Lubegard 19250 Assemblee Goo Green Firm-Tack Transmission Assembly Gel 16oz

This is Lubegard Assemblee Goo in the green firm-tack grade (part number 19250), a 16 oz container of the tacking gel that transmission builders reach for when they need parts to stay put during assembly. The firm tack is the heavier of the two Assemblee Goo grades: it grabs harder than the light-tack blue (19260), which is what you want when a thrust washer, needle bearing, or steel checkball has to hang on an overhead surface or a vertical wall while you get the next piece stacked.

On the bench it earns its keep in the spots where a dropped part means teardown. Smear a dab on the case thrust washer so it does not fall out when you drop the gearset in. Stick the checkballs into the valve body and separator plate pockets so they are still there when you torque it down. Coat new clutch frictions and o-rings on the first build so nothing runs dry on initial startup, and use a finger of it to hold a pan or valve body gasket lined up on the bolt holes instead of fighting it. It also works well seating lip seals and pinion or axle seals that carry a garter spring, since the firm tack keeps the spring from popping out as the seal goes in.

The important part for automatic work: it will not melt during assembly but dissolves quickly at operating temperature and blends into the transmission fluid, so it will not clog a filter, a valve body orifice, or a solenoid screen the way ordinary grease can. It is not harmful with prolonged skin contact and cleans up with the rest of your ATF. One 16 oz container lasts a long time because you use it a dab at a time. Pair it with a master rebuild kit and a fresh filter and you have what you need to close a unit back up clean.