Th350 leaks

[Chisholmcody]

Haven't worked on my truck in a while with diesel school and all that good stuff but here it goes!

I've had a transmission leak for a while and I've pin pointed it to the shift shaft seal and speedo.

I replaced the shift shaft seal pretty easy, no more leak from there. I then went to do the speedo, I replaced the 9in tail shaft as it had a crack by the bolt hole where the speedo mounts. I then replaced the speedo "bullet" with a new one I found on the internet.

Yet I still have a leak? Coming from the speedo box it self,

Also I have a leak from the drive shaft where it enters the tail shaft. Weep hole is welded, tail shaft also has new seal and bushing!


Any ideas!?

Thanks,
Cody


Sent from my iPhone using Tapatalk

[bd]

Check the vent on the top of the transmission case at the base of the bell housing slope for any obstructions.  Remove the speedometer driven gear bushing and gear.  Inspect the gear shaft for any evidence of wear.  The gear shaft is wrapped in a spiral groove for lubrication, but there should be no circumferential or ring groves anywhere around the shaft.  If there is a circumferential groove, replace the gear.  Wiggle the gear side-to-side in the bushing.  If there is any more than ~0.006" of radial play, replace the gear.  Reassemble with a new bushing o-ring and driven gear end seal.

Grab the forward driveline yoke and wiggle it up and down in the transmission tailshaft housing.  If there is more than ~0.015" of radial play, replace the tailshaft bushing.