Duraburb Project

[klmore]

I've been taken a long hard look at your burb pictures and IMHO see those big tires are not centered in the wheel wells front or rear and the tires look like they would hit the body work over rough terrain unless of course the suspension is so stiff there is little or no travel so they'll never hit. Stiff suspension will beat the snot out of the vehicle and you over time.

Lots of lifts out there don't keep the frt/rear differential (s) in the proper location as in when you go up higher the diff moves forward at rear and rearward in front without proper fitment, the diff needs to be moved back so wheels are centered in wheels well.

If I remember right, 35" tires fit that vehicle w/o lift by using cutout fender flares. From here custom mods to front foot wells and rear wheel wells would allow 37's.

The Fabtech lift just drops the front diff in the same factory location. You are correct the front tires do hit. One of my flares is cracked now from that exact problem. In my opinion the front centerline needs to be moved forward 3/4" maybe more.

I have looked at the Offroad Unlimited SAS conversion kit which moves the front axle centerline forward, but it uses leaf springs and is very expensive. I really prefer the Pure Performance SAS kit. It uses the current Dodge AAM front axle and is much more cost effective. I did not use either of those kits due to my current slip yoke style transfer case. The diesel conversion will eliminate that issue so I suspect I will be installing a straight axle in the near future.

 

[TKSC01]

SAS on a burb

The Fabtech lift just drops the front diff in the same factory location. You are correct the front tires do hit. One of my flares is cracked now from that exact problem. In my opinion the front centerline needs to be moved forward 3/4" maybe more.

I have looked at the Offroad Unlimited SAS conversion kit which moves the front axle centerline forward, but it uses leaf springs and is very expensive. I really prefer the Pure Performance SAS kit. It uses the current Dodge AAM front axle and is much more cost effective. I did not use either of those kits due to my current slip yoke style transfer case. The diesel conversion will eliminate that issue so I suspect I will be installing a straight axle in the near future.

So dumb question but what year is your burb? I was under the impression that the newer burbs '00 and up were very sensor heavy and a SAS was a nightmare? Please help I am into this big time but didnt move forward with a burb yet becasue of that reason.

 

[locrwln]

I did not use either of those kits due to my current slip yoke style transfer case. The diesel conversion will eliminate that issue so I suspect I will be installing a straight axle in the near future.

Are you swapping in a 273 from a Ford or spending the money on getting the 263 slip yokes eliminated? The stock t-case in the donor truck will be slip yoked front and rear.

Jack

 

[Off Duty]

Subscribed:drool:

 

[happygilmore]

Me too!!

Hello Klmore,
I have My 2005 at Mr. Swansons shop right this second.
I got a look at Your convertible donor truck as I loaded My Yukon
under it when Herb (the driver) picked Mine Up. Good miles
on Your truck from what I understand. My donor had a little more
miles but, is also a LBZ it is the other one in Your video.
My Yukon had the 8.1 liter 496cid and it got
9 MPG empty , 7.6 pulling a light trailer and 8.4 cruising down the
Interstate. TERRIBLE!! I don't care how long it takes to pay for the
conversion in fuel cost I refused to take it to a gas pump ever again!!
It wasn't worth anything as a gasser and I have 5 children dog and friends
just like You. We are ALWAYS on the road and this vehicle was a must.
The Yukon was paid for and the only other viable diesel was an Excursion.
I have owned 3 Excursions and Loved everything but the ride , it was horrible
like riding in a truck. Also believe it or not alsmost died in Our last
one flipped 3 times no air bag , seat broke and almost killed Mysely and My
Wife no help from Ford on that one either!!
Can't wait to get the Yukon back its an 05 and loaded.
I have dealt with a lot of people in My Life and can tell You all
Eric has dedicated His Life to doing this , and is a VERY professional
knowledgable , and dependable Person that will go to ANY lengths to make
sure You are happy!!
I am having Him do some extras to help increase MPG which is My main
goal in doing this project. I Love tough looking 4x4's but, chose to put
some Michelin LT285/75R16/E with GreenX technology and are having them
nitrogen filled, (I know all about nitrogen so please don't comment) , I want
every chance , gimmick whatever I can get to help with MPG.
I figure if I am going to sacrifice My Tough look I might as well do all I can. This
tire has the LRR (least rolling resistance) of any I could find for My circumstance.
Anyway Klmore , nice post as I couldn't find any actual customer write ups on the
subject before I started. I do however have 120% confidence in Eric at Duraburb
and can't wait to test the Yukon. Good Luck, Happy

 

[FellowTraveler]

Sas

The Fabtech lift just drops the front diff in the same factory location. You are correct the front tires do hit. One of my flares is cracked now from that exact problem. In my opinion the front centerline needs to be moved forward 3/4" maybe more.

I have looked at the Offroad Unlimited SAS conversion kit which moves the front axle centerline forward, but it uses leaf springs and is very expensive. I really prefer the Pure Performance SAS kit. It uses the current Dodge AAM front axle and is much more cost effective. I did not use either of those kits due to my current slip yoke style transfer case. The diesel conversion will eliminate that issue so I suspect I will be installing a straight axle in the near future.

