Downhill Shakey Brake - Montana Owners Club

lfw · 07-17-2009, 05:48 AM

I installed a new Prodigy a couple of weeks ago.. I had a Drawtite control before.. the Prodigy works 100% better than the Drawtite..
We were headed back to Chester Frost going down 127 thru Pikeville..
When we came down the mountain into Pikeville I hit the brakes to slow down a little and the entire truck started shaking.. I thought the wheels were going to fall off.. This is the first time that had happened. It never happened with the old brake control.. I have the entire 2500 HD check out .. nothing loose or ready to fall off..Brakes, steering, drive shaft, ball joints.. everything in good shape.. by the way it only shakes when going down a mountain.. not even a small shake on level ground or a small hill..
Has anyone had this happen to them..
2008 3000RK
lfw

deadeyenevermisses · 07-17-2009, 09:51 AM

Yup, and I have a Prodigy as well. My occurences mirror yours, all headed down very steep long hills requiring numerous applictions of brake pedal. So.........now I set my maximum desired speed at the top of the hill, shift into tow/haul mode and let 'er run. I try and not touch the brake pedal. I've never figured out the shudder/hop.

ols1932 · 07-17-2009, 10:27 AM

I've never experienced anything like that with my Prodigy. I have an older truck. Could that be the reason?

Orv

NCFischers · 07-17-2009, 10:54 AM

From your discription, it sounds as though your ABS system might be acting up.

mail2us · 07-17-2009, 11:02 AM

Not clear what your truck is Chevy, Dodge??2500HD?

We have a 2007.5 Chev 2500HD Diesel CC. I too had vibration when going down 6,7 and 8 percent slope highways in NC area about 8-9 months ago towing the Montana. I took it into the dealer based on a good friends thought that the truck brake rotors could be warped. They indeed were and all fixed/replaced by the dealer under warranty. No more shaking, or vibration and the dealer said they were prematurely warped.

You indicated you had the brakes checked but you may want the rotors inspected as well. Just a thought. Good Luck.

Devildog · 07-17-2009, 11:05 AM

Or possibly boost set too high or amperage also, and it is picking up the downhill before the break is applied.

Different from other brake controllers (I used to have the sentinel), Prodigy is inertia activated also, in addition to receiving inputs from the brake and the pendulum inside. I run Boost 2, at 7 amps, and have not had this problem yet. And have been down monteagle. i would drop the voltage down when next time on that hill, and see if it coninues to occur.

By the way, LFW, being in cleveland, check out the website for Hornsby Hollow off of 58 highway. We haven't stayed there yet, but ran by it a week ago, and it looks pretty nice, and on the lake.

KTManiac · 07-17-2009, 12:43 PM

NEI!, (Not Enough Information) What do you have the Prodigy set at?

When my 5er brakes were new I set it at around 6.5, Now it needs to be set in the 7.5-7.8 range because I think I need a brake adjustment on the 5er.

Also, what boost setting do you have it set for, .c, .1, .2, .3 ??? I usually set mine at .1 boost (sometimes .2) on the highway, and 6.2 for in town. If you have yours at .3, that could be the problem.

Is the controller mounted at near level, or angled with the display high? It does have limitations to its self leveling ability. If it is angled too much, and you are going down a steep grade(making the angle of the controller even more) that can cause problems.

As per the Tekonsha web site:

WARNING The Prodigy must be mounted from 0
degrees to 70 degrees nose up. (See Below).
In hilly terrain it is advisable to leave a margin at
either extent to keep bars from coming on when going
up and down hills. When mounted near level the
lower bars may come on during heavy acceleration
(see Trouble-shooting Chart). This will not affect the
performance during braking.
Failure to install the Prodigy within these constraints
may cause impaired performance.

lfw · 07-17-2009, 02:11 PM

I have a 2500 chev.. I have the prodigy set at 6 and the boost at 2..
They did not check the rotors to see if they were warped. Will have them checked when we get back to Cleveland in the next couple of weeks..

Devildog.. Hornsby Hollow is a nice campground.. We were there a couple of years ago..

Will try a couple of different settings on the next big hill I go down..probably back thru Pikeville.. not sure yet..

I will also try and mount it so it is closer to level. Right now it is in a slot in the center console.

