75 Differential Inspection?
Thread Starter
Racer
Joined: Oct 2007
Posts: 420
Likes: 4
From: Ft Myers Fl
75 Differential Inspection?
I'm documenting the rebuild of my 75 in a separate thread (Small Garage Restoration) but I wanted to ask a question outside of that thread. I'll update it with the results.
Background: My car is a L48 w/ 98K, automatic. I do not know the history of the car and have never driven it. It was a wreck when I bought it. I'm doing a frame off restoration. After the car is done, I intend to use the car as a weekend/show driver but it will not be raced or abused.
The differential is out of the car and drained. I don't feel any slop and I don't hear any strange noise when I turn the input shaft. I checked the left and right end play and they are 0.056 and 0.042.
I'm not a fan of fixing something that "ain't broke" so here's my question: Should I open it up and inspect it? If I do, what am I looking for?
Background: My car is a L48 w/ 98K, automatic. I do not know the history of the car and have never driven it. It was a wreck when I bought it. I'm doing a frame off restoration. After the car is done, I intend to use the car as a weekend/show driver but it will not be raced or abused.
The differential is out of the car and drained. I don't feel any slop and I don't hear any strange noise when I turn the input shaft. I checked the left and right end play and they are 0.056 and 0.042.
I'm not a fan of fixing something that "ain't broke" so here's my question: Should I open it up and inspect it? If I do, what am I looking for?
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Thread Starter
Racer
Joined: Oct 2007
Posts: 420
Likes: 4
From: Ft Myers Fl
Seals are probably a good idea ... I'll be opening up the rear this weekend. I have to see if I have a pair of 90 degree snap ring pliers ... not something I use often.
We all know what's going to happen once I open up the rear ... PROJECT CREEP.
We all know what's going to happen once I open up the rear ... PROJECT CREEP.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Its just one of those things that if something goes wrong later you will wish you had done it because its a real pain to get to once its back together. So where do you draw the line? Down side is that it takes a few specialty tools to rebuild that most of us do not have in the tool box. 
Melting Slicks
Joined: May 2011
Posts: 2,753
Likes: 119
From: Springfield Missouri
when I had mine out, I took it to a speed shop that does corvette rear ends, had them open it up, replaced all bearings, clutch pack, both shafts, and look at the play on the ring & pinion gears, also all seals. Put new fluid and additive from GM back in. Now no worries until after I am gone! ( around $550.00 back then)
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Melting Slicks
Joined: Jul 2010
Posts: 2,503
Likes: 33
From: McGrady NC
St. Jude Donor '15-'16
I agree. It is one of those things that you ought to go ahead and do now instead of after getting everything back together and finding a drip later. Plus it is one of the less enjoyable tasks in rebuilding a Corvette. Bite the bullet and fix it right while you have the opportunity.
Thread Starter
Racer
Joined: Oct 2007
Posts: 420
Likes: 4
From: Ft Myers Fl
I ordered new seals from Bair and they'll be here on Saturday. I've already removed the front/pinion yoke and both side stub axels. Everything appears to be in decent shape and the ring gear bolts are all tight.
I've got some wear on the stub axels, about 0.025 worn and they measure 0.162 (left) and 0.160 (right). Everything is marked to put it back as it was originally installed, especially the pinion nut. By the way, my electric harbor freight impact wrench made easy work of getting this nut off ... I was concerned that it would be tough.
One set of instructions stated that I had to remove the large pin in the carrier before I could take off the c-clips on the axel stubs. Not the case. Both sides came out easily with the pin installed but it would have been tough without 90 degree snap ring pliers.
I've got some wear on the stub axels, about 0.025 worn and they measure 0.162 (left) and 0.160 (right). Everything is marked to put it back as it was originally installed, especially the pinion nut. By the way, my electric harbor freight impact wrench made easy work of getting this nut off ... I was concerned that it would be tough.
One set of instructions stated that I had to remove the large pin in the carrier before I could take off the c-clips on the axel stubs. Not the case. Both sides came out easily with the pin installed but it would have been tough without 90 degree snap ring pliers.
