Thinking about a MMH as a daily driver and TOAD for our MH.

But I worry about the safety of FWD and/or front torque biased AWD during the winter when our mountain pass highways are covered with packed snow and ice.

Does anyone know if it's possible to remove and discard both front halfshafts and build a circuit to continuously engage the rear driveline clutch?

I know the owners manual indicates that the MMH can be towed 4-down but this will allow an additional level of safety as all four wheels would be uncoupled from the driveline during the tow.

 

I'd wait for some response from current owners before looking at such a drastic solution. Presumably it is the same exact system in the 'regular' Escape/Mariners. You might want to check out www.escape-central.com and ask owners over there about snow/ice driving experience.

 

Hi Willard

It doesn't matter if you tow the AWD behind your Motor Home regarding the FWD portion, all wheels are disconnected from eCVT and engine in neutral. At first, I thought the FEH and MMH had a center axle disconnect, but the more I read the patent, they may have disconnects at all drive wheels for neutral towing.

I use neutral all day long for coasting whenever I can to save fuel. You can feel the disconnect and glide 38% further in neutral, engine on or off in EV.

Read more about the disconnect in Ford's patent.

http://www.freepatentsonline.com/679...hlight=5343970

GaryG

 

I don't think that patent applies to the form of coupling to the rear driveline of the FEH/MMH. It appears more to me to be an adaptation of something already commercially available via ramco.com.

The way the patent reads the proposed method is either on or off, nothing in between.

 

That's correct, the neutral disconnect is an on or off condition. Why would you need anything else for towing? The AWD and FWD traction system is a separate mode for driving, not towing.

This is the only patent system that would allow neutral towing in a Hybrid AWD and FWD from Ford. The main reason for the disconnect is to allow control of vehicle in the event of elec motor and drivetrain lock-up. This system is also a benifit to allow 4 wheels on the ground towing up to 75mph. It works great for coasting to improve your MPG like I said also. There are test I conducted back in Dec. '05 documented here on GH showing the difference between coasting in Drive and Neutral. Neutral produced a 38% further coast from 40mph to a stop in both engine on and EV. This is when shifted from coasting in Drive to Neutral. Later on, GreenFEH found this patent that explained why.

If you put the FEH or MMH on a rack in neutral and spin the wheels and the axles turn, then the disconnect is between the axles and the output shaft of the eCVT. I have not done that yet to verify a center axle or wheel-end disconnect.

GaryG

 

Hi:

Haven't been through a winter yet with our FEH. But have been through about 18 of 'em with Subaru's. FWD then AWD as needed. Same idea in the FEH. No Problems.
Steve
Oregon

 

While looking for TSB's, I found that there is a TSB issued for both the FEH and the MMH, with a summary of "NEUTRAL TOW CAPABILITY -- SERVICE KIT REQUIREMENTS."

Unfortunately, one has to pay to read the full TSB, so I haven't. However, that summary makes me wonder if something, like the installation of some "service kit", needs to be done to allow one to tow a hybrid behind a motor home.

 

I think the file has already been posted and as I recall the document lists the hybrid as not needing a service kit. It might be posted at the yahoo group.

 

Yes its there (last file on the list) and it says there is no kit required for the hybrid.

 

In my original post I tried to cover two separate issues...

A: Can the FEH/MMH be towed behind a RV/MH all four wheels on the ground?

The simple answer to that was "yes".

Apparently, as very adequately described in the patent, there is an electromagnetically actuated clutch between the ICE/electric drive motor combination and the driveline output to the front and rear wheels.

The way I read the patent the primary purpose of that clutch is to protect the electrical system should the vehicle be rear-ended, for instance. The AC drive motors use a permanent magnet rotor so a rear-ender might result in the electric motor rotational speed being forced so high that the resulting voltage generated damages the electronics. Therefore an inertial switch is used to detect this event and open the driveline via the patented clutch concept.

Obviously the clutch can have other valuable uses, mine, for instance.


B: Due to my long experience driving/surviving in wintertime conditions I have an inate fear of FWD and front biased AWD vehicles when the roadbed is slippery. There is a really good, sound, reason truckers are required to have a set of "drag" chains on the rearmost wheels of their trailers traveling over our snow and ice covered passes in the wintertime. Greater traction on the front on dry pavement is fine, but that asset quickly turns into a horrible detriment when road conditions become adverse, packed snow or ice.

So the second issue I was addressing was whether or not the rear driveline torque apportioning "method" could be permanently engaged with both front halfshafts removed. Personally I would consider that, RWD only, a much safer configuration in wintertime conditions than the FEH/MMH AWD model even if it already had VSC (PSM, ESC, etc.)and traction control.