2002 2500HD - Solid Axle Tow Rig

Happy to report that the new pyro is in...swapped it earlier while fueling up. EGTs are about 125 degrees lower at an empty cruise and down around 100 degrees while towing. Not bad! They also drop a lot quicker, which is nice. Sure, it's 900ish bucks that could have been spent elsewhere, but it was definitely a worthwhile upgrade to me!
 
Yep. That's it. I can't imagine how much they might suck to do on a truck that's still IFS...then again, it's probably easier since you can get to all of the manifold bolts without a coilover tower in the way.

Not sure it'd be worth it with a stock turbo, but with this 67mm drop in, EGTs are back to how they were stock and it tows almost as good as stock for a bigger turbo.
 
I decided it was time for some better looking tail lights and always like the black trim around the ones that came on duallies. So...I made it happen. Looks much newer and they're much brighter now. Now bad for 100 bucks. I got some new fog lights too. One of the lenses fell off a few years ago. I think they'll be here tomorrow. Probably time for a new third brake light too.

Oh, and I clay barred and waxed it the weekend before last. It's smooooth as silk now and shines up pretty damn good for an 18 year old truck with 293k miles on it.

20200506_193320.jpg

20200506_194556.jpg
 
It's just that big ol' wide ass that makes them look fatter :D
 
Never been much of a fan of painting plastics...plus I don't want to spend more on the painting and tinting than I did the lights themselves
 
Last edited:
Nothing to speak of lately, just been driving it and racking up some miles. I'm 360 miles away from rolling 300,000. Still knocking down a solid 17 mpg average.

Oh wait...I did put new window motor/regulator assemblies in the front doors last weekend. They're much quieter, faster, and more powerful. The passenger's side had broken the wire so it didn't even work.

It'll soon be time to change the oil again and send in another analysis. This go 'round has 20,000 miles on it. I'd imagine in the not toooo distant future it'll be time to put the new set of tires on. I've had a set of 295/70-17 Cooper AT3 XLTs sitting in my shop since last August. These ST Maxxes have been surprising me though. 48,500 miles on them and looking like I may get 55,000 or so before they're gone. No complaints here!
 
They probably had another 10,000 left in them if I had run them bald, but I got tired of listening to the old tires and swapped the new ones on. I know it's irrelevant in an LB7 with 5" exhaust, but damn, these things are quiet!

Took off the old Cooper ST Maxx with just over 55k on them, so I have high hopes for these too. Plus, it's nice to get the tire height back and have my speedometer correct again. They're not quite as squared off at the shoulder and look a little narrower, so they make the truck look a hair taller to me. I like it!

Rolling along at 307,500 miles now. The dash freaked out on me yesterday, but it's back to normal after leaving the batteries unhooked for a few minutes.

Also, happy to report that there's not a damn thing wrong with the AC :D

20200815_181009.jpg


20200815_181116.jpg


20200815_181216.jpg


20200815_181228.jpg


20200815_181202.jpg
 
Last edited:
Nothing much to report. Drove it up to the mountains this weekend and knocked out a solid 18.5 mpg on the way back running 80 or better.

Took a picture of it in the parking lot of Rocky's Hot Chicken Shack the first time I went :D

Up to 312,250 ish miles. Hoping to get the transmission built next year some time, but we'll see. That'll make it a completely different truck.

20201008_214735.jpg
 
Nothing new to report. I did just roll over 313,000 miles though. Still running strong. I've developed a little bit of a leak around the steering box input shaft. That's a bit of a bummer as it's a 900 dollar PSC box and out of warranty, of course. It's had a bit of a popping sound for a while, so it'll probably just get replaced. When that happens, I'll likely throw on a PSC power steering pump too so I have some more steering force. I'm still on the fence about adding hydro assist to it, but I feel like once I add a front locker or limited slip, I will definitely be glad that I did. Honestly just thinking of Detroit True Tracs since I tow a lot. Then again, I could do ARBs, but that's a whole different can of worms. I have kinda always wanted to have onboard air though...

If I can get some things paid off, I'm planning to have the transmission built some time next year so I can really start having some fun with it.
 
Haven't done anything fun to this lately, so I decided to change that.

One of the projects I've had in mind for a while is changing the oil cooler. With a little research, a 2020 Duramax L5P oil cooler will bolt right on and has 20 cooling plates vs 10 like the ones in an LB7. 11-19 (IIRC) LML and early L5P used a 14 plate stack. It's also MUCH cheaper. The cooler assembly, coolant elbow, and gasket between the assembly and elbow came to 240 bucks. Close to half what a stock replacement costs. I got the rest of the required gaskets and o rings for about 40 bucks. Still need to pick up a few new bolts since they're different lengths. The only other difference is they use an M22x1.5 oil filter thread instead of 13/16-16 like the 01-19s and the filter is a touch smaller, but no big deal. Eventually someone will find a larger filter that crosses over.

