Best analogy I've come up with is to compare your bigger/tougher/etc
truck to shoes.
House slipper vs hiking boots with Vibram yellow label soles. Sure
those serious hiking boots can have a soft insert to soften, but they
will wear out sooner and not provide as much fedback, etc.
You bought a bigger/tougher/etc truck and it has bigger/tougher/etc
components and systems. Degrading it will degrade other attributes.
Yes, lowering the tire pressure is the main control attribute for
ride quality. Going to a bigger/higher aspect ratio tire will also help.
-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...
Ok here is a way to help fix this problem in the GM trucks. I will post a campaign number from GM that you can copy and print out. Take it to your dealer and show it to them and ask them to fix your truck if its under warranty. It is said by those that have done this it takes 70-80% of the bounce away.
Has anyone else tried the fix from GM for the absolutely terrible ride the 2500 has over freeway expansion joints?
The "Sulastic Suspension" mod to the rear mount of the axle springs doesn't even come close to helping.
I live in the Thousand Oaks SoCal area and travel the 101 Freeway through Camarillo quite often. It has got to be the MOST eye-tooth jarring ride in history....and that's only at 70mph. IF you even have the balls (left) at 80mph, more power to you! This is the KNOWN bad section of the 101 Frwy from the Conejo Grade, all the way to the Ventura Bend (about 8 miles or so).
GM's fix is to replace only the two rear BODY MOUNTS between the cab and chassis. It's NOT a warranty replacement...although it damn well should be. Luckily, it's only $200 (for parts only).
It's listed as:
""GM Campaign #PIT3009J: Suspension Vibration Or Frame Beaming At 40-60 MPH (64-80KM/H) - keywords front rear shake shock spring tire - (Sept 18,2008)""
Condition/Concern:
Beam shake vibration is usually felt and occurring at speeds between 40-50 mph (64-80 km/h). Hertz readings using an EVA tool are normally bewtween 8-24 HZ. This condition is most common on extended cab and crew cab models but has also been noted in other models.
Recommendation/Instructions:
The severity of the beam shake may vary from vehicle to vehicle. To determine if the concern is beam shake, please perform the following:
1. Test drive vehicle to confirm the condition. A beam shake condition will usually respond to concrete type pavements more than asphalt, so the vehicle should be driven over both surfaces if possible.
2. Place 200-500 pounds in the pickup bed between the closed tailgate and the wheel wells. A beaming condition should dissipate.
-----------
If the concern is determined to be beam shake, this a characteristic of the vehicle. GM Engineering has released updated body mounts to reduce this concern for the Crew and Extended Cab Models. There will be no changes made to the Regular Cab Models.
FOR CREW AND EXTENDED CAB MODELS, REPLACE THE REAR CAB MOUNTS WITH UPDATED PARTS LISTED BELOW. THESE PARTS SHOULD NOT BE USED ON REGULAR CAB MODELS.
New upper and lower mounts should be installed at the left and right rear cab position. The new LOWER mount is a two-piece design, meaning there is a rubber mount with a metal washer. Some models may use a one piece lower mount, meaning the rubber mount has a metal washer molded into it. If the vehicle has the one-piece lower mount design, washers (PN 15854745, Qty 2) will be needed to be used with the new lower mount.
Upper Mount 25791031 Qty 2
Lower Mount 25791032 Qty 2
Washer 15854745 Qty 2 (if needed)
Please follow this diagnostic or repair process thoroughly and ccomplete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
Here is an addition to that if your not under warranty and have to pay for and replace them yourself.
You need two of each one upper and one lower mount. You are only replacing the rear mounts on the cab. To order them from this place the total for the fix to do it yourself is 122.00 with shipping.
Just FYI:
http://www.gmpartsdirect.com/
GM PART # 25791031
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00
GM LIST: $38.78
OUR PRICE: $23.80
GM PART # 25791032
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00
GM LIST: $38.78
OUR PRICE: $23.80
GM PART # 15854745
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00
GM LIST: $3.47
OUR PRICE: $2.13
Dirtbikindad393 wrote: Ok here is a way to help fix this problem in the GM trucks. I will post a campaign number from GM that you can copy and print out. Take it to your dealer and show it to them and ask them to fix your truck if its under warranty. It is said by those that have done this it takes 70-80% of the bounce away.
