Topic: Rearend Fill Plug, Usage and Sealant Discussion

[Bossbill]

NOTE: The following first six posts were separated from another thread that was focused on when the fill plug location took place at San Jose

Have been looking and doing a survey about this subject I should find time to publish. The fill on the housing shows up for a long time well into the spring and possibly beyond.  Maybe there were two suppliers for the housings to the Sterling plant where the rearends were assembled.

On the other (Bills question) about the housing fill and washer we also should consider if the housing and fill were painted as a unit then when it was filled the plug was removed so there would be damage from the wrench would be seen. Also during the process the washer might change it orientation so that you might see it clocked differently exposing areas where there was no paint.

The reason this is confusing is that the housing could be painted with the rear  plug installed and fluid pumped into the 3rd member hole. That would account for a nicely painted rear bung and yellow around the  3rd member fill hole.
Just spit balling...

[J_Speegle]

The reason this is confusing is that the housing could be painted with the rear  plug installed and fluid pumped into the 3rd member hole. That would account for a nicely painted rear bung and yellow around the  3rd member fill hole.
Just spit balling...

As a worker would you use the smaller fill hole on the front at the third member that is at a some what tight location or the later plug at the rear clear of obstructions? Guess it depends when the rearend was filled. Rear end plant out of the car or at the car plant with the exhaust/muffler in place?

[ruppstang]

I think they were filled off the car. I have seen a number of them that the yellow seal paint on the fill plug ran sideways not downward indicating that it was filled pointing upward.

[J_Speegle]

I think they were filled off the car. I have seen a number of them that the yellow seal paint on the fill plug ran sideways not downward indicating that it was filled pointing upward.

Guess your referring to the plug in the third member.

Or at least positioned that way after the sealant and plug was inserted

Of course if filled by the rear the one in the third member may have been sealed and not used. Haven't compared the sealant run pattern on just those rearend with both of the fill plugs

Lots of possibilities - as Bill mentioned - "spit balling" just thinking of the possibilities

[Bossbill]

If the 8" was filled on the side of the 3rd member it may have been just a similar process to use on all.
Again, just guessing.

Here is my original 3rd member after I cleaned it up with the yellow puddling indicating the snout was pointing up.

Just another data point.

[ruppstang]

Here is the 68 HCS, it also shows a downward run.

[J_Speegle]

Here are some examples from unrestored cars. Appears that there is a large range (not really unexpected) of how much sealant a worker used or how neat they weren't.

Two 9" examples. Pictures are shown as they would look with the rearend installed in the car. Looks like the rearend was yoke up during the drying of the adhesive so if these were used to fill, on those 67s with both this fill and the rear housing fill, it was done with the rearend out of the car or filled through another opening

[J_Speegle]

If we're going to expand to 68 also here are two more groups of examples. Like the 67's I posted it appears that the reaends were positioned yoke up as the sealant dried and possibly applied . The first are 8" third members showing that both yellow and possibly blackish or at least dark sealant was used on that line. Yellow sealant example is really messy. Bottom is the same one that Marti posted above Noticed this after assembling and posting

8" examples





And some 9" examples from 68



Do have my fair share of 67 and 68 examples with no visible or just enough sealant used

[Bossbill]

I suspect the factory used a metered fill system so the amount of oil was preset.
Orientation wasn't a factor.

[J_Speegle]

I suspect the factory used a metered fill system so the amount of oil was preset.
Orientation wasn't a factor.

Agreed. I recall the style of dispenser attachments we used at the time with the dial on it so you could set the predetermined amount of liquids. Don't think I've ever seen a picture from the car plant where a worker is filling the rearend but there are ones where it appears they are filling the transmissions for example. Engines would have been run at the engine plants so those would have arrived filled.  Manual transmissions would be another question

[67gtasanjose]

Note: so far, are we focusing ONLY on the later fill location (fill plug in 3rd member)?

[Bossbill]

I don't think so.
This started in another thread when I asked if my rear plug was installed when the still empty housing was painted.
My car is in that changeover period when 9" rear ends had both the housing plug and removable third member plug.

It's thought that the 9" rear end was filled with the snout up and filled through the removable third member plug.
Later cars without the housing plug would also be filled snout up, imo.

Since 8" cars never had a rear plug(?) they might have the same yellow runs in the same direction.
It was my opinion that all rear ends in this time period could be filled the same way as a standard practice.

[67gtasanjose]

I don't think so.
This started in another thread when I asked if my rear plug was installed when the still empty housing was painted.
My car is in that changeover period when 9" rear ends had both the housing plug and removable third member plug.

It's thought that the 9" rear end was filled with the snout up and filled through the removable third member plug.
Later cars without the housing plug would also be filled snout up, imo.

Since 8" cars never had a rear plug(?) they might have the same yellow runs in the same direction.
It was my opinion that all rear ends in this time period could be filled the same way as a standard practice.

8" 3rds ALSO had early/late fill locations but a different topic (sorta).

[jwc66k]

Agreed. I recall the style of dispenser attachments we used at the time with the dial on it so you could set the predetermined amount of liquids.

To further add to the "confusion", in reading the "1966 Comet, Falcon, Fairlane and Mustang Shop Manual", section 4, page 21, there were three different lubricants (plus an additive for locking differentials) that each rear axle type required, each with a different amounts of lubricant, plus different weights, SAE 80 and SAE 90 for different climates (above or below 25C/75F). On that basis, there should have been multiple filler "hoses".
Jim

[J_Speegle]

Note: so far, are we focusing ONLY on the later fill location (fill plug in 3rd member)?

Yes since that is the one that used a visible sealant and in turn the pictures we have been focusing on

8" 3rds ALSO had early/late fill locations but a different topic (sorta).

We have a thread on the change over (San Jose focused on only at this time) for 9"  but we could with ease start a 8" focused on since the change may not line up with the 9" change.  So far the housing filler was used for a long time after the 3rd member change based on the data I've been able to collect