Incurable Rear brake shudder solved?

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I've been one of the ones posting about an incurable rear brake shudder on my 98 2500 QC 4x4. Here is something that may intrest those of you experinecing similar problems with 2500 4x4's.

I just got a page of a fax regarding Dodge's new fix for 2500 4x4 (only, so I hope that's what you have) brake shudder. Here's what it says:

"A vibration on some 2500 4x4 vehicles during light brake applications has been incorrectly
diagnosed as out of round rear brake drums. Although turning or replacing the drums has an impact on the problem, it is only temporary. As the linings burnish the new surface, the vibration returns.

If the vibration feels like out of round drums but occurs at typically lower speeds (10-40mph) with light brake application and does not occur at higher speeds (50-70mph), turning or replacing the drums will not be a permanent repair. "

It then describes a repair procedure involving checking tire pressure (50 front, 40 rear), verifying that the tires are in good shape, and installing shims between the front cab body insulators and the radiator core support. It states that the truck will have to be driven up to 100 miles following the repair to gain the full affect of the repair.

The problem description matches my experience exactly. My truck has been at the dealer (who's service manager has lost a fair amount of hair over my vehicle) 10 times for this problem since 1998. I have an appointment to have the work done the week of 08/14 (the next convenient time for me). I don't have the TSB#, but let me know if anyone wants it and I'll ask my dealer. I hope this helps someone.

Brad

 

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Please post the full TSB number. I looked on Fritz's page but could not find it.
(There is a recall from 98 on replacing the bolts that hold the cab mounts and radiator mounts... ... ... )

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1997 4x4 CC 5spd, CPL1553 engine, Horton fan, Sport headlamps, 98 shift levers and console...

 

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deboer,

I don't have that TSB. Let me know what the number is and I will try to get a copy posted.

Thanks, Dave

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1994 2500HD 4X4 modified for off-road camping
2001 2500 ETH/DEE QC SB 4X4
Fritz's Dodge Ram Tech Page

 

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I tried to get the TSB#, but the service manager is on vacation this week, and the information hasn't been given to the service writers yet. So, I'll try to get in touch with him on Monday. Sorry for the inconvenience.

Brad

 

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Well, here's the deal. I called the Service Manager, and he told me that no TSB is out yet. Basically, Dodge is still working on it. My truck will be the first in the New England region to be outfitted with the new parts, and they're prototype parts at that. He wasn't really supposed to show me the sheet on it either, he just did because I'm a friend and a Mechanical Engineer in the auto industry. Soooo, the work takes place next week (I get it back next Friday), and I'll keep everyone posted on the results, but it will be a little bit before the fix (assuming it works) will be widely available. My truck now answers to lab rat.....

Brad

 

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While we are waiting for DC to issue the TSB, an interesting experiment occurs to me.
Remove the linkage that operates the rear brake proportioning valve. Then there is no chance of a feedback-induced brake shudder, which is my current theory.
(Wife owns a 98 with brake shudder)

The best long term fix would be disk brakes from a 2001.

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1997 4x4 CC 5spd, CPL1553 engine, Horton fan, Sport headlamps, Optima RedTops, 98 shift levers and console... looking for a NV5600.

 

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Well, I got my truck back from the shop. They installed the magic shims and turned the drums b/c they were out of round. They also checked my rotors, which were perfect. Sooo, there is definitely an improvement, but there is still some shudder. However, the shudder now appears sporadically under all conditions (i. e. sometimes the truck shudders while driving under constant speed). So, now, I think I have a bad tire because the symptoms are exactly what my mom's Explorer had when it had an out of round tire. So,this weekend I am going to go to my dad's and see if his 99 Pherd wheels will fit on it. He's got brand new tires on it, so I should hopefully be able to determine if there is a tire problem. So far though, I am optimistic with the fix.

Brad

PS- Adiabatic, my truck was definitely not experiencing feedback shudder, because I could get the truck to shake badly with only the E-Brake, which takes the hydraulic brake system out of the picture. Also, I believe that the 2001's just come with different (smaller, oddly enough) drums, not disks.

 

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Interesting. I had the drums on the wife's 98 turned, and it cured the shudder. I proudly pronounced it fixed.
About a week later she said "it's back".
Sure enough it is gradually going back to shuddering under braking. The weather seems to affect it oddly enough. High humidity makes it worse.
BTW several posts report disk brakes on the 2001.

 

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I too have battled rear brake shudder, on my 96, since late mid 97 . I think your doing all of the same stuff I have done and personally I am getting tired of brake drums from Chrysler at $85 a pop. I have drilled a hole in the backing plate to indicate the drums while they are on the axles. While I believe the truck has other factors making it want to shudder I have had a lot of trouble with drums that wont stay round. Turning or replacing reduces shudder for a reason; the drum are not round.

