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I have it, shoot me an email and I'll send a copy [email protected]
I still driving the same suburban. Have not been very active on the forum, but I have been putting lots of miles on. Almost 350K miles and still going strong. How have you been doing up there in the cold country?
 

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Has anyone else had issues with the intercooler to engine boot being too short or not lining up properly? I am thinking it is because I am using the 8.1 core support... I had to cut some of the lower section out in order for the radiator to mount flush, but everything else seems to mount perfectly, except for that boot... If it were an inch longer it would work and only be off in alignment by a little.
 

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So the Suburban became driveable yesterday. I still have a couple small issues to finish up.
Fuel filler needs to be opened for the diesel pumps
ABS sensor was damaged on the donor vehicle
Airbag needs to be changed to the original clockspring from the suburban
Tap shift wire needs to be connected to the column harness - will be done with the clockspring
Need to wire in resistors to autoride system
Fuel gauge is waiting on the harness plug/adapter because I used the LB7 sending unit
Check engine light, I believe it is the P2160 code. There may be more now that I have put some miles on it.
I ordered some Bilstein 5160 shocks that hopefully will be here by the end of the week.

Wheel Tire Car Land vehicle Vehicle


So far, I absolutely love it.
 

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I'm new here. I have a 2003 Suburban 2500 6.0 gas, working on an LB7 swap. Is anyone still running the factory rear axle with a Duramax swap? or is that just a bad idea?
 

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I'm new here. I have a 2003 Suburban 2500 6.0 gas, working on an LB7 swap. Is anyone still running the factory rear axle with a Duramax swap? or is that just a bad idea?
I've got a 2008 with the stock 10.5" rear end. My conversion was complete in 2013 and I've put almost 100K on her. Best vehicle I've ever had. So versatile. Have fun with your project! Mark
 

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Thanks for the answers, I think mine would have the 9.5" but I'm not sure how to tell for sure yet. I am just wondering if there are others running that with the diesel. I would like to keep it in at least for now.
I also have a question on the dual tanks. I know there are different ways to work it. Did anyone just leave the rear tank alone?? and just lose a few gallons capacity? My thought is: it would still fill through that one and it would add a few gallons of capacity but it would never empty, just down to the large factory hose that connects the tanks... if that make sense.
 

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Thanks for the answers, I think mine would have the 9.5" but I'm not sure how to tell for sure yet. I am just wondering if there are others running that with the diesel. I would like to keep it in at least for now.
I also have a question on the dual tanks. I know there are different ways to work it. Did anyone just leave the rear tank alone?? and just lose a few gallons capacity? My thought is: it would still fill through that one and it would add a few gallons of capacity but it would never empty, just down to the large factory hose that connects the tanks... if that make sense.
If it were gasoline I would not recommend ignoring the rear tank. Diesel is quite a bit more stable though. I still wouldn't ignore it, if you don't mind the diminished capacity then remove the tank and extend or replace the filler hoses with a half ton suburban with a single tank.

I am still working through the issues I am having with the fuel level sender and rear tank on my own project, it's been low on my priority list so far.

For your rear axle, I believe the 9.5 came in the 6.0 subs and the 10.5 came with the 8.1 subs. I have heard of people putting some decent power through the 9.5 without any issues, my luck wouldn't be trustworthy though. I broke a 10 bolt with a 4.8 in my Silverado... I swapped to the 11.5 from the donor truck as much as anything for the 3.73 gears instead of the 4.10's I had.
 

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Discussion Starter · #1,031 ·
The 2500 suburban should have come with the 10.5" 14-bolt semi-floater which is good for towing up to 12,000lbs. The 9.5" is fine if you never plan on towing.
As for fuel tanks you can connect the 2 tanks with a gravity feed hose and just ignore the sender in the rear tank. You retain the 38 gallon total(I can only use 35 in mine) and still have fuel level gauge that shows empty correctly(as me how I know). For me the gauge shows full until after the first 250 miles then it starts dropping.

PS. I am picking up a 2009 to start the adventure over again, going to put up the original for sale. Has been a great rig for 15 years.
 

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OK, so far I have almost everything working perfectly. I still have a leak in my AC system that I need to track down, but haven't spent any time on it yet.

My biggest issues have been in the fuel system. Running a lift pump may not be the best idea. It seems to empty the reservoir for the sending unit and since it reintroduces the fuel at the filler hose in between the tanks, I am only getting 19 gallons before I run out of fuel. I put a bulkhead connector in the top of the tank with the return hose from the lift pump to feed back into the reservoir, so we will see if that works.

I also have not gotten the dual tanks to work properly. First I forgot to connect the electrical connector when I re-installed the tank after cleaning it out, easy fix. Now the fuel pump in the rear tank is not engaging. Looking through the wiring diagrams the fuel secondary fuel pump has no power to the coil unless the primary pump is on and since there is nor primary pump... So I turned the primary pump relay into a jumper and now have coil power to the relay, but no ground signal from the ECM. I noticed the wiring colors are different from the ECM pin and the relay, so somewhere in the harness there is a color change, but I haven't traced it yet. I'm not even sure the ECM is sending the signal. The fuel pump does work if I provide a ground to the relay though.

Also my tune should be set up for the dual tanks. Any suggestions?
 

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Just finishing up my LB7 into 2003 Suburban. Did you get anything figured out for the dual tanks? I decided to just delete my rear tank. I don't know if I will regret it or not but it made it easy...
 

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Also, another thing I wanted to ask: did anyone ever leave out the fuel cooler for an LB7 and just run the return right back to the tank? I don't think the newer Duramax engines have a fuel cooler so I don't know how important it is.
 

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I think I just got the issue fixed for the rear tank yesterday. The only thing I really needed to do was bypass the fuel pump relay in the fuse box. The ECM is seems to be powering the rear pump now. The tune I am running is set up for it as well. I think a lot of my problem was the lift pump sucking the sending unit dry once the fuel level was below the reservoir.

I decided to run the fuel cooler. I figure it is in the return line so it is really not there to cool the fuel from the tank it is to keep from heating up the fuel in the tank since the return fuel just came from the engine. In AZ I imagine it is pretty important.
 

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I still need to get my rear tank to work, been without it since day one. Other non-related projects have kept me from getting it going. But this coming spring/summer will likely have time to do so.

I didn't install the cooler on my LBZ, haven't had any issues. But I don't tow much, and it doesn't get as hot here in MN as it does in AZ for example. I do plan to put a log-style cooler in there someday, and I've even thought to wrap the cooler in the winter, or valve it to be able to bypass it in winter, so that it does give some heating to the fuel in the tank in our colder months.
 

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2001 Yukon XL LB7
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I am doing the swap into a 01 yukon xl the donor is a 01 as well

there is a connector which is only occupied by purple and yellow wires there is no connector present on the yukon for this what its for and what do i do with it
 

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2001 3500 Duramax
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I am in the process of swapping an 02 lb7 into an 01 2500 burb, so far all my wiring has been redone in the c100 connector except, the drk green wire for the recirculation door circuit 1614. Any idea where i need to pull that wire from or do i have to run the wire myself? also there are three wires i pulled out of the c100 plug i dont believe i use, or do i? theyre for the variable effort steering actuator, circuits 1294, 1295, and lastly the ignition 3 voltage. I also dont know if i need to use my entire steering column out of the donor truck or if i can keep the one in the suburban. Thank you all in advance.
 
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