Towing: How much have you towed?

[stratosurfer]

All,

From all of my research, and it is extensive, I believe a C-Max hybrid should easily be able to tow a relatively light trailer. I have studied the HF 35 Ecvt and spoken to a friend who is an engineer at Ford for over 30 years now and I don't see any reason why the Cmax can't tow a light trailer safely and without over-stressing the Ecvt.

Is anyone towing any decent trailers?

Success?

I understand that the manual says 'Not Recommended' if that is your only comment, then save it, it is already noted. My friend Ford's response to the 'Not Recommended' comment in the manual is simply, 'Possibly Ford would like to steer you to a more profitable vehicle?'....

The HF 35 trans is modeled after the Toyota Prius Hybrid drive system, and is even stronger than the Prius Hybrid drive (more HP engine and battery). If you browse the Prius forums you will find people routinely towing trailers over 1,000 lbs, one guy tows a 1,900 lb travel trailer with no problems. Ford is bringing an F150 Hybrid and Escape either in 2019 or 2020, both will be rated to tow and certainly will use the HF35 model.

I have an 1,100 lb Waverunner I would like to tow and believe I can do so safely. I plan on putting brakes on the custom trailer.

Trying to see what other people are towing and the results.

Thanks

 

2013 Ford C-Max Hybrid 102K miles

 

[jestevens]

Can you ask your Ford Engineer friend why the 2013 HF35 had bad bearings?  The HF35 is not a Toyota design, the CMAX is not rated to tow anything, people use it as a TOAD for RVs, and even then it seems to put stress on the transmission if you tow it with wheels down? ( I guess because if the hybrid ICE isn't running it's not being lubricated).

Edited August 14, 2018 by jestevens

[stratosurfer]

The HF 35, on data I could find and in the C-Max alone in the US has only 4 complained online about failures against 38,000 C-Max's sold in 2013 alone. So failures seem to be anomalies at this point and hopefully happened early enough to be covered under warranty. The HF 35 is based upon the design of the Toyota 2nd Gen hybrid drive, Ford acquired the rights to 'copy' the design in a patent sharing agreement with Toyota. 

[jestevens]

I tried doing a google search for towing on the site figuring that someone might have tried it in the past, here are some results:

 

http://fordcmaxhybridforum.com/topic/2399-suitability-for-occasional-towing/

http://fordcmaxhybridforum.com/topic/6561-towing-with-a-c-max/

http://fordcmaxhybridforum.com/forum/19-cargo-hauling-roof-racks-towing/

 

I agree that there are similarities in the design but it is not the exact same transmission so I can't say that it would have the same strain as the Prius or not. 

 

 

The power split device for hybrids was apparently thought up by TRW engineers in the late 1960s, it took a while for battery and electronics technology to be reliable enough to be used in production.

 

https://patents.google.com/patent/US3566717?oq=Baruch+Berman

https://www.autoblog.com/2009/01/02/so-you-think-toyota-invented-the-modern-hybrid-think-again/

 

A friend of mine rented a pickup from U-HAUL thinking he could use it to tow a camper but didn't have proper controls, electric braking, etc. - He lost control coming down a hill and jackknifed - destoyed both the camper and the truck pretty thoroughly.  I know you are planning to tow a lot less, hopefully it will work but I guess my only point is my friend didn't think there was any problem with his tow either until he came down the hill and the front end got lighter than the back.  Hopefully that wouldn't happen in your case.

Edited August 14, 2018 by jestevens

[stratosurfer]

The interesting is it is called an ECVT but it really has zero in common with a true CVT with spindles and a belt. There's no belt or chain at all on the HF 35. The HF 35 is a much stronger, bigger version of the borrowed concept of the 2nd GEN Prius hybrid drive. It can get hot, but not like a normal auto box can, no real clutches, no torque converter. The actual GM1 and GM2 can get hot but the HF35 has water cooling for this. I just want to find out if someone else is towing any weight around 1,000 lbs or so. I have a 3/4 Diesel Suburban (actually a 1 ton) and have towed 12,000 lbs with it, I understand the dangers of towing and as I mentioned I will get a custom trailer with brakes on it.

[stratosurfer]

I tried doing a google search for towing on the site figuring that someone might have tried it in the past, here are some results:

 

http://fordcmaxhybridforum.com/topic/2399-suitability-for-occasional-towing/

http://fordcmaxhybridforum.com/topic/6561-towing-with-a-c-max/

http://fordcmaxhybridforum.com/forum/19-cargo-hauling-roof-racks-towing/

 

Thanks for the links, they were very helpful.

