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1979 Verde Alfa Romeo Spider 2000
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Discussion Starter · #1 ·
Hello gentlemen,

I have a pinion seal leak as im having fluid drip back all over my diff and bottom sump plate. I want to remove the diff and axle tubes and grind/sand all the gunk and grime off them to get them looking close to brand new. I am looking to repaint the axle tubes as well. In order to restore that whole section, what parts exactly are required? Or better yet, what parts am I missing? I have attached screenshots of what I am purchasing, but will list them out as well:

-Diff Pinion nut
-Pinion/Diff case bearings,
-Pinion oil seal
-Diff sump gasket
-Rear wheel bearings
-Press on shrink rings
-Halfshaft oil seals
-Diff sump plug
-Diff fill plug
-2L (though I know the diffs take 1.5 pints) of Millers CRX 75W90 NT+

Will I need a new tab washer for the pinion nut? Also will I need to purchase 2 copper washers for the fill and drain plug? Anything else I am missing?

As for the pinion nut tool, I am either going to borrow it from a local Alfa shop or if anyone in the Orange County/LA area has one at hand that would be amazing so I don't have to purchase a new one as they are pretty pricey.

All help extremely appreciated. Thanks for any and all.

1685415

1685416
 

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The differential pinion seal on my '66 Duetto was leaking just a little. The seal and pinion nut tool were purchased from Classic Alfa. The tool came with a warning: do not use an impact wrench since it is machined out of mild steel as opposed to high strength tool steel. I was concerned having read several disastrous accounts by others, who were unable to get the pinion nut loose. Once the drive shaft was out of the way, I thought it would be good to try the tool with a breaker bar and if that failed, I'd use the impact wrench, sacrificing the CA tool if necessary. I may have sprayed the nut with PB Blaster the night before, I usually do on anything that may be stuck. When the tool was engaged in the pinion nut, I realized the nut was only finger tight. If you can find a factory tool for your pinion nut, you will probably be better off.

Mark
 

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Unless you are ready for major work involving specialized tools, leave your bearings alone. My suggestion is pull the drive flange, replace the seal, use a speedi sleeve if the flange has a groove worn on it, replace the bottom gasket and be done with it. Clean it in-situation with degreaser. You need the pinion seal, the bottom plate gasket, and the pinion nut removal tools. Just re-annual the copper washers and use em again. DO NOT drain the diff oil until you have the full plug loosened.
 

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I agree with Goats here. You may THINK you want to have nice shiny painted axle tubes, but I doubt if you REALLY want them that badly. That's a ton of work that frankly can be done with the axles in place. If you are not hearing excessive noise from the differential now, then I would leave it alone, frankly. Unless you're working on a concours car...
 
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it's almost a alfa romeo spider
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....humm..i lost the ' sheild ' between the nut and flange , years ago
 

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1979 Verde Alfa Romeo Spider 2000
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Discussion Starter · #6 ·
Got it, I trust your inputs and will avoid the axel tubes. So essentially keep the order with everything other than the bearings: pinion seal, sump gasket, drain/fill plugs with new copper washers and obviously new fluids... Do you recommend replacing the pinion nut while I'm at it?

If im not touching the axle tubes I won't be needing the halfshaft seals then, but what about the "press on shrink rings", do I need those as well? To be honest im not quite sure what those are/where they are located in that section...

I also realized I have a guy not too far from me who will power wash and detail the whole underbody for $80. Seems like a much better route than hours of labor just to remove, grind, and repaint the tubes. Definitely going the first route.
 

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I am not understanding why you need new drain and fill plugs?
The ones on my car are 30 years old and still perfectly good after dozens of services.

Just the copper seal ring should do just dandy.
 

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Got it, I trust your inputs and will avoid the axel tubes. So essentially keep the order with everything other than the bearings: pinion seal, sump gasket, drain/fill plugs with new copper washers and obviously new fluids... Do you recommend replacing the pinion nut while I'm at it?

