VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Rear differential plug question

Hi, I have a newly acquired 1954 Bel Air and am still waiting on the manual. I am changing out my rear differential oil and I see a total of 4 plugs on the differential. The plate plug, which is 1/2 way to the top of the cover, Then I see 1 plug at the bottom of the front of the differential which I opened to drain the fluid. I also see 2 additional plugs on the top to the front of the axle on the differential.

1) Should I unscrew both of the plugs at the top and fill both with oil or is only one necessary? I am not sure if they are different chambers?
2) Do I fill the fluid to the very top or only to the plug hole that is 1/2 way up the plate.

Thanks!

To drain remove the two bottom bolts on the cover. Oil will drain out of the open bolt holes.
To fill remove the plug in the center of the cover and fill to the bottom of the opening.
It will take about 3 1/2 pints.
Use #90 or 85W-140---which is what I use.

Can you tell me what the other 3 plugs are for? There are 2 up top and one on the bottom. I removed the one on the bottom and all of the old oil drained out. Were they added aftermarket? Is this for some other fluid like driveshaft?

http://chevy.oldcarmanualproject.com/parts/1929_54/330a.htm

If you are talking about the three things that look like bolts with a nut DO NOT TURN! Those are jam bolts that hold parts inside in a certain position.

However since you have already removed the bottom one someone else will have to tell you if it can be just reinstalled.

http://chevy.oldcarmanualproject.com/shop/1949_53/04rear/4_02.HTM
See #7 . Is these what you are talking about?

Too late. I removed one on top and one on the bottom. The third on top I didn't touch. I guess now I have to figure out how to adjust them back.

#7 is the one I did not touch. I removed the one right across from #7 on the other side of the shaft (driver's side) and the one directly below it. What now? Thanks.

I would run them back in until just SNUG and lock in place with the jam nut. If this is wrong maybe someone else will chime in.

ok. I did not drive the car, it is still up on jacks. I will try that. Thanks. I guess when I drive the car I will find out??

Befor you drive the car retighten the ones you lossened. First back off the nuts a couple of turns and then tighten the screws firmly and then run down the locking nuts. You didn't arm anything as long as you did not drive the car.


Then wait for the shop manual.

OK. I tightened them down until they stopped. They are snug and firm but I did not come down on the wrench and over tighten them. Do you think that is sufficient?

You can not over tighten them as the tip of the bolt is pointed and wedges the pinion bearing in place.

Hi DSVW,

You only need to post once in the forums. Most of us scan all the forums.

Duplicate posts create confusion for everyone and waste time. I just responded to your similar post and now I see that you have received great advice in this section.

Sorry about that. I am new to the website and forums. Originally I wasn't sure what forum to post in....still trying to figure things out.

Welcome to the forum. One post is enough. I agree that the indexing can be confusing even for us regulars.

I am not always sure whether it post in the ”˜37 to ”˜41 section or one of the technical sections.