Tranny downshift noise (1 Viewer)

[miller]

I have been driving my 75 sbc 40 around town now for a couple of months after a almost 2 year restoration. I decided to take a long trip yesterday day which was 140 miles one way. On the way up no issues. Started home and got stuck in some city traffic and when I went to downshift the tranny made a noise similar to a kazoo, it was a oh s*** that doesn't sound good! That was only 30 miles into the trip and what I found if I did not downshift the tranny was fine. I would put it into neutral and then come to a stop and shift into gear with no issues. I made it home fine by making a lot of lights. Once home I took it out about an hour later and everything was fine. Did not rebuild tranny or transfer case, just resealed and painted. Checked fluids this morning both fine. I am running 80w90. Clutch is new, master new, slave new, throw out bearing new. Inspected clutch through bell housing looks good. Tranny was hot to the touch after trip not sure if that's normal or not. My only thought is a bearing spinning in a race inside the tranny. Problem with the synchro mechanism.

 

[miller]

Drained transfer case fluid last night. The magnetic drain plug was clean, but while discarding the gear oil used a flashlight and the oil is metallic for sure. Very fine aluminum particles. When I had the transfer case removed a year ago to reseal it I noticed the transmission output shaft bearing had spun in the housing. The bearing just fell out when I took it apart. I put some bearing locker on it when I reinstalled it and torqued it to spec. I am thinking this bearing is continuing to spin intermittently in the transfer case housing. My thinking is I should not have any fine aluminium particles in the oil! If so what can be done to the housing to keep the bearing from spinning in the housing?

 

[miller]

Drained tranny fluid. Looked good just a little fuzz on the drain plug.

 

[mmw68]

Any updates?.

 

[miller]

I started another thread about clutch noise which I think this was the noise I was talking about. The noise is when the clutch pedal is in so that really takes the tranny out of it. It is intermittent though. I posted a video of the noise on the other thread. I have been driving back and forth to work for several days with no issues. I have purchased a spare tranny and transfer case that I will rebuild this winter and install. I will look at the clutch then to see what is going on.

 

[antFJ]

mine makes a whirrr when down shifting especially when I down shift to first or second a little too early (high rpm) but I find it to be a normal sound.. my parent's corolla and rav4 make a similar sound - it is almost like the whirr a power wheels makes when you take your foot off the accelerator - is this what you are experiencing?

 

[miller]

If u search my name the video is under clutch noise

 

[antFJ]

just did and the only thing that comes up is this thread