Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-27-2012, 03:33 PM   #1
Wise Elder
 
Jammer's Avatar
 
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,119
Chevrolet full-size truck/suburban 1999-2006

A thread to post:
- upgrades
- service difficulties
- experiences
..specific to the GMT800 truck platform used on the 1999-2006 full-size GMC and Chevrolet pickups, Suburban, Yukon XL, and Escalade ESV in both 1/2 ton and 3/4 ton chassis types.

Much of the chassis and power train are also shared with the shorter-wheelbase SUVs: Tahoe, Escalade, Yukon and also the Avalanche.

Some resources:
GMT800 - Wikipedia, the free encyclopedia
Chevrolet Suburban - Wikipedia, the free encyclopedia
Chevrolet Silverado - Wikipedia, the free encyclopedia

Quick reference:

Six engine choices, V8 except as noted:
4.3 gasser v6 (half ton only) .. 195 hp, 260 lb ft
4.8 gasser (half ton only) .. 270 hp, 315 lb ft
5.3 gasser (half ton only) .. 285 hp, 325 lb ft
6.0 gasser .. 335 hp, 375 lb ft
8.1 gasser (3/4 ton only) .. 340 hp .. 450 lb ft
6.6 diesel (3/4 ton only) .. 300 hp .. 550 lb ft

Performance figures are typical and vary from year to year and among models.

The half ton and SUV models generally use the 4L60e automatic transmission. The 3/4 ton gassers use the 4L80e automatic transmission, and the diesels use the Allison 1000 automatic transmission.

Some of the 8.1s are built with a 4L85e transmission which is identical to the 4L80e except for the presence of a fifth planetary gear on the input shaft.

There are a few trucks out there with manual transmissions, usually the NV4500.

Relevant RPO codes

GT4 - 3.73 rear axle ratio
GT5 - 4.10 rear axle ratio
G80 - limited slip rear axle
MN8 - 4L85e transmission
MT1 - 4L80e transmission

4WD versions were equipped with the NP-246 auto-trac transfer case.

A complete list of RPOs is available here.

I believe all models had independent front suspension using torsion bars.

Standard tires were LT265/70R16 for the half ton and LT245/75R16E for the 3/4 ton.
__________________

__________________
Jammer is offline   Reply With Quote
Old 02-27-2012, 03:49 PM   #2
Wise Elder
 
Jammer's Avatar
 
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,119
Maintenance highlights

All engines and years used Dex-cool type coolant.

The NP246 transfer case requires special auto-trac fluid. Aftermarket equivalents are available but specifically identify themselves as being for use with auto-trac. The fluid is marked with a blue dye. Caution should be used when torquing the fill and drain plugs as the case is magnesium and is easily damaged.

Transmission was specified to use Dexron III or VI depending on year. Dexron VI is compatible with all years and can be mixed with older fluid without damage. For the Suburban type vehicles there is a frame crossmember right in the way of dropping the pan but it is possible to raise, carefully, the transmission tailshaft assembly with a jack to get enough clearance to pull it out without removing the crossmember.

GM switched from 80W90 to synthetic 75W90 gear oil for front and rear axles during production due to lubrication failures in extreme cold weather.

Weld failures on the OEM trailer hitch receiver can occur particularly with the use of weight distributing hitches over the course of many miles. Inspect carefully especially if the receiver has had a hard life.

8.1l and diesel are equipped with an engine oil cooler mounted inside the radiator. The lines are prone to leakage after a period of years. Replacements are available through Chevrolet dealers and from rock auto but most other aftermarket parts dealers don't have them. Front axle is right in the way of replacing them on 4wd models but it can be done without dropping it (at least on the 8.1).
__________________

__________________
Jammer is offline   Reply With Quote
Old 02-27-2012, 04:20 PM   #3
Wise Elder
 
Jammer's Avatar
 
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,119
Mods

There are a variety of aftermarket trailer hitch receivers available with capacities to 15,000 pounds. In most cases the receiver height is the same as the OEM hitch. The aftermarket designs I have seen do not rely on the bumper for structural support.

