How to remove and install your Ford 8 & 9 inch differential assembly

[@AlfsMustangGarage]

We are here to keep your classic Mustang on the road and out of your garage. Subscribe to the channel and click on the notification bell. kzbin.info/door/Zi2JnDfxDHwqJoxJzFnIlA

[@coleadcock7555]

I appreciate the simple “do it yourself” video. My 65’ Econoline has a 9” and I was worried I couldn’t handle replacing the seals. Now I’m confident.

[@AlfsMustangGarage]

Awesome thanks! Ya sometimes all we need is a good visual. Good luck and you got this!

[@arturoaguilar3364]

Nice job explaining things. I can't wait to get my hand on some money to upgrade my little brothers 67. I found out i can check for the code of the transmission on my car right on the code plate in the door side. 😊

[@AlfsMustangGarage]

Thank you! Yup it's cool to decode those data plates to see what the car had originally.

[@franciscos7069]

Thank you I have a match 1 that my dad gave me and now I can fix it :)

[@AlfsMustangGarage]

Oh wow that's awesome!

[@dougtotten1767]

May be a helpful tip. instead of renting an axel Puller, turn the hub around backwards, install a couple Lugnuts and use the hub to pull on the axle. Hope this helps!

[@AlfsMustangGarage]

I actually do that all the time. I just like to show the proper tools when demonstrating. Maybe next time I'm pulling axles, I'll show that technique. Thank you 👍

[@andrewdavis6917]

Good presentation of the things a guy needs to know.. thank heaven there was no stupid music..

[@arcorob]

THANK YOU SO MUCH...My last 3rd member I had a trans place do I plan on doing it myself on the next and you are a great help...I have to go watch your other videos to see how to change the seal also

[@AlfsMustangGarage]

Awesome, thanks Robert! And thanks for subscribing I really appreciate it.

[@themusicianandthestuntman6417]

You can also use a tow chain and snap it instead of the slide hammer. Thank you for the video!

[@AlfsMustangGarage]

You're welcome! Oh ya, that works too 👍

[@eclipsetravel4926]

Great job with the videos. This helps a lot.

[@AlfsMustangGarage]

Thank you very much

[@martysomoco]

Thank you for the excellent, inclusive, instructive video.

[@AlfsMustangGarage]

Thank you!

[@christianflores3945]

these videos are so awesome. They really are helpful. Thanks for the content!

[@AlfsMustangGarage]

You're very welcome!

[@shawnlaynejohnson]

Another Thankyou..! Finished the rear axel today also.

[@AlfsMustangGarage]

Awesome! Very good to hear.

[@eddievantailn2882]

Very helpful, my goal is to clean out the differential housing and replace the gasket as you demonstrated. So my question is what do you use to clean the third member? also, do you clean out the inner axel? Thanks again.

[@AlfsMustangGarage]

So if you have just a standard open style differential, I'll just use a can of brake cleaner or even some dawn dish soap and warm water. Same applies for the housing. I especially like brake cleaner in the housing because it evaporates pretty quickly. I only use microfiber or lint free towels in there as well because the classic red towels just leave red lint everywhere. Now if you have a limited slip differential or posi-trac and you intend to just throw it back in, I usually don't attempt to clean them at all. I don't like getting any chemicals on the clutch packs or anything like that. So if your soul purpose of removing is to change the fluid and gasket, well you've got 98% of the fluid out of there and the new fluid will help clean out the gears once she starts moving though. I hope that helps.

[@JasonRust-nc9wy]

as always, great video

[@AlfsMustangGarage]

Thank you!

[@annmaxwell495]

Do the axels truly need to be completely pulled out all the way to remove the 3rd member? Can you just pull the axels out 12" or so?

[@AlfsMustangGarage]

They don't NEED to be completely removed. However, I don't like them resting on the seals for the entire time of the third member repair, causing damage to the seals. I hope that makes sense.

[@corbinjohnson2523]

Are the copper crush washers needed when installing the housing?

[@fatmattsadventures2796]

Very informative, thanks. Ballpark on what you charge to do this service for a customer(trying to gauge the cost before I contact any local shops)? My 8” is leaking at the gasket but I don’t have the space to do the work myself

[@AlfsMustangGarage]

I would ballpark this in the $500 range as long as there are no surprises. Problem with old cars is there are always surprises. If your diff gasket is leaking, your pinion seal and axle seals might also be leaking. Plus shop prices have been going up like crazy around here but anyway, I would expect at least $500.

[@kookookala6251]

THANKS FOR THE START TO FINISH! most these guys are lazy and only show when the housing is already out. Thumbs down to lazy people....

[@AlfsMustangGarage]

Ha ha! You're very welcome!

[@CruisinComPTon]

That looks like the differential on my 68. So to change the gasket i have to pull out the axles?

[@AlfsMustangGarage]

That is correct

[@arcorob]

Hey, on the 8" FORD rear , where do you fill it from? I know there is no drain plug but have to assume there is a FILL plug, yes?

