I know I'm supposed to use 75/90 gear oil in my transmission. My question is: Will using a thicker/ higher viscosity oil help an older manual transmission run smoother? Will using a thicker oil help quiet an older tranny with some wear on the synchros & gears? If so, which "#/#" is the next thickest after 75/90?

Thanks!

 

Redline MT90 which is a 75W90 GL-4 synthetic transmission oil is going to be the best for an old Toyota transmission and it's synchros.

 

Cool dude. Do you think it'll help quiet it down a little?

 

Quiet down the transmisson? I haven't noticed any difference. I don't see why it would. Is the transmission noisy?

 

does the transmission whine? If so, this is typical amongst toyota trannsmissions

 

mines pretty noisy, i was hoping new and heavier fluid would help but it didint, it's just noisy from 3rd on, i thought it was the pilot bearing but no avail its new so i dunno guess ill have to live with it

 

yeah, it's just whiny, doesn't sound like anything's being shredded up/ ground up in there. I've been told it could be the input shaft bearing, pilot bearing, throwout bearing, etc. It runs great, makes great power, shifst great, 4x4 works great, noise goes away when the clutch is in so it has to be the tranny. Doesn't really sound bad, but you notice it when you press the clutch down & it goes away. It's only got 130k on it, & like I said it works great & I don't see any reason to mess with it. What do you guys think?

 

Oh yeah, & I took it to a few tranny/ clutch shops just out of curiosity, & they just said "oh yeah, you need a new transmission" but of course they'd say that.......

 

I use Amsoil 75W-90 GL-4 MTF in my 88 4WD and my transmission is quiet (although he engine and exhaust is not). My transmission works great, you just have to be patient with second gear when its cold. When I get it warmed up good I can shift quite quickly at high RPM with no problems.

 

Thanks ryotto. So given my decsription of my tranny noise- would you guys just leave it alone? This is my first Toyota pickup.

 

I guess my concern is that I don't mind it at all being noisy, or even if it was hard to shift when it's cold, etc.- I just don't want to have some explosive catastrophic transmission failure that's gonna leave me stranded somewhere.

 

Typical toyota whine, just drive it till it stops going into gear or you start losing gears then look into a new transmission.
130k is nothing I've had old 4Runners with well over 200k and the gears were noisy and they whined, they always got me where I needed to go though.

my current truck only has 98K miles and it has half as many miles as every other toyota ive ever owned

old toyota's are like old tractors, they may be slow and noisy but they last

 

Thanks Pruney. That's exactly what my dad said! Like I said it shifst smooth, 4wd is super smooth, it's just a tad rattly & whiny, most people wouldnt even notice. My '95 Accord that I just sold started having trouble getting into 4th & 5th gear at about 160k,- you'd just have to ease off the RPM's or double clutch it, I just sold it with 215k & it had barely gotten worse than when it started (I'd say 15% more difficult) So I know manual trannies can last even though they may have problems, I just wasn't sure if Toyota PU trannies were like that too.

 

didn't you have a thread about getting your clutch replaced?
did that happen?

 

I did, then I decided to do some more research. I got under my truck & used a stehoscope (the doctor's kind) & listened to find the noise, & it was coming from the heart of the tranny, not the clutch. The clutch itself is fine, it was done at 86k, I was considering doing the clutch due to this noise issue, but now that I think about it more, & from what you & others have told me, I'm just going to leave it alone.

 

I would recommend changing the transmission fluid. No need to dink around inside the transmission if it still works. Try the Redline MT90 or the Amsoil 75W/90. Old fluid will cause your transmission to wear out faster. Sometimes simply changing the fluid will correct existing problems. Due to the nature of a manual transmission, you may hear some noise and that's probably normal. I don't hear my transmission make any noise, but then again the 22RE is a noisy engine and my exhaust is kind of loud too so it probably downs out any noise the transmission makes.

 

Buy a gallon jug of the Redline MT90

I just changed my fluid when I did the clutch two weeks ago and it took about 3.4 qts.

The manual calls for 3.2 but I added a little more

 

MTF was changed at 123k, now its at 130k. Should I change it again?

 

Well, if it has just regular old dino oil in it now and you put in synthetic it might help prolong the life of the transmission, you could also get an idea as to what kind of shape it's in if you get any chunks of metal coming out or stuck to the drain plug.

fine metal shavings on the drain plug are normal though

it won't hurt it to put synthetic in it now but it's probably not necessary it was just done 7K miles ago, that said I like to change all fluids i.e front and rear diff, tranny, t case and engine when I get a new truck just to get an idea of what kind of shape everything is in

 

You're right. I'm gonna buy me some Redline MT90 & git 'r done in the morning.