12 bolt Refresh Questions - Chevelle Tech
Chevelle Tech General Tech Area
Please try and post in specific forums

 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 6 (permalink) Old Jun 10th, 08, 3:45 PM Thread Starter
Senior Tech Team
Fred
 
Join Date: Jun 2007
Location: Just a way North of Atlanta
Posts: 2,859
12 bolt Refresh Questions

Had a few questions. Looking for someone experienced to respond.

Stock posi 12 bolt in 1970 Chevelle unless welding the tubes to the pumpkin is not stock. 3:31 gears to the best of my knowledge and passed the eyeball test of axle turns, vs. driveshaft turns etc. to verify.

I don't think it's ever been rebuilt. When I pulled the brakes and axles to remove the backing plates, there was some dried up remnants of gear lube in there, brakes were shot, completely shot. Can't figure out why they put on new drums, but they were in nearly new condition.

The ring and pinion wear look great, the pinion seal did not seep even a drop after driving and then sitting for months, and there is not noticable play at the axles, pinion, or slop in the gears.

Doesn't seem to need much, so before throwing money into something that doesn't seem to need it so my plans are to replace the axle bearings and seals, and button back up. I'd like to install a nicer rear cover too. I like the Moser unit, but as I will basically be installing for looks alone, anyone have experience with the Summit version and/or the Moser?

But I am not sure of the axles. I would like to get an axle diameter measurement to compare to what's there now. If they have worn too much, I'd rather spend a few hundred to do that on top of bearings and seals so I don't begin dripping axle seals after a few hundred miles.

Any rear end specialists that can throw some feedback, specific or in general and provide the axle diameter? Any guidelines to fluid and additives?
Thanks in Advance!
Chicken Coupe is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old Jun 11th, 08, 9:16 AM
Senior Tech Team
Roger
 
Join Date: Feb 2002
Location: Houston, Tx. USA
Posts: 4,542
Re: 12 bolt Refresh Questions

Just look at the axles where the bearing rides on them and you will be able to tell if they are shot or not. If there is no groove where the bearings ride and it is not chewed up there either I'd say your good to go. Add the posi additive from GM first when you go to refill it and it should be fine. The tubes are not fully welded to the pumpkin from the factory so somebody has been it there ahead of you.
67shovel is offline  
post #3 of 6 (permalink) Old Jun 11th, 08, 9:27 AM
Senior Tech Team
 
Join Date: Jan 2004
Location: Ca
Posts: 1,192
Re: 12 bolt Refresh Questions

Also if there is a groove in the axle, you can buy axle saving bearings for it, the seal lip rides in a different spot. Used them on two cars.
442 Harv is offline  
post #4 of 6 (permalink) Old Jun 11th, 08, 10:29 AM Thread Starter
Senior Tech Team
Fred
 
Join Date: Jun 2007
Location: Just a way North of Atlanta
Posts: 2,859
Re: 12 bolt Refresh Questions

Hmmm. Bearing areas look odd. No signs of wear to speak of, but there are a few spots in the bearing area that appear to be lower than the machined area. Not chewed up, lower, like a bad casting.

I have to go do some real work but I'll try to post a photo as time permits.
Chicken Coupe is offline  
post #5 of 6 (permalink) Old Jun 12th, 08, 8:56 AM
Senior Tech Team
Roger
 
Join Date: Feb 2002
Location: Houston, Tx. USA
Posts: 4,542
Re: 12 bolt Refresh Questions

Sounds like a couple of new axles may be in order. I had similar damage on one of my axles so my welder machinist buddy offered to fix it. He welded it up and turned it back down on a lathe. Looked great but wore like butter. I had to replace the axle shortly after since we had screwed up the heat treat and the bearing wore a groove in it.
67shovel is offline  
post #6 of 6 (permalink) Old Jun 30th, 08, 4:50 PM Thread Starter
Senior Tech Team
Fred
 
Join Date: Jun 2007
Location: Just a way North of Atlanta
Posts: 2,859
Re: 12 bolt Refresh Questions

Needed axles. Bearings and seals had been replaced before but the axles were too worn down and the seals were leaking.

Did not whine when I drove it. Ring and pinion looked darn near new as did the 4 pinion gears, pinion shaft, and thrust washers. Someone had the carrier apart before, hopefully to put in new carrier bearings and clutch discs. There were no center section leaks when I got it (not even a drop) so I decided to leave well enough alone. Put on a new alum rear cover and filled it up.
Chicken Coupe is offline  
Sponsored Links
Advertisement
 
Reply
Gear in this thread - Powered by O'Reilly Auto Parts

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome