M1007 - CUCV Suburban Clone Build Thread

[Barrman]

I think they had a few bad batches. 3 of my trucks have 10 year old 60G’s in them and work perfect. I’m on my 3rd set now in 5 years with the Cowdog.

 

[Keith_J]

The ones that burned out were in it since liberated from Ft. McCoy in 2012. AC 13Gs. I had purchased Duratherms that year from Rockauto as they were on sale for under 6 dollars each. Zero defects so far.

 

[Barrman]

I towed the M715 behind the Cowdog to the Rally last weekend. Here is part 1 and 2 of a video I made during the drive showing the Compushift display, boost gauge, EGT gauge and water/meth controller:

I couldn’t get it in the video. But, my coolant temps would rise to 215°-217°. Then my Heath diesel fan clutch would lock up, make noises like a turbo prop plane was landing on my roof and the temps would drop like a rock below 208° within 30 seconds of lock up. I was very pleased with the Snow Performance water injection and Heath Diesel fan, fan clutch and water pump.

 

[chevyguy1976]

I have the O’Reilly’s 1987 Suburban condenser. It is cross flow and fit. However, I have a CUCV front valence so I have to assume it is the same as the civilian truck for condenser mounts. I hate to assume though.

85° is the cut off for between super cold front and rear to around 50 in the front and still cold in the rear. above 95 and I am happy to get below 55 front and rear. I think my problem is caused by a compressor that is just a bit too small. It is a Sanden 508 which fit my serpentine mount. 8.4 cubic inches. The stock GM unit for the dual ac Suburban is over 10 cubic inches. My high side pressure has never been as high by a wide margin as what the book says it should be. Another option I have yet to explore is a possibly partially failed expansion valve at the rear. If it is not closing all the way it could keep the refrigerant flowing faster to the rear and not building psi at the front which is where the pressures are taken. It works good enough that I have put this issue on the back burner for now.

I did get to pretty much finish my passenger side swing away carrier in August.

View attachment 846299View attachment 846300

Sweet set up.

 

[Barrman]

I have written a lot about injection pump timing in this thread with promises of a video of how to read the timing. I finally got around to making such a video:

 

[Sharecropper]

Thanks for your posts and videos. My completely stock 6.2 cranks perfectly and runs best & strongest with the timing advanced the thickness of the line like you have your M1009 set. When I install the supercharged P400, well, setting that timing will be an adventure in itself. I will start with the marks aligned, and then ease it forward slowly and gradually until it sounds and runs the best. Then I will see where the mark is on the flywheel with my DTI 3300 and record it in the truck manual.

 

[srs78]

Barrman, Quick question on your tires and cutting of the fenders.....I just finished installing H3 brakes and Method 8.5x17" 0mm offset on my 1991 Suburban...V1500, 5.7 TBI, NP241, 3.42 gears. The tires are very close to the fenders on a turn....like 3/8" clearance. The tires are Nitto Terra Grappler G2 Lt285/75/R17.... 33.8x11.5". Can you show a picture of how you cut the fenders to clear your tires? I have no lift from factory at this time and would like to stay as close to factory as I can but still need the tires not to rub in turns and especially when stressed. I also don't really want to cut the fenders but would rather do that then to add lift. I think in one of your entries you spoke of installing the three leaf M1009 front springs vs the two leaf the V1500 has and had no change in lift. Did I read that right? I have been thinking about putting M1009 springs in my Burb but "no change in lift" would not help with my clearance problem.
Also....You stated that the (ORD??) reverse shackle change on your M1007 helped the ride. Can you comment more on that.

By the way, I loved your build of your Suburban and have just read it in its entirety in the last 2 days. It took a long time but very enjoyable. I drove a M1009 for 18 years as a daily driver and sold it a few years back when the kids started complaining of the pain to get in the back and the no A/C issue. I bought a 1988 V10 and then a 1991 V1500 both with the 5.7 TBI but I have totally missed my 6.2. I am slowly building up the 91 into a M1007. Eventually I want to change it to a manual and diesel but not today. I do have a set on M1009 bumpers and a brush guard ready to go on but really like the M1008 bumper you put on the back of yours so that is another dilemma.