A front mount hitch is also available that bolts to the frame in the same location as the factory tow hooks. The factory tow hooks are retained in the same location with the hitch frame attaching to the opposite side of the frame rail.

The factory roof rack crossmembers are compatible with some rooftop accessories from Thule and Yakima. You can get a large basket, cargo containers, ski and snowboard racks, watercraft holders, and bicycle racks.

A bug deflector for the hood is a dealer option. Aftermarket ones are also available. My aftermarket one cracked due to shrinkage in the cold weather here. I replaced it with an OEM one which has slots for the screws so it can slide when it shrinks rather than breaking.

The charge line to the 7-way trailer connector is disabled from the factory by removal of the fuse. The underhood fuse panel will have a place for it, marked "stud 1 auxiliary power."

There is a connection for a brake controller wiring harness on the firewall, above and to the left of the break pedal, quite close to the the side. There is a junction box about 6" square with a black cover. The cover must be removed to access the brake connector. If there is not a factory-installed 7 way connector (rare) then the blue and red wires terminate inside the fuse box on the left side of the engine compartment.

Most vehicles shipped with an AD-230 105 amp alternator. The large frame AD-244 140 amp alternator was a factory option, and is bolt-on compatible in most cases (a 1" longer serpentine belt may be required). Both the AD-230 and AD-244 were made with a 4-pin control connection through mid 2005 and a 2-pin control connection from 2005 up so be sure you get the right one.

Dual alternator kits are available, and one or two airforum members have installed them with good results.

A few vehicles shipped with the optional power-exending towing mirrors, which are also available as an aftermarket upgrade.

Oversize aluminum transmission oil pans and rear axle covers are available from Mag Hytec. The PO of my suburban put them on. They increase fluid capacity and are said to improve cooling.
__________________
Jammer is offline   Reply With Quote
Old 02-27-2012, 08:58 PM   #4
Vintage Kin
 
slowmover's Avatar
 
Fort Worth , Texas
Join Date: Nov 2006
Posts: 7,583
Images: 1
Nicely done!!
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 9-cpm solo, 15-cpm towing
Sold: Silver Streak Model 3411
slowmover is offline   Reply With Quote
Old 02-27-2012, 09:20 PM   #5
Rivet Master
 
1987 29' Sovereign
Sparta , Tennessee
Join Date: Mar 2003
Posts: 507
Send a message via Yahoo to wingfoot321
2003 2500HD 6.0 Ext Cab 4.11rear 4drive

I had my trans fluid changed at 59,000 miles. Specified syn fluid but, did not verify brand or actual fluid used.

Question: I don't seem to have ever recorded as good mileage since the change. Does anyone thing fluid could make a difference? I am very careful with my driving and just know that something has changed. It is off at least .5 mile per gallon.
__________________
wingfoot321 is offline   Reply With Quote
Old 02-28-2012, 08:12 PM   #6
Rivet Master
 
r carl's Avatar
 
Vintage Kin Owner
Lin , Ne
Join Date: Dec 2009
Posts: 2,056
Yes better fluids and greases will help with everything.
__________________
r carl is offline   Reply With Quote
Old 02-28-2012, 08:55 PM   #7
2 Rivet Member
 
drunkensloth's Avatar
 
1965 17' Caravel
Knights Landing , California
Join Date: Dec 2011
Posts: 60
I had a couple things to add through my experience. Make sure you do not use dex 6 in a manual transmission that specifies dex 3. Not compatable. Also, I wouldn't synthetic in the front diff unless it's all wheel drive. The GM fluid has friction modifier in it that can wear the bearings prematurely
__________________
drunkensloth is offline   Reply With Quote
Old 02-28-2012, 10:30 PM   #8
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
IMO.... The power extendable "tow" mirror not worth the $$$, too small and no convex. Manual tow a much better option for towing AS wide body.

