8 3/4 axle questions.

[3C's & a D?]

I brought my car, 71 New Yorker 8 3/4, 2:76 sure grip to the shop for a complete rear brake job, and new seals and bearings. When they opened it up, they found the left side axle was rusted where it meets the inner oil seal. I brought them an axle I had from a 71 Polara 8 3/4, 2:76 sure grip, and it was at least one inch longer!? Went back to the garage pulled the left axle from my 71 Newport 8 3/4, 3:23 sure grip, we have a match! The New Yorker has the 489 case, Polara 741, But still, this has me perplexed, any thoughts? Thoughts on the rust welcome as well.

 

[3C's & a D?]

Hello!

 

[65sporty]

Is there a seal out by the axle flange between the flange and bearing?

 

[70bigblockdodge]

Glad my cars are not low mile originals

 

[Big_John]

At first I thought that someone must have switched a rear end in your Dodge, but I seemed to remember seeing something like before.

I looked in the 70/71 Parts manual and now I see there are two different axle shafts listed for the 70 and 71 C bodies.

The listing for the axle housing is a little confusing, but the way I read it, there are two. One is 57 3/4" wide and the other is 59 1/8" wide. The 59 1/8" version going into station wagons and all the Dodges. The 57 3/4" going into the rest of the C-bodies except the station wagons and Dodges.

So... there's an 1 3/8" difference in overall width.

Looks to me like the Dodges shared the rear with the station wagon and that would account for your axle difference.

 

[Big_John]

BTW, the "Drive Shaft" title on the top of the screen shot is correct. Chrysler called axle shafts "drive shafts" and drive shafts "propeller shafts".

 

[commando1]

Now if people wouldn't only stop writing, "axels"....

 

[3C's & a D?]

Is there a seal out by the axle flange between the flange and bearing?

Yes, you can just make out one of the bolt holes of the cover of the grease seal in the lower left corner. The oil seal that goes in the axle housing sits where the pitting is visible. It was rusty there and when they removed the rust the pitting remained.

BTW, the "Drive Shaft" title on the top of the screen shot is correct. Chrysler called axle shafts "drive shafts" and drive shafts "propeller shafts".

Thanks a lot for digging up that info Big_John, I wonder why that was and if the housing is longer as well or if the difference is made up in the center section, I will compare the two housings and add to this.

 

[65sporty]

Are those bearings packed in grease or do they get lubed by axle oil? With a inner and outer seal they wont get axle lube.

 

[Big_John]

Are those bearings packed in grease or do they get lubed by axle oil? With a inner and outer seal they wont get axle lube.

Grease packed.

 

[3C's & a D?]

Are those bearings packed in grease or do they get lubed by axle oil? With a inner and outer seal they wont get axle lube.

The bearings are packed with wheel bearing grease only, heavy weight axle oil for the diff. The two don't play well (oil will wash away the grease). that is the purpose of the inner oil seal and why the axle needed replacement, also axle oil on brake shoes is no good. The outer seal is more of a dust boot to keep brake dust from contaminating the wheel bearing grease.

 

[65sporty]

I have seen the same thing on the AMC 20 rear end in jeeps, I haven't had a 8 3/4 apart in so long I couldn't remember. The older dana 44 in jeeps are that way also and even have a grease zerk on the housing.