My father-in-law has a 30' fifth wheel. He is convinced his truck is shifting into second gear when it grade brakes at freeway speeds when he's in the tow haul mode. Of course, he says this only happens when his Juice is set on level 2, on level 1 or when he removes the Juice completely he says it doesn't happen.


He is also convinced the engine should not wind past 3500 rpm while grade braking, even after I read the TSB to him. When I point out there are lots of guys who tow heavy, with or without the Juice, they do just fine and have no issues with the grade braking. He says that is just becasue they haven't towed heavy on a steep grade.


I am looking for the experiences of you guys who tow heavy on steep grades. I want to know: how much and how heavy you have towed, what kind of downhill grades you tow on, if you have had any engine/tranny problems because of the grade braking, if you notice the Juice--or any other power adder--causing a change in grade braking, and anything else you might be able to add.


Thanks,


Blaine

Just got done pulling some grain bin equip, truck and trailer grossed at 36700 over certified scale. pulled it up and down some moderate grades, not steep but long. Dont know what all the hype is on extra power, seems to pull and brake just fine. not to many people pass me ever. 70 - 75 with that big of a load and able to maintain it seems pretty good to me.

Regardless of TSB I would not want engine cranking the hard braking. He might look into a exhaust brake for it and they can be quite effective on a diesel.

Just got done pulling some grain bin equip, truck and trailer grossed at 36700 over certified scale. pulled it up and down some moderate grades, not steep but long. Dont know what all the hype is on extra power, seems to pull and brake just fine. not to many people pass me ever. 70 - 75 with that big of a load and able to maintain it seems pretty good to me.

Man would not want to run into you on the road. If that got away from you your truck would be like a cork on a string and take out everything in its path. You need more truck to safely haul that much weight regularly. I have hauled 22,000lb loaded grain trailers years ago more times than I can count but I never went much over 35 or 40 with them because you really cannot control that much weight effectively in emergency situations so I keep my speeds down on purpose. Power was not a problem back then. Safety before ego with me anyway.

It is not recommended to use an exhaust brake on the D/A combo as far as I can find.


As far as redline on the engine I think you'll find that in grade braking mode, engine RPM's could go as high as 4800 RPM's. Remember, the engine is not under normal loading at this rpm range. You're using the ability of the Allison to bleed some of the speed off.

I pulled a CAT 277B (tracked bobcat), the 277B wieghts 9500, and the trailer is 2500, i pulled both ways over Parley's Summit in SLC Utah. I was not worried about getting over, the grade braking work fantastic. I was in 4th coming up to the summit, then went to fifth over the crest, applies brake pressure, tranny kicked it to 4th, i got to about 65 mph and needed to slow her down some more, more brake pressure, Tranny kicked it to 3rd and rpm's shot to 4300. I had heard that this might happen and was no problem, with alittle brake pressure intermittenly, i kept it between 55 and 65. I heard, trust the tranny and the Dmax, computer will not let it self distruct. That is my understanding of STOCK.


I can not speak to the Juice setting and finding. I run pretty stock...

Hey snowman, theres no ego thing here. Its a common thing probly done weekly. been pulling loads like that for 10 years with a cummins dodge, just finnally got something else that can do it also. Hauled many loads of livestock also that is pushing the same weight. What kind of country arre you in, farm, city etc. on the farm its nothing to put one tractor on the trailer an be grossin over thirty also.

My father-in-law has a 30' fifth wheel. He is convinced his truck is shifting into second gear when it grade brakes at freeway speeds when he's in the tow haul mode. Of course, he says this only happens when his Juice is set on level 2, on level 1 or when he removes the Juice completely he says it doesn't happen.


He is also convinced the engine should not wind past 3500 rpm while grade braking, even after I read the TSB to him. When I point out there are lots of guys who tow heavy, with or without the Juice, they do just fine and have no issues with the grade braking. He says that is just becasue they haven't towed heavy on a steep grade.


I am looking for the experiences of you guys who tow heavy on steep grades. I want to know: how much and how heavy you have towed, what kind of downhill grades you tow on, if you have had any engine/tranny problems because of the grade braking, if you notice the Juice--or any other power adder--causing a change in grade braking, and anything else you might be able to add.


