9.25 Axel issue. Need input Please

[75LandYacht]

Good day all, I need your input and expertise on an issue I’m having with my 9 1/4 axle I just had rebuilt A couple months back. I pulled the axle because the bearings were going bad. I pulled the axle and delivered it to my machinist to be rebuilt. Just to give you a full background, after my machinist disassembled the axle I delivered it to be powder coated. I also ordered a rebuild kit from Dr. diff which included all bearings and seals. Once the axle was Powder coating , I delivered it it back to my machinist With the rebuild kit for assembly, The carrier ring and pinion and yoke were all in good shape and reused. Once the machinist had completed the rebuild, I installed it in the New Yorker along with new springs, shackles, bushings and brake lines, so essentially everything in the back of the car is brand new. Upon the first drive, I noticed a heavy vibration at 25 to 35 miles an hour. It disappears beyond that until you reach 65 to 70 and then they have a vibration is back. I went to the machinist and he seems to think it was the crush sleeve, it may have been too tight, he readjusted the nut at the end of the yoke, we took the car for a drive and the vibrations are still there. He did another adjustment on the yolk and yet again the vibrations are still there. I’m starting to get very frustrated with the situation having spent a lot of money to have all this done. I like my machinist, and he is a friend, what I’d like from you guys is what you think might be the issue.

If I left you with an answer questions, please feel free..

What say you? Lol

 

[HWYCRZR]

I would check to make sure your U-joints are seated properly. Assuming if you spent the time on the rear-end, you did new u-joints as well. Sometimes when one presses out the u-joints on the front yoke. One can bend the yoke causing a slight misalignment causing vibration at different speeds. Usually a rear-end will cause more whining issues than vibration.

 

[rags]

I noticed a heavy vibration

heavy vibrations can't come from the diff. drive shaft or tires are out of balance

I like my machinist, and he is a friend,

and he did a good job. now he's f'ing with the pinion nut (he used a new one correct?) trying to fix a problem that he didn't cause. no doubt he checked the preload with a torque wrench. and once the crush sleeve is crushed, it's done. it really should be replaced if the preload is correct with nut now backed off. the pinion bearings and yoke need for the sleeve to be correct for them to be tightened to the pinion correctly.

 

[Big_John]

A vibration that comes in at lower speed, then goes away and comes back at higher speed is usually something with the driveshaft. Possible bad U-Joint or the shaft itself is out of balance or even bent or twisted.

I'm with @rags on the crush sleeve. You don't back those off. I don't think it would cause that problem anyway.

 

[Blusmbl]

The pinion angle could be off with the new springs- do you have the ability to measure it?

my first instinct is u-joints though, the preload on the pinion shouldn’t do it.

I’ll also say I have backed off pinion nuts that have crush sleeves, either to change a yoke or to change the pinion seal. I have not had issues doing it as long as you mark the nut and get it to similar torque so it doesn’t crush further. I don’t recommend this but I have done it.

 

[CBODY67]

As I understand it, a crush sleeve that's once been "crushed" you can only crush it more, not decrease the load on it. BTAIM Usually, when something inside the axle is wrong, NOISE happens, not vibrations.

I'm leaning moer toward "pinion angle", though. Some FSM, somewhere, tells how to measure it, I supsect. Like with a v-shaped magnetic level which sticks to the driveshaft tube? As a substitute, there are some magnetic meter levels which might be found at HomeDepot, like to level a metal fence post or similar.

How much difference did the new rear springs make in the height of the rear bumper? As they "stock" ride height or otherwise? Might need to give them some time to settle-in before finalizing any pinion angle change. Were there any wedges on the rear springs when you took them out?

AND . . . what about the rear trans mount?

Just some thoughts,
CBODY67

 

[rags]

I don’t recommend this but I have done it.

same here. trick to understand is that the pinion nut on a crush sleeve rear is a lock nut. it's the locking part that keeps it tight not the torque applied. the torque spec. is the bearing preload. really the nut should not be reused, but yeah we do it all the time.

 

[rags]

Sometimes when one presses out the u-joints on the front yoke.

and that's really how it should be done, with a ball joint press and very carefully. i've seen people hammering out u-joints with the driveshaft tube in or on a vice. if the u-joints were replaced over vice and not hammered properly then that shaft is done.

