2020 Cummins ISB 6.7 Exhaust Brake Installation

[Forkfish]

I have a 2020 Winnebago 36H I just purchased. Apparently it does not have a exhaust brake installed. My question is has anyone had one installed??? I have contacted Cummins and they act like they could do it. But I'm not sure. I need some advise. Thank you in advance!

[dwaugh10]

The ISB6.7 uses the variable gate turbo (VGT) to perform the exhaust brake function. It should already be there.

David

[jacwjames]

I just looked at a brochure and it indicates that your rig has an exhaust brake.

Do you have a manual, it should have a section covering this.

[chuckftboy]

Did Cummins not explain that your turbo does act as an exhaust brake? I previously owned a ISB with a VGT and it did an excellent job holding speed in the mountains.

[Caliber]

To install a exhaust (VGT) brake on a 6.7, you'll need the switch installed along with the wire harness. Program the ECM ( turn on the feature) and program the TCM to downshift to the pre-selected gear.
A Cummins shop can do it as long as they can program the TCM. Otherwise it will also need to go to Allison for the transmission programing.

[Ray,IN]

Originally Posted by dwaugh10

The ISB6.7 uses the variable gate turbo (VGT) to perform the exhaust brake function. It should already be there.

David

[R.Wold]

Someone else here recently was confused about this too. I think they may have moved the control to a stalk on the column, and if so it may be less obvious, or even somewhat hidden. A lot stuff is now actually menu driven () now that used to be controlled by switches. Probably a closer look at the manual will lead you to it.

2020 36H Chassis Specs:

Freightliner® XCS Chassis
26,000-lb. chassis, Allison® 6-speed automatic 2100 MH transmission (34T)
27,910-lb. chassis, Allison 6-speed automatic 2500 MH transmission (36H)
29,410-lb. chassis, Allison 6-speed automatic 2500 MH transmission (38D, 38F, 38W)
340-hp Cummins® ISB 6.7L
NeWay® front air suspension
V-Ride rear air suspension
OptiView™ dash, digital instrument panel cluster
DriveTech driving system
160-amp. alternator
Air brakes w/ABS
Engine exhaust brake
Rear cap engine intake screen
Automatic hydraulic leveling jacks
7-pin trailer wiring
Trailer Hitch6 10,000-lb. drawbar/500-lb. maximum vertical tongue weight
Stainless steel wheel liners (34T)
Stylized Aluminum Wheels (NA 34T)
Slide room lock system
Information display center

[Forkfish]

My coach does not have the stalk and also no switch. Push button transmission.

[capnqball]

Did your dealer go thru a PDI when you purchased this coach (new?)?
I think a call to your dealer is in order and also to Winnebago customer service. I have not seen a 6.7 in RV service without an exhaust brake. Switch maybe missing?

[schad]

There should be a row of buttons left of the driver's seat above your leveling controls but below your mirror controls. Based on this blurry video I found, it may be the leftmost or second-from-left switch on that row. In particular, the leftmost switch looks like it may say "ENG BRAKE" while the second-from-left may say "EXH RET" (exhaust retarder).

If it's not those, you can take a good, well-lit, high-resolution picture of the buttons and switches over there and attach it to this thread. We need to be able to read the text or make out the icons printed on the buttons. I bet we can figure it out from that.

Or a call to Winnebago customer support could probably do it too.

It's almost inconceivable that your coach doesn't have that feature. Forza 36Hs with the stalk gear selector do -- I can see the icon for it in pictures. It looks like this: (((AUX)))

[Long Island Mac]

have a 2020 34T. Dealer did not explain very well, or not at all. Different tranny than last MH, a 3000 Allison, now a 2100?. Finnally figured the stick on right of steering wheel. Forward and down, exhaust brake on. pull back and down, manually downshift. Can't believe you do not have an exhaust brake, Drove 1500 miles trying to figure it out.

[grtharris]

Forkfish, This is what the drawing shows.

[Forkfish]

Mine is missing that button. Just a cover over that spot. Also no lever on the steering wheel.

[capnqball]

Are you the original purchaser? Call the factory! Provide your coach VIN or production number. There's something definitely amiss here. Go up the chain until someone gives you a good explanation.