Per my original 1985 do it yourself manual that came with my car: Remove drain plug on bottom of transaxle to drain, when filling remove check plug on side of case and fill thru the hole with a plastic tube connected to a funnel until fluid is level with the fill hole. I wish I would have read this before taking out the VSS and having to fish the gear out of the transmission.
Why take the chance of the gear falling off, I plan on using the fill hole from now on.
I've said this in the past but few listen. ^
Pull bottom plug, let drain, replace plug. Remove top plug, fill until level is at bottom of plug hole, reinsert plug. It is a tight space but better then messing with the VSS, especially with the know potential of the gear falling off.
1985 Manual says to use 5-30W .... but I just used Valvoline Synchromesh ( designed for General Motors or Chrysler manual transaxles) and will check for leaks when installed next week. The PO used trans fluid ( I drained red fluid out) there were no leaks prior to my engine rebuild but I replaced the 2 output seals while I had it out.
The 30-year-old manual recommended 5-30 when the car came out (still fine to use).
Once GM (or someone) developed Synchromesh Manual Transmission Oil, that has been the recommendation since. They released a Technical Service Bulletin (TSB) when the product became available. It's the stuff to use. See here: http://home.comcast.net/~fierocave/stick.htm
Works great. Many people have found "sticky" transmissions shift much smoother after the changeover.
[This message has been edited by fierosound (edited 04-02-2014).]
I think the Isuzu 5-speed used Dexron-III ATF. But I see no reason why you couldn't put Synchromesh in it.
I've been telling people for a long time about the side fill hole. On gearboxes that don't have a "real" dipstick, this is the way to go. You can get a funnel with a flexible spout, or a spout that has a piece of hose attached to it, and the job gets a lot easier. Then you don't have to mess with the VSS.
Exactly where is the transaxle filler hole on a 85 V6 4-speed? I realize that the the VSS is easy enough to get at but if there is a specific filler bolt for that purpose, I'd rather go that route. Is it the bolt next to the VSS? I would think that it should be located at the same height as the VSS but this bolt is actually higher.
[This message has been edited by TOM SUTCLIFFE (edited 11-18-2021).]
Exactly where is the transaxle filler hole on a 85 V6 4-speed? I realize that the the VSS is easy enough to get at but if there is a specific filler bolt for that purpose, I'd rather go that route. Is it the bolt next to the VSS? I would think that it should be located at the same height as the VSS but this bolt is actually higher.
From 84 Do-It-Yourself Manual (auto and 4-speed only that year)
Some images. I ended up pulling the VSS to add the transaxle fluid. Used the GM Syncromesh product. You should be careful because there is an o-ring to seal it in the casing and there is very little clearance for the gear. My fluid was very old but no evidence of any shiny stuff or metal. I will likely drive it a for awhile and change the fluid again.
[This message has been edited by TOM SUTCLIFFE (edited 11-19-2021).]
Because there are no clutchpacks to contaminate the manual transmission fluids, it has a very long life. The only thing would be as you note, possible metal pieces from grinding gears.
I noted the plastic piece around the plug. My Getrags have that at the dipstick on top.
