6.4 Hemi 2500 Towing Advice, Please...

[Rick Ram-jet]

Greetings All, it`s been awhile...
Looking for 1st hand feedback on towing an aprox 10.5k bumper-pull toy-hauler with a 6.4l hemi 2500.
I`m about to upgrade from a 7,800k (loaded) travel trailer (my truck, 2016/2500, 6.4L, 5k air bags, weight dist hitch) tows this no problem what so ever) to an 10.5k full load/7800k dry) toy-hauler...
Looking for first hand experiences concerning any issues towing this weight with the 6.4Hemi/2500.

Thanks in advance for you feedback and let`s please keep on topic avoiding the usual diesel vs gas debate..

 

[BlkZrx]

Is your WDH rated for the heavier trailer? I towed a 13,000 lb generator across the country with my gas 2500, no issues..

 

[HEMIMANN]

Well, I don't tow as heavy as you, but I'd sure consider where - up and down mountains? Diesel. Hot weather towing? Diesel.

Likely ok if flat or mild terrain and temps.

Remember, you got a 66RFE trans in yours too - not a ZF 8 speed.

 

[Rick Ram-jet]

Appreciate the comments, looking for feedback from those with experience towing 10-10.5k weight! I`ll be upgrading to a higher rated weight distribution hitch and don`t plan to do a lot of hill/mountain routes...from San Diego mostly across the southern part of the country ending up in Texas, Mich, Tenn to look at real estate.
Probably upgrade to a deep pan on the trans and probably larger or aftermarket cooler as well.
Anyone?

 

[HEMIMANN]

Appreciate the comments, looking for feedback from those with experience towing 10-10.5k weight! I`ll be upgrading to a higher rated weight distribution hitch and don`t plan to do a lot of hill/mountain routes...from San Diego mostly across the southern part of the country ending up in Texas, Mich, Tenn to look at real estate.
Probably upgrade to a deep pan on the trans and probably larger or aftermarket cooler as well.
Anyone?

I did not go to bigger pan or aftercooler, but definitely get rid of that trans oil line thermostat. It's restrictive and fails.

Both RevMax and ATS make thermostat bypass blocks to retrofit. I went with RevMax, though it was better. Use good synthetic trans oil. I went with Red Line C+ATF

 

[dhay13]

I towed a 9300lb travel trailer with no issues at all. Hardly knew it was there. Doubt an extra 1000lbs would be much strain on it.

 

[2003F350]

The 6.4 WILL do it no problem, as will your 6-speed as long as you've cared for it. Is it going to like it? Not really. Is your suspension going to grenade right away? No. Will it handle it? Yeah, probably.

I pulled a park model camper with my 'Wagon on about a 200 mile trip (moving it from my property up north to my house to sell it) a few years back. It did it, didn't have any power issues, but I was wishing for more suspension. I don't run air bags as they are a bandaid on a problem at best, they don't redistribute weight, all they really do is allow you to overload your suspension.

Did everything blow up? No. Did I have any issues? No, but I only ran 60mph with that 42' sail behind me. Would I do it again? Not without a bigger truck, 3500 SRW minimum, wouldn't really matter which motor to me. The 6.4 is up to the job, I contend that the 6 speed is up to the job, but you're lacking in suspension. Will you have problems? I can't say. Is it going to grenade right away? No. Will you be wishing for more suspension? Depends on how you drive but I'd venture with yes, especially with how far you're traveling.

Case in point, we pulled our 35' TT all over with the 'Wagon. Even with a properly set up WDH and sway control, it felt unstable over 70 mph, so I only ever cruised at 65 and went faster only when needed. With the new truck (2500 CTD 4WD, otherwise same configuration) and the exact same camper, I accidentally found myself running 75mph and had to slow down - the stiffer suspension took care of a LOT of the squirrely feeling. Do with this info what you will, but more suspension is never a bad thing when towing.

 

[ronheater70]

I did exactly what you are proposing, I went from about an 8K RV to somewhere around 10.5-11K and I got say I was miserable in the truck towing anywhere other than flat or relatively flat ground. Going to the Beach it was livable, but going into WV I hated it on the Hills. The thing that made it worse than it needed to be was the transmission. that Big Leap between 1st and 2nd screwed me sometimes trying to merge on the highway if it was an uphill merge.. Scream its guts out in 1st then hit 2nd and fall on its face and bog. I know the newer 8 speeds have helped a lot on that regard, And I probably would have been happier with the 8 speed.
Looking at your Sign, if you are running 37's and have the stock 3:73 You will really be struggling IMHO unless your going downhill everywhere.

