There may be a doughnut under there...

The Magic Fiat · Post by **The Magic Fiat** » Fri Apr 20, 2007 10:13 am

...but there are no pieces of cake!!
The other day I took off for a short hop in the Fiat and was greeted to a "Blam! Blam!" sound coming from under the car someplace.

I thought about every piece of hardware that could come off and slam against the floorboards, and stopped to see which one was the offender.

I thought of the sway bar, or the tailpipe, or even the emergency brake cable or some of the other dangly things under there.

Nothing.

When I was headed home I got another "Blam!" and eased the little car back to the garage.

All the way home I tried to think of what could sling to my side of the car that I would feel under my feet.
Because of the rotation of the engine, the only thing I could think of was the flex disk, or doughnut as it's affectionately called.

Sure enough, I got up under there and felt around and an entire section was missing.

So off with the support brackets, off with the brake springs, and off with the bolts at either end of the driveshaft (interestingly when I took the shaft down at the differential end about 2 tablespoons of oil ran out. Anyone ever have that happen??)

I got the flex disk out and here it is in all its glory...

I think a little expansion foam in there and it will be good as new....

Yeah right.

Since I wrote this post a couple of days ago I decided to go ahead and put the other used flex disk I had on the car.
After completing the job I've discovered the toughest part of the whole operation was getting the slip joint back together while crawling around under the car.

I'm still going to get a new flex disk, it's too important to leave something like that to chance.

Neil

So Cal Mark · Post by **So Cal Mark** » Fri Apr 20, 2007 2:57 pm

that was a new flex disc that failed?

manoa matt · Post by **manoa matt** » Fri Apr 20, 2007 3:11 pm

Youre lucky it did not totaly fail you could have been hurt. Good idea to put a new flex disk on. Considering whats involved in replacing it you might want to just order a new one and put that on right away. No sense doing things twice, the used one could also fail. Also check the condition of the two universal joints(spider bearings) while you have the drive shaft out. If you see alot of orange dust around the small dust boots on the joints that could be a no greese condition that leads to the needle bearings failing. I replaced mine when I had the shaft out I think the bearings were around $11 a piece.

Also a good idea to check the condition of the pillow block(bearing support) and the bearing. The rubber diaphram of my pillow block was bad and caused the driveshaft to wobble, the bearing was still good because once the diaphram is broken the bearing no longer spins against itself. I used a needle greese fitting to inject grease under the dust cover.

Ther rear section of the driveshaft should be sealed at both ends. Did the oil come out of the differential at the driveshaft oil seal?

Matt

The Magic Fiat · Post by **The Magic Fiat** » Fri Apr 20, 2007 6:08 pm

Mark,
That was the original flex disk that failed.
I'm pretty sure it had never been replaced before, everything I took out had that "factory" look to it.

Now I have cleaned everything and repainted the brackets, so when the new disk arrives it will be a quick job to change it out.

The used one I put in looked really goood, I twisted it this way and that to make sure it wasn't showing signs of cracking.
That said, I don't trust it, so when the new one arrives I will snatch it out and put in the new one.

Matt,

All the u-joints looked and felt good, I didn't feel too bad about leaving them in place for the time being, however I'm going to replace them all at the end of the summer just for the sake of doing it.

I was a little concerned when I broke the connection at the differential and about 2 tablespoons of oil dribbled out, all I can suppose is that it worked past the seal.

It didn't show signs of being a continuous leak.

Neil

So Cal Mark · Post by **So Cal Mark** » Fri Apr 20, 2007 9:34 pm

I see that fairly often, diff oil leaks past the splines and threads of the pinion gear filling the yoke

The Magic Fiat · Post by **The Magic Fiat** » Sat Apr 21, 2007 11:07 pm

Mark,
Here's something that turned up while I was cleaning up the area where I was working that spooked me a little.

I felt sure that a little oil leaking forward of the differential would be normal, but when I looked at the floor I found this...

and it looks like a piece of some sort of o-ring.

I haven't detected any other leaks, but I wonder where this thing came from!!

Any thoughts??

Neil

So Cal Mark · Post by **So Cal Mark** » Sun Apr 22, 2007 1:23 am

maybe a PO tried to seal the flange to driveshaft with an o-ring?

mbouse · Post by **mbouse** » Sun Apr 22, 2007 10:15 pm

just a suggestion. Since you are down there, check the u-joints and center shaft support bearing. quite possibly, you could save yourself some future time by replacing these items while the donut is disconnected.