[murderface]

ran to the store Christmas Eve morning.. no problems... ran to the store again several hours later and my 4runner was vibrating pretty badly.. mainly on acceleration, my first thought was a motor mount .. slower i took off the worse it was, decided to see how it would act on the freeway and when i hit 55 or so it was vibrating pretty badly.. like a deep loud humming/vibration sound... i'm thinking its something going on with the drive shaft.. any opinions before i take it into the shop?

[Kurtis]

U-joint... crawl under the truck grab on to the drive shaft near the U-joint. Give it a few yanks to and fro. The u-joint should not have any play in it... A good quality replacement part would be around $30.

[nissanh]

I had the same issue. at 65 MPH, the truck vibrates crazy.... It is the Drive line. I found it is easy and pretty cheap to replace the whole drive line with a good used one($ 45 at my local junk yard). As Kurtis said, no free play in any of the 3 U joints.

[murderface]

Thanks guys... gonna check it out this morning and get it over to the shop

[murderface]

Alright guys.. driveshaft seems solid on both ends.. but its also 35 degrees outside and i didnt want to lay on the ground long. not sure what it could be, looks like i get to put her in the shop

[Bishard]

I had a bad vibration when accelerating a while back almost like continuous little bumps. Turns out it was something to do with wire arcing. I replaced plugs and wires and it went away.

[murderface]

Bishard... if it were that i would think i would feel the engine not rev smoothly... engine runs good.. anyways.. dropped it off around the corner at the Lexus-Toyota specialist shop

[KSWAY]

Hmmm..Hope it's not it. But sounds like it could be a bad rear diff. Do you feel the vibration through the floor board?

[ToyOtis]

My deep humming vibration from hell came from a bad u-joint that was nearly seized from the previous owners lack of proper lubrication. Joint was rock solid when I crawled under the truck and yanked on it.

Once I actually unbolted it from the rear diff, it became real obvious that the joint was bad. This also let me check for play/tightness in the double cardan with it still attached to the transfer case.

Back it up onto ramps, undo the four bolts at the diff, and drop that end!
You will probably need to get some slack in the slip yoke by jacking up the rear of the truck just a bit at the hitch, or have a friend hop on the rear bumper once or twice.

[fourwd1]

I've seen several bad u-joints appear OK mounted on the vehicle.
Unbolt it from the diff and then check it.
Start at the diff, it's the first to go, next would be the center carrier bearing if you have one.

[murderface]

Originally Posted by KSWAY

Hmmm..Hope it's not it. But sounds like it could be a bad rear diff. Do you feel the vibration through the floor board?

A little i suppose

Originally Posted by ToyOtis

My deep humming vibration from hell came from a bad u-joint that was nearly seized from the previous owners lack of proper lubrication. Joint was rock solid when I crawled under the truck and yanked on it.

Once I actually unbolted it from the rear diff, it became real obvious that the joint was bad. This also let me check for play/tightness in the double cardan with it still attached to the transfer case.

Back it up onto ramps, undo the four bolts at the diff, and drop that end!
You will probably need to get some slack in the slip yoke by jacking up the rear of the truck just a bit at the hitch, or have a friend hop on the rear bumper once or twice.

Originally Posted by fourwd1

I've seen several bad u-joints appear OK mounted on the vehicle.
Unbolt it from the diff and then check it.
Start at the diff, it's the first to go, next would be the center carrier bearing if you have one.

Mechanic said everything was solid underneath.. he's saying its bad shocks and cupped tires .. i think hes full of crap.. im just going to pay him for his lousy diagnostic and take it to the Toyota Service Dept in the morning.. he did tell me my timing belt was cracked pretty badly so it looks like ill be having my fiance's uncle change it.. come to think of it, he's a mechanic at Toyota.. i may just take it to him

[Bishard]

I just changed my shocks that had near 200k on them and my tires look like cereal bowls and I had no vibration. Take it to your yota family member

[murderface]

Yea.. he must've thought i was re****ed... chances are he never checked the drive shaft.

[murderface]

Well... he called me again this morning and told me it IS the driveshaft .. so i told him to go ahead since he had it apart already... i also mentioned the family member from Toyota and i guess he knows him... hopefully he'll do a good job because of it

[ToyOtis]

So, did that fix your problem?
What did he charge you?