decoding the rear end tag.
Thread Starter
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Mountain Pass
Joined: May 2011
Posts: 235
Likes: 1
From: Alamo, TN
decoding the rear end tag.
Can some one tell me what all the numbers on my rear end tag mean. Is it useful information of is it just a part number?
Top line is S847F (the S may be a 5)
Bottom line is 3L55 88 4021
Top line is S847F (the S may be a 5)
Bottom line is 3L55 88 4021
Thread Starter
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Mountain Pass
Joined: May 2011
Posts: 235
Likes: 1
From: Alamo, TN
I've been searching some since I posted this. It looks like the 3L55 stands for a 3:55 gear with a limited slip differential.
I'm guessing that the 88 stand for a 8.8in rear end. Mine is a 10 bolt.
I'm guessing that the 88 stand for a 8.8in rear end. Mine is a 10 bolt.
Fleet Owner
Joined: Oct 2005
Posts: 20,784
Likes: 1,751
From: Kentucky
The info in this thread might help decipher what the other alphanumerics are: Ford Ranger Rear Axles - The Ranger Station
Post Fiend
Joined: Mar 2002
Posts: 19,402
Likes: 38
From: Bonita Springs FL
One is a build date and I forget what the other one is. You've already got the most important pieces of information off the tag.
GM guy in this thread 
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Elder User
Joined: Jul 2010
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From: Saint Charles, Missouri
i thought the exact same thing!
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Fleet Owner
Joined: Aug 2005
Posts: 23,666
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From: Easton,Ks
The S847F says it was made at the S=Sterling Plant and the 847F is the application code for the type of Ford it was used on and how much the axle can hold.
It is also a 3.55:1 ratio limited slip 8.8" rear end.
Your date code is not right at it says it was made on the 21st day of the 14th month of 1994.
Tag decoding :
3L55 88 99H06
Second part is the axle ratio: There should be a "3L" preceding the 55 if it's a Limited Slip. If it's open, it would just say '355' .
4th is the ring gear diameter, in your case an 8.8 inch.
5,6,and 7 are the build year, month, and day, in this case, August 6th, of '99. (9=1999, H=8th month [and there is no 'I' in the sequence]) and '06' is the 6th.
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It is also a 3.55:1 ratio limited slip 8.8" rear end.
Your date code is not right at it says it was made on the 21st day of the 14th month of 1994.
Tag decoding :
3L55 88 99H06
Second part is the axle ratio: There should be a "3L" preceding the 55 if it's a Limited Slip. If it's open, it would just say '355' .
4th is the ring gear diameter, in your case an 8.8 inch.
5,6,and 7 are the build year, month, and day, in this case, August 6th, of '99. (9=1999, H=8th month [and there is no 'I' in the sequence]) and '06' is the 6th.
/
Thread Starter
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Mountain Pass
Joined: May 2011
Posts: 235
Likes: 1
From: Alamo, TN
Awesome thanks.
It's not really acting like a limited slip rear. I guess I need to change the rearend fluid and conditioner. On the other hand it would explain why it wont burn the tires when I punch it.
It's not really acting like a limited slip rear. I guess I need to change the rearend fluid and conditioner. On the other hand it would explain why it wont burn the tires when I punch it.
Fleet Owner
Joined: Oct 2005
Posts: 20,784
Likes: 1,751
From: Kentucky
The clutch packs are known to wear out. You can get replacements from many online vendors. For a few $$ more you can upgrade to the kevlar model. A simple fluid change is probably not going to fix your problem.
Elder User
Joined: Jun 2010
Posts: 568
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From: Northern IL
I was wondering the same thing, cool to know I have a limited slip and not open.
I thought it was just low on power, but since my truck's been at the tranny shop this week and I'm driving my dads '00 Jimmy, that makes my truck feel like a sports car!