If im not touching the axle tubes I won't be needing the halfshaft seals then, but what about the "press on shrink rings", do I need those as well? To be honest im not quite sure what those are/where they are located in that section...

I also realized I have a guy not too far from me who will power wash and detail the whole underbody for $80. Seems like a much better route than hours of labor just to remove, grind, and repaint the tubes. Definitely going the first route.
Question: Except for the oil leak at the pinion seal you describe, is there any other problem with the rear axle, such as excessive noise? If not, then I would only replace the seal and then refill the differential with new oil.
 

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pashad3:

Agree with what the others have said: these differentials last a long time, so if your's isn't exhibiting symptoms (except for the pinion leak) then don't mess with it.

If im not touching the axle tubes I won't be needing the halfshaft seals then, but what about the "press on shrink rings", do I need those as well?
The rings retain the outer axle bearings, so if you aren't replacing the bearings, you don't need the rings. The symptom of bad axle bearings is a rumbling sound.

I also realized I have a guy not too far from me who will power wash and detail the whole underbody for $80. Seems like a much better route than hours of labor just to remove, grind, and repaint the tubes.
Well, whatever you want to do. Cleaned & painted (or powder coated) axle tubes do look pretty sharp, though you yourself will probably be the only one to appreciate them.

I live in San Juan Capistrano and have a pinion nut socket. Open a conversation with me and we can discuss your borrowing it.
 
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Discussion Starter · #10 ·
I am not understanding why you need new drain and fill plugs?
The ones on my car are 30 years old and still perfectly good after dozens of services.

Just the copper seal ring should do just dandy.
Good to hear--just taking advice from on of the earlier diff seal discussions I saw. forget which user, but he recommended switching out the plugs as well as washers.
 

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Discussion Starter · #11 ·
pashad3:

Agree with what the others have said: these differentials last a long time, so if your's isn't exhibiting symptoms (except for the pinion leak) then don't mess with it.



The rings retain the outer axle bearings, so if you aren't replacing the bearings, you don't need the rings. The symptom of bad axle bearings is a rumbling sound.



Well, whatever you want to do. Cleaned & painted (or powder coated) axle tubes do look pretty sharp, though you yourself will probably be the only one to appreciate them.

I live in San Juan Capistrano and have a pinion nut socket. Open a conversation with me and we can discuss your borrowing it.
Hi Jay,

Seems like the moral of the story is just do the seal, gasket, new copper washers and refill gear oil. I won't try and fix something that doesn't need to be fixed as I have no symptoms of a failing diff/axle. It is just really ugly down there and as a bit of a perfectionist, I like looking at a clean bottom when getting under her.

I appreciate your kindness, offering to lend the tool out. That is huge, as the shop I go to (APC over in Orange) probably won't lend me theirs as they are always packed. I will send you a PM now. Thanks again.
 

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when you remove the flange, examine the sealing surface (where it rotates against the oil seal) for any wear. Any groove, if you can feel it with your fingernail, will leak even with a new seal. If it has a groove, buy a 'speedi-sleeve' and install it over the groove so that the seal has a new, ungrooved surface to run against,
 
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1. The differential sump plate gasket is basically cardboard, and will not seal unless coated with a gasket sealant.
2. You need more than just a new pinion seal and a smooth mating surface on the outer diameter of the flange to guarantee no gear oil leaks out of front end of the differential, and this is what many don't realize. You also need to apply sealant to the pinion/flange splines, else gear oil seeps forward along the splines, and out past the pinion nut.
3. Before loosening the pinion nut, mark it's clock position in relation to the pinion shaft, then carefully count the number of revolutions it takes to get the nut free. Record that number, and when reinstalling the nut, tighten it exactly the same number of turns. You don't want to re-torque it, just put it back the same number of revolutions.
 

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As a wise old country boy once told me, "Never kick a sleepin' dog." ;);)
 
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