5r55 hisses

[nesbit]

I hear a hissing noise coming from the transmission "area" when i select either drive or reverse. Sounds similar to an air leak. Worse when warm. Can hear it at idle when stopped.

Otherwise the transmission seems ok. I checked fluid level and it's fine. I've read similar posts on the net, but no real conclusions to the problem.

2003 xlt 4x4 with 27k miles.

Any ideas?

Thanks!

 

[fangotango306]

i just rebuilt a 5r55 in my wifes explorer because the OD planet exploded. on first drive i experienced the "hiss" while in reverse and drive with foot on the brake. i re adjusted the intermediate band and it went a way. however, this is not the kind of thing that will happen by it self. you dont seem to have enough miles on your truck to worry about servo bore wear either. i would find a transmission shop that knows the 5R55's and have it checked out. these transmissions are touchy and can be expensive to fix.

 

[nesbit]

Hi fangotango306,

Thanks for the reply. I just noticed it the other day. As you can guess by the mileage I don't use the truck often. But I do run it every week or so to keep things lubricated.

Since it only hisses in gear I assume it's the transmission but I would have to let a shop confirm that. I guess it's possible it could be a head gasket leak but I doubt that would be sensitive to gear position...

 

[fangotango306]

very doubtful that its a head gasket with that low of miles, unless you are very hard on the truck. If you are not a mechanic or comfortable with your own diagnosis i would still stick with the recommendation of taking it to a shop/dealer. I have run into a lot of strange things on vehicles. I've been working on my own junk for 20 yrs. sometimes it has saved me tons and sometimes i have replaced the wrong thing and over spent when i needed something else..