Jmac...you stated you "cured" the problem of your "shudder" by changing the rear pinion angle.....but you changed the driveline angle at the center bearing....just like outlined in the TSB. I've tried three different shim/brackets outlined in that bulletin with NO success, matter of fact lowering the center bearing brought on a 64mph "drone", but did nothing for the launch shudder. I'm currently trying to adjust the rear angle by installing shims. I hope it works, but my gut feeling is that I'm wasting my time. Personally I wish the guy would just step up and get air bags as that what most seem to do, but I can see his point of having a truck that should be capable when it leaves the lot.

PS I'm a dealer tech and sometimes wish I had the option you mentioned that "we all" seem to have and do nothing.

 

Installed a 2.5 degree shim. Give the total pinion angle 4.5 degrees empty. Road tested it with the trailer and while it did not "cure" the prob, it certainly helped. I was only able to drive the truck empty up to 50mph, and didn't note any vibes or noise with the change. It was shuddering all the way through first gear with the trailer on. Now it has a 5-7 mph window, but quits shuddering before the 1-2 shift. It didn't do that before...it was completely through first gear.

 

Not true. How could the transfer case be located anywhere other than at the end of the tranny?

Mega's and quad cab long boxes are the same powertrains.

 

I guess I'm lucky... no shudder here loaded or unloaded... I havnt touched nuttn on my truck yet...... Did change the oil, but no mods (or repairs knock on wood.....)

 

I had shudder on take-off loaded or unloaded bed and a slight amount on take-off when towing, but was less than when not towing. I also noticed some shock pogoing when towing in windy road turns, especially downhill.

I put in rear air bags and the slight towing shudder went away, and the pogo in turns decreased. I keep the air bags at 5-7#s when empty and the ride feels like the day I bought the truck - smooth.

Interestingly enough, when I installed the KORE Leveling Kit with the heavier springs, Bilstein shocks, and stabalizer blocks my empty take-off shudder ended completely. That leads me to believe that the stock front springs and shocks are not heavy duty enough for the truck and the stock stabalizer articulation angle may be wrong. I also installed the Bilstein shock on the back.

I have 9K on the truck now and my suspension issues are gone.

CD

 

I am having similiar issues to J Body with my 2006 Mega cab 4x4. Spaced down the steady bearing 1/2" and it went away unloaded, but is very bad once I hook up the trailer. Last night I put in 1 1/2 degree shims to increase the pinion angle. I will hook up the trailer today to see if it is any better.

J Body-Did you angle the pinion down to get the 4 1/2 degree pinion angle? That is about what I have with the 1 1/2 degree shim. I am not sure I am comfortable leaving that much angle across that joint. Priced out air bags, this may be the best way to go.

 

Hooked up the trailer, seems quite a bit better. Still a bit of vibration at slow speeds, but l can live with it.

It is disappointing DC can't engineer a real solution to this problem. I moved up to the Mega cab from a Quad cab shortbox, and had no issues pulling the same trailer. Really love the Mega cab otherwise.

 

Yes, I went "down" with the pinion angle and ended up at the 4.5 degree (no trailer). While it did improve it, it didn't rid of the "shudder" with his 5ver hooked up. Customer took the truck and reported back that "it didn't help at all" and that he thought it had noise at 55 now.....again, this one is NOT a mega, but a long box quad cab. Not being a "fifth wheel" kind of guy I had our retiree shuttle driver help with the hook up as he currently owns one and has had a few others. On driving up to the camper he immediately started to tell me of how he looked at the same brand but steered away from them due to the "heavy weight" of them. Biggest issue is that the customer traded in a mildly bombed 98 in the same configuration and had no issue. Looking at my 01 2500 the differences are: Helper springs, shorter spring length (front segment), and more leaves. I'm also feeling that some other issues that helped his 98 NOT have this issue would be the crap stock torque converter which many can attest to. When pulling with those your rpm's immediately go to 1800-2000 and your engine makes alot of noise, but it very slow in getting the load moving. He now has a 48re, which acts alot like the better convertors in the aftermarket and gets the load moving faster at a lower rpm, and he now has quite a bit more torque than he used to. I came to this conclusion after the first time I towed my race rig a couple weeks ago for the first time with my Goerend trans. It does have a little "buck" when you leave a stop, especially if you are pointed up hill a bit. Bottom line is the customer feels, which I can't say I blame him, that this "new" truck should not have these probs. I've taken the service manager for a cruise and he stamped it "acceptable" (he's the one with the 06 Mega that "shudders") and felt for the load that he was moving that it was ok. Once you get the load moving it does awesome and the customer will attest to that. Personally I would be buying either: overload springs, or air bags and move on. Guess it would be similar to me modifying my own truck to suit my needs. Sure I think DC should have done a few things better, but if they built the "perfect" truck for all those using them, their wouldn't be an aftermarket would there.

 

mine has the shudder. so does my bosses. so does the one i drive for work. so does my bosses dad's. so does my buddys. so does a few ive test driven off the lot at the dealer. guess its a dodge trademark....

Actually i just changed the differential fluid in my truck and i swear it seems a lot less noticable but it is certainly still there.

 

Seems my happy medium adjustment of the pinion angle did not work out afterall. I ended up shimming down the steady bearing almost 3/4" to keep the pinion angle to 4 1/2 degrees empty, which means that everytime I hook up the trailer, I would need to take out the steady bearing shims. I have also concluded that the fix does involve the addition of something to stiffen up the suspension, or keep the truck from squatting so much. I think the rear leaf springs aren't stiff enough, probably because they were designed for a smoother ride and not load carrying. The wimpy steady bearing also has me wondering.

