The Nissan Path

Here is the issue - i've been trying to fix some driveline related vibrations and in the process have replaced both front u-joints (big improvement). Tying to fix small remaining vibrationg I have replaced both rear shaft u-joints only to discover the vibration is back! Now it shakes at 70MPH and up, mostly felt when you release the gas, letting the truck coast. What else could have caused it? It was much better with old u-joints in place. All the precautions were taken - driveshaft position was marked and it went back in the same way it came out and both driveshaft balance weights are in place. What could I have done wrong to make it shake at higher speeds?

The drive shaft could be slightly bent, remove the driveline, or all drivelines and take them to a driveline shop and have them spin them to see if they are bent or need to be rebalanced. Have you checked the wheels to see if they need to be rebalanced? are the tires worn?

Kevster, thanks for your reply. Tires are new, replacing them did not help much. This has started after rear shaft u-joints were replaced. I'm also seeing some wet spots on the plastic cover/flange on the back of the transfer case, where rear u-joint is connected. This could be the result of the driveshaft vibrating, I guess. Is there a bearing in which the u-joint spins going in the transfer case? I wonder if it can get loose/worn out and cause the drive shaft to vibrate..? I'm lost on this one. The weird thing it mostly happens when you let go of the gas pedal going about 70-80 MPH.

There's typically a bearing there. However, when these and the other t-case bearings wear, they tend to create a lot of backlash instead of vibrations. You notice it when you get on an off the gas and get a big "CLUNK". At least that's my experience. Get under there and with both hands, grap the yoke and yank it back and forth. There should be no play. When I've had driveline problems, I used to jack up one rear tire(just one with an open diff), crawl under and rotate the tire with my foot while looking at the shaft and joints.

Could you have pressed the new u-joints in a bit too hard and they are binding up a bit?

OK, here is a quick update on this vibration issue. We took the rear shaft out and all looks good - new u-joints were pressed in correctly and feel good - nothing is binding, nothing is loose. We took out a front drive shaft (it had new u-joints installed recently) and took it out for a spin to eliminate the chance of the front u-joint acting up - the problem was still there - high frequency vibration/resonance between 70-80 MPH. Looks like it is the rear shaft after all. Again, this problem has started after new u-joints were installed on a rear drive shaft a few weeks ago, so I'm pretty positive it has something to do with the new u-joints or the drive shaft itself.
At this point we are trying to see if the rear drive shaft is balanced properly and then maybe replace those new Spicer u-joints with a different set of u-joints to see if that improves anything. I will keep you guys posted on the progress - I'm really curious as to the cause of this problem.

Did you ever find the cause of your vibration? I think I am having the same problem.

My vibration problem ended up being in unbalanced rear drive-shaft after the new u-joints were installed. Dealer did the u-joints initially and could not figure out what was causing the problem afterwards. Since I could feel a distinct difference before and after the u-joints work, I knew it was drive-shaft related. I swapped out the rear drive-shaft with a new unit and its back to normal. New u-joints is a good thing, but you better make sure that things are balanced afterwards.

what would cause a balance problem with a driveshaft after a u-joint replacement?
a u-joint should be a precision-made part, and the new joint itself shouldn't cause the problem.
slavabon, when the dealer initially installed the new u-joints, did they replace the whole driveshaft or did they install new u-joints into your old one?
if they installed new u-joints into your old driveshaft, is it possible that they did not re-mount it into the same position, or perhaps damaged it while doing the work?

Im not sure what may have caused the drive-saft to become unbalanced after the dealer replaced the u-joints. Looks like they have marked everyhting and have installed the shaft back the same way. U-joints were pressed in correctly with retainer clips installed properly and the balance weights on the shaft were not missing. I took it back for another check and they could not find anythgin abnormal - visually it was fine. But I could clearly tell that it was drive-shaft related, since there was a distict vibration that started after they replaced the u-joints. Well, I just gave up and installed another drive-shaft and it was back to normal. I think that my old driveshaft got damaged during the u-joint install - perhaps one of the yokes got bent when they pressed the u-joints in, not sure. If you have replaced your u-joints and it still vibrates, take it to the drive-line shop of some sort, they can remove the shaft and check the balance on it.

wow slavabon, that's a huge amount of patience you've got there
did you replace the driveshaft as a whole new assembly w/joints?

Definite patience...if this problem wasn't there before the u-joint work, I'd definitely be hassling my dealer for the cost of the new shaft. Sounds like you got "shafted" on this one

I had the exact same problem. If I got the Pathfinder above 75 it felt like I was on a set of low grade rumble strips. Mine turned out to be I had not one but 2 bad U-Joint. The back U-Joint on the rear drive shaft was frozen not allowing any flex. The front U-Joint on the front drive shaft was worn out and had far too much play. I replaced all 4 and now it is back to being a smooth ride.

my 06 pathfinder has a low frequency vibration (bass like tone) over 70 when letting off the gas. very similar. i also had u-joints replaced. do you think the drive shaft needed to be balanced or was it bent? should i replace the drive shaft? ballpark cost?

My '08 SE with 148,000 miles developed the same vibration a couple of weeks ago. I removed the front driveshaft, checked it out (okay) and ran the truck without it: still a problem. The rear driveshaft seems fine on the truck but I'm going to plan on changing the rear u-joints as a precautionary measure. I had started to swap out the tires with the spare, to determine if I had a bad tire, but I'm betting on a bad joint. I'm limited on downtime so to pull the shaft and check it for balance, I need to be ready with options. I'll let you know how I make out.

Hey

My 05 pathfinder sometimes Vibrates, I had the Transmission replaced fully by Nissan of the Radiator problem. New torque converter all new parts. 9 K service.

I know one of the U joints were replaced last year.

Is it worth getting all my U-joints replaced and shaft balanced or a waste of money.