hatRunner

I have a 93' 4Runner 4WD that is about 400 miles away from 150000. A few weeks ago I noticed this humming/buzzing/grinding noise from under my center arm rest. It only happens at partial throttle (25% - 50%) around 35mph and only briefly. When I first noticed it I thought it was my auto tranny and got the fluid replaced (it was old and black anyway). That did not resolve the problem. I did some research and thought maybe there was some play in my drive shafts. I lubed the entire drive line and the problem still persists. It seems to be getting worse and I don't really want to go spend a 1000 at the dealership. Any thoughts?

Other Notes:

Other than the specific instance I can kind of feel it/hear it around 45, sometimes at idle (but its more of a pulsing on, then off, then on, and i can only feel it not hear it).
Same situation in 4H 2H, haven't tested in 4L
Happens on upgrades and downgrades
Not specific to any road surface or location.

Thanks A million
Gary

just call me smithy

well your rear heater is under your arm rest have you checked that ?........just a thought.

waskillywabbit

iTrader: (-1)

U joints or space aliens.

874runnersr5

ujoints?

hatRunner

Drove around with the center console removed and the buzz was coming from the floor not the heater but I checked and the bolts are tight. Thus Heater locked down!

How would I inspect my U-joints? Climb under and shake the drive shaft around?

Thanks Gary

874runnersr5

remove the dshaft, and play with the mounts then youll deffs know.

buckz6319

I think you have the same issue as me.... when you notice this buzzing noise and grinding going, on place your hand on the console where the rear window and ECT buttons are(assuming you have the automatic A340H like I have).....and if you feel, what you are hearing you problem may be in the hydraulic transfer case, a needle bearing, or the O.D. gear...mine has been doing this for almost 2yr now and is still going.....It feels worse when the transmission down shifts from O.D. and is not so bad in O.D.?

I'm no expert but what you are describing sounds like what I have been chasing

hatRunner

Thant is exactly where I hear/feel the noise from. My OD shifts up around 39MPH and down around 35MPH with light throttle.

buckz6319

well finally someone else has the same transmission noise I have, so I don't feel like I'm crazy

these A40H transmissions are a complex mechanical nightmare, they are full of snap rings, and are a pain to work on, and also share the same transmission fluid as the main tranny.I know because I separated one last summer( I bought a donor) even managing to remove what some refer too as a married transfer case.


my suggestion is go to a transmission shop, maybe several and have them check it out

I did this but no one could determine exactly what was going on, they offered to break it down and explore the internals, but said it would be about $2,000.00-$3,000.00 FOR A REBUILD!....or I could just keep driving it until it got worse so the problem could be pinpointed.I have been driving this 4runner with this problem for almost 2 years and it still going and shifting fine

it's your call

Stuwy123

iTrader: (1)

He's just kidding, those are all the parts that feel out of the jeep he was following.

hatRunner

Just wondering how many miles you have and drive per day. Also are you saying that my auto trans and transfer case are sharing fluid, and actually one unit? I was under the runner Saturday and they looked like two distinct units?? I was checking the drive line more than anything though so?



This is driving me nuts... and nays to 3000 on tranny work

buckz6319

I have almost 189,000 on the engine and tranny, I drive 25 miles to work and 25 miles back 5 days a week and even run around in the runner on the weekends.
The A340H (Asian 340 Hydraulic transmission) has what is called a married transfer case and it does use transmission fluid in the transfer case.The units do look detachable from each other but you have to go deep into it to detach
the two...all though some one may have swapped transmissions and put a different one in your runner?...you should see a Tag on the side of the tranny where the linkage is for the shifter(P R D 1 2)...I think the A340H also has a number like 3080LE

I feel you on the $3,000.00 transmission bill, that's the reason I'm still driving mine that way....you need to have a professional check it out for you

hatRunner

One more question, does your noise only happen at certain times or is it like an all the time thing? Also does it seem to get worse over time. Going to the pros tomorrow but i want to have the best information possible before I go.

Also: It's not an OD gear thing because the sound is still there if I shut the OD off.

buckz6319

well the noise is there all the time but is more noticeable when not in O.D. I can feel a vibration in my auto shifter almost all the time and it is worse when the O.D. is off, put your hand on the shifter whie driving and notice if you feel what I'm talking about and let me know

over time I feel like it has stayed consistant

You can also buy a cheap stethoscope with a extension, and have some one drive the 4runner, and you put your probe on that part of the console where you here the noise.That will at least confirm that indeed you have something going on in that area


It maybe something else causing you problem....and I hope so!
Good luck and keep me posted

hatRunner

UPDATE

It was a fractured drive shaft... cost 400 bucks. Problem Solved

Thanks for the help Yota-Tech

buckz6319

it's nice to see someone post a problem solved

hatRunner

Gotta share the Love

Teuf

I like a good ending.