synchromesh fluid expanding?

[c2xejk]

Since I started using Pennzoil Synchromesh fluid in my 543 trans, I have noticed after a while the transmission will be over full when later checked. The first time I noticed this was last year at Drag Week with my Spirit. Thursday of Drag Week I checked the fluid level and when I pulled the plug the fluid started pouring out. At that time I thought maybe it had something to do with the temperature (it was a hot day and I had made several passes.).

Last night I checked the fluid level on my Shadow and again the fluid poured out. In this case the ambient temperature was much cooler and the car had not been driven in over 36 hours. The trans was filled last August when it was much hotter.

Guessing that the fluid is getting whipped up and retaining air. That doesn't sound good for protecting the transmission... Is this normal? Did I get a bad batch of fluid?

[cordes]

Did you jack it up to fill it? Is the vehicle on level ground or the same ground as when filled?

[contraption22]

Is the fluid foaming?

[Reaper1]

IMHO Synchromesh doesn't work that well in our transmissions for some reason. At least the few times I tried it I did not like the result. It would work great cold (easy shifting, no grinding). Once it got warm it was exactly the opposite. I switched to using Red Line MTL and never looked back.

[iTurbo]

Never had a problem with good 'ol 5-30 conventional motor oil.

That GM Synchomesh is expensive ----!

[Vigo]

This is probably not useful info to you but i once burned up a 520 because it filled up with water from an (apparently..) not-well-sealed shifter plate while driving around in rainstorms. After it started making noise i checked the fluid and it was several quarts overfilled.. WITH WATER.

[c2xejk]

Last night I jacked up the front end and pulled the plug and allowed the excess fluid to drain into a container. Based on some math, about 1/2 quart of fluid came out. That does not include the amount that came out when I attempted to check the level over the weekend.

I will try an post pictures of the fluid tonight.

On fluid choice, originally I filled the trans with Redline MTL, but then had to pull the trans to rebuild the engine and MTL is not available locally so I switched to the Pennzoil Synchromesh which is available locally. Before the Redline, I did use motor oil, but that was way back when the ZDDP levels were higher. Not sure that current off the shelf motor oil is a good choice these days (there are several threads about this.)

[turismolover22]

5W-20/30 has done fine for me. 30K plus on my oil change in my ranger, minimal to no wear indicated. Of course, not as much abuse a boosted car might see, but its a daily.

[ajakeski]

I have Pennzoil Synchromesh in the 525 of our DC GLH. So far it's been great. The fluid level has not increased.
before synchromesh, the trans would grind into 2nd when cold.
I didn't use Redline MTL in this trans because I didn't want to take a chance of it leaking past the old seals.
No more issues with this trans after synchromesh.
Our other GLH has Redline MTL. Both transmissions feel about the same.

[c2xejk]

Here are the pictures of the fluid I drained off.

[Reaper1]

Does that transmission have an OBX or Quaife in it?

[supercrackerbox]

I use Redline in the Charger because it rarely sees severely cold weather, but the Daytona has Royal Purple syncromesh due to the cold weather shifting. I've never had the Charger's transmission apart, but the Daytona's trans looked beautiful when we rebuilt it last fall. Except for the end of the input shaft being snapped off and dropping 5th gear of course. But even then, I did have some difficulty shifting the Daytona in some of the -20° weather we had this winter.

Although now that I think about it, I wonder how much of the Charger's hard cold-weather shifting was due to the fluid, and how much was due to the plastic bushings in the pivots being beyond shot? They've been replaced with bronze bushings now, so maybe I'll find out next fall.

[c2xejk]

Does that transmission have an OBX or Quaife in it?

OBX, why do you ask?

[Reaper1]

The fluid is "sparkly" from what I can see in the pictures. I've seen at least 3 others that have the same thing (mine included). I don't think it has anything to do with your problem, I just wanted to get a better understanding as to why the fluid looks the way it does.