Thanks for all the suggestions..
lfw

KTManiac · 07-17-2009, 02:37 PM

Quote:

quote:Originally posted by lfw

...I will also try and mount it so it is closer to level. Right now it is in a slot in the center console.

From what I get from their instructions, perfectly level isn't good either. I would guess that 20-50 degrees, display end up, would be optimal. If you are somewhere around there, it should be fine. Mine is at around 10 degrees and it works fine. Just trying to eliminate some possible problems. Being axially straight, front to back with the truck, and level side to side is also important.

hookman · 07-17-2009, 02:53 PM

It sounds if the rotors are warped that is the only time I have experienced this type of condition.

grampachet · 07-17-2009, 03:35 PM

I was trying out a used car to purchase and all seemed perfect. Then I "rode" the brakes to heat them up and then the shuddering began. The warped rotors show their ugly head when hot. You might try riding your brakes when you are not towing and see if they shudder, if so your rotors need replaced or turned. However if you have them turned they are then thinner and can warp much sooner if they are not thick enough.

sreigle · 07-18-2009, 10:01 AM

Mine is a P3, which is essentially a Prodigy with a few additional features that I really don't use. I used to have a Prodigy when they first came out, too.

My understanding of the boost setting is that its purpose is only to increase the Initial braking power for rigs that are significantly heavier than their tow vehicle. It has no effect at heavier applications of the brake pedal once the braking power surpasses that intial boost level. Isn't that how everyone else understands it? Mine is set at 3 because the chart in the book (I think it was a chart) indicated 3 is what I should use.

8.1al · 07-18-2009, 11:42 AM

I believe you're correct Steve, The boost kicks in at whatever you have it set at regardless of how hard you are braking, after that it is based on how hard you are.

MAMalody · 07-18-2009, 06:46 PM

I have my boost set at 3 and the controller at 5.7. I have had shuddering before. I did have warped rotors. Once those were fixed it significantly reduced the shuddering, however, on long downgrades it can come up again. It drives me nuts and I don't like it. KMy controled is mount at a 50 degree angle.

Trailer Trash 2 · 07-19-2009, 10:24 AM

Quote:

quote:Originally posted by hookman

It sounds if the rotors are warped that is the only time I have experienced this type of condition.

Ditto on the rotors. or they could be glased up real good too.

FLSTS03 · 07-19-2009, 03:30 PM

lfw, I was going to order my P3 from AdventureRV tomorrow($119). Are you going back to time based? Off topic, since our son is a photojournalist with ch 3 Chattanooga and now lives in Soddy Dasiy, My wife is chompin at the bit to get over to Chester Frost. What a beautiful campground....Steve

lfw · 07-20-2009, 02:11 AM

FLSTS03 I did not get the P3.. I got my from Tweety's for $107... not a bad price.. I found out that the rotors are warped thanks to all the member's on the forum.. A great forum for sure..
I will keep the Prodigy for sure..
I thank everyone for all their information...A great help..
lfw

Glenn and Lorraine · 07-20-2009, 06:10 AM

Now that Ifw's problem has been solved I hope he don't mind hi-jacking his thread for a quick question about Hornsby Hollow Campground.
As I'll be heading from Florida to Indiana for the Fall rally. I can head up I-75 to Lexington before cutting back over to I-65 BUT can anyone give me more info on Hornsby Hollow Campground?

Trailer Trash 2 · 07-20-2009, 11:17 AM

Quote:

quote:Originally posted by lfw

FLSTS03 I did not get the P3.. I got my from Tweety's for $107... not a bad price.. I found out that the rotors are warped thanks to all the member's on the forum.. A great forum for sure..
I will keep the Prodigy for sure..
I thank everyone for all their information...A great help..
lfw

They should be able to put them on a roter lathe and shave off a few thousandths off them, hopefully they will be within tolerance so you dont have to buy new roters.

well at least you got a starting point.

lfw · 07-21-2009, 01:40 AM

You would get off I75 at Sweetwater, TN.. I think it is about 20 miles west of there..
We were there a couple of years ago with our popup.. It was a nice clean campground when we were there.. Do not remember how big the sites were.. It rained all weekend when we were there..
lfw

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