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Discussion Starter #1
Every since we got our new much heavier trailer (usually between 10-11k pounds) we have been getting this.

It usually happens when starting out in granny 1st and shifting into 1st gear. By that time when shifing into second the truck is rolling enough it will stop doing it.

It doesn't bother me persay, I just don't want to bust a U-joint and end up stranded.

A little background, the truck has a set of blocks in it that are 1 inch taller than stock to level out my leveling kit lol. I run the airbags so the truck is close to my unloaded height. My truck sits failry level unloaded. 1" inch high in the back, not the normal 3 inches or so of cheese wedge factory look.

When I was towing 7k pounds my truck never did this nor did I feel the need to start out in granny gear with that trailer. With the new trailer I feel like I am abusing the clutch to get the 10k pounder rolling if I don't use granny 1st.

It does it really bad when taking off with any kind of uphill slope.

My opinion, is that the increased weight is wrapping the axle up to the point of u joint binding. To me this is a different kind of driveshaft vibration then say a lift induced angle problem.

So my question is, would I try shimming the center bearing up or down?
If the axle is winding up then wouldn't dropping the center bearing compound the problem?


I apologise for the wordy thread but I wanted all the details I could give.

Advice?
 

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Discussion Starter #3
I don't think there is any probably about it lol. ;)


Not sure what there is available out there that isn't too cheesy. I don't want any big ole lifted 4x4 looking show jobbers under there. Something more stealthy maybe?
 

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What if it's just the clutch? If you take off a 80k lb. tractor trailer in 4th gear it shudders and bucks terrible. Just some food for thought.
 

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Discussion Starter #6
Clutch is all the way out and throttle rolled on. Once torque builds against the turbo the shudder comes in.

I can make the clutch chatter. This is totally different and if you have ever felt it you wouldn't forget it. I have been in a couple Dodges that did this as well pulling very heavy loads.

I did just go out and check again since we just got back from a 2k miles trip the U joints and stuff down there. The drive shaft flange is still tight in the T case (I have had that come loose once before), the u joints still have no play in them. The only thing I did notice is the rubber around the center bearing is really floppy. I know it has always had some play but this is quite a bit.


As for traction bars? 500+? I'll build something myself if I can find a design that works and I like.

Thanks so far guys.
 

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PMR = JUNK
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Sounds like you need to shim your carrier bearing down a bit. Since you raised it you changed the driveline angle.

The carrier bearing is that bearing in the middle of your d-shaft.
 

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Discussion Starter #8
lol, I know what a center carrier bearing is. Sorry, don't mean to be sarcastic sounding as I know you are just trying to help.

Did you read all of my original post? My question is would it be shimmed down or up?

If the axle housing is winding up that means the pinion is rising, right? If it rises to the point of binding a u joint, then wouldn't lowering the carrier bearing worsten the problem?
 

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PMR = JUNK
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lol, I know what a center carrier bearing is. Sorry, don't mean to be sarcastic sounding as I know you are just trying to help.

Did you read all of my original post? My question is would it be shimmed down or up?

If the axle housing is winding up that means the pinion is rising, right? If it rises to the point of binding a u joint, then wouldn't lowering the carrier bearing worsten the problem?
Sounds like you need to shim your carrier bearing down a bit. Since you raised it you changed the driveline angle.

The carrier bearing is that bearing in the middle of your d-shaft.
You are probably getting some wrap, but i think the real problem is from the added height. Picture it in your head, you raise the truck, now the driveline is going to be at a steeper angle, therefore you will want to lower the carrier.:thumb:
 
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