I was driving my buddy's 2008 GMC diesel PU in Colorado a few weeks ago. When we went down some 6% grades he had me put tow haul on. Simply tapping the brakes at that point caused the truck to use engine braking that would have stopped the truck had I not used the accelerator.

So what does my 2008 F-350 6.4 psd have as far as engine braking? I've never noticed the tow haul helping out like that when I have been towing. Recently I saw a full page ad for Banks Speedbrake directed squarely at Ford 6.0/6.4 owners. I read what I could find and went to Bankspower.com, but I wondered what it cost. In order to find a dealer I had to give Banks contact information, and someone called me the next day. He wanted me to buy the six-gun, IQ, and speedbrake. I told him I did not want a tuner, and, oh by the way, was the speedbrake going to lose me my warranty. It accesses the turbo and the torque converter, so I can see Ford trying to blame it for something. He told me Ford won't know about any of it, and the tuner is not a programmer. And I never did get the name of a local dealer, he told me he'd have to call me back. Who knows, maybe he will.

I don't know about the tuner, but I can see a value to having the engine braking capability on the diesel. Unless I missed something, Ford seems to be the only one of the big three without it. I looked over the forum and have not seen anything on the Banks Speedbrake. Anyone tried it? Former Duramax owners, perhaps? Is this just another way for us to risk losing our powertrain warranty? Or is this a fairly safe add on. Putting in an aftermarket exhaust brake would be a definite no-no according to my dealer, but this doesn't require any exhaust or engine modification.

Rdog1

 

Well here is the deal. Right now you need the IQ to control the speed brake. I don't think they have made the speed brake a stand alone unit yet, hence the need for the 6-gun.

The IQ is going to be a stand alone (no 6-gun required) very soon. So maybe then the speedbrake could simply just plug into the IQ and a couple of wires going to the turbo. Not sure about that one just yet.

As for local dealers vs dealing with Banks themselves. I would recommend just dealing with Banks as they are actually easy to work with and anyone can do these on their own.

Now for your trans now to downshift in tow/haul. I tap my brakes and it will drop a gear and act as a eng brake. So no real need to for the speedbrake to me.

 

X2

When in tow haul mode mine does the same as senix explained, just tap the brakes and the truck will downshift and hold that gear the whole way down. For the remainder of the hill I don't need to continuously use the brakes.

Kyle...

 

Fortunately I haven't towed down any long 6% grades on the east coast yet. Going through the Adirondacks, Appalachian and the Green mountains I have only noticed a few places with runaway truck ramps. But I never noticed the braking help in tow haul mode like I got with that GMC (Sierra? not sure the model). I will be more sensitive to it now, to see how mine really performs to my needs. I'll pay attention when I tap the brakes in tow haul mode on a descent. I couldn't find anything in the owners guide or Diesel supplement that referenced this.

I'm trying to resist the temptation to do anything to my truck that will void the warranty. This truck has enough power to easily pull my current toy hauler, and I don't think the mpg improvements provided by a tuner/programmer would pay for the tuner in fuel savings over 4-5 years given my average annual mileage. So a tuner doesn't make sense for me. But I was intrigued to read about the speedbrake. I've read some of Senix's other posts about IQ becoming standalone - something the Banks guy didn't let me know. Sounds like that could be a very useful tool, too. I thought it would be interesting to start up a discussion on the speedbrake since I hadn't seen any posts.

 

Yes, I am very interested in the iQ as a stand alone unit when it becomes available as well.

And as far as tapping the brakes goes... It isn't so much as a "tap" more of a apply pressure until the truck downshifts, then release and it will hold that gear for the remainder of the descent. Sometimes it takes a little more to get it to downshift.

 

I had the Banks engine brake on my '99. It was a nice addition. Cool to use and helped control downhill speed, until it broke.

Also used Banks exhaust, turbo upgrade and other performance parts and enjoyed the extra HP and torque, until they broke too.

Both worked well for about 5 years until problems began to surface.

Banks is great to deal with during the sales period, and tried to be helpful during the repair work. However, the bottom line for anyone considering these types of aftermarket parts is that it will be (1) difficult to coordinate with your local repair shop and Banks unless you are blessed with a knowledgeable Banks installer in your area, and (2) expensive to ship parts back and forth to California, and purchase replacement parts from Banks. My truck was in a Ford dealership for 6 weeks while I tried to get all the Banks stuff working again, which was finally accomplished at a cost in excess of $3,000.00.

I like my 08' 6.4. The towhaul works fine once you get the hang of it. You won't find any after market parts on this truck until the Ford warranty expires, and then the pollution crap goes in the trash and I will put on whatever parts will best help fuel mileage.

 

If you work with Banks directly, buy from the them directly then shipping and everything is free, paid by them.

