Forward Hub Tech.......
TH400 Forward Hubs are Cast Iron, Good to around 500 ft lbs in most applications, More if your not shocking it with a big stall or a big hit of nitrous.
4L80E Forward Hubs are Cast Steel, Good to around 750 ft lbs in most applications, Not phased by big stall's or small hit's of nitrous.
Identification.......TH400 Forward Hubs will make a dull thud sound when lightly struck with a wrench, A 4L80E piece will ring like a Bell.
End Play, Forward Hub to Direct Drum specs.......
Using a Thrust Washer..... .008"-.015"
Using a Torrington Bearing....... .003"-.008"
If using a Thrust Washer between the Forward Hub & Direct Drum, You will need to buy a thicker Thrust Washer as no shims are available for this location.
Stock Plastic or Brass thrust thickness...... .059"-.064"
Sonnax Part# 34301-078 ...... .078"
Sonnax Part# 34301-094....... .094" This is the one usually needed.
Rollerizing the Forward Hub.....
This is highly recommended mod.....Almost needed if your trans spends long stints in low gear.
The best fitting bearing to use is a final drive sun gear bearing out of a Ford AXOD Part# E6DZ-7F404-A
Ford has discontinued this part, But Green Sales has them in stock Phone# 1-800-543-4959
Machining the Forward Hub rear thrust pad is necessary, Be very careful on your measurements because you will need to set Forward Hub to Direct Drum end play with the machining.
Start with +.035"......Lets say the bearing is .150", The original thrust is .064"
.150"-.064"=.086", .086"-.035"=.051"........051" is what you need to remove from the Thrust Pad. These are hypothetical numbers!! Measure your new Bearing & old thrust BEFORE machining!!
Checking Forward Hub to Direct Drum end play, Stack the gear train up to the Direct drum, Place the Forward Hub over the Main Shaft, Hold the forward hub down with your palms & lift the direct drum with your fingers.....The play you feel is the end play.....Picture......
