TH400 Conversion from M6

Transmission Pan Temperature Gauge Tap
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Tools Needed
Drill bit
Adjustable wrench
Brake cleaner
Liquid teflon
Parts List
AEM Digital Trans Temp Gauge 30-4402
Remove the transmission oil pan. This transmission had two 13 mm bolts and eleven 6mm allen head bolts.
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My kit came with to bushings. A 1/4" NPT and a 3/8" NPT. The 1/4" NPT should be used first in case a mistake happens you can have a redo with the larger bushing.
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I drilled a 7/16" diameter hole on the rear side of the pan on the passenger side. The hole was located about 1.5" off the inside bottom of the pan.
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Using the appropriate sized tap, 1/4" NPT in this case, carefully tap the hole. It is absolutely critical to take care during this step. You need to run the tap almost to the end and back out. Repeat several times to ensure the threads are good.

Also, run the tap the perpendicular and level to pan wall and floor. The bushing should go in nice and straight, not cockeyed.
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Apply liquid teflon to the bushing and tighten. Wipe off excess teflon on the inside of the pan.
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Clean the inside of the pan with brake cleaner. Do this in a safe location wear the appropriate personal protection equipment (PPE) and in a place that is safe to spray brake cleaner liberally but friendly to the environment.

Be sure that there are NO aluminum shards or pieces left in the pan. Again, be sure there are not pieces of aluminum or anything else left in the pan. The pan must be spotless clean.
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Install transmission pan back on to your transmission.
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