K2500 and 12,500 lb Keystone Raptor 3712

[jklennon]

Hello everyone. I am trying to prepare my truck to pull a trailer slightly over the tow capacity. I know it's not ideal but I don't have a choice at the moment. So please if you are going to tell me why I shouldn't do this move along. This is only temporary, but at the moment it's my only choice.

Truck specs. 2000 GMC K2500 ext cab, LWB, 7.4L Vortec Automatic 4.10. Tow package, tranny cooler ect. Cat back single exhaust, K&N air filter, 93 octane computer tune. Reese 15K pro series Hitch. BFG, T/A K.O 265/75/16 E. Truck is rated to pull 11,500lbs stock.

Trailer specs. 2007 Keystone Raptor 3712. 39.1ft long, 13.5 ft high. Shipping weight 12,415lbs hitch weight 2920lbs. Tri axle.

I haven't picked up the trailer yet and I am trying to prepare my truck before I do so.

Planning on tranny flush, oil change, fuel injector clean.

Maybe airbags? Helper springs? Brake upgrade? 4.56? Camshaft? Supercharger? Shift kit? Please, serious answers. I know the 3500s are rated for 13,500lb with the same engine tranny and 4.56 and stiffer suspension.

Thank you for your help in advance.

[Bedlam]

Going to 19.5" wheels takes care of tire flex and capacity, but you're looking at putting $2k or more into the truck for this upgrade.

[Jwmoehrle]

I have a 2007 raptor 3712 and the tongue is a little over 3200 lbs.and the tailer weighs about 13700 unloaded. at one time I towed it with a 2004 gmc 3500 dually 410 gears. and also a 2005 ford 3500 SRW. The Ford would get pushed on occasion descending hills but otherwise towed fine. The GMC would tow and handled it fine with the exception of it had no guts to pass, or get back up to speed after someone did a break check in front of me. The 2000 will probably hold and move it, but it is asking allot to make the truck last real long towing those kind of weights. Your biggest concern will be the tire flex of a SRW and if you are going to be over their weight. If you have to do what you have to do, do it, but I would be looking for a newer tow vehicle with more capacity in the future.

[hawkeye-08]

IMHO, take personal responsibility and make sure you have done all you can to avoid problems. Recognize you are over loaded and go slow, allow more room to stop, don't use cruise control, don't ride your brakes, etc.

Make sure tires and brakes are 100%, when you put new rotors and pads on truck, did you properly "bed" them (not sure of terminology, but you can google it and figure it out, involves some repeated near stops to heat up the pads and bed them to the rotors)? Make sure you have spare tires in good shape, perhaps an extra.

On my 73 Chev C20, I added a deep pan on the trans to increase qty of fluid along with the large cooler up front. Those helped with the trans temp. We pulled a 10,000lb command bridge boat on 2,400lb trailer (12,400 total behind us) and then added an truck camper (8.5'). We could run with traffic no problem and the brakes were setup optimally and we could stop very well in straight line. Our biggest problem was side winds and we added some helper springs to resolve that. IIRC, our combined gross was 22,500lbs on DOT scales.

I know a boat is much different than a FW trailer, but with the truck camper and large boat, it was certainly a load. The FW is going to have more frontal area I would expect and be more impacted by winds.

Travel when it is cooler and try to avoid peak traffic times.

[Thunderbolt]

In the 90's and up to 2000 GM 8,600 GVWR 3/4 ton trucks came with a 14 bolt semi floating 9.5" rear diff if equipped with a small block. The big block trucks got the 10.5" full floater. In the 2000 NBS trucks with the 6.0 liter they had the 9.5" semi floater. Not sure if the full floater was an option. In 2001 when the HD came out all 6.0 trucks had the 10.5" full floater and the 8.1 and diesels got the 11.5" full floater.

[jklennon]

Rear axle is 14 bolt 4.10 8 lug full float. 8600 GVWR HD

I have ordered the firestone " ride rite" airbags.

I am working on a full tune up, plugs wires, Cap rotor,oil ,filter ,fuel filter, trans service, coolant flush, front and rear diff service.

truck has 120,000 miles. Fleet maintained. Driven by myself.

Pads and rotors are New.

My tires are new with 123 load index for 3417lbs ea.