[plus 3 golfer]

The interesting is it is called an ECVT but it really has zero in common with a true CVT with spindles and a belt. There's no belt or chain at all on the HF 35. The HF 35 is a much stronger, bigger version of the borrowed concept of the 2nd GEN Prius hybrid drive. It can get hot, but not like a normal auto box can, no real clutches, no torque converter. The actual GM1 and GM2 can get hot but the HF35 has water cooling for this. I just want to find out if someone else is towing any weight around 1,000 lbs or so. I have a 3/4 Diesel Suburban (actually a 1 ton) and have towed 12,000 lbs with it, I understand the dangers of towing and as I mentioned I will get a custom trailer with brakes on it.

There is no water cooling of MG1 and MG2  in the HF35.

[cr08]

Check over on the Ford Escape section of the Green Hybrid forums. There have been some posts quite a few years ago of people towing, and some with very large loads, in the Escape hybrids. They have pretty similar versions of the same transmission we have in ours and likely similar load capacity engineered in. Still boils down to a 'no towing' by Ford but some have done it to varying degrees.

 

https://www.greenhybrid.com/forums/f26/

 

As jestevens alluded to, I think the biggest concern is ensuring control and braking of whatever is being towed. That is a much bigger issue over simply being able to pull the load from a stop or maintain speed.

[jestevens]

My guess is that the lake is a long way from your house?  'cause otherwise I would use the big truck to tow and have peace of mind.  ..and I did have the exact problem that instructor states in the video, Toyota service thought they were doing me a favor flushing the transmission on my Prius with good standard less expensive transmission fluid instead of the WS ATF that was spec'd to help cool the windings rather than degrade the insulation on them.

 

I think the HF35 has a mechanical oil pump, In the hybrid it operates whenever the engine is on, in the Energi it is electrically driven since you can go longer without using engine.  For a while people thought maybe that was an issue, that people going extended range with the hybrid on battery might cause more stress on the transmission. 

 

If you are towing I'm pretty sure the engine will be on, so the transmission will get cooling but I don't know if it's sufficient or not, your engineer friend apparently thinks so.

 

From what I understand the liquid coolant loops are for the engine and the HV charging electronics, the DC to DC inverter, etc. gets pretty hot.

[plus 3 golfer]

...

 

I think the HF35 has a mechanical oil pump, In the hybrid it operates whenever the engine is on, in the Energi it is electrically driven since you can go longer without using engine.  For a while people thought maybe that was an issue, that people going extended range with the hybrid on battery might cause more stress on the transmission. 

 

If you are towing I'm pretty sure the engine will be on, so the transmission will get cooling but I don't know if it's sufficient or not, your engineer friend apparently thinks so.

 

From what I understand the liquid coolant loops are for the engine and the HV charging electronics, the DC to DC inverter, etc. gets pretty hot.

The AC-DC inverter (not DC-DC) is liquid cooled.  The HV DC - 12V DC converter is under the rear hatch floor and is air cooled.

 

I've monitored ECT, TFT, and MG1 and MG2 coil temperatures under high load conditions (80+ mph, up and down steep grades) at 100F+ ambient with AC on and around 500 pounds of  cabin load.  I never came close to any temperatures that would trigger an alarm, DTC, or emergency operating conditions to protect engine / transmission from damage.  I've also run with grille covers on the middle and lower grilles at similar conditions except at max. ambient of about 40F with no issues.  Adding 1000 pound tow would certainly increase load and temps absent the tow.  But, if one drives "conservatively", I doubt overtemperature will be an issue.

Edited August 15, 2018 by Plus 3 Golfer

[ptjones]

I also agree with Plus 3 Golfer, WT will not be the problem, with having my trans fail I would be very reluctant to adding more stress to the trans. IMO :) 

 

Paul 

[stratosurfer]

My guess is that the lake is a long way from your house?  'cause otherwise I would use the big truck to tow and have peace of mind...and I did have the exact problem that instructor states in the video, Toyota service thought they were doing me a favor flushing the transmission on my Prius with good standard less expensive transmission fluid instead of the WS ATF that was spec'd to help cool the windings rather than degrade the insulation on them.

 

I think the HF35 has a mechanical oil pump, In the hybrid it operates whenever the engine is on, in the Energi it is electrically driven since you can go longer without using engine.  For a while people thought maybe that was an issue, that people going extended range with the hybrid on battery might cause more stress on the transmission. 

 

If you are towing I'm pretty sure the engine will be on, so the transmission will get cooling but I don't know if it's sufficient or not, your engineer friend apparently thinks so.

 

From what I understand the liquid coolant loops are for the engine and the HV charging electronics, the DC to DC inverter, etc. gets pretty hot.

