Dana 60 Problems
 

1970 C20 with HD leaf spring suspension and full floater D60 4.10 gears. I have a vibration that comes in at aprox 50 strong at 60-65 and fading at 70mph. Also causing a loud rumble type noise in the cab.

Putting the truck on jack stands I can duplicate the issue. Items eliminated are wheels, brake drums and driveshaft/u-joints. I can remove the wheels and drums with no change. Entire 2 piece driveshaft has been rebuilt balanced and then later shortened (trans change) and rebalanced again.

Rearend shop said my pinion angle was off, so I installed 2 degree shims, shimmed the center carrier support lower. Working angles of the 3 u-joints are all under 2 degrees. Nothing has changed after all this work

I don't notice any noise but the vibration is strong, shakes the rear view mirror.

Any experts out there have comments?

Re: Dana 60 Problems
 

Was the vibration there before you shortened (trans change) the driveshaft?

Re: Dana 60 Problems
 

Yes been there for quite a while. I can't really say when it started. When I had the TH350 trans in the engine screamed and had unknown to me a mis installed clutch fan that ended up breaking the front of the water pump off. I was always thinking just poor tire balance. Even bought new tires and had everything road force balanced.

If this helps I also ran it on jack stands with the rear portion of the drive shaft removed. Silky smooth

Re: Dana 60 Problems
 

Is the yoke installed deep enough?
Same motor with the t350 as it is now with the 700?

Also, is the output shaft on the trans at the centreline between the frame rails or offset towards the passenger side rail?

Re: Dana 60 Problems
 

Ill have to check, same trans mount just moved back in frame. Different 350 engine, like I said I can't really pinpoint when the vibration started, but it seems to be getting worse. I do drive it daily

Re: Dana 60 Problems
 

Just throwing this out there, but over tightening the Ujoint caps can cause the joints to bind. Empire drive line gives the spec of tightening till the lock washer flattens then another, I think, half turn, it's on their web site. Or look up torque spec. Anyhow, I always start with the Ujoints.

j

Re: Dana 60 Problems
 

Back story on drivetrain and changes recently--pics help sometimes also

Re: Dana 60 Problems
 

Could be a case of the square body vibration mystery. There are multiple threads about a similar vibration at similar speeds. Most trucks don't have it. A few do. Those that have it generally resist attempts to fix. My 75 C10 does it sometimes although the speeds where it happens tend to be 65~75.

Things on mine that have been replaced over the years without fixing the vibration issue:
All u-joints, Center drive shaft bearing, rear axle bearings, engine, flex plate, rear drums, front rotors, rear spring bushings, several sets of tires. Also had the front end redone with many parts replaced.
Most of these parts were replaced because they needed replacing or I thought they did and not just to chase the vibration issue.

Sound like what I’ve been thru. Front end rebuilt disc brake upgrade in front new drums in back wheel bearings replaced I’m really at a loss as to what is causing this.
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Re: Dana 60 Problems
 

Have you measured the trans position between the frame rails yet?

Re: Dana 60 Problems
 

A few things. What engine and transmission mounts are you using ? Poly will transfer vibration.

All 3 u joint operating angles must be equal. The rear axel when viewed from the side should be pointed down 1-2° less. Allow for that in your calculations.

Re: Dana 60 Problems
 

How much movement is in the pinion? Does the seal leak.

Re: Dana 60 Problems
 

Factory replacement mounts. Rubber. I'll have to check my notes on the measurements. The operating angles of the u-joints are small, but I don't believe they are exactly the same.

Re: Dana 60 Problems
 

Here are my measurements with the truck sitting in the garage. All measurements are based on angled down from front to rear of truck I'm also including the rear axle in this definition.

Engine/trans 2.2, front drive shaft 3.3, rear drive shaft 4.3, rear end 2.6. Per Spicer's app operating angles of the u-joints are 1.1 1 and 1.7

I obtained these from shimming the trans mount up slightly, shimming center carrier support down little over 1" and 2 degree shims at the left spring perches.

I have not had a chance to measure the center line of everything horizontally yet, but eyeballing it trans looks to be centered and rear end is slightly towared the passenger side.

Re: Dana 60 Problems
 

If I am reading your measurements correctly you should be good with the driveline angles. My 57 dump has way worse angles and doesn't vibrate. That has 5.14s so the shaft speeds are up there.

Re: Dana 60 Problems
 

Thats what I think, the rear end shop is convinced that my driveline is the issue, since there is no noise from the differential that they could hear. They did look at it prior to shimming the trans mount 1/8" up and the carrier support 1/8" down (I already had shimmed the center support 1" down) Just trying to get this fixed, its the only issue I have for the truck outside of the body/bed rehab.

Re: Dana 60 Problems
 

Still waiting for a pic of the driveshaft

Re: Dana 60 Problems
 

No pictures as of now.

Back story: Always had a vibration at 50+ MPH blurred the rear view mirror.
Totally stock C20 suspension with HD suspension and leafs in back
Always thought it was tires.
New wheels and tires: no change
balanced tires multiple times: no change
Went from TH350 trans to 2004R trans: no change
Brand new crate 350 engine: no change
Had driveshaft rebuilt including carrier support and balanced: no change
swapped out th2004r for 7004r and had driveshaft shortened and rebalanced: no change
Disc brake upgrade in front with rebuilt suspension: no change
New rear brake drums: no change
New tires (thinking old ones were the cause): no change

Now I really started getting into this

Put truck on jack stands supporting the rear end.
Could duplicate vibration at speed.
Remove tires: no change
Removed brake drums: no change
Removed rear half of driveshaft: smooth

I reinstalled drums and wheels and only lifted one side of rear (open diff so you can do this) ran truck up to speed in gear: no change
reversed sides up and retried: no change
This told me it definitely was not axle or wheel assembly on either side:

Read up on this as much as possible and shimmed center carrier support down 1": made it smoother on acceleration at lower speeds

Rearend shop said my pinion angle was bad. Shimmed the rear up 2 degrees and replaced all the leaf spring bushings: no change at hwy speeds

Rearend shop still says pinion angle is bad after test drive. I added a 1/8" or so plate moving rear of trans up and another 1/8" plate dropping center carrier support down. The addition of the 2 shims had the effect of changing the rear driveshaft angle a little. No change

From what I can see without measuring the trans tailshaft is centered in the frame as well as the center carrier support. Looks like the pinion yoke is slightly on the passenger side of the frame.

Re: Dana 60 Problems
 

No movement that I can feel. Does not leak. Rear end was rebuilt by a dealership years ago. they had my folks source a used ring and pinion as they didn't have one. All new bearings. I'd be surprised if not more than 20K miles on it.

Re: Dana 60 Problems
 

My next test would be to load the suspension down or physically strap the suspension to simulate a load. If this changes it you have an angle issue. That said I think that you have a bearing issue with the axle. Either a loose pinion or wheel bearing. The axle being centered is not that big of an issue. Many axles arnt centered. Think of this. If the axle is square and the driveshaft is centered then the driveline angle, side to side, should be good. Same operating angle. As long as the angle isn't a true zero you can have angles bigger than recommended with no harm. The guide is for max ujoint life before you hit the vibration limit.

My 5500 dodge has had an empty vibration at 55mph since new. Once some wieght is on the flat bed it is basically gone. My angles are within spec. It does happen.


Another thing you can try is flipping the driveshaft yoke 180 degrees and check that. Only seen 1 truck that this worked on.



Edit late thought. How is the engagement and spline wear after the carrier bearing. This can add alot of potential vibration.