Differential help

[keithsranger]

1999 Ranger XLT SuperCab 4WD vin#1FTZR15V4XPA55995, was making a popping noise in rear end - found ring gear and pinion have teeth missing, large chunks of metal in case.
I am replacing everything, how do I know what gear ratio and ring gear size? Tag has S374S at top, then 4 10 75 8 K 26 across bottom.

I measured the ring gear as best I could, and it looks like 87/8" dia. Any help would be appreciated.

 

[wildbill23c]

Ok so according to another forum, the 4 10 is your actual gear ratio 4.10. The 75 actually means 7.5" ring.

 

[kunar]

welcome to TRS. take a look here ( http://www.therangerstation.com/tech_library/index-axles.shtml ) that should get you started in the right direction. absolutely tons of good info available. from the sounds of things, your truck has a 3.73 limited slip axle. on your tag, there is likely a "3" that you can see in front of the "S734S" (so it should read 3S73, which is a 3.73 l/s) and if you measured right, it would be an 8.8 axle. you can also tell by the shape of the cover, and by the door tag code as well. check the link above for info on both.

 

[kunar]

Ok so according to another forum, the 4 10 is your actual gear ratio 4.10. The 75 actually means 7.5" ring.

i dont think thats right bill, but i can say for sure. i would really like to see a pic of the tag, as well as the axle. the axle ratio should be at the top left of the tag, the rest of the tag doesnt really tell us anything important for our purposes here.

edit: the pic in the tech library shows the axle ratio at the bottom left of the tag. its been so long since ive seen one in person, i cant say for sure. maybe im wrong would still really like to see pics.

 

[LIMA BEAN]

Count the teeth on the pinion and on the ring gear then divide pinion into ring gear. If you have 9 on the pinion and 37 on the ring gear its 4.11

 

[keithsranger]

Thanks to all. There are 41 teeth on the ring gear, and 10 on the pinion, so that would be a 4.10, and the 75 does probly refer to the ring gear size as that is the one everyone keeps trying to sell me as original in the truck. I don't see a 3 preceding the S374S, so I don't know what that means? I'll take the guts and the tag with me to the salvage yard tomorrow and try to match it up. Again, thanks to all who replied..

 

[kunar]

Thanks to all. There are 41 teeth on the ring gear, and 10 on the pinion, so that would be a 4.10, and the 75 does probly refer to the ring gear size as that is the one everyone keeps trying to sell me as original in the truck. I don't see a 3 preceding the S374S, so I don't know what that means? I'll take the guts and the tag with me to the salvage yard tomorrow and try to match it up. Again, thanks to all who replied..

definitely 4.10 gears, i have to admit i was in error. you should be able to tell weather its a 7.5 or an 8.8 by the shape of the cover. the 8.8 is an improvement over the 7.5 though, and if youre buying one anyways, might as well upgrade. 7.5 on the left, 8.8 on the right.