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Questions for 6" SFD owners


XPLORx4
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Hi guys,

 

A couple of months ago I installed the SFD in combination with my AC 2" lift, so now I'm running about 6" total lift. After installing the lift, I noticed a growling vibration at the rear end when lightly decelerating (very light pressure on the accelerator while still slowing) when driving at any speed above about 40 mph. It is most noticeable at higher speeds. There is no sound under acceleration or under deceleration (engine braking). There were no such issues before installing the additional 4" of lift.

 

After talking with a couple of different shops, the consensus seems to be that the rear driveshaft angle is too steep and the vibration is caused by this angle. We measured the pinion-to-driveshaft and slip yoke-to-driveshaft angles, and they are about 18°. It is believed that in order to fix this, I'll need a double-cardan (CV) driveshaft. Tom Wood's Custom Driveshafts makes these for the Xterra, which uses the same driveline as the R50. (http://www.4xshaft.com/Xterra2.asp). In addition, it is believed that I also need to reduce the pinion angle, so I also need custom adjustable upper links. It seems that there is not very much more axle droop possible with the 6" lift installed using stock upper and lower suspension links.

 

This morning, I visited a wrecking yard that has a 2WD '96 R50. I discovered that the 2WD driveshaft is split into 2 sections after the transmission, and the rear section of the shaft which moves with the suspension is much shorter than the 4WD driveshaft. Moreover, it also has 2 double-cardan joints.

 

I wonder if it would be possible to take the 2WD shaft, attach the slip yoke to the front joint and have a custom-length center section made for cheaper than it would cost to have Tom Woods build one ($569). Thoughts?

 

Finally, my questions for you who have installed lifts over 4" are these:

Who has lifted their R50 more than 6", and what did you do to the rear suspension to achieve this?

Have you noticed any new driveline noises after installing the lift?

Have you had to make changes to the rear suspension links in order to improve the pinion angle?

What is the angle of the driveshaft if you haven't made any changes?

 

Thanks?

 

Edited by XPLORx4
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Hi guys,

 

A couple of months ago I installed the SFD in combination with my AC 2" lift, so now I'm running about 6" total lift. After installing the lift, I noticed a growling vibration at the rear end when lightly decelerating (very light pressure on the accelerator while still slowing) when driving at any speed above about 40 mph. It is most noticeable at higher speeds. There is no sound under acceleration or under deceleration (engine braking). There were no such issues before installing the additional 4" of lift.

 

After talking with a couple of different shops, the consensus seems to be that the rear driveshaft angle is too steep and the vibration is caused by this angle. We measured the pinion-to-driveshaft and slip yoke-to-driveshaft angles, and they are about 18°. It is believed that in order to fix this, I'll need a double-cardan (CV) driveshaft. Tom Wood's Custom Driveshafts makes these for the Xterra, which uses the same driveline as the R50. (http://www.4xshaft.com/Xterra2.asp). In addition, it is believed that I also need to reduce the pinion angle, so I also need custom adjustable upper links. It seems that there is not very much more axle droop possible with the 6" lift installed using stock upper and lower suspension links.

 

This morning, I visited a wrecking yard that has a 2WD '96 R50. I discovered that the 2WD driveshaft is split into 2 sections after the transmission, and the rear section of the shaft which moves with the suspension is much shorter than the 4WD driveshaft. Moreover, it also has 2 double-cardan joints.

 

I wonder if it would be possible to take the 2WD shaft, attach the slip yoke to the front joint and have a custom-length center section made for cheaper than it would cost to have Tom Woods build one ($569). Thoughts?

 

Finally, my questions for you who have installed lifts over 4" are these:

Who has lifted their R50 more than 6", and what did you do to the rear suspension to achieve this?

Have you noticed any new driveline noises after installing the lift?

Have you had to make changes to the rear suspension links in order to improve the pinion angle?

What is the angle of the driveshaft if you haven't made any changes?

 

Thanks?

 

i just made my own UCA’s for the rear and that took care of the rear diff angle and growling on high speed decel.

