Removing Diff housing
Thread Starter
Racer
Joined: Mar 2002
Posts: 406
Likes: 1
From: Maroochydore QLD
Removing Diff housing
My repair manual suggests leaving the rear cover to the housing on the car and undoing the 8 bolts, losing the oil then removing the diff. This is most likely becasue you can not get to the two bolts that hold the cover to the support member, can anyone out there tell me if I can remove the diff as a complete unit without spilling a drop of oil?
If so, how?
Thanks, Dennis.
If so, how?
Thanks, Dennis.
Racer
Joined: Nov 2005
Posts: 409
Likes: 5
From: Orange County CA
I just finished removing and installing mine after rebuilding my entire rear suspension including the trailing arms.
I searched some of the posts here on the forum and some were suggesting cutting holes in the floor above the holes in the crossmember to gain access to the 4 bolts that bolt the Diff housing to the crossmember
.
I did not want to go that route and the crossmember would not budge after removing the 2 bolts.
I was able to get a deep well 5/8 socket with a long flex head ratchet in the holes on top of the crossmember and was able to get all 4 out without a problem. Getting the bolts started when reinstalling was the challenging part, but they went in alot easier after I chased the threads on the bolts and on the housing with tap and die.
One word of caution.. the Diff is very HEAVY. I was lucky that I had a transmission jack from a previous job. A floor jack may work, but I am not sure if there would be enough surface area.
I searched some of the posts here on the forum and some were suggesting cutting holes in the floor above the holes in the crossmember to gain access to the 4 bolts that bolt the Diff housing to the crossmember
. I did not want to go that route and the crossmember would not budge after removing the 2 bolts.
I was able to get a deep well 5/8 socket with a long flex head ratchet in the holes on top of the crossmember and was able to get all 4 out without a problem. Getting the bolts started when reinstalling was the challenging part, but they went in alot easier after I chased the threads on the bolts and on the housing with tap and die.
One word of caution.. the Diff is very HEAVY. I was lucky that I had a transmission jack from a previous job. A floor jack may work, but I am not sure if there would be enough surface area.
Racer
Joined: Sep 2008
Posts: 387
Likes: 2
I took mine down as a unit:
After loosening the crossmember bolts I squirted lots of WD-40 in there to loosen those "eyes" from frame. Only had to use crowbar gently to wedge the crossmember loose. At that point I had a floor jack under diff and longer bolts on the crossmember ends. Took the whole piece down and out single handedly.
After loosening the crossmember bolts I squirted lots of WD-40 in there to loosen those "eyes" from frame. Only had to use crowbar gently to wedge the crossmember loose. At that point I had a floor jack under diff and longer bolts on the crossmember ends. Took the whole piece down and out single handedly.
Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
got mine out as well. broke the 2 cross member bolts loose, and unscrewed them about 3/4 of the way. put a jack up against the bottom of the diff. also. my diff/xmember refused to let go after a serious beating and prying. i put a 3 prong jaw puller on the xmember, and centered it over the bolt that was still partially screwed in. within 5 mins the xmember popped loose and i had the diff out.
reinstalled it as a single unit. set it on the jack, jacked it up, put the bolts in, and tightened the bolts up. not a single bit of trouble.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I also remove as a unit 95% of the time using a floor jack. Its easy but its a little bit of a balancing challenge. If you have someone operate the jack and you keep both hands on the unit you should be fine.
In my case I keep my left hand on the unit and my right hand operates the jack.
In my case I keep my left hand on the unit and my right hand operates the jack.
Melting Slicks
Joined: Oct 2002
Posts: 2,315
Likes: 111
From: St Louis MO
Although the book recommended removing the diff by separating from the rear cover and leaving the cover and cross member in the car, the expected bath in stinky gear oil is not for me.Remove it as a unit - the hardest part is breaking the crossmember loose from the frame. Loosen each mounting bolt about 1/4 inch and then use two crowbars (on each side of the mount) to pry the crossmember away from the frame; repeat on other side.
To hold the diff so that it can be opened, place diff between two sawhorses staggered so that the beams can be placed about 9 inches apart - and then just set the diff between them held up by the side yokes. It will rotate nose down and cover up.
__________________
1978 Corvette
406 SBC AFR heads Lunati roller Quadrajet TH-350 3.08
11.59 sec / 118.9 mph 1/4 mile
Thread Starter
Racer
Joined: Mar 2002
Posts: 406
Likes: 1
From: Maroochydore QLD
Thanks for the replies and some excellent advice.
I will be working on mine from a pit in my garage floor so advice on weight of diff is noted, I now need to work out a way to lower it without it falling 4 feet to the floor of the pit and probably mashing my toes along with it.
Does anyone have any advice on painting (type of paint, color etc.) the housing after its cleaned up? I will media blast it at work so it will be like new cast when I am ready for paint.
Thanks, Dennis.
I will be working on mine from a pit in my garage floor so advice on weight of diff is noted, I now need to work out a way to lower it without it falling 4 feet to the floor of the pit and probably mashing my toes along with it.
Does anyone have any advice on painting (type of paint, color etc.) the housing after its cleaned up? I will media blast it at work so it will be like new cast when I am ready for paint.
Thanks, Dennis.
Racer
Joined: Nov 2005
Posts: 409
Likes: 5
From: Orange County CA
I used POR 15 factory gray cast manifold paint on mine...came out very clean looking it looks like fresh cast iron... I didnt media blast mine..I coated it with semi gloss black POR15 and top coated it with the gray manifold paint.
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Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
i can tell you spray paint primer and paint doesnt hold up well. i had my diff open and sandblasted the cover. used rust encapsulator on the back half. i primed and painted it about 2 years ago. when i took a look at it this summer, theres no rust on it, but theres yellow splotches appearing in the paint on the frost cover, i havnt taken a look at the back half. im assuming the yellow splotches i see is rust working its way through.
it did look nice when i finished it, just wish it held up a bit better.
it did look nice when i finished it, just wish it held up a bit better.
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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I have always been impressed on the cleanliness and the meticulous detail that everyone has put into restoring our Corvettes to better than new condition, but the reality is that if you are going to enjoy your Vette as a daily driver there is no was to keep it in 'As New' condition.
After doing a total ground up restoration in 2002 and having used the car as it was intended, to be a reliable daily driver, there is road dirt, dust and mud from the few times that I got caught in the rain. Enjoy your ride and use it as much as possible, clean off the dirt from the top and be proud to pop the hood at any local show. PG.
After doing a total ground up restoration in 2002 and having used the car as it was intended, to be a reliable daily driver, there is road dirt, dust and mud from the few times that I got caught in the rain. Enjoy your ride and use it as much as possible, clean off the dirt from the top and be proud to pop the hood at any local show. PG.