I'd consider the FORD hi-pinion front diff over most others.

If I remember right Dodge AMM diff uses the same carrier that the Burb 2500 IFS diff uses, however, the Dodge AMM has other issues "housing I think"? and research would be the best bet before installing one.

I've been mulling the idea of modifying the wheel wells and front foot wells on my burb to allow for 37" tires w/o lift a big project that more likely than not would require going to conventional hubs and bearings for easy PM.

Anyway, good luck with your project!

 

[klmore]

Sheet Metal

The front end was painted and packaged today.

 

[klmore]

Here it is all packaged up and ready for the transport to show up any minute.

 

[klmore]

So dumb question but what year is your burb? I was under the impression that the newer burbs '00 and up were very sensor heavy and a SAS was a nightmare? Please help I am into this big time but didnt move forward with a burb yet becasue of that reason.

The sensors are the easy part. That is one reason the Dodge AAM axle is so appealing. It uses all of the same ABS sensors as the GM IFS. To me the bigger issue is the slip yoke on the front of the transfer case. You have to pony up and go to a fixed yoke set up, which is why I haven't done this to date.

I will get the Duramax project wrapped up and I will go from there on the SAS conversion.

 

[klmore]

Are you swapping in a 273 from a Ford or spending the money on getting the 263 slip yokes eliminated? The stock t-case in the donor truck will be slip yoked front and rear.

Jack

I'm planning on working with the transfer case I have, but I'm going to have to do some more research on that. I want to put a couple of thousand miles on the Duramax conversion before I change any thing else. Is the 273 from the Ford a direct bolt in?

 

[klmore]

I'd consider the FORD hi-pinion front diff over most others.

If I remember right Dodge AMM diff uses the same carrier that the Burb 2500 IFS diff uses, however, the Dodge AMM has other issues "housing I think"? and research would be the best bet before installing one.

I've been mulling the idea of modifying the wheel wells and front foot wells on my burb to allow for 37" tires w/o lift a big project that more likely than not would require going to conventional hubs and bearings for easy PM.

Anyway, good luck with your project!

I was really wanting the high pinion Dana 60 from Dynatrac. They can install the tone ring for the ABS and it is really a bolt in deal other than the brackets being installed. The issue with that is the price. They want almost $8k just for the front axle. By the time I purchase the steering kit and other items it is $10k not installed.

 

[klmore]

Off it goes on the transport. I got lucky the driver was heading back to Florida and has no other stops. It should be there today or tomorrow at the latest.

 

[locrwln]

I'm planning on working with the transfer case I have, but I'm going to have to do some more research on that. I want to put a couple of thousand miles on the Duramax conversion before I change any thing else. Is the 273 from the Ford a direct bolt in?

I don't blame you for "proofing" the set up first. If you contact Toby at XXX Traction. He does a SAS conversion (very sweet by the way) and he has a 273 (fixed yoke from the factory) reworked on the input and motors changed over to bolt up to the Allison and switch through the ranges with the stock GM dash switches.

I was really wanting the high pinion Dana 60 from Dynatrac. They can install the tone ring for the ABS and it is really a bolt in deal other than the brackets being installed. The issue with that is the price. They want almost $8k just for the front axle. By the time I purchase the steering kit and other items it is $10k not installed.

Toby also uses the 2005+ Ford High Pinion Dana 60 on his SAS system. He adapts the ABS sensors/tone rings to work on the GM ABS system. He also converts the bolt pattern to match the GM/Dodge/Old Ford 8 on 6.5" bolt pattern. He has the coilovers dialed in for the duramax as well. His kit is really well thought out and probably the best SAS on the market for GM rigs.

The only reason, I haven't gone that route, is that 7" is about as low as he likes to build it, which is too much for me. Considering you are already lifted around that height, it might be the deal for you.

Website:

http://api.viglink.com/api/click?fo...om/index.htm&jsonp=vglnk_jsonp_13154337248521

Email:

lavenderbrothers@aol.com

Jack

 

[Larry]

I'm planning on working with the transfer case I have, but I'm going to have to do some more research on that. I want to put a couple of thousand miles on the Duramax conversion before I change any thing else. Is the 273 from the Ford a direct bolt in?

Klmore,

As I mentioned before, I am not much of a late model diesel engine fan but this is going to be a really nice project to an already great Suburban. You are definitely doing this swap right!

I doubt a Ford 273 would be a direct bolt in. A stock manual shift tcase NV261 from a Silverado/Sierra HD from behind either an Allison equipped truck or a S6-S650 6 speed manual would be a direct bolt in with a 29 spline input shaft for your Allison. There are ways to convert the 261(manual) or 263 (electric) to fixed yokes for SFA swaps if you end up going that route later. Unlike Ford and Dodge, all manual transmission equipped GM HD trucks came with manual shift tranfercases so that might help narrow down your search if you go looking for one (I have a stock 2001 Silverado HD that I bought new with a 8.1L, S6-650 and manual tcase and love it). Prior to moving to a field job I served time on the GM Technical Assistance hotline in Detroit and will tell you the electric shift is probably the most unreliable system on the entire truck. They are famous for not shifting at all, throwing “Service Transfercase” messages or shifting in to 4 low and never coming out again. I wouldn’t use an electric shift tcase if it was the last one in the pile to chose from. I hate my Tahoe for having it as standard equipment!

