Rear Axle De-Coding

[BigDaddyCee]

Hi All,

Wondering if you guys could help me out with my 8" Carrier. I know you guys don't like to hear this but I borrowed one from a 1978 Mustang II, it had a 2.8 Litre V-6 with an automatic tranny. The axle code was "7". BTW it was slated to get crushed soon at the wreckers so I salvaged the carrier. It now resides in my 65-289 coupe. The mustang red book doesn't list an axle code 7 for this year. It does list a 7 for 75-76's and that says it is a 3.40. Can you guys help me out to decipher this? Thanks.

 

[Camshaft78]

I'm still working on it, but does this help?

http://www.mustangii.net/axle_ratio.asp

 

[welder4956]

Axle code 7 is for a 3.40 open rear (non-locking). This was used in 77-78 models also.

 

[BigDaddyCee]

Thanks Guys,

I originally thought that it was a 3.25:1 open by my crude method of spinning the tire one revolution and watching to see how many times the pinion spun around. My calculations were out just a bit! I appreciate the replies. Camshaft 78 I had a look at that site. My question is; Are those the codes that are on the rear axle tag, or are they on the carrier itself? I don't know if I got the tag with this carrier?

 

[itsaMustangtoo]

Thanks Guys,

I originally thought that it was a 3.25:1 open by my crude method of spinning the tire one revolution and watching to see how many times the pinion spun around. My calculations were out just a bit! I appreciate the replies. Camshaft 78 I had a look at that site. My question is; Are those the codes that are on the rear axle tag, or are they on the carrier itself? I don't know if I got the tag with this carrier?

The codes on that site are for the tag itself. I do not know of carriers being marked with gear ratios,as they can be changed. Probably just a casting number of sorts. The only mark I would know of would be an "n" for nodular on a 9" carrier. Hence your caculation of 3.25:1 may be correct if you do not have the tag. I would check the site again for that ratio. But who is to say it was not replaced during it's street life?? The only surefire method would be to count ring/pinion teeth.