 

 

Sent from my iPhone using Tapatalk

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My rear end shredded itself about ~150km after lifting 6". I never was able to figure definitively if it was because of the driveline angles or if it was because I messed up somewhere when I installed my locker because I did it all at once. Looking back though my guess is that it was just the driveline angle because we installed a locker on my brother's pathfinder at the same time and he has not had any problems, plus I remember feeling a bunch of play in the pinion bearing when removing the 3rd member. If I were you I would check my diff oil, as when mine was on it's way out I started feeling vibrations and hearing grinding when decelerating like you have said and it very quickly got worse. When I dumped my diff oil as a check it was full of metal. If you scroll back through my build thread you will see what I am talking about.

 

So far I have made all new longer adjustable trailing arms to push the rear axle back to where it should be and square up the pinion with the transfer case. I had to get a regular 1 piece driveshaft custom made locally after all that ($400 CAD unbalanced), but it isn't a double Cardan style. DC will be my next step if this does not all work out. And I have not yet reinstalled my locker just in case, I want to isolate variables and I don't want to expose it to a metal slurry again if I can help it.

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Well, except for the ring and pinion, the rear end is new and has been pulled 3 times to double-check the pattern. New ARB. New pinion bearing. New carrier bearings. Though the gears are old, they show no signs of abnormal wear and the pattern is perfect. The shop has been doing rear ends for 40 years and swears that everything is set up perfect. At least it's good to hear that I'm not the only one who has experienced some driveline issues after moving up to a 6" lift.

 

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Fair enough, mine was all original as far as I could tell when it did the work. It may have just been ****** luck even but who knows. I have not been able to drive my pathy since I've done all the work but I'll be sure to let you know how things progress as I put some miles on the new setup.

 

Also, I had a hell of a time finding info on this when mine went, I couldn't find any info from anyone who had had the same problems as me upon lifting. The other problem was there are no specialized small shops locally, and my local Nissan dealership is less than useful when it comes to this kind of thing.

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I have a similar noise a few thousand miles after installing ARB springs and some spacers (about 3" lift). Put a JY rear end in it (full assembly), same noise, gonna try replacing just the carrier next time so I can see the gears before I drop it in. Definitely interested in the resolution to this. I'm a 2WD guy so the driveshaft should be extending to fill the gap but Idk really.

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I just picked up a 2WD driveshaft from a 96 Pathy at the local junkyard hoping that it can be modified and adapted to fit on my 4wd. I didnt realize that the 2WD shaft is a two-piece shaf with the section attached to the rear end being a dual double cardan CV shaft that is actually shorter than the single cardan 4wd shaft. Is your driveshaft also similar? If youre having vibrations on your 2WD at only a 3 lift, its making me wonder if itll work for me.

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I just picked up a 2WD driveshaft from a 96 Pathy at the local junkyard hoping that it can be modified and adapted to fit on my 4wd. I didnt realize that the 2WD shaft is a two-piece shaf with the section attached to the rear end being a dual double cardan CV shaft that is actually shorter than the single cardan 4wd shaft. Is your driveshaft also similar? If youre having vibrations on your 2WD at only a 3 lift, its making me wonder if itll work for me.

His 2wd shaft is shorter, so it won't take nearly as much lift to put it at a wild angle, so his experience won't relate directly to you since you'll be using the same joints but with Michael more length in between, so significantly less angle.

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Yeah I have the two shafts as described but like ^ said I have way more gap between transmission and rear axle. I've been driving it this way for the better part of a year now, I check the diff fluid ever now n then, no big sparkles paint so far, it's just noisy. Hopefully once my yota is running I can do the 4wd conversion I've been planning.

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  • 1 year later...

Anyone have any more insight into this? Kinda dropped off the map but I've started working on my pathfinder again now that I have time.

 

I ended up swapping another whole 3rd member into my diff housing. Put everything back together, and pushed my rear end back with my adjustable trailing arms. I admit, I forgot to check my pinion to transfer case angle at the time. I didn't drive it at all.

 

This week I put like 20km on my vehicle in a shakeddown to remember where I left off. Still chattering like crazy on deceleration. So I checked my pinion angle, and it was out by like 10 degrees. I fixed that, did a tape measure alignment on the rear end and topped off the diff oil. Checked my transfer case oil, it was fine. Greased both rear U joints just because. Drove it once more around the block last evening and the chattering only got worse. 

