When my GMT400 isn't enough...

[bugdewde]

Tow rating isn't a function of engine power, but more of a balance of braking, stability and handling.
Remember, those semi trucks from the 50s & 60s hauled 40k lbs with less power than today's diesel pickup trucks.

I'm sure the 800's bumped towing rating came from 4 wheel disc brakes and improved frame/suspension goodies.
Power is not a factor.

 

[Supercharged111]

Tow rating isn't a function of engine power, but more of a balance of braking, stability and handling.
Remember, those semi trucks from the 50s & 60s hauled 40k lbs with less power than today's diesel pickup trucks.

I'm sure the 800's bumped towing rating came from 4 wheel disc brakes and improved frame/suspension goodies.
Power is not a factor.

Speak for yourself. While I agree that a Cummins swapped 1500 can't pull 30k#, power is absolutely a factor, just not the only factor.

 

[bugdewde]

Speak for yourself. While I agree that a Cummins swapped 1500 can't pull 30k#, power is absolutely a factor, just not the only factor.

Well, yes.... technically, it is a factor....... but the most relevant factors are braking and handling safely.

"Propulsion" is the term used, which is described in this article about tow ratings. It involves accelerating from a stop and on grades.
... From the article:
"The upcoming SAE J2807 recommended practices will include five areas of testing: structure, propulsion, thermal, handling, and braking. "

I was merely alluding to the fact that safe braking and handling were what allowed an old semi truck to haul 40k lbs back in the day...... not 700 lb-ft of torque.

Neat article if you have some spare time.....
http://www.trucktrend.com/news/163-0910-truck-towing-capacity/

 

[someotherguy]

Dead set on staying in a Suburban? Bear with me.. you can get a factory 8.1 in a gmt400 with a high tow rating.. 2001-2002 3500hd. Plenty of springs, brakes, gearing. Get a crew cab, do a pickup bed conversion (a little work, won't lie) and throw a camper shell on it.

Just know they ride rough as hell unloaded.

Richard

 

[Jermaine Smith]

I have a 1998 k3500 crewcab long bed, 140k miles. it has the vortec 454, 4l80e trans with 410 gears. Engine only has a cold air intake other than that it’s stock. It struggles to tow my 32’ travel trailer that’s weighs 9k lbs. It is a dog up hills. I live in Nevada which has tons of hills. I was tired of shifting down to 2nd gear up hills and going 40-50mph( depending on grade) . Needless to say, Last month I bought a 2006 Chevy 2500hd duramax 150k miles and it is night and day. It has a tow mode programmed in. I set the cruise control at 70mph and climb hills with ease. If you want power then get a diesel. If you don’t mind going slow then stick with what you have. The 454 will handle the abuse and last forever but it does it slowly. I’ll be selling my gmt400 soon.

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Nice trucks!! I want a duramax to tow my Camaro to tracks etc. If i had a duramax i would still keep my GMT 400 as a spare tow rig/vehicle. Diesels are king of the hill towing but they are also the king of the hill in expensive repairs. Something to think about.....

 

[BNielsen]

Dead set on staying in a Suburban? Bear with me.. you can get a factory 8.1 in a gmt400 with a high tow rating.. 2001-2002 3500hd. Plenty of springs, brakes, gearing. Get a crew cab, do a pickup bed conversion (a little work, won't lie) and throw a camper shell on it.

Just know they ride rough as hell unloaded.

Richard

OR....located wrecked 3500HD with an 8.1L;
Find a roller Vortec wired Burb, swap in engine harness, engine, and BOOM.
496 LS GMT400 Suburban! Then do all the good stuff like air bags, disc brakes, sway bars and junk until it's rock solid pulling whatever needs pulled.

Did the 3500HDs get Allisons or did they retain the 80E/85E?

 

[Supercharged111]

Well, yes.... technically, it is a factor....... but the most relevant factors are braking and handling safely.

"Propulsion" is the term used, which is described in this article about tow ratings. It involves accelerating from a stop and on grades.
... From the article:
"The upcoming SAE J2807 recommended practices will include five areas of testing: structure, propulsion, thermal, handling, and braking. "

I was merely alluding to the fact that safe braking and handling were what allowed an old semi truck to haul 40k lbs back in the day...... not 700 lb-ft of torque.

Neat article if you have some spare time.....
http://www.trucktrend.com/news/163-0910-truck-towing-capacity/

I really feel like we're on the same page, but damn that link was generic. I think the better answer here is to google the new standard for how they rate GVWR and tow capacity. They definitely alluded to what matters, but no way to extrapolate how an older truck falls into the newer rules which are clearly the way to go to rate a truck's capacity. I'll say my dually has not exceeded 210 coolant regardless of what I've put it through.

 

[scottydl]

Is coolant temp a relevant measure of how hard the engine is working while towing, as far as what can be seen from the driver's seat?

On my extended towing/camping trip last week, I was fairly pleased at my Suburban temp levels which looked to be around 195-200 while pulling over 9000#. Air temp that day was in the low 80's. A few days later it was hotter in the mid 90's and we had more 2-lane and stop & go delays because of road construction. Engine temp exceeded 210 several times in those conditions and I could hear it boiling into the overflow tank anytime we stopped for food or gas. That made me a little nervous.

 

[L31MaxExpress]

Dead set on staying in a Suburban? Bear with me.. you can get a factory 8.1 in a gmt400 with a high tow rating.. 2001-2002 3500hd. Plenty of springs, brakes, gearing. Get a crew cab, do a pickup bed conversion (a little work, won't lie) and throw a camper shell on it.

Just know they ride rough as hell unloaded.

Richard

I still dreaming of a newer 8.1 Kodiak/Topkick with the firewall back an Express van.

 

[Burb99]

If the motor has low miles And good compression, my suggestion would be to upgrade to the 96-99 SUV Vortec. Heads, RV cam, intake and direct injection. You should be able to pick up at least 50hp for less than 1500 bucks. You already have the block you just upgrade from the heads up. Courteous if anybody has tried this, the big question is can you go from TBI to direct injection.