 

[max2bob]

i towed a 11,000 lb 5th wheel for a few years in montana. i came from a diesel truck and was surprised at the performance of the 6.4 hemi. the only thing that is a negative is when you get into 35-40 mph head winds , it would struggle with them where my diesel you would apply a bit more throttle and run a lot more boost so the diesel handled the winds a lot better. i am happy with the 6.4 and only thing i would change would be to have the 8 speed instead of the 6 speed transmission .

 

[62Blazer]

The 6.4 WILL do it no problem, as will your 6-speed as long as you've cared for it. Is it going to like it? Not really. Is your suspension going to grenade right away? No. Will it handle it? Yeah, probably.

I pulled a park model camper with my 'Wagon on about a 200 mile trip (moving it from my property up north to my house to sell it) a few years back. It did it, didn't have any power issues, but I was wishing for more suspension. I don't run air bags as they are a bandaid on a problem at best, they don't redistribute weight, all they really do is allow you to overload your suspension.

Did everything blow up? No. Did I have any issues? No, but I only ran 60mph with that 42' sail behind me. Would I do it again? Not without a bigger truck, 3500 SRW minimum, wouldn't really matter which motor to me. The 6.4 is up to the job, I contend that the 6 speed is up to the job, but you're lacking in suspension. Will you have problems? I can't say. Is it going to grenade right away? No. Will you be wishing for more suspension? Depends on how you drive but I'd venture with yes, especially with how far you're traveling.

Case in point, we pulled our 35' TT all over with the 'Wagon. Even with a properly set up WDH and sway control, it felt unstable over 70 mph, so I only ever cruised at 65 and went faster only when needed. With the new truck (2500 CTD 4WD, otherwise same configuration) and the exact same camper, I accidentally found myself running 75mph and had to slow down - the stiffer suspension took care of a LOT of the squirrely feeling. Do with this info what you will, but more suspension is never a bad thing when towing.

Sounds like you are talking about Power Wagon. If so there is a significant difference between the Power Wagon suspension and a regular 2500 suspension. We regularly have 3-4 trucks hauling trailers in a caravan going to competitions. I have a PW and another guy has the same year regular 2500, both 6.4 engines. The same trailer that just causes some squat on his will put my PW on the bump stops, and the reason why I run airbags. I do agree that the soft suspension is the limiting factor on a PW, but there really shouldn't be any difference in handling between a regular 2500 with the 6.4 vs. Cummins engine. I don't disagree that the Cummins is "better" for towing that much weight. But again regarding the suspension....the issue you had was that the one truck was a Power Wagon that comes with soft rear springs versus a regular 2500, which would have the same basic rear suspension setup regardless of the engine.
FYI...I think airbags are a good option when towing heavy. Not just to get rid of squat, but it made my truck feel way more stable on the freeway. Gets rid of that floaty feel.

 

[2003F350]

Sounds like you are talking about Power Wagon. If so there is a significant difference between the Power Wagon suspension and a regular 2500 suspension. We regularly have 3-4 trucks hauling trailers in a caravan going to competitions. I have a PW and another guy has the same year regular 2500, both 6.4 engines. The same trailer that just causes some squat on his will put my PW on the bump stops, and the reason why I run airbags. I do agree that the soft suspension is the limiting factor on a PW, but there really shouldn't be any difference in handling between a regular 2500 with the 6.4 vs. Cummins engine. I don't disagree that the Cummins is "better" for towing that much weight. But again regarding the suspension....the issue you had was that the one truck was a Power Wagon that comes with soft rear springs versus a regular 2500, which would have the same basic rear suspension setup regardless of the engine.
FYI...I think airbags are a good option when towing heavy. Not just to get rid of squat, but it made my truck feel way more stable on the freeway. Gets rid of that floaty feel.

You're right, I had a Wagon - but aside from softer springs there isn't much, if any, difference between that and a regular 2500. The Wagon uses the softer springs to get suspension flex. So yes, going to a regular 2500 does make the suspension stiffen up a lot.