I considered having the 3rd set, that I put on a week ago, electronically stress relieved and then turned but I don't have the time or money and, frankly, I was hold out hope for the TSB you mentioned.

Anyway, If your starting to look at tires and rims, find a tire dealer with the new Hunter Match balancing and road force measurement capabilities (Model 9700 or somthing like that). They can appraise your rims and your tires and give you a match balance job that will make your tires run smooth. Really, no other equipment can give you a ride like this system. All those wasted hours at discount tires stores; what a joke. I had that done a week ago with my new tires and it rides smooth again. Of course I am waiting for the shudder to return.

Besides, Ford Wheels, common! Seriously, I will be getting on the TDR roundtable soon so I will want to know how you progress.

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Well, sorry to keep you all waiting. Tonight,I (finally) had a chance to put on my father's Ford (yes, Ford) wheels on my truck. I was only able to drive about 10 miles, but it appeared to be much better, against any expectation of mine. So, tomorrow I am going to take it out for a longer drive and see what I can find out. Right now I'm leaning towards a bad wheel as opposed to a bad tire, simply because my problem has existed through three sets of tires. If I do determine that it is the wheels/tires, I am going to buy a new set of tires (my father-in-law is a Tire Rack wholesaler), put them in the back of the truck, and bring it to the dealer and let them worry about figuring out which wheel is bad and mounting the tires. I'll try to post again tomorrow to update everyone on the longer drive. See ya.

Brad

PS In my father's defense (i. e. , Ford PSD owner) he needed a full-size diesel van, and since our beloved Cummins does not come in a van, he owns a Ford. He loves my truck, though... .

 

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I'm glad there seems to be a chance at solving this nightmare. I've been living with this shudder since my truck was new. I have replaced a wheel and all four Badyear tires. One shop in town has a high tech balancing machine (maybe the type mentioned in an earlier post) and they said the tires are so out of balance they cannot add enough weight to balance them. Unfortunately I had the tires replaced with more Badyears and I still have the problem although not as severe. I also had the rear drums turned and was thinking of having the rotors turned.

The good news is a set of BFG 285's are living on a shelf in my garage just waiting till I can afford the M/T Challengers I want. Anyone want to sell a set of those wheels?

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98 2500 SLT, QC 12V, 4X4, Auto, 4:10's, SB, LSD, Alpine alarm, Tekonsha brake controller, 5th wheel hitch, DeeZee stainless boards, Stull billet grille, MTX Thunder sub enclosure, Kenwood amp, Trans. temp gauge, CB radio, White/Driftwood, Camel interior. BINFORD TOOLS decal on rear window

 

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Well, it's been about a week now, and I do really believe that the different wheels have solved my problem. The truck is a different truck since changing the wheels. I took a closer look at my wheels/tires, two of the wheels have over 6 oz. of weoght on them when you combine the inside and outside. That it a TON of weight on a single wheel. The tires I've been using (after the OEM Badyears) have been Dunlops, which I have had good luck with in the past. I am going to switch to Michelins, either LTX A/T's or XPS Tractions (a commercial tire sold in smaller sizes). Hopefully al will go well. I called the service manager to tell him of my findings, and he was really surprised. I guess they have runout specs for the wheels, but not a max balancing weight spec. Anyways, I'll post again when I have more news. It'll be a few weeks before I get some new tires.

Brad

 

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Just a thought. Some Mitsubishi trucks had the exact same problem in the early 90's, I know I had one. The only cure that lasted was to bevel the brake shoes on the surface. Apparently the drum material deformed ever so slightly after repeated heat/cooling cycles, and the edges of the shoes would cause osculation and hense, shudder.

May be worth a cheap try.

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D. O. C. I. Doctor of Compression Ignition
Former Cummins of Atlanta Technician
Get Amsoil at WHOLESALE (including the new synthetic transmission fluid made just for D. C. automatics) BY PASS THE DEALER!!
-- email address removed --

www.synthetic-motor-oil.com

 

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Interesting that better (ie more accurately made) wheels may have solved DeBoer's problem. I do believe my wife's 98 truck did not have this problem until I rotated the wheels and adjusted the rear brakes. When I get a chance I will re-rotate the wheels and see what happens. She has Michelin LTX MS from stock. It's really a shame that 2k Dodge alloy wheels won't fit the 98... . we could dump these pressed steel chrome rims.
VWTdi, was it the leading and trailing edges that needed bevelling or was it the side edges?

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1997 4x4 CC 5spd, CPL1553 engine, Horton fan, Sport headlamps, Optima RedTops, 98 shift levers and console... looking for a NV5600.

