I am starting to notice my transmission making more noise now at lower speeds...its got 105,000 on it, around 85k i changed it to Amsoil MTG, purchased here from ed anderson I'm just wondering if this is normal for the age, or if the fluid could be low, or synchros wearing out...
Basically in any gear at a lower speed(less road noise) I can hear a whirrrrrrrrring sound. If I put it in neutral and just rev the engine to 2-3k all you hear is motor, if its in gear say 3rd @ 40 mph you can hear a "rrrrrrrrrrrrrrrrrrrr" kind of winding noise.

I realize its a mechanical mechanism, synchros and helical-cut gears that arent going to be quiet buuut its not as quiet as it used to be

 

synchros could be wearing, but its also possible for something else to be wrong. i get the same sound in my 65 chevy, but im sure we all know its the synchros at that age.

 

helical cut are 10 times more quieter than straight cut ones. That's why some race cars you hear them whine. It's the straight cut teeth gearbox. Now that has lowest loss of power but for street use it's not feasible. So they have helical cut gears (at an angle). Now only exception is reverse that's why you hear that noise.
Your problem is associated to a bad bearing inside your tranny most likely. Can't be there to diagnost but there are bearings inside your transmision that hold the clusters of gears. When those wear out they make noise. So you need a tranny Re&RE

 

Synchros are just there to match the speed of two gears while engaging preventing "gear clash". Once engaged (shifted gear) synchros act like dummies. so it can't be synchros

 

when synchros start to wear on the shaft, they can make noise simply because they are spinning fast. you only notice at slow speeds because at higher speeds road noise, wind noise and other noises take over. like you also said though, it could be a number of bearings causing the sound

 

the synchro spins with the shaft after lockup so how can it make noise? Friction makes noise not the fan effect. Moreover synchro gear sits in the synchro assembly and yopu will hear the whine only in a gear or not more than 2 gears only and the other 3 will be quiet. 1 synchro assy for gear R and 1, anotherone for gear 2, 3 and last synchro assy. for 4 and 5. Now each synchro assy shifts 2 gears and has 2 synchros per assy or 1 synchro gear per gear.. (with reverse gear not being synchronised though) so if a synchro ring is bad u would only hear it in 1 gear only if your theory stands true.
Like i said though 99% of the times it's the bearings inside the tranny that hold the gear cluster shafts that allow them to rotate inside the tranny housing.

 

Thanks for all teh info...is that one of the axle bearings that are fairly common on these 5 speeds? That cause leaking of fluid out of the sides of the trans./axle seals?

You know, between the northeast arctic typhoon and lake effect snow I got stuck maybe three times last week, did a decent amount of rocking forward/reverse and wheelspinning...

 

Have you checked your fluid level? It may be a simple as that.

 

Yeah i'll do it when I get home later...I hope thats all it is, I'm hearing these manual trannies are fairly tough

 

nope you are talking of a trans shaft seal that could leak. I thought u already checked the fluid lol. Hope you know how to do that. Make sure you take off the top 1/2 inch plug not the bottom one and stick your finger in there it should be either slowly dripping out or at that level.
While you're there check the left axle seal it's when the shaft from your front driver wheel goes into the tranny and where they meet it has to be dry no greasy spot etc. They are more comon on the left axle than right one.