Bob
Attached Thumbnails
Click image for larger version

Name:	DSC07358.jpg
Views:	121
Size:	200.1 KB
ID:	152230  
__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 02-28-2012, 10:51 PM   #9
Wise Elder
 
Jammer's Avatar
 
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,119
Quote:
Originally Posted by drunkensloth View Post
I had a couple things to add through my experience. Make sure you do not use dex 6 in a manual transmission that specifies dex 3. Not compatable. Also, I wouldn't synthetic in the front diff unless it's all wheel drive. The GM fluid has friction modifier in it that can wear the bearings prematurely
The lubricant specified for the front diff is 75W-90 synthetic gear oil without a friction modifier. This oil is now widely available from aftermarket suppliers and does not have to be obtained from GM. If the rear axle contains a positraction diff then a friction modifier must be added to the 75W-90. I have 75W-90 synthetic in the front and rear axles of both my 2004 Suburban and my 1997 K2500 and have been running it for several years with good results. Both have posi rears and therefore have the additive in the rear axle.
__________________
Jammer is offline   Reply With Quote
Old 02-28-2012, 10:53 PM   #10
Wise Elder
 
Jammer's Avatar
 
2010 30' Classic
Vintage Kin Owner
South of the river , Minnesota
Join Date: Dec 2009
Posts: 4,119
Quote:
Originally Posted by ROBERT CROSS View Post
IMO.... The power extendable "tow" mirror not worth the $$$, too small and no convex. Manual tow a much better option for towing AS wide body.

Bob
You might be right. It is true that your mirrors are wider. However it is possible to add a small convex circle to the inside of the mirror portion of the power mirrors. I had this arrangement on the right side at one point and it is now missing since I had to replace the glass after an unfortunate incident involving a concrete pillar in a parking garage intended for subcompacts. I plan to replace it.
__________________
Jammer is offline   Reply With Quote
Old 02-29-2012, 06:06 AM   #11
CLOUDSPLITTER "Tahawas"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , WNY
Join Date: Jun 2007
Posts: 11,153
Images: 1
Thumbs up

Quote:
Originally Posted by Jammer View Post
You might be right. It is true that your mirrors are wider. However it is possible to add a small convex circle to the inside of the mirror portion of the power mirrors. I had this arrangement on the right side at one point and it is now missing since I had to replace the glass after an unfortunate incident involving a concrete pillar in a parking garage intended for subcompacts. I plan to replace it.

The one PITA with the manual retracting tow mirror..... is the onset of manual retracting tow mirror brain fade when entering the garage. No broken glass yet...just the ohcrap scrapping sound.

Bob
__________________
PFC.....

“After all these years the reason I continue to love Thanksgiving.....I still sit at the kids table.”
RLC

Sandra wanted to go to Cleveland on vacation,
but I’m the Husband, so we went to Cleveland.
RLC
ROBERT CROSS is offline   Reply With Quote
Old 03-12-2012, 09:23 PM   #12
Rivet Master
 
r carl's Avatar
 
Vintage Kin Owner
Lin , Ne
Join Date: Dec 2009
Posts: 2,056
Silverado/Sierra 2500HD & 3500HD - GM-Trucks.com
__________________

__________________
r carl is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
2006 Safari 20ft ID help VeggieBullet 2006 Safari 6 04-23-2014 04:25 PM
Doing full monte on my '58 Traveler Chlyman 1958 Traveler 77 06-13-2013 08:36 PM
What size truck or SUV is best? Marinablue Towing, Tow Vehicles & Hitches 265 04-20-2012 12:39 PM
Using truck convex mirror w/ stock mirrors barts Tow Vehicles 7 02-28-2012 10:55 PM
How to...trailer/ truck connection AIR-Quarius Tow Vehicles 14 02-27-2012 08:46 AM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:23 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.