BoulderG

Today I confirmed my 1989 Pickup, 4cyl (2.4L) 4x4 Extra Cab, has a new noise.

When I shift into fifth gear (in 2wd) there's a prominent noise that sounds like it is coming from in front of the shifter. Way in front, like the front of the engine bay.

The noise sounds like a bearing whuuush. First through Fourth or neutral, no noise. Engage fifth and there it is. It's not throttle-load dependent and changes in pitch with speed.

It's not a grinding or scraping noise. It's not a noise like a wheel-bearing. It's a noise like a soft scraping. Like a bearing, it's a sort of shhhhhhh or a whuuuush noise. (Pretty hard to to describe these in words.)

Not loud but definitely present.

I don't know trannys, but it sounds like when you shift into fifth, something on the front of the tranny shaft is gently rubbing on something. Like some sort of bearing on a tranny shaft might be starting to go.

The truck has about 138K on it, nearly all in Colorado or Utah, so dry and often cold. Weather here has turned cold - not much above freezing this week.

I've never noticed this before, and did have the truck last winter. The manual hubs are disengaged.

Any ideas?
Thanks!

Elton

synchros in the tranny ??

seaflea

Do you hear the noise in reverse? 5th and reverse are on the same shaft, if there is a bad bearing on it, I think you will hear it in either gear. I realy have no other ideas.

Edit; Check the fluid level. It could just be low.

Flamedx4

The 4cyl trans is notorious for the 5th gear shaft support not staying put, and the bearing going out.
Well, not notorious, that's just the weakest link....

kyle_22r

yep, 5th gear is the weakest in any toyota transmission. most tend to howl a little but let it go too far and it'll be rebuild time.

Flamedx4

When it starts going "clack- clack - clack" you're in trouble...

84sr5yoty

Might be a good idea to change the tranny fluid. If you live in the colder climates, synthetic would be a really good idea.

adam86pickup

check to make sure you are not getting bumped in to 4wheel drive when shifting to fifth. That would explain the noise in the front differential because it would be spinning the gears without the hubs being locked in. Know a guy it happened to.

rockota

My truck had a howl in 5th gear - turned out to be two chipped teeth. Odd.

Flamedx4

Don't think you can shift into 4wd with the hubs unlocked - the front driveshaft wouldn't be turning and much grinding of tcase gears but no shifting would result.

BoulderG

Thanks everyone for the responses. It's been cold, windy, and dark, plus I've been busy and have a sore throat: Totally unmotivated to work on the truck outside. Now I can't find my manual.

Checking tranny fluid level is a great idea. I changed it 9 months and 6,000 miles ago. I think I used Synthetic, or at least quality Valvoline.

Is there any dipstick for the 5-speed tranny?
Just check the tranny fluid level by pulling the plug on the side and making sure it is full to that level?

If the support shaft is "starting to go," What is the cure?

Thanks!

Flamedx4

No dipsticks on manual transmissions. Pull the side plug and insert finger.

I forget the correct name for the 'support,' but as I remember it, one end of the shaft goes into a bearing on the case end-plate, the other end of the shaft hangs out in thin air, supported by a "support." It's like a little tower that sticks up and holds the end of the shaft. That shaft gets side-loaded pretty heavily (as opposed to being in 4th gear where the load goes straight through from input to output - 4th gear is the strongest gear in the transmission) and this side loading can eventually weaken the 'support." The fix is a new thrust bearing and a new support. People who lug the engine in 5th all the time rather than downshift have this problem more than those who row the shifter around...
While you're at it, might as well replace the synchros. While you're at that, might as well replace the other bearings. Put it back together with new seals and you have a rebuilt transmission!