Since I'll need to change the oil anyway, I figured I'd splurge and replace the lower oil pan. PPE makes a nice one that adds another quart to the sump capacity and has a flat bottom so all of the oil actually drains out. It's just one of those things I wanted to do, so screw it...why not? It also has a threaded hole for an oil temp sending unit. That means my next project will be buying a temp sending unit, EAS expansion cable, and starter cable for my Edge CTS2 monitor. Then it will monitor and display oil temperature. Since the harness will adapt two sensors, I'm planning to get a pressure sending unit and let the CTS display oil pressure too. I want to nerd out and study the oil pressure vs temp with the new cooler. Ideally, I'd do a before and after, but screw it.

The last two oil samples I sent in had elevated sodium levels, but not elevated potassium nor any traces of coolant contamination. I figured changing the oil cooler wouldn't hurt and I wanted to try it out anyway, so screw it. It'll provide some tech for others that may be interested in the cooler upgrade as well. Plus, I post links to this thread all the time. I'm sure it drums up a lot of extra traffic for our site :D

Stay tuned for pictures, tech, and part numbers. This is going to be the most complicated oil change yall have ever seen!
 
Last edited:
Well, I ordered a few things.

- PPE hammered black finish oil pan
- 2020 L5P oil cooler -PN 12701592, replaced by 12706188
- Cooler Elbow - PN 12675428
- Elbow to Cooler Gasket - PN 12676826

I run Amsoil filters and their oil. Old filter was an EA052 and the new one is an EA011. Sump capacity is now 11 qts vs 10. I wish it was an even 12, but whatever, right?

Of course, the cooler, elbow, and gasket have to be ordered from GM because nobody has them in stock yet. Good news though...the cooler is 205-210 bucks, the elbow is 8-10, ans the gasket is 3-5. All of that depends on which online parts dealer you use.

I had ordered those three items (on Sunday) from GM Parts Warehouse. The total was 240.83 with shipping. I got an email today telling me the order was canceled. So I ordered from somewhere else, but they were nice enough to tell me the oil cooler part number was superceeded, they replaced it for me, and sent the order to GM. Looks like this process is on hold for a little bit. I want to do everything at once so I don't have to change the oil twice.

In the meantime, I had been thinking about my quarter tank fuel draw issue. I discovered that S&B makes a really nice 62 gallon replacement fuel tank. Guess who ordered one! Me...yeah, it was me. I hate stopping for fuel on the interstates. Diesel is 1.86 here, so...f it! It has a built in sump that draws right off the side of the tank and comes with everything needed for install...including a new sending unit assembly. It'll be badass to get over 1000 miles on a single tank of fuel!

62 Gallon Replacement Tank For 2001-2004 GM Duramax 6.6L, Crew Cab Short Bed

I took some pictures of the oil pan and other items I have for the oil cooler install that I'll include. I'm pretty jazzed about all of this. I'm hoping to get the fuel tank and have it installed before next Thursday. I have to go to Maryland for work and it'd be a nice maiden voyage. We'll see though.

Once the oil cooler and associated items arrive, I'll be changing the oil, putting on the new oil pan, swapping the oil cooler, rotating/balancing the tires, and changing the fuel filters on the lift pump. I will likely have to relocate the lift pump to make room for that big ass tank. It'll either need to go as far forward as possible or be relocated to the outside of the frame rail. We shall see!

The oil pan has a flat bottom and all of the oil can drain out. The drain plug is magnetic. "Supposed" to offer some extra cooling. Pretty straightforward though. Take the old one off, swap in the low oil float, and bolt the new one in place. It was one of those "just because" purchases. Although, it does have that 1/8th NPT hole for a temperature sender. Comes with some nice stainless SHCS. I went ahead and got a Mahle gasket and sealant kit for it. PPE sells them with a hammered black finish or raw aluminum. I thought the black one would be more aesthetically pleasing.

The various o rings and gaskets are for the oil cooler install. Only other thing I need are some different length 8x1.25mm bolts.

Then, obviously, you can see 11 qts of Amsoil, the Amsoil filter, the Baldwin fuel filter, and Baldwin water separator.

20201105_200136.jpg


20201105_200219.jpg


20201105_200253.jpg


20201105_200316.jpg


20201105_200336.jpg


20201105_200357.jpg


20201105_200411.jpg


20201105_200428.jpg



If the fuel tank comes in before my work trip, I'll get that installed. Otherwise, all of this will be on hold until I get the oil cooler stuff from GM.

If anybody needs more pics, info, or part numbers, feel free to ask!
 
The couple of fittings that I ordered from Summit are supposed to be here Tuesday and the fuel tank is supposed to be here on Wednesday. I leave Thursday for a work trip, so I may stay up late getting that done. I ordered a male 1/2" NPT to male -10 AN fitting for the tank. I already have a 90* female -10 AN to 1/2" hose barb fitting on the suction line from the tank, so it should just be a matter of drilling out the plastic behind the threads in the tank and running the suction line down to the side where the sump is located. I don't think moving my AirDog lift pump will prove to be very difficult either. All the way forward or flip it around on the outside of the frame rail. I'd just really like to have this tank in before I head out. Diesel is 1.86 here and it would be nice to not have to stop for fuel during the entire trip. I'd go ahead and change the fuel filter and water separator while I was at it. There's likely nothing in the tank since it's brand new, but you can never be too careful!

