Refilling Tranny

[GTpaul86]

I Have An 86 Gt And I Was Wondering How You Refill The 4spd Tranny And What Do You Use 10w-30 Or Somthing Else And How Much Does It Hold Thank You

[Ragtop_Renegade]

5W-30 Motor Oil. There's a fill plug in the top and a oil level plug in the side. Remove both, fill from the top and when oil starts to drip out the side hole it's full. If you want to do a complete change there's a drain plug in the bottom.

[goatnipples2002]

Are you sure you use 5w 30 in the tranny? my friend use something like 80w 90.

[Ragtop_Renegade]

Pontiac specifies 5w30 for all Fieros with manual transaxles.

80w-90 is the most common gear lube used in older gearboxes like the Borg Warner T10 and Muncie "rockcrushers"

The reason the thick stuff isn't used is because of technological improvements to shift synchronizers over the years, the gears don't require such intense lubrication to avoid burning up.

Point in case, my 87 LeBaron GTS Turbo (RIP even if it was a pile of crap.) Used Dextron II automatic tranny fluid as lubricant in the 5 speed manual gearbox. Weird, eh?

You can use 80w-90 in any modern gearbox, but it doesn't really do much unless you're going to drive like 190mph and get those gears really screaming. Synthetic 5w30 or 10w30 will do fine in most street performance situations, while plain old Texas Tea is all you need for daily driving.

[goatnipples2002]

On pennocks they talk about using synchromesh gear lube. GM revised their manuals from what I hear and now they say use synchromesh.

And how do you change the fluid in the 4 speed?

[Ragtop_Renegade]

I forgot about syncromesh!!!! Never used the stuff myself... The only two high powered cars I ever owned (74 Lemans conv 400 4bbl, 70 Ford XL conv 390 4bbl ) were autos. All my stick cars were 4 bangers that ran plain 80-90, 5w30, or the red stuff.

The following is true for 90% of all gearboxes: you have a drain plug(bottom), level plug(side) and a fill plug(top). First you pull the drain plug and let the old stuff drain out, then you pour lube in the fill hole till it runs out the drain hole onto the garage floor and you realize you forgot to put the plug back in. Replace the drain plug, drink another beer, and pour lube in the fill hole until it just starts to trickle a little out of the side oil level hole. Replace the fill and level plugs, then reward yourself with another beer.

*The Izuzu 5-speed has a dipstick, the Getrag does not.( I have not had the pleasure of seeing a 4 speed in person so I don't know what it has), a good rule of thumb is if there is a dipstick, there is no level plug and the process is similar to changing engine oil, minus the filter.

[goatnipples2002]

The getrag does have a dipstick, my friend has a formula with a mg2 and a dipstick on it.

[Ragtop_Renegade]

Maybe it was a early model getrag I saw, or it was actually a 4 speed.... It was in a junkyard car and the shifter, cables, and build sticker were missing. I THOUGHT I found 5 gears playing with the select linkage but can't be certain.