Rear Differential on a 01'ST

[Terry Jackson 2]

So i have a questions are all Ford 8.8" 31Spline 10 Bolt the same? I purchased an Eaton Limited Slip unit a while back. After many phone conversations with Eaton they reassured me it would fit with no issues. However i have a friend with a ranger who attempted to put the same model L.S. differetial in his truck and it did not fit (i do not know the complete details as to whta/why it didn't fit). According to all of the factory specs i can find he has the "exact" same rear axel assembly as my 01' ST. Any and all input would be greatly appreciated. Also if anyone know of a Limited slip unit that will definately fit that would be great too. I just don't want to go through all of the work only to find out it does ot fit and then not have a vehicle for two weeks waiting for a different unit to come in. Thnkas ahead of time

 

[Chad Merry]

Rangers have 28 spline axles I beleive.



Chad

 

[Terry Jackson 2]

This was a 91' i believe. Not sure exact year but by looking up the vin on AllData it said it was a 31 spline.....

 

[Johnny O]

Virtually all Rangers with an 8.8" have 28 spline axles. All Explorers and Tracs have a 31 spline 8.8".

Exactly ONE Ranger model has a 31 spline 8.8" and that is the FX4 Level II with the Torsen diff.

4-banger and some 3.0 Rangers have 7.5" axles.

 

[Terry Jackson 2]

Maybe he had the ONE Ranger model...... Still not answering my question though.

 

[Johnny O]

Maybe he had the ONE Ranger model...... Still not answering my question though.

I doubt it. If he did have an FX4 Level II there is no need to install an Eaton L/S because that model already has a Torsen (and the Eaton would be a step down actually).

If the same Eaton L/S didn't fit, it's because his Ranger had 28 spline axles, which again 99.9% of Rangers 8.8's do. OR if it's a matter that the diff wouldn't even fit into the pumpkin, then it's a 7.5" axle and not an 8.8".

 

[Terry Jackson 2]

ok lets forget about the Ranger for a minute. If i have an 01' job1 ST i Want to replace the rear differential assembly with and Eaton/ or similar Limited Slip unit. Will ANY

8.8" 10 Bolt 31 Spilne assembly work. All of the fit guides tell me it is the same as most E-250's and Explorer's. If anyone has an answer either Helping or to the contrary that would be helpful. I have purchased an Eaton unit and i just want to know if there is anything to worry about before i tear the rear end apart and realize it does not fit.

 

[Dingo]

Terry, the three preceeding people all told you why it DIDN'T fit the Ranger. It should fit yours.

 

[Chad Merry]

ANY L/S for an 8.8 with 31 spline axles will work.



Chad

 

[Tom Schindler]

Maybe he had the ONE Ranger model...... Still not answering my question though.

He did not have the ONE Ranger model. In 1991, there was never an FX4 Level II Ranger.





Tom

 

[Johnny O]

Terry, the three preceeding people all told you why it DIDN'T fit the Ranger. It should fit yours.

'Scuse me for trying to help, I thought that's what the question was.

 

[Terry Jackson 2]

Ultimately i just wanted to know if the unit would fit MY ST. i used the Ranger as a concern as to why i had some doubts. Thanks for all the help from everyon though. :blink:

 

[Tom Schindler]

The Ranger is a different design that the Explorer/Sport Trac. Not the same.



The 1991 Ranger never had a 31 Spline 8.8" differential.



In the end, you should have no trouble installing it. The Sport Trac has a 31 Spline 8.8" rear differential. If the unit is designed for an 8.8" 31 spline, nobody in thier right mind would/should think a differential that is an 8.8" 28 spline would work.





Tom