I have a 1999 F350 with the 7.3 and when I pull my goosneck trailer the trans leaks trans fluid big time after it warms up. But it does not if I'm not pulling the trailer. Can anyone tell me why it is doing that?

 

You ovbiously don't have a trans guage - get one asap or get a larger trans cooler or Xtra one (6.0 cooler or V10 cooler are great upgrades)


Your trans is overheating and the front pump seal is leaking. It doesn't take much to overheat the stock trans -- I did it in my 01 F250 pulling our short 22' 5er @ 70 mph on the highway during the summer... accept mine kept leaking

 

Thanks I'll do both.

 

Tranny gauge and front seal... If it gets too soft it will never seal up again.

 

I put the 6.0 cooler in my truck, the hottest it ever got was 180 pulling my 28' enclosed trailer

 

No problem bud -- hope it works out for ya! Trans issues are a PITA