[@AlfsMustangGarage]

The fill/check plug is located on the driver side of the third member. They are usually just a 3/8" ratchet to remove them.

[@AlfsMustangGarage]

Here is a link to a good picture of one images.app.goo.gl/wvybsiwPpKsZ6TpS6

[@richardnott9587]

How do you service the fluid? Didn't see a drain plug but saw the fill plug.

[@AlfsMustangGarage]

Well the best way would be to remove the third member and then you can clean all the old fluid out. Another way that isn't as effective would be to insert a suction tube in through the fill hole and suck it out. Probably won't get all of it out that way though.

[@grivolas2144]

If you have factory disk in the back you will need to pull calipers and disks. Don't mix up the disk they are left and right, at least on my little 77 lincoln.

[@grivolas2144]

My shop manual list the 9" third member at 75lbs so be ready.

[@markhooper6674]

Ok.. Thank u for the response on your other video.. so I break it down clean it with some kind of (what do u recommend) cleaner.. then new gasket, axle seals and that's pretty much it right ? Also I was curious if u were to buy a new 3rd member and it comes complete.. u just bolt it in ? U don't have to mess pinion or reloading stuff like that.. I was thinking a new 3rd member with posi gears ???? What do u think ???

[@AlfsMustangGarage]

That's why people love these ford 8 and 9 inch diffs. You could buy or build a completely different third member and just swap em out. I usually just glove up, scoop out all the oil then use brake cleaner and microfiber towels to clean. Then new gasket with a thin coat of permatex ultra black silicon and then install the third member. If you're looking to replace one for posi, check out Quick Performance. They can build whatever you want for very reasonable price.

[@markhooper6674]

@@AlfsMustangGarage Awesome thank u ! So if I keep the current 3rd member just spray it all down with brake cleaner.. and thank u for the quick performance recommendation.. I have a question.. I have the C-4 so what gears would b good for performance but also not so low that highway driving will b sacrificed??? Currently she has 3.00 .. and don't forget GO PACK GO!! 😁

[@nathanmurdock3213]

Great Videos ! do you have a recommendation to remove and replace bearings on the axles?

[@AlfsMustangGarage]

I'm afraid I don't have any tricks but those bearings have to be cut off and new ones pressed on.

[@mando82jr]

What type of transmission did the car have? I'm swapping my C4 for an AOD, so trying to decide between 3.55 or 3.80. Mainly for street driving. High revs on highway was reason why I upgraded to AOD. Thoughts?

[@AlfsMustangGarage]

This car had a C4 in it. What gears do you currently have in the rear? If you want to lower your highway rpm, you'll want to know your overall ratio with trans and rear end.

[@mando82jr]

@@AlfsMustangGarage The rear end is 8" with stock 2.79.

[@AlfsMustangGarage]

If you wanted to lower your rpm at higher speeds, perhaps keep the rear end the same? The action of adding overdrive could potentially be eliminated by changing the rear ratio from 2.79 to 3.55 you'll want to calculate your overall ratio with your current setup and potential setups to achieve an optimal overall ratio if that makes sense lol

[@mando82jr]

@@AlfsMustangGarage yes. u got a good point. I was using an rpm gear calculator and the 3.80 would be revving very similar on the highway as the C4. Which would negate the whole reason why I went with the AOD in the first place. I might just wait on the rear gears and see how the AOD feels with stock 2.79.

[@AlfsMustangGarage]

I think that would be a great idea! You could always swap the rear anytime if you're not happy with it 👍

[@shawnlaynejohnson]

So what is the difference in The Right Stuff and Ultra Black?

[@AlfsMustangGarage]

Lol probably not much difference. Both are made by permatex.

[@AngieBland-o9i]

What kind of cleaner do you use to clean the 3rd member

[@AlfsMustangGarage]

Brake cleaner / soap and water

[@AngieBland-o9i]

@@AlfsMustangGarage Thanks. Brake cleaner on the gears won't ruin the seals or gears?

[@AlfsMustangGarage]

Probably don't use it on a limited slip diff

[@ziakhan3070]

Very helpfull!

[@AlfsMustangGarage]

Glad it was helpful!

[@shawnlaynejohnson]

What oil do you use to fill it with?

[@AlfsMustangGarage]

I will use valvoline or Lucas oil 80w90. I can't remember if you said that was a Trac lock differential so if it is, you need to add a friction modifier first.

[@BillGamble-y7b]

Why do u have to pull the axles all the way out? My space is limited. Only need to disengsge the splines...yes?

[@AlfsMustangGarage]

You don't have to pull them all the way out. However, I also don't like them resting on the axle seals.

[@BillGamble-y7b]

@@AlfsMustangGarage How far do the axles need to be removed to allow removal of the third member? ok to push them back in while the third member is being repaired?

[@AlfsMustangGarage]

They don't need to pull out far. You can put them back in after removing the third member.

[@richardnott9587]

Thank you for muting the air ratchet.

[@jbwood6116]

thanks

[@AlfsMustangGarage]

You're welcome!