Grease Fitting behind Flex Disk

[bpossel]

Hi All,

While under the car yesterday doing the transmission service, I continued my search for my missing nipple....

With the help of this photo, I was able to determine why I cant find mine...  it's missing!  I reached into the cavity behind the transmission plate and felt around the shaft and found the hole...  no nipple (ok, this is starting to sound like an X rated story...)

Anyway, now I need to know what the nipple looks like and its size?  Is it a straight nipple, similar to the ones on the inner control arms, or is it a right angle nipple similar to the outer control arms?

Is there a part number for this nipple?

Any comments on the possible damage on the shaft since I have owned the car and driven it for ~10k miles with no grease in this fitting.  This may have been removed and left out when the previous owner had the transimssion rebuilt?

Thanks for your comments!
Bob

Download Attachment: flexdisk.jpg
21.77 KB

bpossel
Memphis, TN.
1971 280SL
1997 E320

[ja17]

Hello Bob,
This is a nice photo with labels. The assembly is exactly correct with washers and bolt in the correct place. You probably notice that the heads of the long and short bolts are different so you can easily identify the different lengths. Placement of the washers is critical and the tabs on the rubber flex disc must be correctly positioned or the flex disc will not last.

The three flanged aluminum centering bushing is sandwiched between the driveshaft and the flexdisc. The grease nipple is to keep it lubricated. It is not likely that it is damaged from not having a grease nipple. It is important the the thick rubber seal (not visible) is installed. Without it the grease from the centering bushing will work its way onto the rubber flex disc shortening the life of the rubber. Since this grease nipple is usually missed during regular lubrication service, this is not usually a problem.

However those who  make it a habit to lubricate this grease nipple should be certain not to over-grease this nipple since excess may end up on the flexdisc. The centering bushing does not require much lubrication.

Early cars used cotter pins and castellated nuts on the driveshaft. A real pain. The latter cars were equipped with nice "nyloc nuts" so you do not have to mess around with the cotter pins in cramped quarters. You should always be certain that the hardware is installed carefully. When these bolts accidentally come loose on their own they can do a lot of damage to the transmission and the driveshaft.

It looks like you ordered the  nice driveshaft flexdisc kit which is  costly but included all the new hardware, and the rubber seal along with the new rubber flex disc.

Bob, you should be able to order  a new grease fitting , or unscrew one off the old lower trunnion unit you replaced several weeks back.

Joe Alexander
Blacklick, Ohio

[George Des]

I should get my new flex disk kit this coming week, so I'll be spending some time on the "floor" next weekend. I really eny you guiys with lifts!    

George Des

[A Dalton]

The zerk fitting is a 45 degree fitting...part # 071412-006200
 Also...There should be a pressure relief/vent on the opposite side of the shaft from the fitting. This is so that the grease will not pressure past the seal when greasing and cause disc damage. When grease starts to come out that hole , you know the cavity is full and not under pressure ..  stop pumping  grease and wipe excess off.......It is also a good idea
to use slow , low pressure pumps on this fitting , just to be sure...