Complex situation... I live in San Angelo Texas and work one week per month in Friendswood Texas, 420 miles away. I have 2 Waverunners and have determined to tow one down to the coast (Friendswood area) where I will do some group river, bay and Gulf rides with a great group of folks in the Houston area in conjunction with my trips down there. I will tow one of my two down there and leave it there in storage. I could drive the 3/4 Suburban Diesel just to tow 1 ski and leave it, or tow it down there with the C-Max and leave it there and have the C-Max to drive around all week in Houston area traffic. The Suburban is 20 years old and I was hoping to not have to drive it to work and around in Houston area traffic. I will have the 1,200 lb Waverunner and trailer left down there so the tows thereafter will only be local, maybe 50 miles max flat-earth tows to the meeting place to launch our ski's. This is my quandary of working to ensure this C-Max hybrid will handle this situation without damage to drive train. As mentioned I will have a custom trailer built with surge brakes to avoid the controller install which appears challenging. 

Edited August 15, 2018 by stratosurfer

[stratosurfer]

The AC-DC inverter (not DC-DC) is liquid cooled.  The HV DC - 12V DC converter is under the rear hatch floor and is air cooled.

 

I've monitored ECT, TFT, and MG1 and MG2 coil temperatures under high load conditions (80+ mph, up and down steep grades) at 100F+ ambient with AC on and around 500 pounds of  cabin load.  I never came close to any temperatures that would trigger an alarm, DTC, or emergency operating conditions to protect engine / transmission from damage.  I've also run with grille covers on the middle and lower grilles at similar conditions except at max. ambient of about 40F with no issues.  Adding 1000 pound tow would certainly increase load and temps absent the tow.  But, if one drives "conservatively", I doubt overtemperature will be an issue.

This is the data I am looking for, and yes I will drive -very- conservatively. Probably between 65 and 70 max on freeways. Looking at the design and build of the HF35, I believe if I do drive very carefully, and with the trailer with brakes, I can't imagine this would stress anything on the car or be unsafe.

Edited August 15, 2018 by stratosurfer

[stratosurfer]

I also agree with Plus 3 Golfer, WT will not be the problem, with having my trans fail I would be very reluctant to adding more stress to the trans. IMO :)

 

Paul 

Did you get any report on specifically why and which parts of the HF35 failed? When I ran searches, I found that 38,000 C-Max hybrids were sold in 2013 alone in the US, there are only 4 total -complaints- on the 2103 C-Max's transmission on carcomplaints.com, I know this is not all the complaints/issues but it a starting point.

 

https://www.carcomplaints.com/Ford/C-Max_Hybrid/2013/

[ptjones]

The failures have to be in the hundreds, maybe more.  The Dealer that replaced mine had already done 3 before mine and that was almost 3 yrs ago. :sad:   Probably more like a  thousand or so.

 

Paul

[plus 3 golfer]

stratosurfer, are you familar with FORScan?  With the appropriate ELM327 device, about $10 (HS CAN data) upto about $80 (if one wants to monitor data on the HS and MS CAN automatically) and the appropriate ForScan APP for a smartphone, you can monitor virtually all the PIDs in the C-Max. Then, you can monitor temperatures while towing for anything unusual.

 

Below are two DTC for temperature conditions of the transmission.  I have not seen any temperatures remotely close to triggering the DTCs or Over-temperature Warning. Typically at high speed interstate driving (75+) in summer in Phoenix area, TFT runs less than 165F and traction motor coil temps are no more than 30F above TFT and generally only when doing maximum regeneration down long hills when filling the HVB.  Also attached are typical temp values from the Service Manual.  TOT (Transimission Oil Temp) = TFT.  ECT (engine coolant temp = about 195F).  ECT (Cylinder Head Temperature proxy for ECT) is further down the list of typical values and not shown in the attachment.

 

Motor Coil Temp (P0A2B)

| Transmission Fluid Temperature - Generator Coil Temp | < 10 deg C AND

| Transmission Fluid Temperature - Motor Coil Temp | > 30 deg C AND

| Motor Coil Temp - Generator Coil Temp | > 30 deg C

Generator Coil Temp (P0A37)

| Transmission Fluid Temperature - Generator Coil Temp | > 30 deg C AND

| Transmission Fluid Temperature - Motor Coil Temp | < 10 deg C AND

| Motor Coil Temp - Generator Coil Temp | > 30 deg C

 

 

Motor/Generator Coil Temp Over Temp check malfunction thresholds:

Motor/Generator Coil Temp over Temp

Motor/Generator Coil Temp > 140 deg C OR Transmission Oil Temp > 115 deg C

 

 

 

[plus 3 golfer]

As far as the transmission failures, you can glean from this TB that the issue is with the transfer shaft bearings.  What causes the failure is not clear (only Ford can answer this). The TB covers 2013-2016 MYs which might indicate a design issue since one would think that issues with the "bad" parts would have been resolved by the date of the TB.  So, additional load on the transfer shaft might exacerbate failures.  

[ptjones]

It seemed to me that a bearing was wearing out, because the longer I drove MADMAX the more slop there was in the planetary gears.  I guessed that they didn't heat treat some of the bearings right and there was probably a number of ovens so some would be OK and a few wouldn't. :sad: IMO, we will probably never find out unless someone tares a trans apart.

 

Paul