would have agreed to the job. I probably would have just dropped a used engine in it like he suggested in the first place.

 

Wayne

[GPGuy]

Hey if it can help even one person then your efforts weren't in vein.

[jaded13640]

Well, of course you're right. my point is that so few are not 4 x 4 that it might literally be ONE PERSON. LOL

 

But thank you for the encouragement. And your right, most of the information applies. And as I said in the write up, if it's a 4 x 4 then you've got two choices. pull the motor or drop the axle.

 

Wayne

[BigBurb2500]

In the middle of doing an Oil pump on my 4x4 6.0 suburban right now. Front differential had to be moved out of the way in order to remove oil pan.

Tried to cheat it and just take front cover off then wiggle a magnet in there and undo the pick up tube bolt but that went horribly and I dropped a wrench into my oil pan forcing me to take it off.

If you remove differential from its mounts and support it with a trans jack you can move it around enough to remove and reinstall oil pan without dropping the entire differential out of truck, which requires a lot of wiggling and its a real pain.

Wish I would have started out doing the procedure this way would have made the job much quicker.