Hey guys, last weekend I was in a rush and needed to get somewhere quick but my 99 also needed an oil change. Normally I do it myself but figured I was short on time and took it in to Valvoline's drive thru service. When I got out I noticed that it was rattling but kept driving. Later on I checked the oil and saw it was well over the top mark so took it back and they took out 2qts and confirmed it had been overfilled. Still vibrating, I looked it over and saw they had also left my factory skid plate loose and so I torqued the bolts down hoping that would do it but the problem remained.

I went ahead and let it warm up and revved the engine but there was no vibration so thought maybe it was a suspension issue since I had recently raised it about 3" about 3 months back but thought it was a weird coincidence that it happened right as I got the oil change done. Anyhow, I wanted an unbiased opinion and took it over to firestone for their 9 point inspection and they're saying it's the driveshaft that needs repair or replacement but since it's the weekend they can't get me a quote.

After searching how difficult it is to replace one, I found this video where it says it's a common thing that might happen when lifting a 4runner and to just grease the driveshaft. My only problem is that I know I checked about a year ago and saw no fittings and after doing some reading it seems some don't come with zerks at all so what would my options be? Just replace it? Or is there a guide on how to grease it some other way?

Lastly, how long can I drive it like this? I drive 100 miles a day for work so not sure if that's just going to kill the thing sooner rather than later.

I would verify it myself, by crawling under there, grabbing the shaft at each u-joint, and try to shake it in up & down and left & right. If you get any noticeable play in any of them, then those are worn out.

If the u-joints on the driveshaft are worn out, then you will either have to buy a replacement shaft, or do like I did and cut out the old u-joints, and install new ones. The bonus is that you can get new ones that are both serviceable and easily replaceable, should they ever wear out, which they probably won't do, because they can be greased.

Back when I did mine, 11-13 years ago, a new shaft would have been about $1,500, IIRC, but I did mine for under $150, including the $50 arbor press that I bought for the job. It was kind of tricky, using a cutoff wheel and die grinder to remove the old ones, but anyone who is handy and has some certain tools can do it.

Thanks for the response man, I'll get under there tomorrow hopefully. Any particular guide you used to do the job? Also which ones did you purchase?

I just skimmed through my T4R bookmarks, and didn't see anything that looks like it was related to u-joints or the driveshaft, but I have changed computers a couple of times since then - sorry.

I wish I could recall the brand that I bought. And, I doubt there was a guide, so I probably just figured out what to do. Maybe with a little help from a thread here where someone else had done it. It would probably take a whole bunch of searching to find that info. I wish I still had the bookmarks for that. Sorry.

Lots to unpack here.

You need to figure out if the rattling is engine related (damage from incorrect oil level - overfilled can foam and cause serious issues) or just a suspension/driveline issue. You may also want to try filling with 91 octane in case the rattle is pinging. The 5VZ ignores the knock sensor below about 3k RPM, so it can have uncontrolled knock at low RPM (normal accelleration).

Second - the 2WD has a completely different driveshaft than the 4WD, so you have to be careful following most 4WD specific advice on here. The factory 2WD shaft has non-greasable u-joints, no CV/double-cardan, a slip yoke and the main section of the shaft is a 2-piece that is rubber isolated. If/when the rubber breaks down it will vibrate at high speeds. The only fix for that is a new shaft. Lifting the 2WD will make this much worse, especially 3". You can get a new one from parts stores (or RockAuto) since this is such a common issue on the 2WDs.

-Charlie