z28fan

allright all you folks who tow a lot i have a question i will be hauling an 8k lb trailer from oklahoma city to seattle and i have a 6.7 with the factory exhaust brake i was wondering how to use it correctly do i just leave it on the whole trip or turn it on when i think i need it also i have been pulling it around town for the past couple days and i have had the brake on when i come to a stop light/sign the ruck really down shifts hard is that normal when i had my 06 i towed a boat from time to time and the tranny never shifted that hard is it because the exhaust brake is slowing the truck down faster than the wheel brakes and the tranny is having to compensate for that or is there a problem (auto 48rfe) thanks a lot

staarma

You can leave it on or just turn it on when you need it. Either way it doesn't hurt anything. I think your trans is the 68 series not a 48RE. Anyway, the trans will shift harder during decel because the ECU is controlling the convertor lockup and shifting when the brake is engaged. It is nothing to worry about. The 48RE acts the same when equipped with an exhaust brake. My dad has an 06 with the Jacobs and his downshifts hard when the exhaust brake is engaged. Nature of the beast. In order for the brake to be effective on an auto that's just what needs to happen, higher line pressure and a locked convertor.

JThiessen

So I've been doing some experimenting with mine on my 06. Since I bought the truck, I've generally run with the Jake on all the time. In that time I've noticed that having the Jake on affects the truck even when you are just driving. It will stay in the lower gear quite a bit longer. This is especially nice when driving on 35mph up and down roads. You dont have to put the pedal to the floor to get it to maintain 35-40 going up the hill. Since I installed the new Quad X2, I've also found that there is definitly potential to save some fuel by turning it off. When braking normally to a stop, my Rail Pressure runs about 670. When using the Jake, Rail Pressure is up around 800-900 depending on speed. Also, when "cruising" at about 45mph, with the Jake on, the tranny wont shift into OD at that speed. In a nut shell, I think I could save some $ on fuel by turning it off except when I need it for braking, or for climbing a hill.

chrleb1

Dodge is recommending to use the exhaust break as much as possible. I think they say this so that the turbo keeps its full range.

ccoop769

KEEP IT ON 24/7 and your truck will last longer in the long run

Treker

How do you figure the truck will last longer?

Just curious... I know it saves on wear and tear on the brakes. I bought mine, cause we tow a 11,600# 5'er, it makes hill descents and stopping a whole lot easier.

Like the other posters have mentioned, the transmission locks up like it's in tow mode with the EB engaged.

JThiessen

Huh?? Brakes, maybe.

ccoop769

Call up any dealer, they will tell you the same!!!!! Im not just talking about brakes, it has to do with the whole egr system and stuff

schv

Does that apply to the 6.7L engines only? My dealer has never told me that and nothing in the owners manual for my truck says that. Brakes is all they mentioned.

HOV

The 2006-07 models don't have an EGR system. The 07.5+ do, but when you make a statement like "it makes your truck last longer", people assume you're talking about all model years. The connection between the EGR system and the use of constant exhaust brake needs to be explained. You wanna take a hack at that?

ccoop769

Sorry, thought it was common sense to the 5.9 owners that they dont have a factory exhaust. Figured if you had the money to spend on these truck, you would have common sense. Im just helpin out the fellow who started the thread who has a 6.7. But ya, your correctly right, unless an enginneer from dodge would like to jump in, im just saying what dealers told me and alot of everyone else

BlueDually

I think statement "it will make your truck last longer" comes from the idea that with the brake on, it will run higher egts at idle/ warm-up, which will, in the long run keep your engine cleaner. Instead of slobbering fuel at warm up and, extended idle periods.

JThiessen

I think that falls under the Myth category. Its basically unprovable either way.

HOV

That's a super awesome explanation, thanks. We have more money than brains and the dealer told you so. Great post!

CD in NM

I like that explination too - We probably DO have more money than brains and coming from the dealer who know the real underlying motivation??

Since I know little about the 2007.5's and the DPF/EGR stuff, let me make what could be a real stupid guess at how/why the dealer might say running it all the time could be beneficial.

When the regen is taking place, it is actually heating things up to clean the filter, right? So, suppose the dealer sees this as a way to assist the filter cleaning and actually decrease the amount of regen runs?? What actually is it that sets a regen run into play - hours, temps, carbon buildup?? We know that some have discussed a decrease in mileage on their overhead while a regen is taking place, fuel event or overload of fuel to burn the filter clean?

I'm not saying it actually WOULD do that, just trying to make sense out of the dealers reasoning.

IF that IS a correct guestimation behind the dealer saying it will be beneficial to the overall engine life, then another correct guestimation would be that the regens actually shorten the engine life or have some negative effect??

Oh well, just thinking out loud as to the dealers reasoning. We all KNOW that by using an exhaust brake the service life of the brakes is increased, how it would affect the service life of the engine may well be another story.

CD