Chevy Nova Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
386 Posts
Discussion Starter #1
I recently purchased a used set of 308 gears, not asking enough questions got me wondering , the ring gear is is marked '68 and the pinion gear is marked S70, is this common ? or is this a mismatched gear set, that I got took on ? Iam guessing manufacturing dates of 1968 & 1970.
 

·
Registered
Joined
·
472 Posts
never install used gears...it will seize sooner than later
That's just not true.
Gear sets can be moved to another housing withoout problem, as long as the set-up is correct. It is best done where you can take a pattern check of the gear in the original housing, and the backlash, so that the set-up can be matched in the next housing.
I've set up more than a dozen used gear sets, most without even the original pattern or backlash help, and not had a failure. 12-bolt, 8.5" and 8.2" 10-bolt, 7.5" 10-bolt, 8.8" Ford, 9" Ford.

To the OP's question of whether the gear set in matched or not based of the numbers he posted, I don't know, I've never paid that close attention to numbers on factory ring and pinion sets.
 

·
Registered
Joined
·
235 Posts
That's just not true.
Gear sets can be moved to another housing withoout problem, as long as the set-up is correct. It is best done where you can take a pattern check of the gear in the original housing, and the backlash, so that the set-up can be matched in the next housing.
I've set up more than a dozen used gear sets, most without even the original pattern or backlash help, and not had a failure. 12-bolt, 8.5" and 8.2" 10-bolt, 7.5" 10-bolt, 8.8" Ford, 9" Ford.

To the OP's question of whether the gear set in matched or not based of the numbers he posted, I don't know, I've never paid that close attention to numbers on factory ring and pinion sets.
I had a set of used 5.38s put in my Chevelle he said it might last 1 run if I'm lucky ...maybe it's HP related but was really nervous about it exploding...drove it a few times and it scared me it was too fast (on the street)...so I parted it out
 

·
Registered
Joined
·
1,596 Posts
I’ve done a ton of gear swaps on cars. Used gears from one differential to another. If you set them back up to have the same pattern as they had before, you won’t have any issues. The only issue you may have is noise if the backlash is off or pinion depth isn’t the same causing a new pattern to be worn in.
 

·
Registered
Joined
·
218 Posts
Back in the 80s when I was heavy into bracket racing I came home from the track and next day found a puddle under the rear. a tooth from the ring gear had chipped and punched a hole in the cover. I was using a Zoom 4.88 and a buddy had the same set with a cracked pinion gear. My pinion was good, and though everyone said "you can't do that", I took his ring and my pinion and it lasted 2 years running low 11s every weekend. It was open exhaust but I never heard a sound out of it.
 

·
Super Moderator
Joined
·
3,833 Posts
I have had 4 differentials rebuilt in the past. I have used used headsets 3 of the 4 times. All of them worked great. Properly set up with a good used gear set, I've never had a problem. One of those differentials went for 90K miles, and is still good.
 
1 - 7 of 7 Posts
Top