Vibrations after coming out of 4wd

I put my truck in 4wd just to make sure everything was working properly before winter hits. I know you shouldn't do this on pavement but thought if you went straight for a short distance it wouldn't be a problem. I went no more than a hundred yards or so and after I took it out of 4wd there was an unusual vibration at 30-40 mph and rpm read out seemed off and erratic. A friend of mine is a mechanic and he told me to take it to a dirt lot and put it in 4wd and do some figure 8s to get all the tires spinning and then take it out of 4wd and test it on hardtop to see if vibrations went away.

It seemed to do the trick but anyone know what this could have been?

I will never put my truck in 4wd on dry pavement again. My friend said one of the mechanisms that engages the 4wd could have got stuck. But I would have thought indication light would have stayed on saying it's not fully out of 4wd. I live in NH and haven't used the 4wd in a long time. Don't think I have used 4wd since my truck was lifted late this summer so wondering if that played a role.

 

Did you take it out off 4wd when you were stopped completely or rolling?

 

I believe I took it out of 4wd while still rolling slowly on pavement. After taking it on a dirt lot and doing some turns in 4wd and taking it out of 4wd the major vibration I was experiencing is gone. Just hoping no permanent damage was done.

How bad is a needle bearing failure and what would be the symptoms?

Could vehicle still be driven with needle bearing failure and if so would it do more damage?

 

You're probably fine. I wouldn't worry about it. It's happened to me multiple times in different vehicles when I first thought you had to be stopped to go in 4wd. Now I do a slow roll

 

Sub'd

 

As said above, take it out of 4WD ONLY with the front wheels straight and while coasting. You can get a pretty Big Bang if your turning and or accelerating.

 

There is a Formal Toyota TSB (Technical Service Bulletin) that covers this problem under warranty if your vehicle is still under warranty. Mine is being repaired as I type this. Front Needle Bearing issue in the front differential.
https://www.tacomaworld.com/threads...differential-bearing-vibration-thread.152173/

 

What is odd about the vibrations I got after coming out of 4wd is that after using 4wd in a dirt parking lot and making some turns it seemed to resolve the issue after returning to 2wd. I tested my truck and was comfortable with it and drove about 250 miles round trip this past weekend with no issues and drove on the weekend slow speeds with no trouble in 30-45mph range.

Has anyone had a similar vibration problem arise after using 4wd?


I am trying to determine if my issue is a 4wd issue vs front differential/needle bearing. Maybe using 4wd put a bit extra strain on needle bearing and caused it to fail.

I spoke with a Toyota technician to see if it could be a stuck solenoid or something not disengaging properly from the 4wd and he seemed to think that was unlikely. He said if it didn't disengage properly the 4wd light would flash, but I wonder if its possible that if not used often if a 4wd system can get jammed or stuck from lack of use.

After the problem seemed to go away for a few days it returned on Monday, but much more subtle than how it was initially. I brought it Toyota and the master mechanic took it for a test drive. At first he thought it was a tire issue possibly bad belt inside tire, but after the problem seemed to go away when I switched into 4wd he seemed to think it was the front differential.
Why would problem go away in 4wd if it was a front differential issue?

I did bring up the needle bearing TSB, but unfortunately I am just over my 5 year warranty by a few months and way over on mileage. I am dealing with Corporate to see if they can assist with repair cost since I am just outside warranty and since this is such a pervasive issue.

What I don't understand is why the issue is so inconsistent. I put my truck in and out of 4wd several times with the tech in the truck and each time after returning back to 2wd the vibrations varied from subtle to very noticeable and sometimes seemingly gone completely. However, the vibrations are mostly between 30 and 45 mph.

Anyway I have done quite a bit of research, but just hoping someone might be able to tell me if there is any chance this is a problem with 4wd.


Also, if it is in fact the needle bearing how much success have people had with the TSB Needle Bearing that is supposedly different than the OEM Needle Bearing?

Am I doing damage by driving this until I am able to get a fix?


If my issue is the needle bearing I am debating going with the TSB part or the ECGS bushing. I think if I can get Toyota to pay all or partial I may just go with their TSP replacement part since they probably will not put in ECGS bushing for me.

Any assistance with my questions above in Bold is greatly appreciated. I am kinda freaking out that I am doing damage to differential and CVs etc.

Thanks!

 

You are on track. Let them diagnose what is really wrong. My TSB repair was done yesterday. So no time for feedback, especially since I'm driving to work in 4WD mostly due to crappy roads in winter.

The needle bearing issue specifically goes away when in 4WD because it engages the drive system which locks the bearing in place. In 2WD it allows the bearing to move around, thus causing vibration.

In my case the tech told me the TSB bearing is slightly smaller (thousandths of an inch) than the original and seats tighter in place. They played with it because they wanted to know what Toyota actually changed. They had to polish the socket it sits in because it left scratches from moving around over the 10k miles I've got on my truck so far.