Towing vs engine capacity

Nutravlr · 05-14-2011, 08:44 AM

Well, on to something new (used). Have gotten a 2005 36 ft with an ISL02 400 hp cummins. I understand the axle or such ratio is 4.63. Any ideas what is a good, practical, limit for the weight of a toad for this engine? I understand that the hitch capacity is important, and GCVWR. Mike

Mekanic · 05-14-2011, 09:24 AM

Quote:

Originally Posted by Nutravlr

Well, on to something new (used). Have gotten a 2005 36 ft with an ISL02 400 hp cummins. I understand the axle or such ratio is 4.63. Any ideas what is a good, practical, limit for the weight of a toad for this engine? I understand that the hitch capacity is important, and GCVWR. Mike

As I understand it that engine is used in some Over the road tractor trailer trucks, so it should be able to pull all the weight that the hitch and Trans could ever handle.
I'd be more concerned about keeping the trans cool than I would worry about the engine.

Triker56 · 05-14-2011, 09:47 AM

Your limit will be what your tow bar is rated for or the GCWR.
Whichever you go over first.

Is your hitch a 10K or 15K one?

**RickO** · 05-14-2011, 10:02 AM

I have the ISL 400 in my 40' coach and pull a Ford Explorer. Can't even tell it's back there. You have plenty engine to tow whatever you want.

Rick

FlyingDiver · 05-14-2011, 10:19 AM

Quote:

Originally Posted by Nutravlr

Well, on to something new (used). Have gotten a 2005 36 ft with an ISL02 400 hp cummins. I understand the axle or such ratio is 4.63. Any ideas what is a good, practical, limit for the weight of a toad for this engine? I understand that the hitch capacity is important, and GCVWR. Mike

The hitch and GCWR are way more important than the engine. Use those as your guideline, not the engine.

joe

Nutravlr · 05-14-2011, 10:45 AM

Thanks to each of you, very much. I do not have delivery yet so do not recall the GCWR. The blue ox I am taking from my diesel Endura is a 10,000 model. I do not know what the hitch is on the MH, it kinda sticks thru the bumper, all I can report is a 2005 36 ft MH with that engine.

DriVer · 05-14-2011, 10:48 AM

Quote:

Originally Posted by Nutravlr

Well, on to something new (used). Have gotten a 2005 36 ft with an ISL02 400 hp Cummins. I understand the axle or such ratio is 4.63.

Mike, Who made the coach body? That will help. Typically vehicles with 400HP ISLs normally do a good job haulin' 10,000 pound toads.

Nutravlr · 05-14-2011, 12:15 PM

Foretravel U270 2005 36 ft

I probably should know more but have been a bit overwhelmed with info. It similar to the Endura in some ways but more different, so new learning curve just begun. Thanks for your and others interest.

Mike

Cat320 · 05-14-2011, 12:18 PM

Somehow, maybe call the factory, you need to find your GCWR and the hitch capacity. The formula for tow capacity is the GCWR minus the weight of the coach when ready to tow (ie loaded)...or the hitch capacity, which ever is less.

For example, say the GCWR is 50k and hitch capacity is 15k. If the coach weighs in at 30k, the tow capacity is 15k. If the coach weighs in at 40k, the tow capacity is 10k.

Nutravlr · 05-14-2011, 05:11 PM

Thanks but my concern is not violating weight limits but rather the limits of the engine and transmission. The transmission is a 3000 allison. My MH we are selling is a 300 hp duramax, 520 torque, maximum loaded MH of 19500 and GCWR of 26,000. So in theory I could go up to 6,000 or so toad. Nonetheless, to avoid stress to the system (I thought!) stayed with 3,700 toad, SMI brake. Under that same philosophy, wondered what I can do with this new (to us) system-------not stress that 8.9 cummins and 3000 alison and have plenty of power for hills and mountains

Cat320 · 05-14-2011, 06:33 PM

Quote:

Originally Posted by Nutravlr

Thanks but my concern is not violating weight limits but rather the limits of the engine and transmission. The transmission is a 3000 allison. My MH we are selling is a 300 hp duramax, 520 torque, maximum loaded MH of 19500 and GCWR of 26,000. So in theory I could go up to 6,000 or so toad. Nonetheless, to avoid stress to the system (I thought!) stayed with 3,700 toad, SMI brake. Under that same philosophy, wondered what I can do with this new (to us) system-------not stress that 8.9 cummins and 3000 alison and have plenty of power for hills and mountains

You are missing the point. The weights are based on the drive train...the engine and transmission, and everything else. Stick to the weights and you'll be fine.

**Gary RVRoamer** · 05-15-2011, 02:52 PM

I'm towing a 4900 lb toad with my ISL370/3000MH combo. The combined weight of coach and toad, loaded for the road, is 37,700 lbs. Don't even know its there until I reach a 4-5% grade.

You have plenty of power - just stay within the hitch limits (probably 10,000 lbs or more).

Coma · 05-15-2011, 03:19 PM

It says here that 18k is hitch rating.

This says the difference between GVW and GCW is 10k. If I read it right.

So, if you load your MH to max then you can tow 10k.

Cat320 · 05-15-2011, 07:12 PM

Quote:

Originally Posted by Coma

It says here that 18k is hitch rating.

This says the difference between GVW and GCW is 10k. If I read it right.

So, if you load your MH to max then you can tow 10k.

There is no MH with a hitch rated for 18k that I know of.

Read post #9...that explains it.