Allison leak question

[dmax515]

I bought my truck (2001 Chevy 2500HD D/A 4X4, 46K miles) about 3 weeks ago. I noticed when I first purchased it that it had a very small drip coming from the tranny, driver side from out of the shift linkage or the box that the linkage connects to. Anyway, they fixed it, saying it needed a seal and all seemed well. I towed for the first time (filter had been changed and fluid was at proper level) this weekend and on the way down towing our trailer it seeped some after about 30miles. After the next 50 or so there was no longer any leaks? Nothing on the return trip either and we pushed it pretty hard to see if that could have been the reason but not a drop??

Thanks for any insight

[More Power]

The ATF cooling lines used in these trucks are a push-lock design, and sealed by an O-ring. The clearances are pretty variable, and should the ATF lines not be in just the right alignment, it can create a leak potential. I suspect the O-ring in your case swelled enough due to heat and pressure to seal effectively, and stopped leaking on its own.

For everyone else, if you have a persistent ATF leak, check the alignment of the steel line where they enter either the Allison or radiator/cooler. If the alignment is not correct, it can induce a pesky ooze or drip now and then.

MP

[dmax515]

Thanks for the info, much appreciated.