 

Got back home, dropped the diff oil and boom, metal dust everywhere again. fskc. Pulled the 3rd member out late last night and nothing is obviously fskced but I all I did was a quick look and wiggle. I have no idea at this point. The only thing I wonder is what are the odds of this being like a bad wheel bearing or something, where perhaps an oil seal has failed and is allowing crap to seep into the diff? Going to rip it all apart tonight and investigate but I'm kind of at a loss right now. I can't see a known good 3rd member just annihilating itself over that kind of small distance but who knows.

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I still have a noise on deceleration with at 6" of rear lift.  Been that way ever since 9448's and 2" spacers.  Have torn everything apart, too, with no resolution.  Rebuild my diff, locker, pulled axle shafts, everything.  It's relatively tiny, only occurring at very low pedal on/off, but it's there.  May try adjustable/longer upper links and some point, or possibly a driveshaft spacer to get the yoke into the t-case a little more.

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There is nothing subtle about my noise. It could be exagerated due to the fact that I have no carpet, rear seats or any sound deadening mechanisms at all any more but when it starts it is loud as hell right out of nowhere. But I think I may have found it now. I pulled both axles completly out and low and behold the passenger side inner wheel bearing seal was not sealing any more. The area between the inner and outer bearing seal was filled with metally oil, and there were some small metal chunks trapped in there too. There was no grease left on the wheel bearing, just oil and little blobs of metal powder sludge. I'm guessing the inner seal failed a while ago, allowing oil to reach the old grease and wash it away? Possibly it even failed when I did the locker install originally. The grease left on the drivers side is definitely done, it's black and it smells burnt BUT it is still all there, and there is no metal in it from what I can see right now.

 

Holy @!*% I hope this is finally it. Gonna order new seals and bearings tomorrow.

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Good luck, hope that’s it. My grease had also seemed to disintegrate, but seemed intact. It was previously greased when I did my disc brakes. As best as I could tell, the noise only came from my driver’s side of the axle. 

 

But now, is your noise constant?  Mine only occurs under that slight load on/off, and that’s it, and it’s more like a rapid rumble noise. Beyond that, nothing I can hear or feel. 

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I have a minor clunk at the moment of acceleration/deceleration that was present before 6" but no constant howl or noise. Made adjustable control arms when I went up to 6" and have had no issues. I've clocked a few thousand miles since including wheeling and long road trips.

 

  

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It's a loud constant chattering/howling noise when decelerating from any speed above 50kmph. It got louder after the last batch of work I did, and now is noticible through all speeds while either decelerating or just cruising along maintaining speed, but it changes in intensity depending on the speed. At 5kmph it almost sounds like warped brake caliper rubbing softly on a high spot if that makes sense. There is zero play that I can feel in any direction on the pinion bearing or the carrier bearings so I don't think it is them. 

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On 3/26/2019 at 11:05 AM, TowndawgR50 said:

Made adjustable control arms when I went up to 6" and have had no issues. I've clocked a few thousand miles since including wheeling and long road trips.

 

  

Did you make new adjustable upper and lower links?

 

When I used adjustable upper mounts, I tried to tilt the axle rearward to align the pinion yoke with the driveshaft, but the panhard rod mount was angled too much and the springs were curved like this:  ) because the axle mount was cocked rearward too much relative to the upper.


I ended up having an adjustable panhard rod made, so that I could re-index the upper and lower mounts to account for their non-parallel orientation. Ultimately, I swapped back to the fixed-length upper links, and now with my double double-cardan driveshaft, at highway speeds, I get a slight growl that you could mistake for performance exhaust droning. I may need to remove the shaft and see if it needs rebalancing. I have even considered swapping back in the original driveshaft to troubleshoot a little more.

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Yes, new adjustable upper and lower. I do have a slight bow to the springs but nothing severe and my pinion angle is good while retaining my original one piece driveshaft. I have the materials to make an adjustable PHB but havent gotten to it yet. 

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Well, the noise is still there. A quick test drive around the block confirmed it. I did find a fskced rear wheel bearing, bad enough where the race was chewed up a little. It was the one that was full of oil instead of grease. I was pretty hopeful that that was source of the noise I have been hearing but obviously this is not the case. When I get the chance to get some work done again I'm going to drop the fluid on the transfer case, diff and transmission just to see if I see anything else out of the ordinary that might explain what the hell is going on.

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i have been lifted with sfd and wheeling for almost 3-5 yrs owning my pathfinder. ive had this growling ever since and until now i havent had any issues with my rear end. just reporting back. 

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