Exhaust brakes - Montana Owners Club

TAKPAK · 12-08-2008, 04:00 AM

Just curious for those Chevy/GMC Duramax owners out there...has anyone added any kind of exhaust brake to their TV? I have an '08 GMC D/A combination. I am considering the Banks "speed brake" that is simply an electronic add on that utilizes the turbo vanes, the transmission, etc, to help provided additional help slowing the vehicle down. While the Allison/Duramax combination is a slick deal, it still makes me nervous when the RPM's on the engine are closing in on 3400 RPM going down a steep hill. I would just like to give it a little more help, so to speak. Any comments/experience?

rogue · 12-08-2008, 07:16 AM

I've had no problem with my 2007 classic D/A and using T/H mode. I thought about an Exhaust Break, but found that voids the warranty. So as long as it works OK without the Exhaust Break, I'm happy.
Bob

Delaine and Lindy · 12-08-2008, 09:03 AM

I've pulled with the Exhaust brake and the Allison and really liked the Allison better. We have also pulled the Rockies and haven't ever had a problem with the RPMs. I do keep the RPM under 3700 and the Allison does the rest. That was with a Cambridge pushing the Truck, and believe me the Cambridge did the job it was much heavier than the Montana's. Before I would invest in the exhaust brake , I would put Disk brakes on the Montana its a whole world of difference. I don't know about the warranty issue but would for sure check with GM. As we all know the warranty issue will be looked at close before repairs. Good Luck. GBY...

ols1932 · 12-08-2008, 10:06 AM

I have a Ford F-250 with a Banks Exhaust brake. The older Ford diesels really need an exhaust brake but I would not think the Duramax/Allison combo would need one. It seems to me that the Tow/Haul mode of operation would negate the use of an exhaust brake.

Orv

wild willy · 12-08-2008, 10:12 AM

I put the BD exhaust brake plus 4" intake & exhaust. Not only do I use it in the mountains but we take a lot of secondary roads so when we come to a town just flip on the brake, it slows down w/out using foot brake. Also use it on freeway off-ramps. Cost vs. brkae shoes- I don't know but like the added braking power. As for the lg. intake & exhaust, it's noisy! But it does have lots of power & never an overheating problem. Another thing I added was a cast aluminum pan on the tranny which holds an extra 4 qts. that keeps the tranny cool. This is all on an 03 Duramax.

wild willy · 12-08-2008, 10:14 AM

BTW the warranty is not affected on any of the additions.

HughM · 12-08-2008, 10:50 AM

I've had exhaust brakes on M/H's and liked them. They save the brakes. I also like the Allison transmission on my Duramax and don't need an exhaust brake with that combo. Save your money.
Hugh

TLightning · 12-08-2008, 02:08 PM

Put it in T/H and let the Duramax and the Allison do their jobs.

Emmel · 12-08-2008, 02:55 PM

Terry, I would be very sure these additions didn't affect my warranty on an 08 GMC. Having a 02 myself, I would be ok, but I'd be careful in an 08

garyka · 12-08-2008, 04:27 PM

Save your money

bncinwv · 12-09-2008, 01:16 AM

As others have stated, the engine brake is not really needed with the D/A combination. Be sure you understand how the grade braking system works with the Allison transmission (as bad as it sounds for us men....it is explained in the owner's manual....GULP!!). Our D/A is used primarily in the mountainous terrain of WV (6-8% grades are common-place). With the transmission in Auto (D) and T/H engaged all I have to do is the initial braking at the beginning of the descent (a hard pressure on the brakes until the grade braking feature kicks in at the speed that is slowed to) and I rarely have to use the brakes (grade changes will require additional braking). As an advance warning on steep grades when the transmission and the transmission fan kicks in hard, it will sound like a jet airplane is landing under the hood...as loud as it is, it is normal. Hope this helps you in making an informed decision.
Bingo

garyka · 12-09-2008, 02:01 AM

When that fan kicked in hard and I saw the tach hit what I thought was the red line (it is the orange zone)I almost died.I since learned the red zone is about RPM and everything worked like it was supposed to.It is a very good combination and no need for a exhaust brake(more gizmos more problems)

TAKPAK · 12-09-2008, 01:24 PM

Thanks all, for your comments about the exhaust brake, or lack of. I shall save my money. I agree, the D/A combo works pretty good. I'm just used to driving the big rigs on the farm with the "real" exhaust brakes on the engine, and they work REAL well. Been down a 6% with the GMC and the Monty 3400, and it shifted down three times until RPM was abouit 3400 RPM. I know it's OK, and with a gas engine it would be fine...just makes me a bit nervous to hear a diesel revving that fast. Modern diesels, I know.....I'm used to the old truck Cummins/Cats/and the "old" Detroits, that SOUNDED like they were turning at "6 million RPM," but were "considerably less."

bncinwv · 12-09-2008, 03:41 PM

There is nothing that I have seen or heard that compares to that jet airplane racket under the hood. I remember on the way to the Northeast Rally at Gettysburg we were eastbound on I-68 from Morgantown down into Cumberland, Maryland and the racket woke DW up from her snoozing (Seems like I remember something about an 18 mile 6% grade?? She thought there was something severely wrong with the truck, but it held 55 as it was set to.
Bingo

mtheo · 12-10-2008, 01:28 PM

I have an 02 dura max, and I look my Banks brake. I was told that it won't void the warretty, but who knows I've been lied to before.
As for the use of the exhaust brake I love it(IMHO). The Allison braking work good, but it works lots better with some engine braking. We regularly travel the Grapevine(I-5) and the Tehachapi (Hwy58), with the exhaust brake I never have to use the brakes. With the only the Allison I was using the brake regularly.

Mark

sreigle · 12-29-2008, 11:27 AM

My Dodge has the factory installed exhaust brake as well as the tow/haul transmission. Each, by itself, does a really good job. Both, working together, is awesome. On downgrades no more than 6 percent, towing this 14,620 lb. Montana, I have to give it a little bit of throttle as tow/haul with exhaust brake slows me down too much. In other words, your tow/haul is good but adding an exhaust brake makes it that much better. Is an exhaust brake necessary when you have tow/haul? Probably not. Is it nice to have? Absolutely. In my opinion, anyhow. I've towed with the Ford tow/haul, for over 100,000 miles, and it's tow/haul performance is about like the Dodge's. I would imagine the GM works very much the same.

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