Strange gear noise whine (?)

[skatehouse]

Truck just developed a strange gear noise. Sound reminds me of a noisy power steering pump although it's definitely a drivetrain noise. It is noisy in every gear except 4th, 5th is a little noisy. No noises at idle, coasting or downshifting. Anybody ever had this or repaired this? Thanks in advance!

1987 4Runner, 22RE, 5spd manual.

 

[flyinhawaiian01]

does it still make noise if you put your foot lightly on the clutch pedal?

Does the noise change its pitch evenly from 0mph on up while using every gear, or does it have the same change in pitch for each gear?

These should narrow it down to either diff or transmission noise.

 

[skatehouse]

Same noise through every gear except 4th. 5th isn't so bad, but definitely louder than it used to be. I'm leaning toward something in transfer case wearing out. Being that the truck has over 300,000 and I bet it's the original trans and tcase. Unfortunatley for me, I just bought this less than 1000mi ago. Everything else is awesome though!
Anyone in San Diego/ OC have one for sale?

 

[grumpin]

I read where the transmission doesn't make noise in 4th because it is the direct gear.

 

[02SE]

Just based on the description, I'd say you probably have worn bearings for the counter gear shaft, in your transmission.

As the power flows through your transmission, all of the gear positions which are not a 1:1 ratio, send power through counter gear shaft.

Gears 1-3 are underdrive gears, as is Reverse.

5th is an overdrive.

4th is the only gear where the power flow remains with the input and main shafts.

Here, I quickly Googled a link with a power flow diagram for you: Transmission: Automotive Engineering Fundamental: Toyota Manual Transmission and Manual Transaxles Powerflow System

 

[2014 Warthog]

Definitely need to have a mechanic (or two) look at it. But it does sound like a transmission bearing. I had the same thing in my old 86 Toyota truck.

Needed to rebuild the tranny. Got new bearings, seals, synchros and clutch. Ran like a dream since (Friend still owns the truck and still running fine) Don;t remember the cost but that was also like 15 years ago or something so not applicable now. I don;t remember it being TOO terrible though. Not like an engine rebuild.