One Thing Leads To Another
Thread Starter
Racer
Joined: Feb 2011
Posts: 384
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From: Northern New Jersey
One Thing Leads To Another
Thought I would have a nice day under my vette installing a new rear spring. But as usual nothing is as easy as expected. One of the diferential ears had an weld repair attempt. I have removed the crossmember and diferential cover but have a few questions about assembly. I know to torque the bolt plate with a full load on the spring but I see specs from 35 to 75ft/lbs. I also need to know if I should use any sealant on the cover. I would appreciate your advise so this hopefully is a one time repair. Thanks,
Melting Slicks
Joined: Apr 2004
Posts: 2,008
Likes: 38
From: Space Coast Gator Territory
The four bolts in the crossmember down into the carrier is torqued 75-100 ft lbs
The carrier cover bolts are torqued 35-55 ft lbs (50)
The spring perch bolts are torqued 35-50 ft lbs (35)
If your cover ear is questionable, it is best to replace the cover now. A heavy duty cover can be had for a little over $100 new. Good used covers can be had for a lot less, but not always available.
There is a gasket that goes between the carrier and cover. I put a little silicon sealer on both sides before installing torquing the bolts.
The carrier cover bolts are torqued 35-55 ft lbs (50)
The spring perch bolts are torqued 35-50 ft lbs (35)
If your cover ear is questionable, it is best to replace the cover now. A heavy duty cover can be had for a little over $100 new. Good used covers can be had for a lot less, but not always available.
There is a gasket that goes between the carrier and cover. I put a little silicon sealer on both sides before installing torquing the bolts.
Last edited by Red 69; Dec 3, 2011 at 09:29 PM.
Thread Starter
Racer
Joined: Feb 2011
Posts: 384
Likes: 0
From: Northern New Jersey
Thanks for the info. Have already ordered a new cover. Some install a dry gasket but I like the idea of using silicon. You do mean on the entire gasket and not just a few dabs to hold it in place, right? Thanks again.
Melting Slicks
Joined: Apr 2004
Posts: 2,008
Likes: 38
From: Space Coast Gator Territory
Yes, a thin coat on both sides of the gasket is what I use. Use too much and the clamping pressure will just squeeze out excess and make a mess.
Another tip, watch out when you tighten the four spring perch bolts. There are blind holes and you don't want a bolt to bottom out and continue tightening. This can crack the carrier and you don't want to do that. If you are using the original spring and parts it shouldn't be a problem, just be aware of it. Best wishes on your repair!
Another tip, watch out when you tighten the four spring perch bolts. There are blind holes and you don't want a bolt to bottom out and continue tightening. This can crack the carrier and you don't want to do that. If you are using the original spring and parts it shouldn't be a problem, just be aware of it. Best wishes on your repair!
Last edited by Red 69; Dec 3, 2011 at 10:08 PM.
Thread Starter
Racer
Joined: Feb 2011
Posts: 384
Likes: 0
From: Northern New Jersey
The new spring is 1/4" in thicker. The original bolts are slightly under 3 1/4" so I will be using the 3 1/2" bolts. Corvette Central sells the 3 1/2" bolts as replacements for stock springs and 4" for after market springs. I think the 4" would bottom out even with the after market spring that I bought from them.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Warning! The 4 bolts from the Xmember to diff housing are 7/16" and there is NO WAY they survive at 100 ft/lbs of torque more like 55 ft/lbs same for Xmember to frame off the top of my head.
Another WARNING! It is quite common to crack the diff cover if the spring bolts are too long and bottom in.the casting. I would take some cartilage measurements and trail fit stuff before hitting it with an impact driver. Measure twice before installation would be my apprach, you can shorten bolts with a hacksaw or cutoff wheel (it is my opnion that the heat generated by the cutoff wheel can effect bolt hardness and I would hacksaw this critical bolt myself.)
Another WARNING! It is quite common to crack the diff cover if the spring bolts are too long and bottom in.the casting. I would take some cartilage measurements and trail fit stuff before hitting it with an impact driver. Measure twice before installation would be my apprach, you can shorten bolts with a hacksaw or cutoff wheel (it is my opnion that the heat generated by the cutoff wheel can effect bolt hardness and I would hacksaw this critical bolt myself.)
Thread Starter
Racer
Joined: Feb 2011
Posts: 384
Likes: 0
From: Northern New Jersey
I have measured and the 4" bolts they sell for the after market spring will bottom out in the cover. Don't know what application they are for but anyone replacing a rear spring, beware. Measure for correct bolt lenght.
Advanced
Joined: Nov 2011
Posts: 60
Likes: 0
I too swapped out a spring while changing the rear diff. You will swear that the hole pattern is off as one of he bolts will not align and start, loosen all of the bolts up a lot until they are all started, then draw them up tight.
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