Diesel Place banner

My Upfit Build Story

Info: 
40K views 129 replies 24 participants last post by  DMAX-ATTY 
#1 · (Edited)
For a long time now I've been meaning to write up at least the highlights of my build, as it is to my knowledge the only OEM/like operational 2008+ M.Y. Escalade with a Duramax/Allison power train. I honestly don't get much forum time with the busyness of life right now but I'll try to put some of it together here out of my 500+ picture archive and videos of the project.

Mentally this project started about 17 yrs ago when GM launched the Duramax pickup. As the youngest of 8 kids and always having an absolute blast with my siblings I knew that someday I would likely have more kids of my own than could fit in a pickup and I just hoped that GM would make a "Duraburb" by the time I reached that stage. So, here I am today with a beautiful wife, 5 kids and a trailer chucked full of camp gear toys etc.

My wife finally gave her blessing to this project a few years ago when we were towing our 12,000# trailer up a 10% grade in the Bighorn mountains in first gear and the the ole 6.0 Escalade was barely keeping up.

Taching redline the whole way up the mtn she looked at me with a concerned look on her face and said "are we going to make it?" I said "I hope so... We really need a diesel suburban", her reply was "then do it!"
 
See less See more
1
#2 · (Edited)
I must admit my 6.0L escalades have been impressive machines to have clocked nearly 200,000 miles EACH and stood up to the abuse of a family of 7 and towing 150% of specified capacity for tens of thousands of miles. Here is what the rear tires of a 10bolt rear end look like after towing thousands of miles with nearly 2,000# of tongue weight, 7 people and trunk full of junk [emoji16]


And a few other pics of me abusing my old 6.0 Escalades.


Rzr1000, 4x 500cc dirtbikes, 1 kids bike, Brute Force quad and a junk load of coolers, camp gear, water, stoves, cooking iron, propane tanks and other gear packed in between and in the v nose... No wonder the tongue was 2,000#. I load up differently now.

Yes, we are towing a trailer with 5 snowmobiles and my mother in law's Lexus up Logan canyon in a blizzard.


The ole hitch pin hole is stretched and all worbled out from getting worked by the 30' trailer.
 
#3 · (Edited)
With the wife's blessing, I set out to procure a newer SUV and donor Dmax in hopes to remedy all of the above problems. I originally wanted a GMT 900 Yukon XL Denali, because I actually prefer that exterior to the Escalade, but I do like the fit and finish of the escalade interior much better. After test driving several Yukon Denali I was quite disappointed and discouraged by the ride quality. None of them seemed half as smooth or quiet as my old GMT 800 escalades. I began to believe that's just how the 900 series platform was and didn't expect anything better from an escalade because they are basically the same vehicle right? Well I finally decided to go test drive a 900 series Escalade and I could not believe the difference in ride quality, even thought the escalade had almost 100,000 more miles on it than the Denali's I had tested! After much research I discovered the escalades have and extra RPO for "insulation pkg" that to my knowledge is not offered by GMC, I also suspect the suspension tuning is a bit different in the Escalade even though they use the same magna-ride shocks. So I ended up buying a super clean 1 owner 2008 Escalade ESV with pretty high miles, and searched several more months for a low mileage Duramax. Finally got both vehicles and could begin the project.

Went through 2 trailer tires on the way home, but I must admit, this 6.2L Escalade towed that truck back from the auction so much better than I expected, I wondered if I should even do the conversion!
"I'm already this far in I might as well finish it! Right!?" (These words haunted me at several points throughout the project and I often thought... I should have just sent this thing to DuraBurb!)

Note: 2008 Escalade ESV 180,000 miles,
2009 Silverado HD 51,000 miles.
 
#4 ·
nice find on the duramax
 
#5 ·
So very much the same story that started my Frankenstein. I've never looked back. After almost 5 years, it's the best Suburban of the 4 that I've owned. Over a hundred thousand miles with no end in sight. A very capable rig.
This year we've used it to haul a enclosed trailer many times to the 10k elevation in the west Spanish Peaks of Colorado.
 
#6 · (Edited)
Both vehicles are finally at the shop, and the tear down begins. We spent a day carefully getting motor/trans out of both cars, taking notes and measurements and prepping for the project in its entirety.

As usual when I dig into a project like this my mind spools up in overdrive and starts thinking of all the cool/trick stuff I'd like to do, and I really have to cross check myself to make sure I'm not getting stupid with it all and too far off the mark.

I decided that everything I would do to this vehicle had to efficiently and effectively contribute to at least one of my three purpose built objectives I call my three "C's", Capability, Comfort and Class.

