Drive Shaft Center Support Bearing?

[MMeier]

MMeier.



Just got on the net, have been off for a few days, family visiting for the holidays, etc.



I should have measured the diameter, it has to be a good 6"s or more. I can get a measurement tomorrow. Most all GOOD driveshaft shops can shorten it for you, even a good machine shop could.



I have a couple more pics of the install, I'll send them to you so you can see how it looks.



CD

Thanks, you have mail also ! If you could... hopefully not being a PITA, could you measure how long the new one is ? Hopefully give Rich some more info to go after.

 

[CDonaldson]

You have mail back at you. I will get some measurements tomorrow. I have a friend coming over, an extra pair of hands will make it easier, that shaft is a long bugger, longer than my reach. If you need any more pics let me know, I'll get them while I'm under the truck.



CD

 

[MMeier]

You have mail back at you. I will get some measurements tomorrow. I have a friend coming over, an extra pair of hands will make it easier, that shaft is a long bugger, longer than my reach. If you need any more pics let me know, I'll get them while I'm under the truck.



CD

Just the ones in my latest EMail I sent... if anything, maybe try to measure just how far that shaft goes into the tcase.

 

[MMeier]

More pics from CD !

Various shots of new one piece shaft !

 

[cumminalong]

Folks, this is Rich from Doghouse Diesel.

Here's what I'm finding with the 1-piece driveshafts.....

G56 and Autos are no problem, those fit fine.

Where we're seeing issues is on the NV5600's. The part number and driveshaft code is the same, whether it's 1-piece or even putting a 2-piece on one of the factory trucks that came equipped with a 1-piece.

This is on some, not all, NV5600 trucks. When installed and unloaded, the driveshaft fits, but is VERY close to the limits of the slip yoke. When a load is added to the bed, it nearly, or does, bottom out the slip yoke on the t-case. Again, this is some trucks, not all of them, but their doesn't seem to be any specific ones to say yes or no on whether they'll fit or not.

Again, G56 and autos are no problem, just the NV5600's.

I've gone line by line on each drivesahft in th OEM catalog and can't find a seperate part number that is NV5600 specific, it keeps coming to the same part and code for both.

I want to do some more research in the Body Builder's Guide today for actual measurement, but at this point, if you have an NV5600, I can't guarantee that the 1-piece will fit..... it's hit or miss.

 

[cumminalong]

Okay, did a bit more digging and the Body Builders guide doesn't have the driveshaft lengths listed.

So... . what I need is this.

I need the measurement from the face of the pinion flange to the edge of the t-case output shaft boot... . straight line distance for.....

1 - 4x4, LB with a G56
2 - 4x4, LB with a NV5600

I don't have any manual trucks in the shop right now to verify them and most of my local customers have autos, so if someone doesn't mind crawling under the truck, it'll speed up the process.

 

[tkerrigan]

I had to have the aluminum drive shaft shortened 1-1/4" for my truck. Cost was $95. There is no doubt in my mind that this is a good mod. It probably added 10-15 hp, the overhead display now runs 2 mpg better than it did. The ujoints on my two piece were all 1 degree off of each other in rotation. I think they are probably true when manufactured, but high torque sets each shaft a degree off later. By the way, anybody who wants the stock drive shaft and mounts, can have them for hauling them away. 27,000 miles on it.

 

[MMeier]

Okay, did a bit more digging and the Body Builders guide doesn't have the driveshaft lengths listed.



So... . what I need is this.



I need the measurement from the face of the pinion flange to the edge of the t-case output shaft boot... . straight line distance for.....



1 - 4x4, LB with a G56

2 - 4x4, LB with a NV5600



I don't have any manual trucks in the shop right now to verify them and most of my local customers have autos, so if someone doesn't mind crawling under the truck, it'll speed up the process.

Rich, give me about an hour , I'll try to get an actual measurement for you on a QC LB 4x4. Do you want it by the truck it self, with a load at normal height... meaning air bags to level out , or ... . ?

 

[MMeier]

Rich, on my truck... 03 QC LB DRW 4x4 w/ 5600 I measured the distance to be right at 76 3/8 ". That is from the front side of the pinion flange to the opening on the end of the dust boot on the TCase. Truck has my 20' enclosed on it , but is set to level with airbags, should I measure again without it ?

 

[cumminalong]

No, that's fine. I appreciate you taking the time to do that. I don't want to cause you any trouble with it, I just want to see how far off they are and if there is any way we can get one sized right for the NV5600 folks.

The driveshaft was designed to go behind the G56 on the 07. 5+ trucks, not the NV5600.