Thanks,


Blaine





Blaine,you should be able to monitor trans gear with the Juice Attitude display. Set up display to show selected gear while towing to verify what gear it is actually in.

Good idea, except I talked my father-in-law out of the Attitude so he wouldn't have to fuss with the uninstall if he ever has to take his truck in for service. I think if I mention this to him he'll just get mad at me................


So far, I have seen some who like grade braking and some who don't. However, no one has had any engine issues becasue of grade braking wrapping the engine 4000-4800 rpm.

I haven't towed some of the loads these guys have but you can read my Sig to see what I do. I'd be careful of the exhaust brake. I do believe their is one though that GM puts on the medium duty series that would probably be safe. As far as slowing down though I use the trailer brakes only when the Allison can't do it by itself. That always leaves me the truck brakes as a backup.

The trick is to keep speed down on a long down grade to begin with and keep things more managable from the start. If you are cranking your Dmax at 4500 to slow down you are going to fast to begin with and not using enough gear to hold it back. With gassers I use a combo of brakes, gear down and speed to control this and I have crossed the rockies a few dozen times without any problems. The nice thing about a gasser in this is that whaen you are cranking 4000RPM or more slowing down you can use throttle if you need to for some reason and not have to change gears to do it.

I have said this on other threads and I will repeat it here. The amount you can safely pull on a trailer with your truck is based on the total, truck and trailer, amount of axle/brake capacity. The truck alone is NOT the limiting factor. If you have a trailer that is rated to haul and stop 30 tons, no problem. Getting it moving is another matter.

Back to grade braking. You are taught in the big rigs, you go down a posted steep grade one gear lower than you can pull up it. This may not slow the truck down with the engine alone, but it keeps you mindful of going to fast and overheating your brakes. The engine is a constant reminder of how fast you are going. This is the "Reduced Gear Zone" that you see so much of. The grade braking in the Allison is working in a similar fashon. If the engine reving is bothering you, good, slow down. You just might save a life.

Like Fingers said,


If your RPM is higher than you would like it to be, SLOW down, quit complaining that the DMAX is engineered to rev to 4800 (rev to, not fuel to). QYB.


I pull a 35' Alfa @ 26000+, I have no problems and there are no special risk to the public, I know how to drive this combo.


Snoman;


When you learn to drive a big truck, I'll listen more closely.


Idahofox, (oldtime trucker)Edited by: idahofox

Like Fingers said,


If your RPM is higher than you would like it to be, SLOW down, quit complaining that the DMAX is engineered to rev to 4800 (rev to, not fuel to). QYB.


I pull a 35' Alfa @ 26000+, I have no problems and there are no special risk to the public, I know how to drive this combo.


Snoman;


When you learn to drive a big truck, I'll listen more closely.


Idahofox, (oldtime trucker)

You are really kidding yourself if you think a 6000lb truck can control 25000GCW effectively in any situtation. Set it down hard suddenly without warning on a curve ( like someone pulls out in front of you) and you will loss it! Have a brake failure (I did once when I lost axle groung wires) and you will not stop it (that is way OTR rigs have air brakes, fail safe) Even OTR rigs that can weight up to 80,000lbs have about 1/2 half or more of this total weight on tractor axles for control of load. To get then same level of control with a P/U with 25000lb GCVW your "truck" loaded would have to wieght about 13,000 lbs with 9000lbs (about 7000lbs hitch weight) of it or so on rear axle alone. This is more ego than realityEdited by: snoman

If the brakes fail on a tractor trailer you are screwed too. Fully loaded the tractor will not stop the load on a steep grade. (which is inevitably when the brakes go south)

You spend a lot of time placing the load on the truck, but the considerations are, in order:

Axle loading
Traction
Ride comfort http://www.dieselplace.com/forum/smileys/Big Smile.gif

Tri-axle and quad trailers will frequently have the majority of the load on the trailer axles. Ever see the wide spread axles on some trailers? Among other things, it helps keep the load off the tractor.

Snowman, the difference in opinion between you and I is the differnce between those that haul and the layman. What you propose is "safe" no argument, and I guess makes sense from the outside. But it is way too conservative aof what can actually be done safely. The DOT's are in agreement with me and others that have tackled the issue to haul bigger loads than you think are possible safely. It isn't rocket science.