If you go the route of a manual shift someday, the stock GM transfercase you would actually need would be model NV261SHD. If you plan on doing this swap now would be the time to do it being you have the guys with the electrical expertise as it looks like there would be some minor wiring changes (you do not need to wire it exactly the way the General did it).

Here is some information straight from the GM service manual. If you would like the Autocrap 246 tcase diagrams to compare the two, PM me as there are several of diagrams to the Autocrap system instead of one simple diagram like the manual shift.


Transfer Case Description and Operation

The New Venture Gear (NVG) 261, RPO NP2 transfer case is a 2-speed, part-time with mode shift-on-the-fly capability. It has a chain driven front output shaft and an epicyclical low range planetary arrangement. The NVG 261 transfer case features a 4 position shift lever control located in the vehicle floor plan. As required, the operator can select 4HI position from 2HI on-the-fly, as described in the owners manual. A dash mounted 4WD lamp continues flashing during shifting, until all criteria have been met and the new mode/range position has been reached. Once the new mode/range position is fully engaged and the front axle disconnect locks in, the dash light 4WD indicator lamp remains ON constantly. Range shifting functions similarly, although it should be limited to speeds 5 km/h (3 mph) or less.

The 4 manual mode, or range gear positions, of the NVG 261 transfer case are:

• 2HI - 2-wheel drive high range
• 4HI - 4-wheel drive high range, part-time
• 4LO - 4-wheel drive low range, 2.72:1 gear ratio reduction
• N - NEUTRAL, 4-wheel

When the ignition switch is in the run position and the 4WD shift lever is in 4WD, the transfer case switch closes, supplying a ground to the axle actuator control circuit. With the ground applied, the logic of the front axle actuator actuates a DC motor to engage the front axle and supply voltage to the axle switch signal circuit. The axle switch signal circuit notifies the powertrain control module (PCM) and the anti-lock brake system that the vehicle is in the 4WD mode. The 4WD indicator is commanded on via a Class 2 serial data signal from the PCM. When the 4WD shift lever is in 4WD low, the transfer case switch closes and supplies a ground on the 4WD low signal circuit; this informs the PCM that the vehicle transfer case is in low range. When the vehicle is in low range, the PCM changes the shift pattern of the automatic transmission.
During normal driving situations, the transfer case can operate in the 2WD mode. The driver may choose to select any of the mode/range gear positions while driving the vehicle. However, the transfer case should not be shifted into or out of 4LO unless the following criteria have been met:

• The automatic transmission is in NEUTRAL or the clutch pedal is depressed.
• The vehicle speed is less than 5 km/h (3 mph).

This transfer case also has a NEUTRAL position. A shift to NEUTRAL allows the vehicle to be towed without rotating the transmission output shaft. In NEUTRAL, the rear propeller shaft rotates the transfer case rear output shaft, which rotates the oil pump, providing constant lubrication during towing. Note, this NEUTRAL position is a 4WD NEUTRAL, meaning the front and rear outputs of the transfer case are engaged as though in 4HI. With a disconnecting front axle, there is no power flow to the front wheels, allowing towing with the front wheels off the ground or flat towing without driveline binding. Again, the transfer case should not be shifted into or out of NEUTRAL unless the following criteria have been met:

• The automatic transmission is in NEUTRAL or the clutch pedal is depressed.
• The vehicle speed is less than 5 km/h (3 mph).

The NVG 261 transfer case is available in 5 variations, depending on the engine and transmission configurations. The variations allow the transfer case to handle different torque loads. When servicing the transfer case it is important to understand which variation is being serviced because of the difference in components.

NVG 261 Variations
Model
Transmission

Light Duty (LD) M30 - 4L60E 27 Spline
Light Duty (LD) MG5 - NV 3500 32 Spline
Heavy Duty 1 (HD1) MT1 - 4L80E/MW3 - NV 4500 32 Spline
Heavy Duty 2 (HD2) MT1 - 4L80E/MW3 - NV 4500 32 Spline
Super Heavy Duty (SHD) ML6 - ZF S6-650/M74 Allison 29 Spline

Looking forward to following your swap!

 

[locrwln]

I doubt a Ford 273 would be a direct bolt in. A stock manual shift tcase NV261 from a Silverado/Sierra HD from behind either an Allison equipped truck or a S6-S650 6 speed manual would be a direct bolt in with a 29 spline input shaft for your Allison. There are ways to convert the 261(manual) or 263 (electric) to fixed yokes for SFA swaps if you end up going that route later.

Actually once the input is changed on the front of the t-case to the 29 spline, the ford 271 (manual shift) or 273 (e-shift) do bolt up. Plus they already have fixed yokes front and rear, so no custom parts from anyone. Everything is factory parts to do the conversion (my understanding; there may be some custom work I'm not aware of). No waiting on ORD to maybe get you the parts for the conversion.

Jack