Now, the good thing with this is that folks with lifted trucks with NV5600's have a good driveshaft to use. When we get trucks with 6" of lift or more that have the G56's, we need to install a 1" aluminum spacer to get enough spline contact at the slip yoke.

Right now I'm leaning toward the shaft for the auto's, but I don't want to give a definite yes on it until we have enough numbers.

 

[MMeier]

I had to have the aluminum drive shaft shortened 1-1/4" for my truck. Cost was $95. There is no doubt in my mind that this is a good mod. It probably added 10-15 hp, the overhead display now runs 2 mpg better than it did. The ujoints on my two piece were all 1 degree off of each other in rotation. I think they are probably true when manufactured, but high torque sets each shaft a degree off later. By the way, anybody who wants the stock drive shaft and mounts, can have them for hauling them away. 27,000 miles on it.

Tom, how many miles on the new shaft ? Have you towed with it yet ?

 

[tkerrigan]

About 4,000 miles, towed my 32' FW to Las Vegas, then Pahrump, then back to Oregon. Missed May Madness because a friend died. Never a shudder during any of the towing.

 

[cumminalong]

Here's the main reasons why those 2 piece driveshafts cause vibration.

1 - Everyone understands that the rubber mount in the center carrier wears out and this allows the shaft to flop around. No real brain surgery there and that's the main cause.

2 - U-joints need to be at opposite operating angles to cancel each other out. The farther out they get from each other (1*, 2*, 3* is okay), the worse the vibration gets as they don't cancel each others vibrations.

The geometry of the 2-piece shaft doesn't allow the u-joints at the center carrier and the differential to maintain those opposite angles and you get the vibration at certain speeds and load conditions. It's most common without a load in the truck because the angles are the farthest out of whack due to it being designed to to have a load in it.

The 1-piece shaft, by increasing the distance between the 2 joints, decreases the angle that the joints operate at and reduces the effect on that angle caused when the rear axle "wraps" under load or when the suspension is compressed.

Maintaining matching operating angles is the key to getting rid of the vibration and shudders (and having a driveshaft that's not flopping around during rotation). The only thing those dampers on the 2-piece shafts do is mask the condition, they don't really solve the problem.

What the dealers like to do is shim the carrier bearing support for this complaint, but this isn't the best solution and it doesn't make a significant change. The easiest (and cheapest) way to fix some of the vibration is adding an angled shim under the spring packs and changing the angle of the pinion. This puts the u-joint angles where they need to be in most cases.

To do this, you need to measure the angle that the back section of the drive shaft comes out of the center carrier and the angle of it at the diff. Once you have these angles, you can figure out what angle shim you need to put them in alignment.

You want to get these measurements with the truck at the ride height that you normally use it. If it's a daily driver, you take the measurements empty. If you're a hot shot, you take the measurement with a load on the back.

Shims are cheap and easy, you just need to figure out the angle.

Here is what you're looking for.....

Chassis & Suspension - SummitRacing.com

 

[MMeier]

Rich, how long is the one for a MC SB 4x4 G56 ?

 

[cumminalong]

The shaft for the G56 is 74. XX".

The shaft for the auto's is 75. XX"... . a bit more than an inch longer, so it definitely won't work on the NV5600.

The only option on the 5600's right now is the one for the G56 and having it shortened by ~1. 5".

 

[tkerrigan]

That's what I had to do on mine.

 

[MMeier]

The shaft for the G56 is 74. XX".



The shaft for the auto's is 75. XX"... . a bit more than an inch longer, so it definitely won't work on the NV5600.



The only option on the 5600's right now is the one for the G56 and having it shortened by ~1. 5".

And how was that measured ?

 

[cumminalong]

I had one of my customers measure them on two of his trucks, so I'm "assuming" he measured just the shaft length, not including the yokes, being that they're installed already.

 

[MChildress]

I measured my 04. 5 3500 4X4 QC Long WB NV5600 empty from where the diff flanges meet to the end of the metal tail shaft cover on the transfer case not the rubber and got 79". I don't know how much is going into the tail shaft. I have talked to a couple driveshaft shops and most only go up to 5" diameter but are using . 125 thick material on their aluminum shafts.

I found a outfit in Houston tonight on ebay motors Driveshaft Source but only can find a phone number and no address on them. Has anybody had any dealings with them.

 

[ELABAY]

MChildress, If your are looking for someone to build you a new driveshaft in the Houston area try Randy's Driveshaft. I dont have there number on hand but I am sure you can find it on the web somewhere. They have built new driveshafts for us at work and do a good job. I have been thinking of calling them myself but havent gotten around to it.