OTR tractor/trailers do use air brakes, (fail safe, not true). Air brakes on these rigs are air/air (air-over-air). When you lose your air you have no brakes other than the MAXIEs and they are applied by a mechanical SPRING and they are only on one axle of the tractor and one axle of the trailer, that reduces your braking by 80 percent; fail safe?





Idahofox

Good idea, except I talked my father-in-law out of the Attitude so he wouldn't have to fuss with the uninstall if he ever has to take his truck in for service. I think if I mention this to him he'll just get mad at me................


So far, I have seen some who like grade braking and some who don't. However, no one has had any engine issues becasue of grade braking wrapping the engine 4000-4800 rpm.





To bad,Attitude is well worth the money,able to monitor several engine perameters,EGT,boost,%backdown etc. Also to protect by defueling when EGT get to high on long pulls. I don't pull what I would call heavy for my dually though,usually 12-13k with 5er.Mountains here in Appalachain mountains are the norm though and have experienced the high rpm with the grade braking and am not concern,trans does upshift if they get to high. Like others have said,the key is to keep vehicle speed in control with the service brakes but in moderation as to not overheat them. I would recommend purchasing the attitude if nothing else for its monitoring and protection aspects.


You don't say what wieght your towing that you call heavy,just a 30' 5er,what's GW? I can't believe what some people on this site pull with 3/4 ton trucks. 26k,not even with my 1 ton.Edited by: TVolDMax

Yeah, I know about the Attitude because I have one. However, my father-in-law just isn't ready to fuss with the de-install of the attitude in case he needs warranty work.


I would guess his fiver weighs 10-11K. However, I am asking the question of those who tow heavier becasue my father-in-law's contention was guys who like grade braking never had to tow a big load down a steep grade. He also thinks the Juice causes higher RPMs on grade braking. I know this is poppycock, and hopefully I can convince him of that with the responses I get here.

Yeah, I know about the Attitude because I have one. However, my father-in-law just isn't ready to fuss with the de-install of the attitude in case he needs warranty work.


I would guess his fiver weighs 10-11K. However, I am asking the question of those who tow heavier becasue my father-in-law's contention was guys who like grade braking never had to tow a big load down a steep grade. He also thinks the Juice causes higher RPMs on grade braking. I know this is poppycock, and hopefully I can convince him of that with the responses I get here.

I think that the reason it appears to add RPM's to braking is because they are pulling more weight with juice than they would otherwise.

Also, I bet he reaches more speed at the top of the hill, which will result in a higher rpm during grade braking.

Also, I bet he reaches more speed at the top of the hill, which will result in a higher rpm during grade braking.


Yes, good point. When I climb a bad hill, if I know it is steep going down the otherside, I will start backing out of the throttle just before a crest to bleed some speed before I start down with a load. Edited by: snoman

Its called common sense.http://www.dieselplace.com/forum/smileys/Ermm.gif


Blake

I tow an 11,000 lb toyhauler, and live in the Rocky Mountains, so it seems like I am always either climbing a grade, or descending a grade. We have 25,000 towing miles on our '03 Duramax/Allison, with that weight behind it, and have had no problems whatsoever from the drivetrain. It is very common to see engine RPM go up to as high as 400 RPM above red line when the transmission downshifts in tow/haul mode coming down steep grades. It happens all the time, probably a dozen times each weekend, and no problems so far. I have towed the same load with an Edge Juice installed, and noticed no difference in grade braking on level II.


It sounds like your father in law simply does not like this feature of the Allison transmisson. The drivetrain can handle it just fine though, whether your father in law likes it or not. Some people really let this bother them for some reason. I have a friend that sold a brand new Durimax/Allison truck, after owning it for just six months, because he was convinced something was wrong with his transmission, for just this reason. He had never had a problem with his truck, but he hated the grade braking feature so bad that he bought a Dodge. To each his own I guess.Edited by: Yamahauler

I've had trouble accepting this fact about the Allison but you guys have convinced me otherwise......I can say that the first time it went into the red I was alarmed......


YamahaHauler...on a long grade situation how long have you let it stay in the red and what's the highest rpm you've seen? they say it will shift at 4800rpm.

