Ford 4630 transmission noise

I have a 4630 with MFWD and the 8x8 trans. I have a noise in the rearend or trans when I put my loader on it. If the loader is off there is no noise. It is a growl that happens when you are driving, Fluid levels are good, when I apply the brakes while driving it seems to go away, but why only with the weight of the loader???? Anybody have any ideas. Also can I increase hydraulic pressure somehow?? Thanks for the help.

I dunno.... There can be a lot of noises in that box. None of them tend to be good or cheap.

Really I think the first thing I'd do is check ALL mounting bolts for that loader. Then I'd check all the bell housing bolts and the rear transmission bolts to make sure nothing's loose or broken. Then I'd check the steady bearing on the drive shaft, and the oil level and condition in the hubs and front differential. I'd also turn the wheels from lock to lock and get a REAL GOOD look in at those U-joints. It's nothing for tha axle to drop a spider, and believe me, they will GROWL.
It may seem to you that the noise is coming from the transmission, but it can be hard to tell exactly where the source is in a driveline because sometimes it will transfer... but U-joints and steady bearings are the top things to check I think. I've changed several of both on my 3930.
Going into the transmission is a last resort. I've not had any bearing trouble in there but it's had three 3rd/4th gear syncro's at this point. You can expect a 2-10 grand expedition if you go rooting in that thing yourself. It would probably be close to 2 grand for bearings, seals and shims along with the PTO input and a clutch/PP.... doing the work yourself.
Labor mounts up quickly too because that's one poison puncture wound to work on.

Rod

Rod, Thanks for the info. By steady bearings, do you mean the carrier bearing on the front driveshaft? It seems odd that the weight of the loader makes the differce. The mounts stay on all the time. It really sounds like a bearing, the extra weight must put more strain on something. Do you have a cab on your 3930? Do you have a loader?

Mine has a Ford 7410 loader. No cab. They're just plain hard to work on. A cab would be about 5 times worse again.
The steady bearing I refer to is the carrier bearing on the driveshaft.

The only reason I can imagine for the loader affecting this noise is that there are some bolts broken or loose on the bell housing or the rear axle/transmission joint. That would put something out of alignment that could make a noise. I've had the lower bolts in the bell housing break on this one.... That sounded like a main was bad it was pounding so loud.
I wouldn't really expect a bearing failure in the transmission if it's always had oil, and clean oil/no water. We've put 4000 hours of abuse on this one and not had a bearing failure... but I did change them on the last trip in to try and get everything 'tight' again. Never say never I guess... but I'd be looking at the front axle first I think.

Rod

Thanks again, I'll be looking closer at that front end today. I just put the loader on and I am using the rear remotes. I'd like more hydraulic pressure. I can't raise and tilt the bucket at the same time. Doesn't seem to have the capacity I'd like. I was used to a 335 industrial that was unstoppable. Any easy checks or fixes. It never had a loader before and I've been told they have great hydraulic, but I'm not too satisfied. Thanks, Sean

Rod, Is it possible a hydraulic pump is causing the "growl". I would think a 4630 has plenty of hydraulic gpm"s to cycle for anybody. Maybe with the loader on somethings going amiss with the hydraulic system?

It's not a constant growl. It changes while your driving as to if your going over bumps or climbing a hill or going down an incline. It varies all the time. It really seems like something in the driveline etc. I check the front diff. fluid level today, it was down a pint or so, not much. Hub levels were good. I don't see any broken bolts anywhere. When you drive you can feel the growl in the floor of the cab. Hope a little more info helps. Any of you aren't from WI are you?? It's always easier to diagnose when your here. As far as the hydraulics go???? Thanks to everyone for the help.

I dunno. With those things I'd never say never, but not likely it's the pump.
If a pump(s) got to cavitating it would scream, but not really growl.
I'm just fresh after changing the U-joints on one side of the front axle, and the noise that came from that under load before it went to pieces was best described as a deep growl. That's why I'd suggest looking at the front more... and it was felt right up to and through the foot boards.

Beyond that I'd ask if there's any trouble shifting it? What about the transfer case?

Again, probably 75% of the problems we've had with our 3930 have been FWD related. I've lost count of how many times the hubs have been apart for rings and planet gears.
Also, a drive shaft problem will become much more evident at road speed than at low speeds. It will shake badly...

Hydraulics.... depends on how you have it plumbed. IF it's a dual pump model, the speed is decent, but by no means fast. If you have a loader joystick plugged into a remote, then you have a tandem center valve most likely, and you won't really get simultaneous function from that valve. If you operate the loader strictly off the remotes you should get some degree of simultaneous function from those valves if you set the flow control down somewhat. They are closed center valves... but I wouldn't expect too much if you're used to the performance of an industrial. We've got a larger pump on ours and squeeze a couple more gpm from it, but it's still not fast. It has plenty of power, but slow.

Rod