4104 differential

[T Chellis]

I just returned from a short trip in my 1958 4104 with inline 671 4 speed and in the last 3 miles of the trip I could hear a noise that sounded like I had suddenly gotten noisy mud tires.  Everything seems normal but I did notice fresh oil leak around the hump of the differential.  I am not capable of lifting the back end and working on the differential. I hear this noise all the time when the bus in moving. I babied the rest of the way home. I did feel a bit of a jerk when the noise started at about 50 MPH.  It seemed like the bus started going a little faster.The bus seems to run normal all but the like mud tire sound. My gut feeling tells me something is wrong. What do you guys think?   Thanks.....T Chellis

[NJT 5573]

Maybe a tire is comming apart. Fill the gear with oil asap so you know where you are with that. If the leak is not real bad you can cover several miles between refills-just don't let it get mt.

[T Chellis]

Thanks,
I will check the level asap. and the tires.  ......T Chellis       

[Busted Knuckle]

T Chellis,
1st thing I'd do is drain the fluid from the rear end into a clean and large drain pan. Once drained look for chunks of gear, or large amounts of metal shavings ( the gear oil will have a metal flake look ) as you pour it out of the drain pan into a bucket or barrel for disposal. If you find either, then you need to get someone who can work on it to check it out. My guess from your description of how & what happened is a tooth has broken of the gear and when it did the loud/large pop was the piece being forced through the gears, then while rolling you are getting a roar from the rear end because of the missiing tooth! I've seen this happen quite a few times! And if there are no chunks or large amounts of metal shavings that come out, then your only out a small amount of your time and the cost of the gear oil to refill the rear end! And you'll have a piece of mind knowing that the rear end should be OK! FWIW BK 

[T Chellis]

Many thanks,
I think I am on the correct path. I checked with a co. that knows about this differentical and they said the exact same thing that you said. They also added that they hoped it wasnt the big gear.  They suggested that I drain it check for metal pcs and  refill. Then they said it would be a good Idea to replace the gasket that is leaking.
I really appreciate all of your expertise. It is very reassuring getting your opinions
Sincerely,  T. Chellis

[gus]

Same thing happened to my 4104 but it was the slip joint splines in the driveshaft and the U joints
were pretty loose also.

Check these things before you tear into the diff.

[T Chellis]

Good point about the drive shaft u-joints. I think we need to look at all that.
Thanks again. T. Chellis