Transmission Noise

O.K. I have a noise on start up that lasts until it is hot,then MOSTLY goes away but I still hear it.It's a hissing noise coming from the trans.My mechanic said it's caused by a tiny amount of air in the trans due to it's age and loosening clearances allowed it into the system.Like I said it's pretty pronounced at start up,then after about 10 minutes or so it quiets down quite a bit but it's still there.There is over126k on the trans btw (still shifts great though).Am I hearing the imminent demise of my trans coming on??I will be changing out the trans fluid as it's been on my list of things to do since I bought the car a month or so ago.The fluid looks o.k.,no burnt smell,or anything...nice pinkish/red color.

NOBODY???

I can't say I've ever heard a trans hissing until it gets warm. In fact I've never heard of this on any 3800 powered car. But, I'm not a trans tech either.....

The statement made of allowing air into the system because of tolerances doesn't make sense to me. 126K on the trans means nothing at this point. A well maintained 4t65E can last forever. A lot of us modded Riv's have well over 100K with no trans issues. Most of the time, the problems with this trans are the TCC Solenoid, or a filter that's never been changed. But neither of these issues would cause a hiss.....

I'm no help on this one, just thought I'd add my $.02

madrivage wrote:

O.K. I have a noise on start up that lasts until it is hot,then MOSTLY goes away but I still hear it.It's a hissing noise coming from the trans.My mechanic said it's caused by a tiny amount of air in the trans due to it's age and loosening clearances allowed it into the system.Like I said it's pretty pronounced at start up,then after about 10 minutes or so it quiets down quite a bit but it's still there.There is over126k on the trans btw (still shifts great though).Am I hearing the imminent demise of my trans coming on??I will be changing out the trans fluid as it's been on my list of things to do since I bought the car a month or so ago.The fluid looks o.k.,no burnt smell,or anything...nice pinkish/red color.

...think about figuring out what your mechanic is good at, and let him/her stick to that.

...if you follow the "severe service" schedule the 4T65E just might last as long as you own your car - - plus, there are people out there who really, really understand the transmission. I have more miles (130K) on my rebuilt 4T65E than it rolled new... and the only reason for the rebuild was to replace some stuck plastic bullet-shape part with a billet aluminum one because it was making the TCC stay stuck off.

Albertj

I'm not saying this is it, but another too common problem with the 4T65-E (even the "Heavy Duty") is wear of a stupid aluminum sleeve/spool that they put the steel Reverse and Boost pressure valves in... If this were the problem, the noise would come from the valve body, on the driver's side.

(Also, I should think you'd have some kind of shifting symptoms if this were the case...)

Eldo wrote:

I'm not saying this is it, but another too common problem with the 4T65-E (even the "Heavy Duty") is wear of a stupid aluminum sleeve/spool that they put the steel Reverse and Boost pressure valves in... If this were the problem, the noise would come from the valve body, on the driver's side.

(Also, I should think you'd have some kind of shifting symptoms if this were the case...)

I had a leak between the High Pressure sleeve and spool and yes you will get some serious shifting and or shuttering problems. You will not hear a hiss, I can tell you that.
I had a launch shutter from that one, that would send the front end into a wheel hop and break the mounts, just from normal acceleration into traffic.
The other one will cause very lazy shifts, but no hisses that I ever heard and I listened.
This all happened at around 80K miles after having the Trans FLUSHED by a shop with the correct flushing equipment. The flush and the cleaning solvents were so good that they removed some varnish from these bores and uncovered the problem. The Trans probably never had a fluid change in it's life, IDK.
Wasn't too long after that I had the trans removed for overhaul, even though these can be repaired in the aftermarket world of transmission rebuilding.
The Dealer i brought it to said they would not guarantee that a $700.00 repair would fix the problem.
So it went to a friends shop for an $1800.00 overhaul. (no discount for being a friend) but a Guarantee that it would work and last a long time.
I did have an extended warranty that paid for most of it, not all.

I think Abaddon said it best: Bring it to another mechanic. Preferably a Technician, not a mechanic.

Good info, Rick.
Tell us, did that sloppy spool also cause the tranny to take forever to drop into Reverse or Drive?

Eldo wrote:

Good info, Rick.
Tell us, did that sloppy spool also cause the tranny to take forever to drop into Reverse or Drive?

No, did not have that problem at all.