Ring Gear to Carrier???
Thread Starter
Racer
Joined: Mar 2005
Posts: 334
Likes: 5
Ring Gear to Carrier Series???
Hey guys, been over 40 years since I've rebuilt a differential, so forgive the old brain, lol
I'm using an old Zoom 3.90:1 ring gear and pinion. It's the old standard width.
Will this fit my 3 series that has a 3.55 on it now?
As I said, it's been a long while and now and days they have different with gears to make up for this issue.
Also, what gears fit 4 and 3 series? When I got the half series 3:90, I had a few carriers of both series in the shop. I just have 1 with the 3:55 now that's out of a car now
Thanks....
I'm using an old Zoom 3.90:1 ring gear and pinion. It's the old standard width.
Will this fit my 3 series that has a 3.55 on it now?
As I said, it's been a long while and now and days they have different with gears to make up for this issue.
Also, what gears fit 4 and 3 series? When I got the half series 3:90, I had a few carriers of both series in the shop. I just have 1 with the 3:55 now that's out of a car now
Thanks....
Last edited by tonyd21266; Mar 21, 2023 at 10:21 AM.
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,990
From: Connecticut, USA
Zoom wow that goes back about 45 years. I never used ZOOM gears so I can't say it they made them or reboxed others. 390 is an oddball gear. GM service parts offered them 50 years ago and Richmond made them. I have used USA made Richmond 390 years ago and they bolted on to a 3 series case. The 355 set you have is on a 3 series case. The 4 series case was thicker as the RG was thinner in 4 series as you probably know.
Thread Starter
Racer
Joined: Mar 2005
Posts: 334
Likes: 5
Kinda what I remembered. I have a 4:11:1 Zoom set in my 68. That's the last rear that I did. As I recall, it has no markings except the ratio, a code and number.
Well, I swapped a trans guy I use to race with 25 bucks and my old carrier for the 4 series that I used.
He turned me onto the half gear 390, because of that 4k plus grand on the highway issue, lol. It's not a highway setup obviously, but at least you can drive the car without taching the heck out of the engine for short highway drives at the old speed limit, lol.
Well, I swapped a trans guy I use to race with 25 bucks and my old carrier for the 4 series that I used.
He turned me onto the half gear 390, because of that 4k plus grand on the highway issue, lol. It's not a highway setup obviously, but at least you can drive the car without taching the heck out of the engine for short highway drives at the old speed limit, lol.