By nature I'm a perfectionist and am my own worst critic. I expect more out of myself than anyone else, so I just can't allow corners to be cut and am intolerant of less than professional work. Everything I do must be better than OEM in strength, longevity and function. Especially since this purpose built SUV will be carrying my family of 7 down the road at freeway speeds with often a 12,000+# trailer in tow, so it has to be perfect and perfectly safe.
 
#7 ·
I'll add the comfortable power and performance that can handle just about anything so gracefully.
Longhorse, where do you call home?
 
#8 ·
Nice adds testdrive. I'm just boarding a flight to my next business meeting and have a minute to respond. I live in Wyoming, so plenty of hills and headwinds. I'm still getting used the smooth and subtle power/torque of the duramax. The other day I was between towns and got stuck behind a large gang of motorcycles going 65. The speed limit is 70 and it was still about 53 miles to the next town and I didn't want to follow them for that long. So I pulled out to pass and about halfway through this tight knit gang an incoming car crests the horizon. With no space to filter in with the cyclists I mashed the throttle to finish the pass in the next mile. By the time I pulled in front of the lead biker I looked down at my Gauges and I was going 130mph!!! And 3,000rpm! I couldn't believe it because this thing is so smooth, quiet and the power is so consistent you don't get the sensation that you are accelerating much. 130 isn't much for a sports car, but for an 8,000# SUV!

I have to really watch my gauges to stay out of trouble!
 
#9 · (Edited)
I am watching the story progress with great anticipation. I have 6 kids, 2 dogs, the wife and a 14,000 lb trailer I have been towing for 9 years with by Duramax powered Yukon XL. I could not be happier(except for the 8mpg towing) with my truck all of these years. We have put on more than 75,000 miles and have only been stranded 1 time with a missing belt idler pulley. Luckily I had my Jetta in the Toy Hauler to make a run into Denver for parts. As you have very well seen, this is one of the best vehicles you will ever own and you have the pleasure of saying you built it yourself. Welcome to the club of "Happiest Driver Ever".


PS I left my limiters in place so I stop at 90mph, has saved my bacon many times.


PPS I would like to add you to the Duramax Suburban Brotherhood if you are interested.
 
  • Like
Reactions: Longhorse
#13 · (Edited)
PPS I would like to add you to the Duramax Suburban Brotherhood if you are interested.


Hey Boise, I grew up in SE Idaho, do you still live there? I'd be happy to join the Brotherhood, but you might want to watch the video below and decide whether you want me... this is probably the worst thing I've done to her yet. Producing this kind of smoke is expensive, so I probably won't do it again. Make sure you all get my $'s worth and watch it again on a bigger screen with some good speakers so you can hear what an LMM sounds like at 4500rpm!

https://youtu.be/PblqD8MY7CU
 
#10 ·
Very interested to see more of this. I'm sure you will answer in time, but are you using the 1500 frame from the Escalade?
 
#14 ·
Unfortunately I left Idaho in 2008 for Florida, then Illinois and now Nevada. I will work on getting you on the list.
 
#15 · (Edited)
Ok, now back to work on some of the details it took build this thing. With the body lifted and engine out I wanted precise measurements of the centers of the body mounts for a reverse rake body lift. The gmt 800 blocks wont work because the the 900 platform has the hitch (part of the frame) poking through the rear bumper cover (attached to the body). I took that into account and started the measurements from the appropriate "ground zero" location so it would have OEM fit and finish. Professional frame measurement tools came in handy for this, borrowed from my brothers frame rack/equipment. A few pages of Trigonometry calculated out to the tenthousandth and I had my block dimensions. I had another brother lathe these out of High Density polymer.


Now to figure out motor mounts that would position the motor in the proper location relative to fire wall/radiator, front axle/ hood clearance. The LMM is 4" taller than the L92 that came out and probably about 4" bigger in every direction.



I already knew the oil pan would need a mod to fit around the 1/2T front axle. I'm not sure how Eric got away with a single cut out on his unless it was one big swath. I opted to do a double stepped cut out to maintain as much oil capacity as possible and conform to the shape of the axle with about 1" clearance on each surface, and also to keep the OEM oil level sensor location and bracket as pictured in the pan below.

Sand blasted and double step cut.


With a double step mod there is potential for a lot seams=potential leaks which is not acceptable to me, so I designed a one piece fill in that would only have one perimeter seam and one internal seam to Tig weld. The internal seam on mine is overlapped and shorter than it would have been had I done a single step cut. Minimal chance for leaks.

https://vimeo.com/187288943
Let me know if this video doesn't work since it's not on YouTube.