[discovery4us]

Bedlam wrote:
Our F250's are rated for over 14K lb FW and 12K lb TT towing. A GM that is five years older didn't have nearly those capacities. Remember that 2005 was the year Ford upgraded the frame, suspension and brakes in their Superduties which gave them a big boost in capabilities even compared to the 2004's.

Completely agree but I believe the late 90's - mid 2000 GM trucks were rated 11,000 max TT towing, not sure I have seen a FW max towing for a 2000 GM. With it being a FW he will be at the upper limits based on GM's numbers. I would be more concerned with the hitch weight than being able to pull and stop the trailer. Mine was around 3000 lbs. hitch weight and just over 14,000 lbs. on the axles.

[blt2ski]

Jim,
I have one of them LR axles in my 2000 8 lug C2500.

Marty

[JIMNLIN]

Bedlam wrote:
If the FW is 12.5K lbs dry, then you will be way over your weights once loaded up and the tow vehicle is not a good match for the desired RV. If the GVWR of the FW is 12.5K lbs, I think you will be able safely pull it although the drive may wear on you. If your 3/4t truck is one of those that was equipped with a semi-floating axle, don't attempt to haul this FW.

Expect 2500-3000 lbs of pin weight. A full-floating axle should be able to handle this but check your tire ratings. Depending on the spring package you have on your vehicle you may need some type of supplement to prevent sag in the rear - There are plenty of options which should be addressed in another thread.

The '07 Keystone Raptor 3712 shows a 15500 GVWR with a 3085 lb CCC which is well out of even the '00 GMs 3500 DRW tow capacities.

I think he has the old 454 big block with a 4L80 tranny along with the 14 bolt 10.5" corporate full floater rear axle.
The 14 bolt 9.5" semi float axle came in the LD 7200 GVWR 3/4 ton trucks.

[Bedlam]

discovery4us wrote:
I pulled a 05' 3612 for thousands of miles with an 05' F250 diesel and would do it again. I would be cautious of the 12,500 lb. as mine was much heavier than the weight keystone put on it. That being said install some airbags, a quality hitch, upgrade to 16" trailer wheels and tires, and make sure the truck tires are rated for the weight.

Our F250's are rated for over 14K lb FW and 12K lb TT towing. A GM that is five years older didn't have nearly those capacities. Remember that 2005 was the year Ford upgraded the frame, suspension and brakes in their Superduties which gave them a big boost in capabilities even compared to the 2004's.

[blt2ski]

A bb or 6.5td should have a ff rear. A sb gas a semi floating.

Marty

[CampingN_C_]

His truck "should" have a full floater. Rear ends on those trucks were pretty stout, that being said a fluid change is a must.

[discovery4us]

I pulled a 05' 3612 for thousands of miles with an 05' F250 diesel and would do it again. I would be cautious of the 12,500 lb. as mine was much heavier than the weight keystone put on it. That being said install some airbags, a quality hitch, upgrade to 16" trailer wheels and tires, and make sure the truck tires are rated for the weight.

[Bedlam]

If the FW is 12.5K lbs dry, then you will be way over your weights once loaded up and the tow vehicle is not a good match for the desired RV. If the GVWR of the FW is 12.5K lbs, I think you will be able safely pull it although the drive may wear on you. If your 3/4t truck is one of those that was equipped with a semi-floating axle, don't attempt to haul this FW.

Expect 2500-3000 lbs of pin weight. A full-floating axle should be able to handle this but check your tire ratings. Depending on the spring package you have on your vehicle you may need some type of supplement to prevent sag in the rear - There are plenty of options which should be addressed in another thread.

[blt2ski]

"A jack knife across other lanes" could have occured with a rig UNDER ALL of its ratings. So this example is on the bogus end of things! At the end of the day, ANY trailer can jack knife! The person with the jack knifed trailer was not charged with a weight issue!

With this in mind....I used to pull a 12K equipment trailer, granted a pintle hitch with my 96 SW K3500 CC. While it did ok, one could tell the tail was somewhat in charge. Hence why I also recommend no trailer larger than 2x the GRAWR. As mine was 6080 due to tires, 6400 lb spring pack IIRC. I changed out to 8500 lbs springs, it handled way better. Later I realized about the same as my 05 dually with 8500 lb rear suspension. Dually part made no difference.

My experience with be to say, do not do this! with out some mods to the rear suspension!

Marty