 

I was dealing with Banks directly and the shipping costs were expensive. They may pay for shipping new parts, but I had to pay to ship the broke parts to them for analysis, and Banks charged shipping to send the fixed and/or replacement parts back to me. I am not bashing Banks, just stating for those who may have only dealt with the sales department at Banks for new purchases that communication is not as easy or fast when phoning about older broken parts and it is expensive to deal with a company in California.

 

From Page 268 of my owner's manual:

D (Overdrive) with Tow/Haul OFF

D (Overdrive) with Tow/Haul OFF is the normal driving position for the
best fuel economy. The overdrive function allows automatic upshifts and
downshifts through gears one through five.

D (Overdrive) with Tow/Haul ON

The Tow/Haul feature improves transmission operation when towing a
trailer or a heavy load. All transmission gear ranges are available when
using Tow/Haul.
To activate Tow/Haul, press the
button on the end of the gearshift
lever.
The TOW HAUL indicator light will
illuminate in the instrument cluster.
Tow/Haul delays upshifts to reduce frequency of transmission shifting.
Tow/Haul also provides engine braking in all forward gears when the
transmission is in the D (Overdrive) position; this engine braking will
slow the vehicle and assist the driver in controlling the vehicle when
descending a grade. Depending on driving conditions and load
conditions, the transmission may downshift, slow the vehicle and control
the vehicle speed when descending a hill, without the accelerator pedal
being pressed. The amount of downshift braking provided will vary based
upon the amount the brake pedal is depressed.
To deactivate the Tow/Haul feature and return to normal driving mode,
press the button on the end of the gearshift lever. The TOW HAUL light
will no longer be illuminated.
When you shut-off and restart the engine, the transmission will
automatically return to normal D (Overdrive) mode (Tow/Haul OFF).
Do not use the Tow/Haul feature when driving in icy or slippery
conditions as the increased engine braking can cause the rear
wheels to slide and the vehicle to swing around with the possible loss
of vehicle control.

2008

 

"Tow-Haul also provides engine braking..."

I read that in the owners guide - but my assumption was it refers to the gas engine, which is a lot better braking than with a diesel. If you don't have a diesel you get this owners manual without the diesel supplement, and it applies to the gas engine, which is accurate. So it ignores the obvious difference and begs the question. I couldn't find anything in the diesel supplement about "engine braking". There are, however, warnings (page 6 of the D. supp.) that the PCM will not "..prevent engine overspeeding resulting from downshifting at high vehicle speed or by descending steep grades at too high a vehicle speed for a selected transmission gear..." I take that as a hint to use the brakes as a preventative measure. So the shifting and overdrive stuff I believe. But I ignored references to engine braking in that manual - I'd be more comfortable if it mentioned that it worked for the diesel too, but I doubt it applies to any significant extent to diesels (other than be careful when towing down steep grades to prevent overspeeding). Both Dodge and GM have added active systems to address this issue, but I can't find any reference to Ford having something as well. If it has, I'd love to learn about it and not spend any extra money!

 

It does apply to the PSD. The ECM and TCM will keep the motor from over-speeding. And yes there is considerable engine braking going on.

As an example, last summer I decended MT. Washington, NH. This road is very narrow and sharp turns some of it is 12% or more grades. I used the tow/haul mode all the way down and never exceeded 25 mph, thereby saving my brakes. And yes you can really smell it from those in front of you.

 

Thanks, Senix, good to know. But the last time I descended Mt. Washington I took the cog railway! You sure that smell was from those in front of you?

I do appreciate the benefit of your experience, and I did read the manual, I just didn't believe it. That's why I started this discussion. I've only towed with this truck one season and only had one really steep grade in Conn. on SR 60 (I think). My wife was complaining about the smell too. As I said in my earlier post, I will be paying more attention to how this all works as I gain more experience with it.

 

The way the manual says it, the only way to reach past acceptable RPM's is to downshift too soon (manual transmission only) like senix said, the computer won't let the automatic over-rev the engine. Also mine definately will engine brake going down hills if the brakes are applied in tow/haul mode.

 

I pull a 17,000 lb 5th wheel. Last year I toured north central NY and back through PA. Lots of mountains. I used the Tow/haul a lot and it works great. My previous truck was a 2001 7.3L . On that truck to get engine back pressure I had a choice between a banks style exhaust brake or a mod to the exhaust butterfly valve. I chose the mod. The real purpose of the BF valve was to be closed and help the motor warm up faster. The mod simply provided a switch to close the valve in the exhaust and created engine braking. Then to get the best results I also had a switch to lock the torque converter so the tranny would hold the truck back. The tow/haul must work something like that to create the engine braking. For sure it is just as good and a lot simpler. If it's not holding you back it either isn't working or the hills aren't steep enough. When mine kicks in it really causes a clunk as the slack comes out of the 5th wheel hitch. In fact I would say it is my favorite improvement in the 08 over the 01. Well, maybe my second favorite behind the DRWs.

 

This is what I wanted to hear! I'll feel a lot better knowing this is a feature of this model. I just haven't seen this reviewed or discussed anywhere with this truck - but I am new to it. Thanks!