97-99 Suburbans
- Thread starter Dogmann
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cumminsbronco
New member
I've had a 97 since new, with just under 250,000 miles on it now. About 8000 miles ago I swapped a 5.9 cummins/nv4500 trans/1ton Ford axles.........now it's a good offroad vehicle. Not that it was bad before offroad, but the IFS left a little to be desired. Mine was a 5.7 also. I used it alot for hunting out on the Cheyenne River Reservation in South Dakota. Only got stuck once, and that was right after a drenching downpour, where the prairie dirt becomes teh stickiest MUCK you've ever seen. It'll haul a load of gear too, plenty of room for the 4 of us that always went out that way. I hope to get another 1/4 million with the swapped in drivetrain.
Route55
Adventurer
Good trucks. In 96 Chevy started fully galvanizing the body, so they tend to be less rust prone than 95-earlier models (they do still rust though)
Check build codes in glove box for code G80. If it has a G80 code, it means rear axle is gov-lock. They can be a decent locker if treated right. Never, never, gun or try to "peel out" a G80 rear, they will explode! If you start to get stuck, slowly increase speed until both tires are spinning, then you can "gun" it.
As mentioned, check intake AND water pump for leaks. If it still has orange coolant, flush it out and refill with green.
Reproduction and aftermarket parts are limited at this time, escpecially for all parts from the doors back, so if there are broken plastics, trim, seals, etc. you will be junkyarding it.
That year "should" have a 4L80E transmission, which is very stout. However I have seen some 3/4 suburbans, most with lower gvwr and clamshell doors, that have the 4L60E trans. That trans is light duty and O.K. for moderate driving, but will fail under heavy offroad or towing. Swapping one out for a 4L80E is possible, but not a "bolt-in" and can be pricy to do.
If it matters to you, some have skid plates, some do not. Most with the Z71 build code have them unless removed.
You did mention it was a 2500, which is good. In my opinion the 1500 has too small of brakes and other parts. Upgrades are out there but pricy. I'd definately look for a 2500.
Check build codes in glove box for code G80. If it has a G80 code, it means rear axle is gov-lock. They can be a decent locker if treated right. Never, never, gun or try to "peel out" a G80 rear, they will explode! If you start to get stuck, slowly increase speed until both tires are spinning, then you can "gun" it.
As mentioned, check intake AND water pump for leaks. If it still has orange coolant, flush it out and refill with green.
Reproduction and aftermarket parts are limited at this time, escpecially for all parts from the doors back, so if there are broken plastics, trim, seals, etc. you will be junkyarding it.
That year "should" have a 4L80E transmission, which is very stout. However I have seen some 3/4 suburbans, most with lower gvwr and clamshell doors, that have the 4L60E trans. That trans is light duty and O.K. for moderate driving, but will fail under heavy offroad or towing. Swapping one out for a 4L80E is possible, but not a "bolt-in" and can be pricy to do.
If it matters to you, some have skid plates, some do not. Most with the Z71 build code have them unless removed.
You did mention it was a 2500, which is good. In my opinion the 1500 has too small of brakes and other parts. Upgrades are out there but pricy. I'd definately look for a 2500.
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Route55
Adventurer
Thanks for posting that for him, I couldn't recall that one!
Route55
Adventurer
Another thing to check out is the rear axle. Although there is no "bad" rear axle, the 14 bolt FF is better. It is simpler and much stouter. Both the semi and full float were available.
The semi float (less desirable) rear differential cover is roundish, the full float rear cover looks roughly diamond shape with a sharp point at the top and bottom.
Also, that year "should" have hydroboost brakes, which is good. But make sure to frequently check the hoses and lines for wear and cracking frequently. This system contols both the steering and the brakes. A leak can mean a serious breakdown, or fire. I've personally seen at least three fires do to leaking hydroboost lines.
The semi float (less desirable) rear differential cover is roundish, the full float rear cover looks roughly diamond shape with a sharp point at the top and bottom.
Also, that year "should" have hydroboost brakes, which is good. But make sure to frequently check the hoses and lines for wear and cracking frequently. This system contols both the steering and the brakes. A leak can mean a serious breakdown, or fire. I've personally seen at least three fires do to leaking hydroboost lines.
FellowTraveler
Explorer
AS A SIDE BAR;
In May 1999 the Suburban was available w/enhanced 6.5 turbo diesel (NAVISTAR) then the bottom fell out with the diesel suburban being discontinued, however, the enhanced 6.5 turbo diesel was still available through 2004 in some truck products. This enhanced version was a stout build which eliminated all the previous failures of the 6.5 and extremely economic and reliable.
