Topic: Drivetrain noise driving me crazy!! Toyota tech help???

[wmflyfisher]

I'm getting this noise from my drivetrain in my 85 pickup w/ the 5spd. and I've had a few mechanics listen and they really have no clue. I have heard this noise for a few years and it has progressively gotten worse. Now it is very noticable! When I'm driving in higher speeds it sounds like a bearing going bad. I'm positive its not a wheel bearing, or throwout bearing. Both of those are new and still makes the same racket. I can be driving 50-60 and if I slightly let off the gas to where I'm not pressing the gas nor letting off completely there is a noise coming from it sounds like the mid section under the truck. You can also hear the noise as I'm slowing down with the clutch out and the transmission out of gear til I stop. When I'm driving at higher speeds to hear it I can't be giving the truck gas nor can I have my foot completly off of the gas. I have to keep the pedal right in the middle of gas and no gas to hear the noise unless my foot is off of the clutch and it is out of gear coasting, you can hear it then as well. When I press and depress the clutch it makes no difference. The noise sounds the same when moving. It does not make this noise when still, it gradualy slows as the truck comes to a stop. WHICH BEARING IS GOING BAD? HELP!! 

[79coyotefrg]

check your pinion bearings and tranny output bearings

chock the wheels  and put it in neutral  then get under there grab the drive shaft and see which end  wiggles

[wmflyfisher [OP]]

Just did that and there is minor and I do mean minor play on the transmission end? Its hard to tell.

[79coyotefrg]

could be the output bearing,  is there any oil seapage from the rear of the tcase??

[wmflyfisher [OP]]

nope

[wmflyfisher [OP]]

Is that one hard to replace to just see if thats the problem?

[ZukIzzy]

Grease your slip yoke, if that doesn't stop it pinion bearing is a good bet.

Wayne

[whiteman]

Is that one hard to replace to just see if thats the problem?

Nope, I just gave these instructions in another thread about drivline vibration.
 If you use this link as a reference http://www.marlincrawler.com/htm/transfercase/470install/installation.htm 

You want to remove cover #4 and then look at steps 7 and 8 the two speedo gears and the bearing were shot on my friends, which was causing major vibration through the whole truck, and some hideous noises. 
It was really simple.

[crawlerdan]

dood, i have the exact same problem, its the transfer case out put shaft bearing, lemme guess, yiou have dual cases and shortened the rear driveline without adding a cv? damn im good huh...if so, add a cv!!! it doesnt "fix" the problem but it quiets it the hell down fo sure!! i did, and i only hear it every once and a while, like every few hundred  miles...good luck bro

[wmflyfisher [OP]]

Well, your not that good! All I have is a single case! Good guess though. I hope that the tcase output shaft bearing is all it is. Whiteman, I have very little vibration and mostly noise. Thanks for the thread link! 

[wmflyfisher [OP]]

So I'm assuming that step 8 is the bearing I need to replace? Is there any trouble in removing those spedo gears? Any special way they need to come off/go on?

[79coyotefrg]

thers a detent ball under it,  dont loose that
otherwise they just slide off,  make sure they go back on the way they come off

[79coyotefrg]

do step 1 and 2  to get to the speedo gear and bearing, you dont have to split the case as in step 3-6

[wmflyfisher [OP]]

Thanks for the help guys, I'll try it when i get a chance!

[Yota4life]

I had the same problem your describing...if its a high pitch tinking sound then its your cv or u-joints on your driveshaft. I first thought my r&p blew up, then i thought it was the transmission. I took the d shaft off and greased all the u-joints and the cv and put it back on. It made the noise go away and now i just have lots of vibs over 50mph. Before it wasent greased it just made lots of noise like your explaining. Grease it and see if that noise is still there..