Front Drive Shaft Update

[Tazzieman]

it's a cock ring.

No, too small

 

[Zimm]

So if you did a DC and Ujoint, the damper goes on the ujoint side? which would be the diff. even if it worked, (doubt it), I dont see that as a solution.

 

[Dokatd]

So whete are we thinking to mount them on the redesigned Ineos propshaft? Seems like a complicated solution to a secondary problem to the primary problem
I do know about propshaft dampers and yes they do flex with age! - replaced them on two 60s Benzes in my stable, and the old Disco.

No, I would not used a prop dampener unless I ran out of options. And I have many options

 

[Dokatd]

This funky wheel looking thing is the damper fitted to the Disco II. It's not in line with the drive shaft. And below shows a similar one on an axle near the pinion. This type I would use if viable, but I lack the ability to tune the mass properly. Maybe there is not that much to it, but this exceeds my field of expertise to be sure.

 

[Tazzieman]

This funky wheel looking thing is the damper fitted to the Disco II. It's not in line with the drive shaft. And below shows a similar one on an axle near the pinion. This type I would use if viable, but I lack the ability to tune the mass properly. Maybe there is not that much to it, but this exceeds my field of expertise to be sure.
View attachment 7921356
View attachment 7921358

I removed that hefty lump on my D1 and it made absolutely no difference.

 

[pmatusov]

So part 35 is?
View attachment 7921350

Either that, or just an elastic mount (vibration isolator). That's what I saw in the cars with split driveshafts I dealt with.

 

[pmatusov]

This funky wheel looking thing is the damper fitted to the Disco II. It's not in line with the drive shaft. And below shows a similar one on an axle near the pinion. This type I would use if viable, but I lack the ability to tune the mass properly. Maybe there is not that much to it, but this exceeds my field of expertise to be sure.
View attachment 7921356
View attachment 7921358

That's exactly what it was! Still have those on my Classics, had those on D1s as well.
As Tazzieman said, I took it off my Disco 1 trail truck, and it made zero difference - but that Disco never had any driveline vibrations to begin with.

 

[Dokatd]

I removed that hefty lump on my D1 and it made absolutely no difference.

I'm certain of it.

 

[255/85]

My 2006 Jeep Wrangler has a mass damper mounted at the transfer case output for the rear axle. There is no rubber or other flexible material, it is purely a metal ring designed to absorb harmonics. This is an original OEM part, it was not added as an aftermarket item. That said, it is always preferable to align a u-joint style drive shaft such that the natural harmonics are minimized as much as possible. On my Jeep this is easily done. On the axle side with a single u-joint the shaft is set perpendicular to the diff, 0° to the pinion . The double cardan at the transfer case is at less than 10°. This is the ideal setup for this style of shaft and it runs smoothly to a point, but a CV Rzeppa style shaft will always be naturally smoother. On the Grenadier where by the front shaft joint angles cannot be optimized because of the need for steering caster the harmonics are unavoidable and a damper will only reduce the perceived magnitude of these harmonics. And it is unlikely to reduce the perceived harmonics of a u-joint style shaft to a point which most owners would find acceptable. It would also do nothing regarding the reduced service life of the u-joints because of the harmonics.

The damper in my Jeep is shown in the photo.

View attachment 7921352

Pretty sure the black ring is rubber - or some other elastomer akin to rubber. We have one on an '01 Jeep. The design is similar to a typical harmonic balancer on the front of an engine crankshaft. I've always thought they were used to counteract deflection in whatever rigid shaft they were at the end of.

 

[TCMColorado]

Pretty sure the black ring is rubber - or some other elastomer akin to rubber. We have one on an '01 Jeep. The design is similar to a typical harmonic balancer on the front of an engine crankshaft. I've always thought they were used to counteract deflection in whatever rigid shaft they were at the end of.

My brother has the same model jeep, 2006 Wrangler Unlimited LJ. His does not have the damper. It was removed before he bought it. We cannot tell the difference between the two when it comes to drive line smoothness. Which is to say the damper doesn't accomplish much.

 

[255/85]

My brother has the same model jeep, 2006 Wrangler Unlimited LJ. His does not have the damper. It was removed before he bought it. We cannot tell the difference between the two when it comes to drive line smoothness. Which is to say the damper doesn't accomplish much.

The transfer case damper on manual trans vehicles is pressed directly onto the rear output shaft well inboard of the upper U-joint. Since the short rear driveshaft (TJ models) runs a slip yoke on the output shaft and not on the prophaft itself any DS vibration is carried directly by the rear output bearing as the slip yoke moves back and forth along the splines of the output shaft. The dampers don't really help with driveshaft vibrations. The dampers are only there to protect the ridiculously long output shaft. I don't know why Mopar used this setup rather than a short output and a longer DS running smaller angles. That's why there are so many slip yoke eliminators on the market plus the hillbilly Hack-'n-Tap approach.

As a solution to a vibrating U-joint DS on the front of a Grenadier... maybe?

 

[TCMColorado]

The transfer case damper on manual trans vehicles is pressed directly onto the rear output shaft well inboard of the upper U-joint. Since the short rear driveshaft (TJ models) runs a slip yoke on the output shaft and not on the prophaft itself any DS vibration is carried directly by the rear output bearing as the slip yoke moves back and forth along the splines of the output shaft. The dampers don't really help with driveshaft vibrations. The dampers are only there to protect the ridiculously long output shaft. I don't know why Mopar used this setup rather than a short output and a longer DS running smaller angles. That's why there are so many slip yoke eliminators on the market plus the hillbilly Hack-'n-Tap approach.

As a solution to a vibrating U-joint DS on the front of a Grenadier... maybe?

My Wrangler is the long wheelbase Rubicon model, a TJ Unlimited which is commonly referred to as an LJ. The factory shaft had a single u-joint on each end and no slip yoke. I replaced it with a single joint and double cardan combo after installing a lift. I stand by my position that a harmonic damper is not a viable solution to the front shaft problem on the Grenadier.