Has anyone else tried the fix from GM for the absolutely terrible ride the 2500 has over freeway expansion joints?
The "Sulastic Suspension" mod to the rear mount of the axle springs doesn't even come close to helping.
I live in the Thousand Oaks SoCal area and travel the 101 Freeway through Camarillo quite often. It has got to be the MOST eye-tooth jarring ride in history....and that's only at 70mph. IF you even have the balls (left) at 80mph, more power to you! This is the KNOWN bad section of the 101 Frwy from the Conejo Grade, all the way to the Ventura Bend (about 8 miles or so).
GM's fix is to replace only the two rear BODY MOUNTS between the cab and chassis. It's NOT a warranty replacement...although it damn well should be. Luckily, it's only $200 (for parts only).
It's listed as:
""GM Campaign #PIT3009J: Suspension Vibration Or Frame Beaming At 40-60 MPH (64-80KM/H) - keywords front rear shake shock spring tire - (Sept 18,2008)""
Condition/Concern:
Beam shake vibration is usually felt and occurring at speeds between 40-50 mph (64-80 km/h). Hertz readings using an EVA tool are normally bewtween 8-24 HZ. This condition is most common on extended cab and crew cab models but has also been noted in other models.
Recommendation/Instructions:
The severity of the beam shake may vary from vehicle to vehicle. To determine if the concern is beam shake, please perform the following:
1. Test drive vehicle to confirm the condition. A beam shake condition will usually respond to concrete type pavements more than asphalt, so the vehicle should be driven over both surfaces if possible.
2. Place 200-500 pounds in the pickup bed between the closed tailgate and the wheel wells. A beaming condition should dissipate.
-----------
If the concern is determined to be beam shake, this a characteristic of the vehicle. GM Engineering has released updated body mounts to reduce this concern for the Crew and Extended Cab Models. There will be no changes made to the Regular Cab Models.
FOR CREW AND EXTENDED CAB MODELS, REPLACE THE REAR CAB MOUNTS WITH UPDATED PARTS LISTED BELOW. THESE PARTS SHOULD NOT BE USED ON REGULAR CAB MODELS.
New upper and lower mounts should be installed at the left and right rear cab position. The new LOWER mount is a two-piece design, meaning there is a rubber mount with a metal washer. Some models may use a one piece lower mount, meaning the rubber mount has a metal washer molded into it. If the vehicle has the one-piece lower mount design, washers (PN 15854745, Qty 2) will be needed to be used with the new lower mount.
Upper Mount 25791031 Qty 2
Lower Mount 25791032 Qty 2
Washer 15854745 Qty 2 (if needed)
Please follow this diagnostic or repair process thoroughly and ccomplete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
I have traveled the stretch of the 101 that you mentioned and that would be the only area i've ever complained about the ride of my 2500HD. Did you try this fix on your truck and did it make a differance in ride over this stretch of road. I just assumed that it was more wheel base related for this road because i drove it in a friends F150 and got similar harsh ride through there too. Although if you drive through that area in a car you never notice it.
2003 GMC Sierra 2500HD cc/sb
2003 Eagle Cap 800 lite
the toys:
99 trans am 30th anniversary
79 trans am black se
88 chevy blazer (trail ready)
I am the slow one in our bunch. half a dozen friends have done it and love it. There is a whole thread on it on a Diesel site and every single person raves about it. I have a firend that gets me my parts at his cost so he has my parts for this but he is in Orange County so I am waiting to meet up with him to get them and install them.
Its caused ...(I am told) by the frame flexing inward. The mount that fix it are a solid mount and don't allow the frame to flex under the rear of the cab where its most prone to flex.
Ok here is a way to help fix this problem in the GM trucks. I will post a campaign number from GM that you can copy and print out. Take it to your dealer and show it to them and ask them to fix your truck if its under warranty. It is said by those that have done this it takes 70-80% of the bounce away.
