Differential ratio
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
Differential ratio
Hello. I posted a thread on this earlier and had trouble, sorry.
In the process of finding a Dana 36 with 307 ratio for sale I found many for sale that did not list the ratio and upon asking them they had no idea. When selling a diffferential knowing the ratio is important to the sale. I compiled what I know and learned about figuring out different ways on a c4 Corvette.
1. The C4 rear axle ratio RPO numbers like this:
RPO Rear End Gear Ration
GM1 2.59
GU2 2.73
GW4 3.31
G44 307
2. Read ring gear
If you can look at the large ring gear there you will see 2 numbers.
Example: 43-14 , you divide the smaller number into the larger number and you get 307 ration and so on.
3. Etching from factory on carrier
On most C4 carrier's I find there will be etching on the bottom showing date and ratio.
you will have to clean and scrub usually to read it.
4. Using the rotating method.
Not so accurate but close enough is this method. Mark your drive shaft or drive shaft yoke with tape or a marker, then mark your tire/brake/rotor/half shaft yoke depending on installed or not. Rotate the above 1 revolution 360* while counting how many times your drive shaft yoke turns. for example if your drive yoke turns a tiny bit over 3 turns you have 307 ratio.
In the process of finding a Dana 36 with 307 ratio for sale I found many for sale that did not list the ratio and upon asking them they had no idea. When selling a diffferential knowing the ratio is important to the sale. I compiled what I know and learned about figuring out different ways on a c4 Corvette.
1. The C4 rear axle ratio RPO numbers like this:
RPO Rear End Gear Ration
GM1 2.59
GU2 2.73
GW4 3.31
G44 307
2. Read ring gear
If you can look at the large ring gear there you will see 2 numbers.
Example: 43-14 , you divide the smaller number into the larger number and you get 307 ration and so on.
3. Etching from factory on carrier
On most C4 carrier's I find there will be etching on the bottom showing date and ratio.
you will have to clean and scrub usually to read it.
4. Using the rotating method.
Not so accurate but close enough is this method. Mark your drive shaft or drive shaft yoke with tape or a marker, then mark your tire/brake/rotor/half shaft yoke depending on installed or not. Rotate the above 1 revolution 360* while counting how many times your drive shaft yoke turns. for example if your drive yoke turns a tiny bit over 3 turns you have 307 ratio.
Last edited by dentalfloss; Oct 17, 2023 at 08:22 PM.
Team Owner
Joined: Sep 2003
Posts: 25,344
Likes: 2,727
Why didn't you just 'clean-up' your other post/thread?
https://www.corvetteforum.com/forums...xle-ratio.html
This is quite a mess! I didn't even check this .pdf!
https://www.corvetteforum.com/forums...xle-ratio.html
This is quite a mess! I didn't even check this .pdf!
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
Why didn't you just 'clean-up' your other post/thread?
https://www.corvetteforum.com/forums...xle-ratio.html
This is quite a mess! I didn't even check this .pdf!
https://www.corvetteforum.com/forums...xle-ratio.html
This is quite a mess! I didn't even check this .pdf!
Don't have a heart attack on me please.
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
Why didn't you just 'clean-up' your other post/thread?
https://www.corvetteforum.com/forums...xle-ratio.html
This is quite a mess! I didn't even check this .pdf!
https://www.corvetteforum.com/forums...xle-ratio.html
This is quite a mess! I didn't even check this .pdf!
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
Team Owner
Joined: Sep 2003
Posts: 25,344
Likes: 2,727
Now you've mentioned 'fixing' and you actually haven't GH -zero- is 3.54 NOT GH -oh- !
If I was bothered I'd just post corrections but I'll 'delete' my posts and let you have at it maybe!
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Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
some more stuff
Hello. I posted a thread on this earlier and had trouble, sorry.
In the process of finding a Dana 36 with 307 ratio for sale I found many for sale that did not list the ratio and upon asking them they had no idea. When selling a diffferential knowing the ratio is important to the sale. I compiled what I know and learned about figuring out different ways on a c4 Corvette.
1. The C4 rear axle ratio RPO numbers like this:
RPO Rear End Gear Ration
GM1 2.59
GU2 2.73
GW4 3.31
G44 307
2. Read ring gear
If you can look at the large ring gear there you will see 2 numbers.
Example: 43-14 , you divide the smaller number into the larger number and you get 307 ration and so on.
3. Etching from factory on carrier
On most C4 carrier's I find there will be etching on the bottom showing date and ratio.
you will have to clean and scrub usually to read it.
4. Using the rotating method.
Not so accurate but close enough is this method. Mark your drive shaft or drive shaft yoke with tape or a marker, then mark your tire/brake/rotor/half shaft yoke depending on installed or not. Rotate the above 1 revolution 360* while counting how many times your drive shaft yoke turns. for example if your drive yoke turns a tiny bit over 3 turns you have 307 ratio.
In the process of finding a Dana 36 with 307 ratio for sale I found many for sale that did not list the ratio and upon asking them they had no idea. When selling a diffferential knowing the ratio is important to the sale. I compiled what I know and learned about figuring out different ways on a c4 Corvette.
1. The C4 rear axle ratio RPO numbers like this:
RPO Rear End Gear Ration
GM1 2.59
GU2 2.73
GW4 3.31
G44 307
2. Read ring gear
If you can look at the large ring gear there you will see 2 numbers.
Example: 43-14 , you divide the smaller number into the larger number and you get 307 ration and so on.
3. Etching from factory on carrier
On most C4 carrier's I find there will be etching on the bottom showing date and ratio.
you will have to clean and scrub usually to read it.
4. Using the rotating method.
Not so accurate but close enough is this method. Mark your drive shaft or drive shaft yoke with tape or a marker, then mark your tire/brake/rotor/half shaft yoke depending on installed or not. Rotate the above 1 revolution 360* while counting how many times your drive shaft yoke turns. for example if your drive yoke turns a tiny bit over 3 turns you have 307 ratio.
Last edited by dentalfloss; Oct 17, 2023 at 08:24 PM.
Safety Car
Joined: Sep 2001
Posts: 4,136
Likes: 531
From: Glenbeulah Wi
Thread Starter
Racer
Joined: Aug 2014
Posts: 478
Likes: 66
From: Elizabethtown, NC
I posted this thread to try and help members in finding Dana 36 differential ratios. I have recieved help above in my errors from members more in the know and have edited my post as I go along and any helping comments are welcome. If this helps only one member is good enough for me. Thanks for listening