 

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Well, it's been a long time, but I'm back. As it turns out, I don't think the wheels are the problem after all. I replaced the old Dunlops on my truck with some nice new Michelins. The dealer did the mounting for me, and while the tires were off checked the rims for runout and balance. They were all well within specs. The new Michelins took less than half of the weight that the Dunlops took to balance. I guess that shows you a bit about whose manufacturing tolerances are tighter... .

Anyways, the shudder persisted. So, at my wits end, I've been talking to all around sharp guy Ted Jannetty about the issue. I actually have an appointment to visit the shop at the end of the month, but seeing as I have a lot of equipment available to me through work (I'm a mechanical engineer for a firm that produces automotive steering columns), I decided to do some research. Here's what I found:

I looked at my service records, the truck had new drums at 58K miles, they were turned at 61. 5K miles, and I show 63. 5K on the truck right now. Off came the drums (BTW, drums and pads appear spotless, with no marks of overheating, cracking, corrosion, influenza, or any other problem), and I chucked them up in the (very large, new, true Bridgeport) lathe at work to measure them. The results
show that the left one is 0. 028" out of round, and the right one is 0. 014" out of round. This compares to the Dodge service limit of 0. 008". Hmm. I then brought them home and installed them on the truck inside out, and measured them again to get an idea of the concentricity of the center hole to the lug bolt circle. The results of that were 0. 030" on the right side and 0. 021" on the left. So it would appear that things aren't exactly concentric there, either. For kicks and giggles (hey, I'm an engineer) I also measured the hub flange face and diameter for trueness. Both hub OD's came through with about 0. 003" runout, while the right side hub flange face had 0. 010" runout (I forgot to measure the left one). I have no specs for these measurements. The 0. 003" on the OD seems reasonable, but the 0. 010" on the flange face seems high to me. I'll call
my service rep tomorrow to see if I can get a spec on that. So, my plan is to have he drum turned by a reputable shop tomorrow, bring them back to work and check them again, and then bring them home. Then I'm planning on installing the drums inside out again to see how the runout is. If it is out a bit, I'm going to change the orientation of the drum with respect to the hub and keep checking the runout until I can get it as small as possible. Once there, I intend to mark the stud and corresponding hole, and flip the drum around and install it in the same orientation. Theoretically, this should give me the least possible runout when they are reinstalled. Hopefully that will make things a little better.

In any event, I'll try to keep everyone posted as to the continuing adventures. As a side note, I pulled the rear wheel of of my father's 1-ton Ford van the other day, and a disk conversion using OEM Ford components looks entirely feasible. Also, I just happened to read tonight on Dodge's site that the '01's are supposed to have 4-wheel disks. I certainly have the resources to pursue that option, so I just might... .

Brad

[This message has been edited by deboer (edited 11-09-2000). ]

 

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Brad,
Have you checked the center support bearing on the 2 piece drive shaft? This is very often overlooked and can cause shudder. The problem is it's nearly impossible to tell if the bearing is bad as it's "loose" even when new. I would not believe the dealier if they say it's in spec because they cannot check it under load. If you have any drive line shops in the area you can probably get it replaced and have the drive line balanced for less than $150. Also, worn shocks can cause this. If it were my truck and there was more than 30,000 miles on the shocks and/or center support bearing I would replace them.

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2001 HO 6 speed Regular Cab SLT 4x4 3. 54 anti spin 2500. Used for the daily grind and sneaking away to some secret Baja beaches toting a cabover

 

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Brad: you might try a set of drums from NAPA if all else fails. The NAPA parts cured the brake shudder on my wife's 98 12V truck. I also put NAPA shoes in it.
It's been very smooth for four weeks now, so we hope it's fixed.
Bill was about $200 for parts.

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1997 4x4 CC 5spd, CPL1553 pump, Horton fan, Sport headlamps, Optima RedTops, 98 shift levers and console, RS5000 shocks, red light on dash (vol. FF)... .

 

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I "adopted" the dreaded brake shudder when I had my new rims and tires installed on my truck last month... couldn't believe it!!! So all I did was start playing with the air pressure in the rear tires... . w/40 lbs air, had the shudder... w/38 lbs air, the shudder disappeared, while still keeping good rubber contact on the ground. I will have to air up if I carry a load, but I primarily drive w/ 500 lbs or less in my bed... just my two cents...

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Rob's 98 Ram2500 SLT RegCab 4X4 12-valve Cummins, Automatic, 4. 10 Axle w/ Lim-Slip, Trailer Tow Pack, 285/75R16 BFG All Terrains on 16x8 Alcoa Aluminums... Silencer Ring disappeared; CAT & MUFF gone, 3" straight pipe, Brand New Paint and Sprayed Bedliner, 55,000 miles; Wife's 99 Ram1500 SLT QC 4X4 w/360 eng, Automatic, Trailer Tow Pack; STOCKER! 44,000 miles - both daily drivers. If your STROKIN, your CHOKIN... on CUMMINS smoke!!!