 

[Ripinator]

Good day all, I need your input and expertise on an issue I’m having with my 9 1/4 axle I just had rebuilt A couple months back. I pulled the axle because the bearings were going bad. I pulled the axle and delivered it to my machinist to be rebuilt. Just to give you a full background, after my machinist disassembled the axle I delivered it to be powder coated. I also ordered a rebuild kit from Dr. diff which included all bearings and seals. Once the axle was Powder coating , I delivered it it back to my machinist With the rebuild kit for assembly, The carrier ring and pinion and yoke were all in good shape and reused. Once the machinist had completed the rebuild, I installed it in the New Yorker along with new springs, shackles, bushings and brake lines, so essentially everything in the back of the car is brand new. Upon the first drive, I noticed a heavy vibration at 25 to 35 miles an hour. It disappears beyond that until you reach 65 to 70 and then they have a vibration is back. I went to the machinist and he seems to think it was the crush sleeve, it may have been too tight, he readjusted the nut at the end of the yoke, we took the car for a drive and the vibrations are still there. He did another adjustment on the yolk and yet again the vibrations are still there. I’m starting to get very frustrated with the situation having spent a lot of money to have all this done. I like my machinist, and he is a friend, what I’d like from you guys is what you think might be the issue.

If I left you with an answer questions, please feel free..

What say you? Lol

View attachment 601828

View attachment 601829

View attachment 601830

View attachment 601831

John: Like others, I'm leaning toward u-joint / drive shaft issues. Only other thing I can add is make sure you set the end space at the right side axle. I set mine at 0.18:

 

[75LandYacht]

John: Like others, I'm leaning toward u-joint / drive shaft issues. Only other thing I can add is make sure you set the end space at the right side axle. I set mine at 0.18:

View attachment 601953

Thank you Rip, thank you for reminding me, I did forget to mention that I had a brand new driveshaft made including new U joints. I’m leaning towards a setting of the axles or even backlash as well. But I just wanted to see if anybody out here had a similar experience before I go back to my machinist or find another shop and I can help me..

 

[75LandYacht]

Thank you all for you input, great information.. keep’em coming.

 

[Blusmbl]

Do you still have the old driveshaft you could try? If the U-joints aren't quite in phase they can definitely create a vibration like what you're describing.

 

[75LandYacht]

I did forget to mention, after installing the rebuild axle the original driveshaft and U joints were reused , that’s when I noticed the vibration, the vibration was not there before the axle was pulled for rebuild, the main reason it was was because my bearings were going bad, and we’re growling and popping during turns. So, instead of just replacing the bearings, I thought let’s pull it and do the whole thing.. to “check all the boxes” situation and pull the original driveshaft and took it to another shop to have balanced, the shop said the driveshaft was a little out and since it was 40+ years old recommended a new one. So a new driveshaft and U joints were installed, took the car for a drive in the same vibration was there not getting any better or worse.

It was mentioned above ^^ the pinion angle, possibly being off, when I pulled the axle from the springs, there were no shims, just axle on top of the spring pins. Can opinion angle be adjusted on these axles? If so! Recommendations please.

 

[Big_John]

it was was because my berries were going bad

I hate when that happens.

 

[75LandYacht]

I hate when that happens.

Ops. Damn auto spellcheck.

 

[CBODY67]

Pinion angle is related to the angle between the pinion shaft and the driveshaft. It IS adjustable with wedge-shaped shims which go between the spring pad on the axle housing and the spring itself. Which is why I inquired about how the rear ride height might have changed from OEM to what you now have. Generally, there is a wide window of the desired angles, as the suspension moves up and down in the normal execution of driving. But what can be noticed, even within this window is "shudder" on acceleration from a stop if the angle is pointed too far down. On two=piece driveshafts, driveline shudder can also be due to the height of the center support bearing, in relation to the general arc of the driveshaft between the front (trans yoke) and rear (pinion yoke).

I might also mention that many more-recent axle designs, or updates from pervious designs, have tended to get away from the "crush sleeve" arrangement, using a solid spacder of a particular dimension to achieve the same thing. Possibly due to more refined/sophisticated casting and tooling operations now, as compared to then? Or a different way of doing things such that "anybody can do it" rather than having to know what one was doing and not needing the necessary tools to do it?

Enjoy!
CBODY67

 

[commando1]

Did your rear end guy have this tool? Probably not.
It's a side to side bearing adjusting tool.
I'd ask him.

 

[75LandYacht]

Did your rear end guy have this tool? Probably not.
It's a side to side bearing adjusting tool.
I'd ask him.

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And Stan for the win!! Lol

I’ll ask him Oh Great One.. lol

 

[rags]

the same vibration

keeping in mind that the pinion turns about three times faster than the ring. a higher frequency vibration would be associated with the pinion and driveshaft. a lower frequnecy with the carrier, axles, tires and wheels. my F350 developed a shake in the rear while towing a car in. the carrier had split in two. that's the level of damage that a diff would have to have to shake. wondering if you tried it with the wheels off the ground or the wheels off the car to see if it can be replicated.

 

[rags]

It's a side to side bearing adjusting tool.

that's probably the first tool that i ever made. had to do carrier bearings in a dart. was sometime in the 80's. found that the hex at the end of a c-car torsion bar is the same dimension and works every bit as well as a purpose built tool.