It'll probably be a few weeks before the parts from GM come in what with this virus crap going on. Still going to wait and do all of that stuff at once. Shouldn't be a big ordeal, although I'm ready to knock it out! On the bright side, this will give me time to go ahead and get the starter cable, adapter cable, and temp sending unit for my Edge CTS2 monitor before everything gets installed.

Btw, the 01-04 LB7 tank PN is 10-1023 and the 04-10 LLY, LBZ, and LMM tank PN is 10-1006 in case anyone is interested.


My mom never knows what to get me for Christmas, but I'm considering having my driver's seat upholstered. Hopefully she'll go for that :D
 
Much to my surprise, I got an email from GM Parts Direct this afternoon. My oil cooler, the coolant elbow, and gasket will be here tomorrow! That was much faster than I expected them to get it directly from GM. I'm stoked!

Coolant Elbow PN- 12675428 ($8.91)
Elbow to Cooler Gasket PN- 12676826 ($3.14)
2020 L5P Oil Cooler PN- 12706188 (Replaces Part Number 12701592) ($209.87)

GMPD is out of Winston-Salem, so there was like 20 bucks for tax and about the same for shipping.

Now I just need 2 gallons of coolant, or dump what I drain back in it, and I'll be ready to roll. It's going to make a mess, but that's what brake cleaner is for!

I'll post pics of the parts when they come in and I'll obviously take pics during installation.

As always, stay tuned for more :D
 
Can confirm that all of these part numbers are correct as I received the proper parts. I will likely do a link back to this build thread from the General Tech area like I did with the transfer case so it will make it easier to find for those who Google "2020 L5P Oil Cooler Upgrade". I found information on it, but nothing with definitive part numbers or pictures of what you ordered. I was astonished that the coolant elbow was only 10 bucks. The one for the previous generations is like 70 bucks. Plus, yall know how I love a good tech thread with lots of pictures :D
 
The last new, nifty thing I ordered showed up today!


Ha! Not any more! This is a HUUUGE bitch :D Note the thought that went in to the built-in sump and baffles with a threaded hole on the side of the tank for those of us with aftermarket lift pumps! There's even a molded slot to tuck the fuel line in to and run it up and over the tank. This is a really nice and well thought out product. I think they'll do quite well. Especially since every other tank like this is only 52 gallons.

Oh...it also comes with new tank straps thag are powder coated, a front crossmember/support since the tank is so long, a new sending unit o ring, new lock ring, and a really nice, aluminum topped, pickup assembly that has a new fuel level sending unit on it and a new float/arm to match the tank as wellnas clear the baffles around the sump. The only other thing they COULD include that they didn't are some 1/2 NPT to AN fittings. No big deal though. I'm sure everyone's setup is different and I ordered a 1/2 NPT to -10 AN fitting and a few 1/2" double barbed hose fittings from Summit just to make sure I had what I need and could extend a few of the AirDog fuel lines if need be. Still, a very very excellent product!

20201111_232944.jpg

20201111_232957.jpg


20201111_233009.jpg


20201111_232912.jpg


20201111_232924.jpg




Picked up one of S&B's new fuel tanks. 62 gallon capacity. Stock short bed tank is 26 gallons and I have an issue with the little rubber seal in the bottom of my fuel pickup cup and can only reliably draw about 19 gallons out of it. It's really annoying and I hate going to the gas station every couple of days. Now, with a 1000+ mile range, it'll be more like once a month. Plus, it's reallllly annoying on road trips or any time I'm hauling anything.

I'm leaving in the morning for Pax River, MD and was hoping to get this in the truck before I left, but I'll probably do it this Saturday or Sunday after I get back. It'd be really nice to up for 1.86 a gallon here and not have to get fuel until the middle of next week. Oh well...next time.

I can't wait to get back and get this thing bolted up in the truck! I am going to keep an eye on fuel temps with my Edge CTS2 monitor since the tank goes around the fuel cooler. I can always move it if there's not enough air flow across it...or add a fan to it.
 
Last edited:
Gawd dayum that's a big bitch! She ought to be a ton of fun to hoist up into her new home.
 
The tank itself isn't all that heavy, believe it or not. I'll probably go to the hobby shop though just so I can use a lift. I'll likely do the oil pan and new cooler while I'm at it. Oil pan first so I can let the RTV set up for a little bit while I do other stuff and before I fill it up with fresh oil.
 
Ah, memories of the good ol' days at the hobby shop. That is, before that tick turd Terry took it over.
 
He's long gone. Dave runs it now.
 
Back
Top