The oil level bracket needed to be spot drilled on the top and temporarily pulled out of the way so I could tig the entire perimeter on the inside. I also tig welded the out side.


So long till next time.
 
#17 ·
Thanks Dave, The oil pan mod was a little tricky. As you can see from the video, it took me 4 times of adjusting dimensions on the pan filler piece to get it where I was happy. It's challenging to get one piece of metal bend in that many directions just perfect. My buddies jig table helped allot!
 
#18 ·
Yeah, I've got 4 hunks of twisted metal trying various techniques to make the lower mount for the front diff for my truck (I'm making it 4wd). Finally gave up on bending 1/4" steel with the equipment I've got (don't seem to have the skill/knack/knowledge to get it hot enough to bend, but not too hot to weaken it) and went with just cutting up 1/4" plate and welding it into the right shape.
 
#21 ·
After seeing your thread, my mind has been racing with combining 3 trucks to make the ultimate (at least for me).

1) GMT900 Escalade ESV, something with high miles but good body and interior
2) GMT900 Sub/Yukon XL, preferably something that was rolled, would basically only use the frame, and would keep costs down
3) GMT900 Duramax donor, again preferably something that was rear ended or rolled.

Just have convince the wife it is something that we/she can't live without haha.

Had also thought about the same swaps but with an EXT instead of ESV. My wife did love my Avalanche when I had that.
 
#24 ·
After seeing your thread, my mind has been racing with combining 3 trucks to make the ultimate (at least for me).

1) GMT900 Escalade ESV, something with high miles but good body and interior
2) GMT900 Sub/Yukon XL, preferably something that was rolled, would basically only use the frame, and would keep costs down
3) GMT900 Duramax donor, again preferably something that was rear ended or rolled.


I've had similar thoughts about taking the body of a 2016 or 17 Escalade ESV and putting it on a fleet 1T suburban chassis with 2017 Dmax power train. Maybe in due time I'll tackle that project, but I don't have $190K kicking around at the moment.
 
#22 · (Edited)
Sorry for any typos from my iphone's auto correct.

With the final version of motor mounts done, oil pan finished and retaining the OEM internal oil level sensor and bracket location, new front diff in place and wired for the 4x4 actuator that the Escalade never had, brand new starter motor on the LMM, PPE high flow exhaust manifolds and 30% larger up pipes with thicker tubing and aviation grade bellows (I think PPE makes the best designed pre turbo exhaust), turbo blanket on the exhaust turbine housing with the original shield bolted over top, triple wrapped diamond eye down pipe, (lots of insulation for noise reduction as well as keeping heat in the exhaust system where it belongs). New glow plugs, new serpentine belt, tensioner, and idler pulleys.

It's finally time to drop the LMM/Allison in for the last time!

Custom motor mount brackets for the 1/2T chassis for optimal engine location.


Oh yeah, I also trimmed the passenger side motor perch so the starter could be serviced in the future if needed, and reinforced the perch with 1/4" steel insert ergonomically designed so a socket can get to the mounting nuts beneath if needed (hence the U shaped holes in the plate to be welded in.


Finished oil pan


Turbo Blanket


PPE Pre turbo Exhaust


You can see how nice and smooth these manifolds will flow (pre threaded cast bung for EGT probe is nice too. These up pipes are thicker, stronger bellows, larger diameter and have a much more gradual turn than the OEMs that are a super tight 90 coming off the header. To date I still have not seen EGTs hotter than 1250 with it mashed on the 550HP tune! There is a new starter under that manifold too!


I wanted insulate or wrap the headers for a little comfort (quiet) and capability (keep the heat in where it belongs to help the turbo spool a little faster) but didn't want heat wrap right against the header it's self. So I devised this way of shielding the headers after I put the EGT probe in. Stainless steel tiesto keep these heat stand-offs in place.


Then I bought some of this foil backed insulation and cut it accordingly to shell around the headers.


This what my custom heat shield/insulator/acoustic suppressor looks like now. I used more stainless steel zip ties to secure it.


For some reason I just love this picture. Maybe because this was a big milestone in being confident that the powertrain is in the exact right place after painstakingly remeasuring, recalculating and readjusting in fine increments all the geometric data points it took arrive here. It's a unique view with interesting lighting. I suppose this is about what the center passenger of the rear row would see through the middle captain chairs while driving down the road if the body and interior were see through.

