How to make sure gearing is the same

[Flashflood]

I'm planning on pulling a back axle off 99 explorer to my 91 how do you make sure your diff gearing is right do they have to match

 

[Mbrooks420]

They have to match. Check the door stickers of both for the axle code. You are converting the 91 to discs?

You can also rotate the axle several turns and count how many times the driveshaft yoke rotates.

 

[410Fortune]

YES count the number of turns
SO I have a 98 ranger downstairs I am building, truck came to me with a body lift and 33" tires. The door sticker says it has 3.73 with a limited slip
So before I go installing a disc brake explorer rear axle I have to MAKE SURE nobody ever geared this truck to a different ratio.
In order to do this I count the rotations........ 3.75 turns around to 1 so it is still 3.73
This is the only way to be sure of what axcle ratio is installed without pulling the cover and checking the ring and pinion gears

 

[Flashflood]

They have to match. Check the door stickers of both for the axle code. You are converting the 91 to discs?

Yes I am converting to disk and btw thank you for telling me that cause I have 45 and the 99 got 33 so I would have blown up my diff

 

[410Fortune]

Yes I am converting to disk and btw thank you for telling me that cause I have 45 and the 99 got 33 so I would have blown up my diff

Explorer and Ranger Door Sticker Axle Codes Deciphered

45 = open 3.55 gears
33 = ??

What do you mean? The door codes still have to be deciphered to get the ring and pinion ratio

 

[Flashflood]

Explorer and Ranger Door Sticker Axle Codes Deciphered

45 = open 3.55 gears
33 = ??

What do you mean? The door codes still have to be deciphered to get the ring and pinion ratio

Thank you for the link the axle would swap out. I was also on my phone sorry. I will have to see how long it takes to decide the fate of the poor 99. Before I can swap the axle

 

[410Fortune]

You are welcome!!

I'm still wondering what axle code 33 is?

fate of 99 is easy, rip out the axle and anything else that is good like cat converters and then crush that SOB

 

[Flashflood]

You are welcome!!

I'm still wondering what axle code 33 is?

fate of 99 is easy, rip out the axle and anything else that is good like cat converters and then crush that SOB

No it's got 3.31 limited slip I think is what my dad said which looking at the links. I've got 3.55 so I think they still won't bolt up have to check with him but he may actually save it and rebuild it btw sorry about the 33 I was on my phone getting blasted by ads

 

[Mbrooks420]

No it's got 3.31 limited slip I think is what my dad said which looking at the links. I've got 3.55 so I think they still won't bolt up have to check with him but he may actually save it and rebuild it btw sorry about the 33 I was on my phone getting blasted by ads

It’s not a 3:31, and probably not a limited slip. Limited slips will start with “D” as the axle code.