BUT, for what OP is wanting to do, going up to that kind of weight is still going to make even a regular 2500 squat quite a bit and start to feel squirrely, regardless of the setup. If it were going to be a flatbed trailer that you can play with the loading on, sure, no problem. This is a bumper-pull toy hauler RV that is nose-heavy when empty at best. Sure, it has a bay in the back you can load up with stuff to try to get some tongue weight back off it, but to get it appreciably lighter in the front you've got to add a LOT of weight back there, maybe more than its payload depending on the configuration. You can't really move appliances/furniture/cabinets around to balance the weight.

Again, can it do it? Yeah, I'll say it can. Is it going to be the best setup? I'd argue no, OP would be better served with a 3500 SRW. Is it going to be a comfortable ride? Again, I'd say no, that's a lot of weight behind that truck with a lot of tongue weight.

 

[ronheater70]

You're right, I had a Wagon - but aside from softer springs there isn't much, if any, difference between that and a regular 2500. The Wagon uses the softer springs to get suspension flex. So yes, going to a regular 2500 does make the suspension stiffen up a lot.

BUT, for what OP is wanting to do, going up to that kind of weight is still going to make even a regular 2500 squat quite a bit and start to feel squirrely, regardless of the setup. If it were going to be a flatbed trailer that you can play with the loading on, sure, no problem. This is a bumper-pull toy hauler RV that is nose-heavy when empty at best. Sure, it has a bay in the back you can load up with stuff to try to get some tongue weight back off it, but to get it appreciably lighter in the front you've got to add a LOT of weight back there, maybe more than its payload depending on the configuration. You can't really move appliances/furniture/cabinets around to balance the weight.

Again, can it do it? Yeah, I'll say it can. Is it going to be the best setup? I'd argue no, OP would be better served with a 3500 SRW. Is it going to be a comfortable ride? Again, I'd say no, that's a lot of weight behind that truck with a lot of tongue weight.

I went to the 3500 SRW and the ride is really not that much different IMHO..it IS noticeable, but not a huge difference.

 

[mtofell]

That's roughly the weight of my 5th wheel and I've pulled it around quite a bit. By far the biggest problem is the mile gap between first and second in the 66rfe tranny. You'll get into these situations where you can't hold second and, left in "D", the tranny will just SLAM back and forth between 1&2. It's usually when you're heading uphill on a winding road trying to go in the 35-40MPH range... it just can't do it. The remedy is to just lock into first and slow down a bit. Other than that annoyance it does pretty well. The 6.4 Hemi is a beast of an engine and when you can keep the RPMs up it does great.... I can only dream of how nice feels with the 8spd. I've pulled a 6% grade at some elevation several times on a straight highway and have no problem maintaining 60+. It's just being able to go fast enough to hold second which may or may not apply to where you'll be towing.

 

[HEMIMANN]

That's roughly the weight of my 5th wheel and I've pulled it around quite a bit. By far the biggest problem is the mile gap between first and second in the 66rfe tranny. You'll get into these situations where you can't hold second and, left in "D", the tranny will just SLAM back and forth between 1&2. It's usually when you're heading uphill on a winding road trying to go in the 35-40MPH range... it just can't do it. The remedy is to just lock into first and slow down a bit. Other than that annoyance it does pretty well. The 6.4 Hemi is a beast of an engine and when you can keep the RPMs up it does great.... I can only dream of how nice feels with the 8spd. I've pulled a 6% grade at some elevation several times on a straight highway and have no problem maintaining 60+. It's just being able to go fast enough to hold second which may or may not apply to where you'll be towing.

with a 3.73 axle, my big trans gap is 3--->4. Much wider than the others. 1--->2 is almost too narrow. Really strange gear ratios in that thing (66RFE).

Don't like the took a single overdrive and split it into two, either. And then they activate the OD clutch to make some of the non OD gears anyway.

So to try to preserve the thing, keep the oil running cool (no oil cooler thermostat) and use premium synthetic oil, changing regularly. Hoping the thing might make it. Would have changed valve body 1st if I'd known it needed a re-learn. I had tuned already.

ZF8 is excellent. But I'm sorry, that oil change process is just ridiculous.