The 4L80e behind these 6.5 td have a different bell housing bolt pattern I'm thinking LS series motors are direct bolt on.
Any chevy/gmc truck built after MAY 1999 would be a great choice for whatever you want to throw at it, no it's not a powerful as the 6.6 Duramax but will last 2 to 3 times longer w/o failure depending on PM applied.
My 6.5 td is approaching 400k miles w/oil changes @ 25k intervals however filter are changed much sooner using AMSOIL bypass system and oil analysts. The coolant is EVANS waterless coolant @ 0 psi w/130 gpm pump & dual 180 deg thermostats. There is no indication that my 6.5 td is anywhere near requiring an overhaul. :ylsmoke:
In May 1999 the Suburban was available w/enhanced 6.5 turbo diesel (NAVISTAR) then the bottom fell out with the diesel suburban being discontinued, however, the enhanced 6.5 turbo diesel was still available through 2004 in some truck products. This enhanced version was a stout build which eliminated all the previous failures of the 6.5 and extremely economic and reliable.
The 4L80e behind these 6.5 td have a different bell housing bolt pattern I'm thinking LS series motors are direct bolt on.
Any chevy/gmc truck built after MAY 1999 would be a great choice for whatever you want to throw at it, no it's not a powerful as the 6.6 Duramax but will last 2 to 3 times longer w/o failure depending on PM applied.
My 6.5 td is approaching 400k miles w/oil changes @ 25k intervals however filter are changed much sooner using AMSOIL bypass system and oil analysts. The coolant is EVANS waterless coolant @ 0 psi w/130 gpm pump & dual 180 deg thermostats. There is no indication that my 6.5 td is anywhere near requiring an overhaul. :ylsmoke:
Hi, I have a 99 k2500 6.5 as well. Its not a powerful engine but once I made the cooling modifications were made the only problem I see is the front brakes get very hot after even a moderate length drive. I really hadnt paid attention to them until I replaced the front brake pads and keep thinking "they just cant be this hot and normal" (im talking about sizzling hot when put some water on them sometimes). I even took them to the chevy dealer and they only said "brakes get hot." Tried bleeding line, abs system, changed rotors, pads, caliphers lines and they are still hot. Any suggestions. Also, I have a stock turbo. What kind of turbo do you have?
FellowTraveler
Explorer
You can make your 6.5 td more efficient and powerful w/aftermarket upgrades HEATH and S&S are some sources that come to mind but other out there too. What cooling mods would a 1999 K2500 w/6.5 td need it's already got all the cooling updates from factory except perhaps waterless coolant, is it a pre MAY 1999 build 6.5 td, or?
Front brakes depend on certain compound of pad material and some pads cause poor breaking because of gassing between pad and disk creating excessive heat. A device controller can adjust amount of breaking at calipers by different % for larger diameter tires etc. The hydro-boost and steering cause excessive heat in stop and go traffic while there is a p/s cooler which is a coiled up tube I've found it is not efficient so I went to an additional cooler a PSC hi-pressure p/s pump and an additional plate cooler rated @ 9,800 btu and use AMSOIL synthetic fluid. and inline p/s filters on both return lines.
The turbo a GM8 is a good all around turbo in most applications however the 10cm turbine outlet is the limiting factor and cranking the boost super heats air charge. The only optional turbo IMHO is the A-team turbo which is built for efficiency not performance and does not use a waste gate or blow off valve, after this a larger diameter x-over pipe and larger diameter exhaust is needed. S&B makes a nice higher flow intake setup for the burb too.
Any mods you maybe think you need can be found on the web keeping in mind a larger turbo does not equate to more power and torque without supporting mods like fuel, programming, exhaust, intake etc..
Thanks for the tips. Excuse the novice questions. Fact is, I didn't realize this suburban had all the cooling upgrades already. I didn't see any codes in the glovebox. Beneath the glovebox near firewall reads 7/27/99 1B val60 52476834s so I assume this is a post may 99 burb. When I first bought it a couple or months ago the tstat would go up to 210 but after changing the tstats water pump and fan it will now stay two lines below 210. a new k& n air filter definitely let it breath better. Got a 4 inch diamond eye exhaust on and ordered a insight w a get probe. I have a brand new camaro and Chevy express van that I'm converting to a camper but I prefer driving the burb just wish it was a little bit peppier. And also realize that novody makes a good suspension lift kit for the 1999. They go up to 98 and pick up after 2000. I called offroad unlimited and who claim they get get any kit for any year and they said no to, so,etching about the transfer case. So I added new shocks and por15nd the underside seeing I wasn't going to be doing any lifting or suspension mods. I'm happy w it. I'll see if I can get some pictures up. Thanks again.