Thanks

ballencd
View attachment 829916

May I share a couple of photos of my 1987 “M1007”. It’s a gasser though.

 

[Mullaney]

May I share a couple of photos of my 1987 “M1007”. It’s a gasser though.

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Nice looking truck!!

 

[gimpyrobb]

Ive been off site for a bit. Where is the info on your trans controller?

 

[Barrman]

What do you want to know Chis? It is a Compushift without the bluetooth option since it is now 5 years old:

Transmission Controllers

Easily setup your COMPUSHIFT transmission controller using your smart phone – including shift points, firmness and speed. With full plug and play connectors to make connection easy.

www.hgmelectronics.com

 

[Another Ahab]

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Nice looking truck!!

Yeah! Looks REAL nice!!

 

[srs78]

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Nice looking truck!!

Thanks!

 

[srs78]

Yeah! Looks REAL nice!!

Thanks!

 

[Barrman]

Jennifer and I have spent the last week and a half driving the Cowdog around and over the mountains of Colorado. I never really appreciated what no engine braking with the 4L80E meant until this trip since I am a stupid flatlander type. I now need to move away from stock brakes and go race truck slotted and drilled rotors and better pads it seems. Maybe rear disc as well. But if I do that switching over to a 14 bolt full floater might make more sense.

I have combined our pictures and videos into a daily log of our trip. Subscribe if you like them. I have performance brake parts to buy. Here is the first one:

 

[Sharecropper]

Thanks for posting. I watched every video. Quite an adventure! Sounds like the Cowdog did good.

Regarding brakes, an upgrade is on my list as well. I've already installed rear discs and removed the load equalizer. The truck stops on a dime going forward or backward, even when wet. But I plan on pulling a trailer after the P400 goes in, and would like stronger brakes. I thought I would reach out to Wildwood for advice whenever I get to that point. I will be watching to see what you do.

Again, thanks for your contribution to this site.

 

[Barrman]

Thanks for watching. The Cowdog did do good and I still need to get 1300 miles home with it. But, after the first 90 miles it will all be a gentle decent of almost 5,000 feet.

 

[Keith_J]

I noticed the brake dust on those wheels. You have something not correct if the transmission is freewheeling. The hydraulic pump driven off the engine (through the torque converter shell) delivers plenty pressure and volume at 600 RPM to engage clutches and bands.

The torque converter will flow power in reverse with the clutch disengaged so that is no issue.
I would suspect the controller is missing a logic step for low TPS and OSS showing higher speed than ISS and Tachometer.

 

[Another Ahab]

Jennifer and I have spent the last week and a half driving the Cowdog around and over the mountains of Colorado. I never really appreciated what no engine braking with the 4L80E meant until this trip since I am a stupid flatlander type. I

First time I ever saw (or even heard) about "Runaway Truck Ramps" was when hitchhiking into Colorado (from Maryland) back in the 70's....

they're all over Colorado and they're for real.

 

[Barrman]

Keith, the 4L80E coast in over drive. If 1, 2 or 3 are manually selected it will bring the engine rpm up. But, with no throttle valve or exhaust brake. The diesel just revs but doesn’t really contribute to slowing my 7-8K pound truck on the steep grades. 1st selected would have the engine up to around 3,000 rpm and us rolling near 30 mph. Near as my research has shown. That is how the 6.5/4L80E behave.

 

[Mullaney]

First time I ever saw (or even heard) about "Runaway Truck Ramps" was when hitchhiking into Colorado (from Maryland) back in the 70's....

they're all over Colorado and they're for real.

.
Coming down the hill from Virginia on I-81 and eventually connecting with I-77, there are three "No BS" runaway truck ramps coming south. Coming down through Fancy Gap, the grade drops you down about 1500 feet in elevation for a six mile downhill run.

This is the first ramp: (At about 1 mile)



Second Ramp: (At about 3 miles)



3rd Ramp (At about 5 miles)



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This next picture shows the north bound lane about 150 feet down the hill - off to the left. It is gorgeous country up there...



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