2nd Gen Non-Engine/Transmission Would you put these back in your truck?

[Joe Mc]

Have vibration in rear, wheels off the ground placed on stands - vibrates, removed wheels/tires & run up to vibrating speed. I pulled the axels last weekend to change hub bearings and races, since it's not back together yet I figured I'd dial out the axels. Notice there are smooth areas on the axels displayed by paint pen lines on top two pictures, this is where I place the dial indicator. Of course my primative wood "V" blocks, see two bottom pictures, only give an approximate. But, I'm hoping someone out there can comment as to wether or not these are in an acceptable tollerance or if I should get new. I'm wondering if they left the factory like this?



Please check out dial readings - I appreciate replies.



Oh, right side of each picture is the flange end, left side of course is the splined end.



Thanks.

 

[BILLVO]

I would take a micrometer and measure the axles in several spots in the area you dialed them at to make sure that they are truely round before checking runout with a dial indicator. Axles are not the most true thing to measure that way. You can have that much out of round the way they are made and it will show an inacurate run out reading. Chucking them in a lathe and spinning them up a bit would be a better way to see if one is bent.



jmo



Bill

 

[chuckwilson]

Did it vibrate with the wheels off!!!!!!!!! BILLVO was correct, put it in a lathe or on test centers & check the flange end for wobble with dial indicator & look for bent in shaft, the shafts are rough cast & what you have is not to bad & wont cause a problem.

 

[B.G. Smith]

I agree, you would have to put the axles between centers to check trueness and run the indicator on the machined surfaces. If you can't do that< I wouldn't worry about them, I suspect they are fine. bg

 

[Joe Mc]

Did it vibrate with the wheels off!!!!!!!!! BILLVO

Yep, w/them on and not as bad with them off.



Makes sense test centers and/or lathe and spin em up. Hope I can find a machine shop open tomorrow. . .



Thanks guys.



Howard - when'd you get an 06? Probably 06 - right, hope it serves you as well as the 2nd gen did.

 

[CumminsPower98]

The axles don't even turn that fast so I don't see how there could be any problems there. Have you checked your driveline for balance and made sure you don't have alignment problems? U-joint mis-alignment can cause all kinds of vibrations and shudders. Also a bad joint could cause problems.

 

[NVR FNSH]

Axle shafts would be pretty low my list of suspects for a vibration. Does your truck have a 2 pc driveshaft w/carrier bearing? How are the u-joints & carrier bearing? What about dents in the drive shaft tube(s)?



Brian

 

[Joe Mc]

After I installed new u-joints 5000k ago, had carrier bearing inspected during shaft balancing (which was not bad - they added . 25 oz). Yes, 2500 QC 8' bed has two shafts. Axel shafts were low on my list of suspects until I replaced everthing else . . .



CumminsPower98 - the vibrations are evident at speed on the road and on stands with the wheels on and remains with the wheels off.



So the needle in the haystack for vibes continues . . . .

 

[WDixon27]

i discovered the rear u-joint wasn't tight side to side in the pinion flange on mine, it's been a while and can't remember the exact #s but i think it was around . 15 too narrow for the saddle to fit perfectly, i used a ac compressor clutch spacer under the two pinion flange u-joint caps to center the joint in the flange, and that got rid of the slight buzz at 70 i had, you could move the driveshaft side to side before i shimmed it and a new joint was the same width as the old one

 

[Joe Mc]

I think, since I have the axels out and nothing else is there but the shaft and rear gears, I'll try to run her up to speed on the stands and see if the vibes are still there . . .

 

[Batphreak]

Maybe I'm just paranoid, but that doesn't sound like the best idea. There isn't anything to keep your gear lube in the housing (no axles so seals don't have anything to seal against), and that's provided you're doing this by putting the cover back on and filling your housing with no axles installed. Granted there won't be any load on the diff set, but still doesn't sound like a good idea to me to spin that assembly at those speeds without all the proper lube.

 

[Joe Mc]

There was ample lube for a short spin up to speed remaining in the diff, even with cover off, axels out etc - as I'm nose down my driveway and it slopes down enough to where you'd have to scoop out the residual lube that the ring gear is semi-submersed in remaining. Yes, it flung lube as I was spiining her up.



Here's what I determined the problem was, after taking axels to machine shop - Tech told me he's never seen axels be a source of vibrations on a D70, moreso carrier bearings, spider gears or floating hub bearings - I recall sometime ago the left hub bearing being loose to the point when I pulled the nut wedge and placed socket on nut to check tq, it moved with no pressure more than 1/4 - loose. I retorqued to spec, loosened the 1/8 turn per manual and thought all was well. Since I had the axels out decided to throw another $100+ at it for inner/outer both side hub bearings and races. "BINGO" no more vibrations FINALLY!!!



So it's definitly true that rear vibes can be transmitted thru frame and it definitly felt as if it was coming from the left front the whole time. . . .

 

[Ragain]

Joe, every time I have my drive axle tore apart I notice the inner race on the roadside outer wheel bearing has spun on the axle housing. Enough to wear about 3/64" to 1/16" off the backside of the bearing nut. (wedge-lock still in place) Did you notice any wear like this on the backside of yours? Or, has anyone else experienced this?

 

[jelag]

Axle shafts are designed and machined to be parallel or in line at the splined end and the machined surface where the bearings mount... .

They are checked for balance and testing them in the center gives you nothing important... in some cases axles are drop forged and rough along the shaft except for machining and balance...

Hope this helps...

 

[Joe Mc]

Joe, every time I have my drive axle tore apart I notice the inner race on the roadside outer wheel bearing has spun on the axle housing. Enough to wear about 3/64" to 1/16" off the backside of the bearing nut. (wedge-lock still in place) Did you notice any wear like this on the backside of yours? Or, has anyone else experienced this?

Didn't notice this, but wondered why a bigas washer wasn't in place between nut and bearing?



jelag - thanks - you're comment supports basically what the MAchine Shop Tech told me . . . these axels can be off and are designed that when you torque to the hub they straighten out/should not be an issue unless the bearings in the carrier or hubs are bad . . . as was (apperently) the case with mine. Cause "baby" it's a smooth ride now, minus the tire bands that've been "tweaked" by hitting/going over curbs last winter