New Pumpkin!

[00fxd]

Just about to go out and start pulling my diff out in preparation for installing the "new" one from "Fast Corvette" which will be here this aft! Can't wait!

 

[Ron Miller]

Whatcha gettin?

 

[00fxd]

I'm feelin a little guilty about not doing it myself. I've never done one before and I felt that I couldn't do too much better price wise so I bought a rebuilt from http://www.fastcorvette.com/default.htm . $925 and I'll get $225. back for the core. FREE SHIPPING! I feel real good about the place. I bought a spindle from them in the past. The diff comes comes with the good stubaxles, that's a $250. value alone. Crunching the numbers I don't feel I could do a whole bunch better. Considering todays fuel prices and I drive the car almost every day for 9 mths of the years I opted for 3.36 ratio from 3.08.Hope I made the right choice there, I would like to have tried 3.55 or 3.73.

 

[Ron Miller]

I think you made the right choice in gear ratios, at least for a daily driver. I've got a 3.08 and a 3.36, I find the 3.08 nice for tripping, but need something steeper for local around town driving. The 3.36 is a great compromise, plenty peppy for most driving, but still decent gas mileage. Anything steeper gets more engine revs/mile and gas mileage suffers. My $0.02 worth, enjoy!

rlm

 

[IH2LOSE]

I HOPE YOU MADE THE RIGHT CHOICE ALSO

This from a person going from a 4:11 to a set of 3:36'S.

I think we made a good choice

 

[00fxd]

Sounds great guys. I'm workin on 'er as we speak. Just stoppin' for supper.....

 

[IH2LOSE]

Becarefull I know I followed the service manual to the T the first time I had the rear apart.There was some thing real critical about how the rear spring was torqued up to the rear case cover to avoid cracking the rear case cover.

At the time I was doing it 2 fellow forum members had posted pictures of cracked case covers to re-emfasize the importance of doing it correct.

I am sorry I forgot what the procedure was but it was outlined in the service manual.

I think it had to do with setting the car on its tires for the final torque to make the spring flatten out.

Also if you can I have a 4 post lift I was going to attempt to do mine on, and need to know

When the spring is disconected how far down below ground level do they go.Meaning if were doing this on a garage floor how high up do you have to raise the car off the ground to allow the spring to be fully relaxed to remove it.the last time I did mine it was on a 2 post lift and the rear end just hung in the air know with the 4 post I have to raise the car high enough off the lift to allow the spring to be realised.

 

[JohnZ]

Becarefull I know I followed the service manual to the T the first time I had the rear apart.There was some thing real critical about how the rear spring was torqued up to the rear case cover to avoid cracking the rear case cover.

At the time I was doing it 2 fellow forum members had posted pictures of cracked case covers to re-emfasize the importance of doing it correct.

I am sorry I forgot what the procedure was but it was outlined in the service manual.

What it boils down to is this - when you install the spring to the cover, just snug up the four spring plate bolts; don't torque those four bolts down until everything else is installed and the full weight of the car is on the spring, so it's almost flat. If you torque them fully with the spring unloaded and arched, you stand an excellent chance of snapping off the bolt ears on the cover.

 

[00fxd]

Thank men, I am aware of the caution of torquing the bolts with weight on. I'm not sure of the spring bolt torque tho.......
I asked this question on the the other board but since I seem to have a thread going here too I'll ask it here as well. Should I use anti sieze on the crossmember 'sombrarro's' to aid in dissassembly next time or will that damage the rubber?

 

[JohnZ]

The final torque on the spring retaining plate bolts is 55-75 ft-lbs. Anti-seize won't hurt the rubber at all, neither will silicone spray (just don't use any kind of oil or penetrant on the rubber).

 

[IH2LOSE]

The final torque on the spring retaining plate bolts is 55-75 ft-lbs. Anti-seize won't hurt the rubber at all, neither will silicone spray (just don't use any kind of oil or penetrant on the rubber).

Isnt that a large range? when I see a range like that,am I supposed to split it and set to 65? I know when I am using a torque range, and torque past the low side I am always sweating that last click to get up to the high side.

 

[00fxd]

. Anti-seize won't hurt the rubber at all,
[/QUOTE]

I anti seize not an oil base product?

 

[JohnZ]

To some extent, yes - the one I use is a thick paste of primarily ceramic particles in a synthetic oil base; each one is different. Only a small ring of rubber is exposed at the top of the bushings; the main contact between the bushing centers in the crossmember and the sombrero "hats" on the frame is steel-to-steel, and that's where the anti-seize needs to go - that's where they rust together, which makes them so hard to remove.

 

[66427-450]

I HOPE YOU MADE THE RIGHT CHOICE ALSO

This from a person going from a 4:11 to a set of 3:36'S.

I think we made a good choice

lol, well, for a cruiser, i agree, a 3.36 is a good gear (especially with a M20, with the low first gear, but with a 2.20 1st it's a little weak off the line/at low speeds ).......

it really depends how you plan on using the car & what RPM range your engine us setup for..... mine is going together with 4.11's and a 2.56 1st (like 4.80's with a M21, in 1st)

 

[66427-450]

The final torque on the spring retaining plate bolts is 55-75 ft-lbs. Anti-seize won't hurt the rubber at all, neither will silicone spray (just don't use any kind of oil or penetrant on the rubber).

i use a very thick dow-corning silicone grease to coat the inside of the x-member rubber mounts, and i've never had a problem removing the x-member. i also use the same grease on the sway bar bushings, etc. ......great stuff in my book. it's called "Dow-Corning 11 Compound"

 

[00fxd]

I re asembled with a very thin coat of moble1 chassis grease. I'm guessing with me being the way I am it will not be as long this time till she comes apart again.
Got stuck tonite, the new housing has the 9/16 spring mount bolts, my old cover had th 7/16 bolts. I'll get some bolts tomorrow, stick the spring in and away I'll be! What years had the 9/16 spring mount bolts? I'm under the immpression that my old housing is out of a '74.

 

[66427-450]

Got stuck tonite, the new housing has the 9/16 spring mount bolts, my old cover had th 7/16 bolts. I'll get some bolts tomorrow, stick the spring in and away I'll be! What years had the 9/16 spring mount bolts? I'm under the immpression that my old housing is out of a '74.

63-77 = 9/16, 78/9 = 7/16

you need 9/16 x 12 x 3 31/64 (assuming stock spring).... but not just a std hardware store bolt, i'd order a set of spring bolts from one of the vette parts suppliers

PS: remember, the spring widths are also different.........

63-77 = 2.25
78/9 = 2.50

you may need more than bolts :eyerole

 

[00fxd]

Thanks 427, I had a '74 sb/auto in years past and I remember it had 9/16 spring bolts for whatever reason. When I changed the spring [it broke] I had to buy a bottoming tap for one of the holes and I still have that tap.
When I noticed the difference the first thing I checked is for the spring width. It looks like it will work. I did have to slot the mounting bolt holes on the lower plate because the holes are closer together on the housing - old housing = 3 3/32 apart, new housing = almost exactly 3" apart. With some shorter 9/16 bolts I have in the holes that gives me 2.25" wide which works for my 2.25" spring.
I'll keep ya posted.

 

[00fxd]

It's all together and I've done the test drive. Everyhing is hunky dory and I'm happy again. Guess I'll burn some gas after a late lunch and see how I like the gear set in this car.

 

[00fxd]

Everything is done and I like the gear set. Nice and quiet and very smooth. Goin' for a little hiway drive tonite with the top down. Can't wait. That new 400 likes to run!