Hey gang,

I am new, proud owner of a 1987 Yota $runner that I know is going to need some work. I understand mechanics but I am no "House" when it comes to diagnostics so here it goes...

The buzzing / whirring happens when

1. The engine is warm (on the way home from work / not to in the morning),
2. It doesn't happen all the time, it happens when the engine (or clutch for that matter) is under load going up or down hill or towing, when I pull over it continuously gets quieter then quits.
3. Its coming from under the hood.
4. I thought it was the fan clutch bearing or the water pump bearing. Changed the water pump and checked the fan clutch, all good.


I am new but I am willing to like this truck. My dad had one when I was 10. I have always wanted one. He could have fixed this and I can't wait to call him and brag that I did (with your help of course).


Thanks Ya'll

Ranger Moore

Greers Ferry Lake, Arkansas

 

5. The truck does not loose power when it happens.
6. The sound gradually disappears when you push the clutch in whether i am moving or not.

 

if it gets better when you push in the clutch it might be the throw out bearing.they may have the clutch adjusted to the point that the bearing is against the pressure plate all the time. if it hard to shift into certain gears the clutch might be needing replaced.

 

Thank you. I will take a look at it.

 

Does anyone else agree.

 

Well, it's getting worse and I don't know what to say. The transfer case was empty when I bought the rig so...

THe noise slows and stops with the truck. It has to be a clutch or CV joint issue. The whirring buzzing tells me it's a bearing.

The rig shifts smooth. I am sure it's something I can fix on my own but I am a master of "hidden noises" and I can't track this one down as it has to be going 25 mph+ to make the sound. By the time you pull over it's gone.

My wife heard it the other day and won't drive the truck anymore. I took it to the mechanic who drove it for 3 days and finally heard the noise. He didn't know where it came from either.

I am sorta suprised that I am not getting more hits with advice from ya'll. Oh well! I guess I will start replacing part$. $tarting with the transfer ca$e.

 

can you rev the engine and hear it when is parked or is it at 25mph under load only ?

 

No I have to be driving, under load (won't happen in nuetral), I'd say 25mph + is the ticket. Still thinking thrust bearing?

 

noises are one of the worst things to find. the best thing to do is take your time and try different things. part swapping can get expensive and may not fix it. when you filled the the transfer case did the sound change?

 

Nah, the sound didn't change. I have taken the truck into a mechanic. I hate to do it but he has a lift and I need it done so I can launch my boat. He seemed a little stumped too.

 

To put it simple the engine does the same thing regardless of whether your moving or not. If your only getting noises whilst driving it has to be a gearbox/clutch or drive shaft issue.

 

Agreed. I believe it to be a bearing too. Thank you for breaking that down.

 

Well, I had a mechanic take it for a spin and he suggests that it's the Tcase. I garee with him and need him to do the work. I haven't been able to find any where I am does anybody have a suggestion? How hard are they to remove. He wants to charge me 4.5 hours. Seems bout right?

 

drives shaft U-joint..

 

4.5 hours for a x-case swap sounds about right for a shop to charge, but can be done a bit quicker. takes 2 hours at a shop with a lift and power tools no problem..

 

If I have a 1987 4runner sr5, non turbo, with fuel injection, which models can I pull a transfer case from to match?

 

I found a used case for $100 and it didn't fix the problem. I have the truck at a mechanic and he believes the problem to be in the hubs? He is stumped.

 

try putting it on a lift that supports the frame.with the wheels off the ground, try it in 2wd ,4wd, and any other way that might cause it to act up. have someone listen and maybe you will be able to narrow the sound down to one area. i had my brother do this and it helped to answer some questions on his truck.

 

I know you said that its coming from under the hood, but it sounds to me like a transmission problem. I don't think it would be your hubs, unless it only happens when they are engaged.

Since you said the t-case was dry, do you know if the tranny has ever been dry or ran low on gear oil? Does it do it in every gear?

 

It seems to do it in every gear. Or at least in 2nd and 3rd. The transmission and clutch feel really good. The mechanic ruled out the thrust bearing. With the newer Tcase, I was able to make a 30 mile round trip before the noise happened on the last 1/4 mile. I am having a hard time diagnosing. Maybe the newer (pick and pull) Tcase is bad too?