low speed vibration

No. If they did work, and your truck is worse afterwards, you need to take it up with them.

It has to be coming from the motor. If things are not rotating (drive shaft / u joints, etc) then the only thing is the motor.

I think you should watch Timmy's video on replacing the motor and transmission mounts so you have a better understanding of what they are, and how to diagnose them. I'm not saying your motor mounts are or aren't the problem, but you would have had to beat the shit outta the truck for them to be a problem.

You're either obsessing over something which isn't an issue, or your mechanic messed something up with the transmission mount. The u joints, suspensions components, wheel bearings, etc.. are not in play at a standstill.

Is there any difference in vibration between P or N, and D with your foot on the brake?

 

I think you're trying to refer to the last bearing in the transmission, which would be the output bearing. Otherwise, there is a carrier bearing on the trucks with two piece drive shafts. Other than the carrier bearing (which is not really part of the drive shaft) drive shafts don't have bearings. They have u joints or slip yokes, which could have an impact on a rotational vibration. But not on a standstill vibration.

 

yes, the carrier bearing. just changed mine a few months ago. had to Google that, as we call it a pilot bearing around here, but Carrier bearing is the proper name. thank you

 

Update -

OEM transmission mount fixed the bigger vibration. The garbage Power Torque mount from O'Reilly was the issue.

Now as far as this topic goes there's still the light vibration at 20-25mph no matter if I'm accelerating, braking or coasting, that appeared several months ago out of the blue. I'll see if I can wrench free the 2 front motor mounts with the engine supported, and if that goes well I'll order new ones. They are original. If that doesn't solve it, I might ignore the issue.

 

i was also going to suggest checking the motor mounts. Keep us posted on what you determine

 

Update... Replacing front motor mounts did help with one vibration. After learning more over the last year and servicing other parts, I believe that the drive shaft center support bearing is just about the only thing left that could be causing the ~20mph vibration. I don't think any original rubber part remaining on the truck is in good shape at this point.

If I have it replaced, I'll have some shop put in an aftermarket one, maybe Spicer or National if they can get it, or whatever they can get. I don't know about asking them to diagnose and cause me more grief. There's not much else it could be unless there's something else on the drive shaft (U joints are new), and nobody has been able to diagnose it so far, other than a highly skilled out of town mechanic friend who poked around under it a year ago for a minute and told me it was probably that bearing. I probably should have gone with his instinct from the beginning.

I'm open to suggestions. I'm thinking of putting it off a while. I just spent $$$ for ball joint replacements. I would need to buy an impact wrench, impact sockets, and gear puller to DIY so that's unlikely.

 

You don't need an impact or impact sockets to do this job. A breaker bar (or cheater bar for an existing socket wrench) to get things loose is fine, and a torque wrench for seating the bearing. It's actually one of the more simple DIY's you can do. Check to make sure you have the right size socket for the nut, it's fairly large. Over 19mm for sure. Auto parts stores usually have individual sockets.

I would suggest at least spicer. I went with an auto parts store replacement and it failed within a year. Save yourself the effort of doing this job twice and get quality parts. You do need to get the new stake nut from Toyota though.

 

Ok, I'm giving it a shot!

 

FYI replacing the carrier bearing solved the vibration. I've seen reference to a worn one causing a vibration at high speeds, but this is proof it can cause one at 10mph and 20mph too. I think the rubber was worn out and allowing the shaft to shake. It rides a little smoother at high speed too.

 

Glad you figured it out! I replaced my carrier bearing when I bought my truck. It was making some pretty awful noises when letting off the throttle at speed! Bearing fixed it.

Anyway I landed on your thread because I too still have a driveline vibration at 25MPH both accelerating and coasting in my 95 4x4.

Also in the Bay Area. PM me a list of shops to avoid haha. Might also be able to help you DIY some minor repairs in the future if you’re interested.

 

Cool, I'll PM you.

Cool, I'll PM you.

My new National bearing is holding the drive shaft properly in place better when I try to wiggle the shaft. The rubber on the old one didn't seem to make it horribly loose, but the difference was noticeable when I compared. One old U-joint was locked up a while back, and I suspect that was putting more force on the carrier bearing and eventually causing the symptom which continued even after the U-joints were replaced a year ago because the damage was done to the carrier bearing. Have you done your U-joints yet? I'm imagining that a locked up U joint by itself could cause a wobble but I might be misunderstanding how all that works.