It's a good view of the triple wrapped down pipe too.
 
#23 ·
Great swap, man. Duramax power ,escalade comfort .
Did you swap gauges to Chevy cluster or retained escalade cluster. How did you place 4x4 switch ? Trim panel for 4x4 switch is slightly different on Silverado sierra from the one on escalade.

Sent from my SM-N900W8 using Tapatalk
 
#25 ·
In holding to my three "C's of Comfort, Capability and Class, I kept the classy Escalade cluster because I like it better than the GMC/Chevrolet style clusters, and I wanted to keep the interior looking just like Cadillac intended it to look. The only down side is there is no wait to start lamp (no big deal). I'll post some pics. Better yet, here is a video of the dash, if it will play, and sorry about the glare of the sun in the camera eye.

In this clip I was trying to observe peak boost and rail pressure, and thought I'd record it so I could watch where I was driving and not crash, since I was speeding a little bit. I had removed my FASS 150 pump because the heater probe somehow lost the end of the aluminum tube and it and some porcelain chunks got sucked up and jammed the pump (sending back to Fass under warranty, we'll see how well they treat me).

At the end of the film you will see the check engine light and "Reduced Power" message pop up as I think the CP3 just wasn't able to pull enough fuel at that rpm without the lift pump. (It threw a low rail pressure code when it did this)

https://vimeo.com/190415477
 
#29 ·
As I was looking to see where I left off on the build story, I remembered that some of you guys might like to know that I did not have to cut or reposition the transmission crossmember. I did elongate the holes, but there was still enough room to spin the nuts on the bottom side of the transmission mount, which is the same mount that is on the 6speed Escalade transmission.
 
#30 ·
Challenges I faced getting the duramax in the proper location included:
1) oil pan clearance around front diff and frame cradle. Upper oil pan clearance on steering rack/lines
2) maintaining proper fan/radiator clearance and making sure the cooling stack doesn't change angles when it's finally bolted to the fenders (more trig and math to make sure this would be SPOT ON PERFECT in the end)
3) maintaining appropriate fan/shroud relationships to engine,
4) getting the right mounting location and angle of motor mounts.
5) hood clearance
6) firewall clearance

During the process of getting the engine/trans in the absolute right location, I also re worked the steel transmission lines, configured the cooling stack with a new radiator, upper radiator support needs a little work to mesh perfectly with the Escalade under hood plastics etc.




A seasoned builder here told me to go with an LLY cooling stack in a 3/4T suburban core support, so I bought a brand new OEM 3/4T core support, but then learned the radiator would be smaller so I decided not to sacrifice cooling capacity for the easy way out.

This is a pic of the front with the larger LMM cooling stack.
 
#32 ·
With the Transmission securely bolted in I decided to pull the pan and see what kind of deal I got in the donor.
I think it looks petty clean, and am happy about that. While it was opened up, I decided to put a new filter screen inside.


Removed cover plate to see what it looks like, no PTO gear as expected on an LTZ crew cab.
 
#33 ·
With the power plant finally planted, its time to take the HD rear axle from leaf springs to 5link Cadillac air ride suspension. You may recall the rear tire wear picture earlier in my thread from too much weight on the 1/2 ton 10 bolt rear end causing it to bow under pressure and wear the inner shoulder of the tires right to the cords. That is exactly why I wanted the HD axle under me (adding to the capability category). I had a "professional" fabricator take both the 10 and 14 bolt rear axles to do the conversion for me with the understanding that this thing MUST BE OE SPEC and bolt right in, because this car will be carrying 7 people at freeway speeds with a 12K# trailer in tow, in all types of weather and on winding mountain roads. The next part is probably the most disappointing part of the build because after paying $1,000 I get my axles back, but every piece he welded on was not in the right location! The 14 bolt rear end is actually narrower than the 10 bolt and he did not take this into consideration when planning his design. I could have probably forced the trailing arms in ward and bolted it in but I'm not interested in wearing out bushings every 10,000 miles, or having a ride that dog-tracks in the rear and suspension that doesn't operate as designed! $1000 and a week of time wasted, only to then spend more $ on cutting disks, grinding wheels and sanding pads so I can now spend many more hours cutting/grinding/sanding just returning the axle to its original shape so I can start over!
I figured if I want this done right I'm going to have to do it my self! So I used many more pages of Trig and Geometry, calculating, cross checking, and cross calculating dimensions and angles beyond degree so I was sure it would be right. Now that I have all the data I need, I then had to spec it all out in autoCAD so I could make the necessary brackets beyond OE precision.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top