 

[06 Dodge]

Appreciate the comments, looking for feedback from those with experience towing 10-10.5k weight! I`ll be upgrading to a higher rated weight distribution hitch and don`t plan to do a lot of hill/mountain routes...from San Diego mostly across the southern part of the country ending up in Texas, Mich, Tenn to look at real estate.
Probably upgrade to a deep pan on the trans and probably larger or aftermarket cooler as well.
Anyone?

Umm your going to see a few good hills between San Diego and Odessa TX on I-8

 

[Rick Ram-jet]

Thanks to those who shared their feedback so far!
After doing some add research...along with the higher rated weight distribution hitch I`m planning on upgrading the rear springs to a heavy duty set (less squat,) adding some additional cooling to the transmission along with the usual Amsoil.
The trailer manufacture stated that by design, the empty toy-hauler tongue weight is high, as the load increases in the rear weight shifts off of the tongue and redistributes throughout the rig. Dry weight is 7800 and GVWR is 11,950 32ft
We have plan to bring a 900lb golf cart OR 860lb Harley plus the usual trip related stuff so I think we`ll still be lower than the estimated 10.5k max, probably closer to 9.5k.
As for the 3:73 gears, I have actually found this gear and tall tires beneficial on the road with steep inclines, towing she`ll do 65mph at 2500rpm in 4th which makes down-shifting unnecessary and hunting between 1st and 2ed has not been a problem so far.
Truck only has 24k on it and has been meticulously maintained with limited towing..

HEMIMANN: did you find the Edge programmer helpful when towing?

 

[HEMIMANN]

Yes. Definitely. In tow mode obviously.

@ramffml tried it too.

I understood the 2500 and 3500 frame is the same. Different spring setup and maybe shocks.

 

[ronheater70]

Thanks to those who shared their feedback so far!
After doing some add research...along with the higher rated weight distribution hitch I`m planning on upgrading the rear springs to a heavy duty set (less squat,) adding some additional cooling to the transmission along with the usual Amsoil.
The trailer manufacture stated that by design, the empty toy-hauler tongue weight is high, as the load increases in the rear weight shifts off of the tongue and redistributes throughout the rig. Dry weight is 7800 and GVWR is 11,950 32ft
We have plan to bring a 900lb golf cart OR 860lb Harley plus the usual trip related stuff so I think we`ll still be lower than the estimated 10.5k max, probably closer to 9.5k.
As for the 3:73 gears, I have actually found this gear and tall tires beneficial on the road with steep inclines, towing she`ll do 65mph at 2500rpm in 4th which makes down-shifting unnecessary and hunting between 1st and 2ed has not been a problem so far.
Truck only has 24k on it and has been meticulously maintained with limited towing..

HEMIMANN: did you find the Edge programmer helpful when towing?

37" tires are going to be anything but helpful towing 10.5K pounds with the 3:73 rear end. It all depends on where your towing but with that weight, those tires and bad section of road your gonna have a crap shoot between first and second gear. You WILL notice a difference between 10.5 and 9.5K, but if you are closer to the 9.5 you will be happier. If you are towing in 4th gear and 2500 RPMS with 37" tires , then you aren't on a very steep incline. Which may be good if that your normal drive. For reference I was running second Gear at 5K RPMS on several hills, that weren't really Major on the interstate with stock tires.

Im editing this to say that re-reading your post you are towing 7.5K around and seeing 4th gear and 2500 RPMS on hills, I was incorrectly thinking you were towing 10K around like that. My previous 2016 2500 towing north of 10K was in 2nd gear on the interstate a few times, it would upshift to 3rd for a short while then back to second.. I just slowed down and let it stay in second.

 

[HEMIMANN]

Right - don't put on expensive, monster tires to look cool, or whatever the thing is. You're not making a mud-bogger truck here.

Use a good pair of load range E tires in size range recommended for the vehicle.

 

[Rick Ram-jet]

I will be installing new tires before my trip, going to go with a milder all terrain, probably toyo at, may even drop down to a 35.
I realize the truck is currently set-up for the mountains in Big Bear, THE GOAL is to make changes better suited to towing....since the truck is in excellent shape, low miles and paid off long ago I really want to try and make this truck work, I want to avoid adding the sizeable extra cost of a diesel on top of the cost of a new trailer.
After reading some of the 1st hand feedback it sounds like it can be done, just need to choose the right combo and plan my routes wisely!