BTW I was in Cedar City on my way to Bryce & Lake Powell last month....Nice country up there..http://www.dieselplace.com/forum/smileys/Cool.gif

I have gotten the impression that it would stay up above redline for a long time if I were to let it do so. The transmission downshifts when you are applying the brake, so when engine RPM goes way up above redline I usually apply the brakes a little harder than I had been doing, and slow the truck down to bring the engine RPM down to at least redline. It usually takes me about five seconds to get the engine RPM down to redline, and once it is at redline I will let it stay there forever if it wants to, it just depends on the hill.

yamahauler, cool...I've been taking mine out of OD and TH at the top of the hill and keep it at 55-60 with the truck/trailer brakes. So basically I'm braking about as much as you are it sounds like. I was getting tired of it going into 3rd everytime I hit the brakes. Next time I'm out I'll try your method.......

AFP1, the guys that have posted have given sufficient intel for your father-in-law to make an educated decision. Print out this post, hand it to him (a cold one wouldn't hurt), then leave him alone to digest the info. You've done your best! http://www.dieselplace.com/forum/smileys/Clap.gif JJ

JJ,


I am thinking along those lines. Hwoever, he's old and cranky about such stuff, just like I hope to be someday!


I think the issue is he had his own tranny shop for 40ish years, getting out of the business in 1999. As such he has certain ideas on how things should be. The problem is it is hargue to argue with his experience..........





Blaine

OTR tractor/trailers do use air brakes, (fail safe, not true). Air brakes on these rigs are air/air (air-over-air). When you lose your air you have no brakes other than the MAXIEs and they are applied by a mechanical SPRING and they are only on one axle of the tractor and one axle of the trailer, that reduces your braking by 80 percent; fail safe?





Idahofox





I drive truck for a living (13 yrs) and am not sure what this quote is about. If you loose air pressure, all the brakes on every wheel will be applied by mechanical spring. To move a truck without air pressure you would need to back off all the slack adjusters on all the brake chambers on every wheel, not just one axle. I just left the 15th from here and ran out to Portland, OR to deliver Wed morning. I was 75,000 going out. Was fun in Butte, MT. That had the longest pull and down grade. Truck speed was 25mph for anything over 12K GVW. Then drove to Grants Pass, OR to pickup and just got back home this morning. 4,612 miles I think.


http://www.dieselplace.com/forum/uploads/99E_mav10.jpg


Anyway, I have towed up to 33-34K with my Dmax dually and a 53' Take 3 car hauler. I have grade braked to 4,000 rpm with no problem. Moving it is the easy part, but like a few of the guys have said, I slow down on the 5-6-7% grades with that kind of a load. I have smoked the brakes on my 18 wheeler by going to fast down a grade loaded heavy. I sure wouldn't want to do that with a Dmax and heavy load.


I ran the standard Juice on level 1 with no problems except going faster up hill. Any levels higher than 1 and I would have to watch the Pyrometer.


http://pic13.picturetrail.com/VOL487/437876/504504/12090371.jpg


http://pic13.picturetrail.com/VOL487/437876/504504/10798232.jpgEdited by: Maverick

Maverick, interesting post. Just goes to show you these D/A combos can take on some pretty heavy loads. http://www.dieselplace.com/forum/smileys/Clap.gif


afp1, dejavue baby! http://www.dieselplace.com/forum/smileys/HiHi.gif My father-in-law was in the tool and die business for 50 years and convincing him to put his sprinkler system in with PVC pipe versus galvanized was a chore. It's amazing what the ole fart can do with galvanized pipes, sheetmetal, etc. I've found it easier to "spoon feed" him info, allow him to digest it, then have my brother-in-law (his own son) reinforce it. Seems to work for us. Good luck! JJ http://www.dieselplace.com/forum/smileys/Big Smile.gif

Mavrick, at what combination weight do you have your dually register at? With that Cat backhoe you must have been running ~28k, maybe more. Just curious.

BTW was that 25MPH going up too?http://www.dieselplace.com/forum/smileys/Wink.gif

Maverick,


Grants Pass is my hometown. I get to go home once a year to elk hunt. I have driven to/from Grants Pass to Texas and the South a couple of times. Aren't those three little passes between Roseburg and Grants Pass steep suckers? I think the contentential divide is easier to get over. Also, between grants Pass and Roseburg is the only place I know of where the speed limit on an Interstate Freeway drops to 50 MPH. Not the recommended speed for the curve, the actual speed limit. There may be others I don't know about. Regardless, it is an awesome drive in terms of scenery, but the hills and corners must be a drag in a big rig.