The thing that irritates me about DCs attitude on this is that when I have the 5th wheel on behind (which weights about 9500lbs wet), it is not just an annoying little shutter, but a teeth rattling vibration that lasts most of the way through first gear. I bought a 1 ton diesel truck to pull my trailer, and it is not capable of that. If I wanted a truck to get groceries, I would have bought a 1500 gasser. The truck I traded off was a 2005 QC short box 3500 4x4 with a cummins/auto. I was very happy with that truck, and it pulled my trailer over 3500 miles with not a hint of problems of any kind. I thought it would be a lateral move to the Mega cab in the towing department, but it was a big step backwards. The concept of a long wheel base truck with a 2 piece driveshaft is not a new one. Seems the other major manufacturers can do it without vibration issues, so why can't DC. I am not looking for perfection, just a truck that will do what I bought it for in the first place.

I am not meaning to offend anyone, just venting.

I have spent allot of time and effort on a problem that will not be acknowledged by DC, even though there seems to be many trucks with similar problems, although mine seems worse than most.

Looks like my next move is going to involve installing airbags, and starting over to find the happy medium.

 

......and it's by no means "fun" to be the middle man who is supposed to "fix" the customers truck in these situations. Sometimes "wrong" can't be fixed, but has to be "re-engineered". If you go the air bag route please post back......and I agree with you on your thoughts about the leaf springs and trying to make a "soft" ride. By the way, for those interested, the RV on my subject was a Sea Breeze. While I don't have hard data, I would venture to say it weighs in the 12,500-13,000 lb range. It does drop the ride height of the truck 3.5 inches, but I don't think it's the "squat" that causes the issue as much as the leaf spring design.

Robert.....is your new "mega" a 2500 like your old one, or a 3500?

 

Both trucks are/were single wheel 3500s. I went with the heavier trucks in case we ever move up to a bigger 5th wheel. The 2500 just doesn't have the payload.

I sympatize with you j-body, you can be a victim of the "shoot the messenger" syndrome. I wouldn't want to be the bearer of bad news either. I agree there is no fix for this one without re-engineering.

I think the air bags will be the ticket, but knowing how the suspension reacts to the engine torque, maintaining a consistent ride height (and driveline geometry) under load may not be enough because of all the extra torque to get the load moving (twisting up on the diff.) Addding extra leaf springs may be the safer route, but my wife loves the way it rides, so it is not really an option unless I have to.

The first time I towed the trailer I noticed the Mega cab is much more "tippy" feeling, so the air bags will have an added benefit there.

It just grates me to have to spend my time and money to fix this, thinking I had bought the "Cadillac (no I don't wish it was a GM) of tow vehicles."

I don't regret buying the Mega cab, and the family loves the extra room. I hope this gets solved soon.

 

I'm just wondering, and thinking out loud about another 3500 mega that I know has this issue, that if a guy were to get an extended bump stops for the overload springs on the single wheel 3500 if that wouldn't stiffen things up enough. The 3500 has the bump stop mounts on the frame, but sit awfully high in comparison to the older BE body trucks (2nd gen). The 2500 has no bump stops, or overload springs. We noticed this while looking at different builds on the lot. We also noted that the 03 3500 seemed to have a different spring configuration all together. Looked to be much more "heavy duty".

 

""I'm just wondering, and thinking out loud about another 3500 mega that I know has this issue, that if a guy were to get an extended bump stops for the overload springs on the single wheel 3500 if that wouldn't stiffen things up enough. The 3500 has the bump stop mounts on the frame, but sit awfully high in comparison to the older BE body trucks (2nd gen). The 2500 has no bump stops, or overload springs. We noticed this while looking at different builds on the lot. We also noted that the 03 3500 seemed to have a different spring configuration all together. Looked to be much more "heavy duty".""


I was actually wondering the same thing. When I was talking about how much my truck "squats" I was thinking more about air bags keeping the same ride height loaded or unloaded. As the suspension sinks, you loose the pinion angle which seems to aggrevate the problem. ( but I still agree with you this wouldn't be a problem if the springs were stiffer. The pinion angle is merely compensation)

My truck only squats about 2" and does not quite sit on the overloads. I realized that is probably why my truck is so bad when towing, it has more torque applied, but doesn't have the extra support of the overloads.

My truck has 3 "spacers" (about 3/8" thick) in the spring pack under the main leaf springs between them and the diff. I was thinking if you were to re-arrange these spacers to the top of the main spring pack, between it and the overload, the overloads would be closer to the bump stops, and become effective sooner. It would lower the unloaded ride height a bit, and may also have the negative effect of possibly making the ride choppy because when unloaded, and you hit a big bump, the overloads may "slap" more. It would be easy to try because the overall thickness of the spring pack is the same, so you don't need different u-bolts etc. If it did work you could get spacers for below the main spring pack to restore ride height if needed.

I may actually try this... The more I think about the air bags, I wonder if they wouldn't turn into a big PITA. I think the onboard inflation kit would be a must have, and I am beginning to wonder if they would really cure the problem. The extra stability when towing would be nice though... decisions, decisions


By the way, how do you make the "quote" function work? I did a cut and paste, but it seems there is a different way to do it.

 

"That's why the quad's aren't experiencing the problem."

Sure they are. Mine has had the shudder since day one. I just have gotten used to it. I don't tow heavy loads and have had no problems caused by it other than the initial annoyance.