Harmonic Vibration

[Frankenchevy]

All buttoned up. While adjusting my shift linkage part of my gauge cluster broke free and now my gear indicator doesn’t work. I guess I’ll try gluing it back on with some epoxy. Not happening today though.

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[Craig 85]

I resolved that problem on mine by putting the tach on the column. When the tach is straight up, I'm in drive. Who needs a shift indicator anyways?

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[Frankenchevy]

The saga continues...

I still feel a little something. I think I have way too much slip yoke exposed. As far as I know this is the stock driveshaft, but it has 3-3/16” yoke exposed. Everything I read says 3/4 to 1-1/2” max?

What do you guys think?

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[DoubleDingo]

I think you're on to something. Sucks it's more expensive to lengthen though

 

[Craig 85]

My truck measures 2 13/16" with the 3" lift. It moved out about 1/2" after the lift, so it would have originally been 2 9/16". FYI my drive shaft is 56 1/2" from center to center on the U-joint. I don't know if my 205 is the same length as your transfer case.

 

[Frankenchevy]

I think you're on to something. Sucks it's more expensive to lengthen though

Yeah, the aluminum tube alone is $300

 

[Snoots]

TREMEC Introduces Free Driveline Angle Finder App
April 14, 2014

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Take the guesswork out of your chassis setup with the TREMEC Driveline Angle Finder.

By using your iPhone as a measuring device, the app will calculate each u-joint angle and provide an overall driveline operating angle with a Pass/Fail response.

This unique App will help you avoid vibration problems associated with incorrect driveshaft and u-joint working angles. The three-step graphical interface provides measurements essential for proper driveline setup, along with tips and instructions that make it possible to check angles like a pro!

The TREMEC Driveline Angle Finder App is designed to measure driveline angles on RWD vehicles equipped with a one-piece driveshaft.


Click here to get the free TREMEC App Store Download on iTunes

For additional information, please contact Michael Kvicala, Marketing | Tel: (734) 456-3731 | [email protected]

I'll dig deeper for length equations.
Considering all you have done to (for) your truck $300 seems fair. Jest ma 2 cents.

 

[Snoots]

The saga continues...

I still feel a little something. I think I have way too much slip yoke exposed. As far as I know this is the stock driveshaft, but it has 3-3/16” yoke exposed. Everything I read says 3/4 to 1-1/2” max?

What do you guys think?

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Found this:

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Also found a lot of chat and confusion on yoke length. The overall consensus appears to me as follows;
1. with the wheels on the ground, disconnect the driveshaft from the rear
2. push the driveshaft towards the tranny until it bottoms out
3. pull it back out 1 inch (a LOT of statements going from 3/4 to 3 inches here)
4. your rear should mate up at this point
5. if not, the yoke is too short or the driveshaft is too short.

It seemed most yokes should be about 4.5 to 5 inches.

What you have seems to be too much out and not enough engagement. But that's just my opinion. I've never seen that much exposed.
Also confirm that your yoke is 'toothed' its full length or it will bottom out too soon.

 

[Snoots]

Concensus seemed to be that the splines of the tailshaft to yoke should be engaged 2 to 2.5 inches. Makes sense to me. If the yoke is too long you risk punching the rear seal out. Too short you risk twisting the end off or spitting the yoke out.

 

[Frankenchevy]

Just an update:

New longer driveshaft and spicer lifetime ujoints

replaced transfer case seal, yoke bushing and rear output shaft bearing

replaced new urethane trans mounts with new oem type rubber mounts

rehung exhaust with a little more 'slack' and increased header to frame clearance on driver side

installed third torque converter since truck was rebuilt--this time I used a local shop instead of Hughes Performance


harmonic still there.

next up will be replacing rear wheel bearings since I already have the parts on hand. next cheapest step will be rebuilding the np208 transfer case at ~$200 in parts. If that fails to remedy the situation it's finally off to the diff shop. Lastly, a rebuild on my TH400 will run about a grand. Those are the last pieces.

 

[Snoots]

If you're going to pull the axles for new bearings, check them for TRUE.

 

[shiftpro]

This is just unbelievable...

 

[Octane]

I had a high mileage engine with excessive crankshaft end play causing a vibe once.

 

[bucket]

Just wondering, how much have you really looked at the front driveline? Perhaps the t-case isn't disengaging the front output, or maybe a locking hub is stuck engaged?

 

[SquareRoot]

Remove front shaft. Get your spare tire balanced and make sure it's true. Swap it one position at at time.