Rumbling sound...rear?

[Fiat88]

Just got the car out winter storage...yes a very late start but was busy with classes and had some other stuff going on in my life which got me down for a while.

So to the problem:
I had the noise last year as well and maybe asked about the cause but forgot. The sound comes after going about 15-20 mph until I think the trans shifts. Last week, had my mechanic put a new rear differential seal in because I had a leak for a while. The gear oil was being thrown onto the exhaust,stinking the car up. While doing that they said the driveshaft had a large amount of play. The differential shaft bearing was shot he said. He said he put a new one in. So I noticed the car still has the rumble noise. What else can this be? They didn't mention anything else?

Could a worn automatic transmission mount be the cause? Any ideas on what to check? Thx.

[azruss]

look at the driveshaft bearing and pillow block, he didnt solve the issue. Also a lot of play would indicated worn U-joints.

[Fiat88]

look at the driveshaft bearing and pillow block, he didnt solve the issue. Also a lot of play would indicated worn U-joints.

He said the play was in the shaft coming out of the differential caused by a bad bearing.

[fiat218]

The yoke?

[narfire]

Excessive play in the diff/ drive shaft on my car was from the pin holding the pinion gears was moving about more than they should.
I had another diff/axle, put that in and all is good now.
When I moved the drive shaft, I felt I had a lot of play (lash?) before the gears contacted and I felt resistance. There should be some, I was told perhaps 3/16-1/4 inch or less movement in the driveshaft before resistance. I'm far from an expert and don't really know the name of the parts but that pin was pressed in and with time had elongated the hole a tad giving the extra lash and then the gears were not contacting correctly creating a noise that I could hear...

Your mechanic would/should have checked the u-joints if he replaced a shaft bearing. Did he show you the old bearing, was it rusted with collapsed shells, missing bearings ect? The u-joints might give you a bit of a "clunk" at start up then perhaps a high pitched whine as you start going faster. Check for play there regardless.
Chris

[Fiat88]

Excessive play in the diff/ drive shaft on my car was from the pin holding the pinion gears was moving about more than they should.
I had another diff/axle, put that in and all is good now.
When I moved the drive shaft, I felt I had a lot of play (lash?) before the gears contacted and I felt resistance. There should be some, I was told perhaps 3/16-1/4 inch or less movement in the driveshaft before resistance. I'm far from an expert and don't really know the name of the parts but that pin was pressed in and with time had elongated the hole a tad giving the extra lash and then the gears were not contacting correctly creating a noise that I could hear...

Your mechanic would/should have checked the u-joints if he replaced a shaft bearing. Did he show you the old bearing, was it rusted with collapsed shells, missing bearings ect? The u-joints might give you a bit of a "clunk" at start up then perhaps a high pitched whine as you start going faster. Check for play there regardless.
Chris

Nope he didn't show me. First before he removed the seal he said that he noticed the play and said some kind of spacer could help. Then he called 1-2 hours later saying that when his worker was replacing the seal the bearing was bad and needed to be replaced. At this point I'm kind of fed up the guys service. We've been going to him for years but I really don't trust him. He always quotes one price and then almost everytime he jacks up the price another $80 to $100 more. Never gives a receipt listing what parts he replaced. I find that kind of weird. I really only brought the car in to fix the leak for the automatic trans pan in which I've tried myself but kept having a small leak. He worked on it but I'm still having a small leak. So it cost $275 to "fix" the leak from the pan which is now still leaking, change the differential bearing and seal. At first he wanted $350 but my pop got him down. What you guys think about that price?

[So Cal Mark]

sounds like the trans leak is something different from the pan. In Calif, it's illegal to charge more than the agreed-upon price and a itemized repair order is also required

[toplessexpat]

Absolutely no help with your problem but...

We've been going to him for years but I really don't trust him.

...that seems to be the root of your problem

A

[Fiat88]

Good news... I checked the level in the differential and it needed some more fluid. I don't think they topped it off after replacing the seal even though the fill plug seemed much tighter than last week when I added gear oil.Took the car for a 20 minute drive around town and on the highway. Had more power and didn't do the rumbling noise.

As far as the trans leak is concerned, I think Mark is right. Looks like its leaking a little from the Automatic trans lever? passenger side of the pan. Is there an o-ring in there?

[fiat218]

Hmm more power adding fluid, good job

Hey I'm glad it don't rumble, you don't need more trouble, great work

[Fiat88]

Hmm more power adding fluid, good job

Hey I'm glad it don't rumble, you don't need more trouble, great work

Maybe it had to do with the techron gas cleaner I put in. Car was sitting almost have a year so may have been dirty.