Has anyone else tried the fix from GM for the absolutely terrible ride the 2500 has over freeway expansion joints?
The "Sulastic Suspension" mod to the rear mount of the axle springs doesn't even come close to helping.
I live in the Thousand Oaks SoCal area and travel the 101 Freeway through Camarillo quite often. It has got to be the MOST eye-tooth jarring ride in history....and that's only at 70mph. IF you even have the balls (left) at 80mph, more power to you! This is the KNOWN bad section of the 101 Frwy from the Conejo Grade, all the way to the Ventura Bend (about 8 miles or so).
GM's fix is to replace only the two rear BODY MOUNTS between the cab and chassis. It's NOT a warranty replacement...although it damn well should be. Luckily, it's only $200 (for parts only).
It's listed as:
""GM Campaign #PIT3009J: Suspension Vibration Or Frame Beaming At 40-60 MPH (64-80KM/H) - keywords front rear shake shock spring tire - (Sept 18,2008)""
Condition/Concern:
Beam shake vibration is usually felt and occurring at speeds between 40-50 mph (64-80 km/h). Hertz readings using an EVA tool are normally bewtween 8-24 HZ. This condition is most common on extended cab and crew cab models but has also been noted in other models.
Recommendation/Instructions:
The severity of the beam shake may vary from vehicle to vehicle. To determine if the concern is beam shake, please perform the following:
1. Test drive vehicle to confirm the condition. A beam shake condition will usually respond to concrete type pavements more than asphalt, so the vehicle should be driven over both surfaces if possible.
2. Place 200-500 pounds in the pickup bed between the closed tailgate and the wheel wells. A beaming condition should dissipate.
Dirtbikingdad, thanks for the info.
Our truck is a 2009, just bought it in Dec 2008 and have not gotten anything either the dealer nor GM as to this "fix".
The concrete sectional freeways are very notable, however the area you talk about I have driven and its pretty bad.
Anyway I'm gonna check the GM site for this GM Campaign Bullite.
Thanks
Doug
I just upgraded the rear cab mounts on my '05 2500HD, they do make a difference, but not in the undulating/pulsating/reverb of the expansion joints. They soften the jolts felt from the bumps/holes, etc. They don't get rid of the reverb from a bad highway!! The ONLY thing I've found that will help this is to slow down or change lanes.
HERE IS THE KICKER: In my case, I have factory installed (dealer installed) side/running boards, when the tech installed them, he must have used an impact to tighten them, thus negating any softening from the bushing since the bushing was crushed so the cab mount was basically metal on metal. I am going to replace the other 4 bushings with originals ($12.00/ea) from dealer.
If you are experiencing a severe jolting from every bump in the road and have already lowered your tire pressures, have decent shocks, etc., do yourself a favor and remove one of your cab mounts, you might find you need new ones, or at least replace the bushing if they were/are crushed like mine were. You will be able to remove the lower bushing without having to lift the cab (on the Silverado's anyway).
Chevy has a rear cab suspension replacement for those who whine some about the hard ride. I've having mine installed later this week.
Vanda and Dave Ludwig (Vandave) Spoiled King Charles Spaniel, Ultra spoiled Cock-a-phoo, '08 2500HD, 4WD, CC, SB, D/A, 30U Arctic Fox, Equalizer, Putnam Class V hitch.
Lowering the air pressure made a differece, in overall ride, but very little on the concrete sectional freeways even with the TT attached and the WD/equalizer on.
I'm curious as to removing a leaf from the rear springs (I got the 2500HD for TT towing, doubt I will ever haul 1500 lbs back there)appears to me the 2500 just has one more leaf than the 1/2 ton.
Does anyone know for certain the OEM shock replacement with aftermarkets(which ones) will be worth the effort and expense?
Also why does the 2500HD set up so high (even the 2WD), maybe the additional leaf springs and the spacer in the front suspension torsion arms?
Appreciate any and all feedback.
Regards,
Doug
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