I have a 2004 mustang gt and when I came across this it felt loose to me but I don’t know the torque specs since I can’t figure out what it’s called.
Like @Tester wrote, it is a Rear Axle Differential Counterweight Vibration Dampener for the Mustang 5.0…
It’s suppose to damper out any rear end vibrations and that’s Ford’s Story and they are sticking to it…
Lots of folks remove it, I’m not recommending it, but you Google it and decide if you want to also…
It’s the covid tracking device and the crisis is over…
I’m not familiar with how it works, but by its locations it appears to be designed to control how much the differential/rear axle is allowed to twist. If you are noticing there’s some clearance between driveshaft and damper, that’s probably normal. If the fasteners that hold it on seem loose, that should be fairly easy for a shop to check for you.
BTW, suggest when posting a query here , to include the engine/transmission configuration.
You are correct, you are not familiar with what it is… lol
As Tester and LoudThunder already said It’s a vibration damper for the drive line, nothing more nothing less… Tighten it up or remove it… But if the drive line angles are correct and driveshaft is properly balanced and nothing worn out you shouldn’t need it… I have removed a lot of them over the years with out noticeable difference… but it can eliminate certain harmonics…
I’m sure some of the guys on here can/will explain it better/more technical…
" What is the purpose of the axle damper?
Some OEM axles come from the factory with rubber or metal vibration dampers installed on the center shaft. Dampers are used to combat rotational vibration caused by an axle that isn’t perfectly straight or is out of balance at the time of manufacturing."
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Back in the '60s, we shade-tree mechanics balanced our drive shafts with Hose Clamps. We jacked the car up on a lift that supported the suspension components. Basically, we wanted to rear-end supported at drive height. With a transmission jack or other solid support with a “hard point” (bent screwdriver vice-gripped to the jack) we cranked the car up and put it in high gear and raised those RPMs and got the drive shaft up to a very high speed. We then slowly raised the jack so that the hard point just touched the spinning drive shaft. The heavy side of the drive shaft would have had a slight scrape mark on it and we then mounted three hose clamps onto the drive shaft with all three in line on the opposite side of the mark and called that the "12 o’clock position.
We then repeated the high-speed spin of the drive shaft and noted the scrape mark again. We would then move the second and third clamps to the 1 and 11 o’clock position, and repeat the test. And keep moving the 2nd and 3rd clamp to 2 and 10, or 3 and 9, and so forth until those three clamps counter balanced the out-of-balance drive shaft…
The clamps usually wound up about 12, 4, and 8 o’clock for a pretty well balanced drive shaft…
I know many of you will ask was it worth it, and that we always could have paid to have it professionally balanced, but as I wrote in the beginning, we were shade-treeing it… and there is a lot of satisfaction in a job well done…
@DavesMopar quoted that it helped “to combat rotational vibration caused by an axle that isn’t perfectly straight” Well if we had that issue back in the day, I image that if we had a bent axle we would have noticed that the wheel wobbled when it turned at speed…
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I imagine that just like your driveshaft barely being out of balance that the axle shaft would have been a little tweaked just enough for Ford and others to need the use of a vibration damper on the rear end or transmission as Chrysler like to do, but not enough to see the wheel wobble…
I remember those days well. And you’re right about the satisfaction of shade-treeing a job well done.
It’s still not clear to me how it works. Does the rotating driveshaft ever come in contact with the damper? If so, when? Or is the rotating driveshaft always in contact with it? What does it mean when they say it is installed “on the center shaft”? I presume by “shaft” they mean “driveshaft”. But What part of the driveshaft is the “center” part. And what do they mean by “on”? Does that mean “over”? Or is do they mean it is bolted on the driveshaft? One more question, if a driveshaft arrives from driveshaft-manufacturing that isn’t straight or balanced, wouldn’t the obvious remedy be to reject it as out of spec, & send it back to driveshaft-manufacturing?
It looks like it’s attached to the nose of the differential, no contact with the driveshaft, and the description says it damps vibration from the axles, not the driveshaft.
That is a pinion damper, not an axle damper. It has rubber insulators, it should “feel” loose.
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That makes more sense, hard to see how it would damp axle vibrations.
It seems like the pinion nose, being attached to the pumpkin, might tend to move up and down, vibrate possibly, during accel/decel or if car is stuck in sand, bogged down & driving is trying to accel to get it unstuck, etc. If the pinion nose was vibrating, I guess that could be called an axle vibration too, b/c pinion nose is attached to pumpkin which is attached to both solid axles. It doesn’t seem like that damper configuration would help much for a out of balance driveshaft though.
OK, Axle was probably too loose of a word and meant more for the rear end (differential assembly) and driveline, the damper, helps dampen out vibrations in the driveshaft/drive line due to pinion angle in conjunction to the transmission/transfer case and driveshaft angles, as the rear end moves up/down under acceleration, cruse and deceleration, gear ratios also effect different driveshaft speeds and the purpose of the weight (damper) is to counteract the effects of driveshaft resonance due to it’s given RPM and allows for a greater range of tolerance for driveshaft imbalance. This will help to reduce vibrations and make the U joints last longer.
Chrysler used them on the transmissions close to the driveshaft also, same purpose different location… Always removed them also…
Looking at the OP’s installed photo and the uninstalled part I was guessing the device was designed to catch and support the driveshaft if the rear U-joint failed. I have worked on several light and medium duty trucks with devices installed for that purpose.
I’m curious, why remove it?
Tester
Normally just never reinstalled them if removed for what ever service… Plus most of the time the rubber isolator would dry rot and fall apart and then the weight would just rattle (sometimes customer complaint), instead of repairing, just removed it for that extra tiny bit of weight savings…