Greasing the flex plate

[wwheeler]

When you grease the flex plate, what exactly are you lubricating? I lubed my chassis the other day and pumped 5 shots of grease in the flex plate fitting and didn't see any grease coming out near the area. Is any grease supposed to bleed off like the other joints in the chassis?

Thanks in advance for the expert advice.

[waqas]

Hello Wallace,
By "greasing the flex plate" do you mean greasing the grease nipple on the driveshaft, located closest to the flex plate?
If so, then this would be applying grease to the cavity behind the driveshaft centering spider. I have seen this cavity and I believe it will accommodate "5 shots", especially if the cavity was dry to begin with.

[jeffc280sl]

Attached are two diagrams of the area.  Parts 36 to 39 fit behind part 35.  This is the area that takes the grease.  The purpose is to lubricate these parts which fit on to the tail shaft of the transmission.

[ja17]

Hello Wallace,

Notice #50 in the diagram is the seal which keeps the grease from getting all over the flex disc.  This seal is often left off during repairs. Try not to overgrease this fitting.

[wwheeler]

Thanks for the replies!

I guess I have a good (# 50) seal because I could never find any grease coming out. I did however find some old grease that was slung on the body near the flex plate area. I can now understand where the grease goes. Thanks for the warning Joe. I will just give it a shot or two when I lube the chassis.

[Benz Dr.]

You really can't over grease the drive shaft flex disc. The cavity has a grease fitting inside that has the nipple facing inwards. When the cavity is full, pressure will open this grease fitting. Any extra grease will shoot out a hole on the other side of the shaft from the grease fitting you're filling. Fill until grease shoots out the other side and then it's full.
 
I've seen a lot of broken cross joints that got that way from lack of lubrication so you want to keep it well greased.  I've been told that these cross joints are NLA so you would have to find a used one. The only way you can tell if They're broken is to remove the flex disc although I imagine it would tend to shorten the flex disc life considerably.

[Naj ✝︎]

You really can't over grease the drive shaft flex disc. The cavity has a grease fitting inside that has the nipple facing inwards. When the cavity is full, pressure will open this grease fitting. Any extra grease will shoot out a hole on the other side of the shaft from the grease fitting you're filling. Fill until grease shoots out the other side and then it's full.

Overflow?

[waqas]

Overflow?

Yes-- also part #5 in Jeffc280sl's nifty diagram.

When I replaced my flex disc last year, I disassembled and cleaned all the parts of the centering spider. Before re-assembly, I hand-packed the cavity with high-temp bearing grease. Once I had everything together, it still took a few 'shots' of grease before the overflow showed up.

[Benz Dr.]

Naj,
that's the part. Your picture shows the internal grease fitting from the outside of the drive shaft. You need to fill until grease comes out of this fitting. It isn't done right until it does.

[wwheeler]

Thanks for the good info guys. I will look for that vent on the drive shaft!