JJ,


I am slowly bringing him along..........

Fingers, In WI the truck was registered at 8,000 and the trailer at 16,000. After I moved to Wasilla, Alaska the weights changed based on tire size and length of trailer. This setup had to be over 50,000 to be over weight. I could haul alot more weight up in Alaska legally.


afp1, It is a pretty drive in OR. Cops, 5-O, Vice or whatever you want to call it, have a major hard-on for truck drivers in this state for some reason. Seen 8 squads have vehicles pulled over and they were all Class 8 trucks. Didn't see one 4 wheeler pulled over at all. After Grants Pass I ran up to Crater Lake to Bend to Ontario when I left. Here are some pics I took in Crater Lake area.


http://www.dieselplace.com/forum/uploads/467_MVC-014S.JPG


http://www.dieselplace.com/forum/uploads/71F_MVC-011S.JPG


http://www.dieselplace.com/forum/uploads/ABF_MVC-020S.JPG

Rogure River Gorge near Union Creek and Mt Thielsen a little further down the road. You are making me homesick!

I regularly haul my 14K gooseneck. I've done many pulls over the blue mountains in Oregon (6 mile 6%) and last weekend did a 12 mile 6% over the mount hood range on US-20.


When grade braking, I've had the rpm's go to about 4300. Usually for these grades I can maintain about 3500 at a comfortable speed. When I hit a higher rpm, the roads were wet so I held the speed lower. I try to only use the truck/trailer brakes to slow down and let the speed and then let the grade brake maintain.


afp1,


sounds like you live near Roseberg. I will be hauling that way from Boise in late October. Can you recommend a route into Roseberg? I could obviously take I-84 to I-5 but that is a lot of extra miles. I could take US-20 to I-5 which is about the same timewise and adds the Mt Hood range. I considered dropping south somewhere between Burns and Bend and taking the state highways but am not sure how the route is, especially in October.Edited by: Rockin

Rockin,


My I was born in Roseburg, my hometown is Grants Pass, but I have been active duty USAF for the last 21 years and I only get home once a year.


I made a trip from points east to Grants Pass (about an hour south of Roseburg on I-5) Sep of '98. I was taking my guns and tools to my folks place for them to keep while I was assigned in Japan. I looked at all the routes and decided to go I-84 to I-5 then south. I figured I only lost a couple hours. In '01 I went from Grants Pass to Texas, and went I-5 to I-84.


The problem with cutting across the state at Ontario is there are long stretches of nothing. More than that, I'm told the mountain passes can be tricky. You can get stuck behind RVs going very slowly up and over the windy twisty roads, and there can be snow in October. Usually not, but it has happened before. Normally, 62 is fine in Oct...........


If you do take I-84, beware of the Blues......Coming downhill out of the Blue Mountains on the West side is very steep. In 1998, my rig was an '87 4x4 Suburban, and I was towing a 6x12 U-haul that was loaded to about 4500 lbs. I ruined my new brake pads coming down those grades. However, I am not sure it's any better coming across the middle of the state. Going from I-5 to I-84 in '01 was a much betetr trip, but I had a newer truck then as well.

afp1


Thanks for the response on that route. I've done the blues 6 times already this year. Grade braking is a god-send on that 6%. Even more so on the US-20 12 mile 6%.


I'll watch the weather as it gets closer to the trip. If there is a question, I'll take 84/5 just because the blues should be better maintained than the state highways.

First: I would like to complement this Forum, Staff and members, on their Knowledge and willingness to share that knowledge freely. Kudos all around.


Second: I need to apologize to members that posted to this thread. I used "Dated" information in "My Posts" that may have been misleading and confusing.


I stated that on each set of tandem axles of an Over The Road (OTR) class 8 tractor/semi set, one axle of the tandem is fitted with spring brake modules, (MAXIES). This was true when I owned and operated OTR equipment, (more that 20).


I have since learned that the Fed’s require (since the mid 90’s) that all new equipment are fitted with MAXIES on each axle of each tandem set. No MAXIES on the steer axle. This is a quantum improvement to OTR equipment.


I hope this explains my original Post; further I sincerely hope I have not mislead or confused anyone.


idahofox