2000 reg cab 2.7 4wd w59 OD vibration/rumble

Looking for some thoughts on this. Was driving to the airport this morning and had some nice smooth road to explore noises.

My reg cab with 230k miles has a vibration/noise. It’s a low frequency, almost like exhaust drone on a v8. It got a low frequency change to it, almost like a beat frequency of sorts.

It only occurs in 5th gear, above 65 mph around 2700 rpm, under load. If I let off the gas, it goes away. If I downshift to 4th it goes away, and it also does not appear if I decelerate to a speed with the same rpm in 4th gear.

It’s a Reg cab, so no carrier bearing. I did some searching and some people needed new spark plugs for this, mine are only about 25k old, so I’m not real suspicious of them, especially since gas mileage is good and it’s got plenty of power otherwise.


My gut says there’s a bearing going in the transmission. What do y’all think?


Thanks!

 

I had a similar vibration. It turned out that the pilot bearing went, resulting in a bent input shaft on the tranny. And no the pilot bearing didn't make any noise. None. Never heard of that before but that is what happened to mine.

 

Huh. That’s interesting. At this many miles it might be time to do the clutch soon anyway. Thanks for the input!

 

FYI here is the thread I started about my vibration issue.
https://www.tacomaworld.com/threads/another-vibration-thread-with-a-twist.729423/
I don't know your mechanic experience level but I strongly advise replacing everything when replacing the clutch, including T/O bearing, pilot bearing, rear main seal and clutch fork. Most of the job is labor. Goode luck with your quest.

 

Thanks! Yeah I’ve done a clutch before, definitely do it all if it comes down to it. I think I’ll get under there and wiggle some stuff around first though, maybe it’s just a bad mount or something.