Hyundai Genesis Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter · #1 ·
...Just a quick question. I am going to be swapping out the rear end gears/pumpkin in my 2010 3.8 standard. Going from 3.54 to 3.91.
I know I need the rear end out of a 2010 2.0. Does the 2.0 have to be an automatic, standard... Or does it matter at all? I don't care about a LSD. Open is fine for me. My coupe is presently open. I just don't want to worry about getting different axles etc.
Thanks
 

·
Registered
2013 3.8 Track White Pearl
Joined
·
3,107 Posts
You'd need a pumpkin from a BK1 2.0T manual for a 3.91 FD, most of the BK1 autos will be 4.10. Knowing that, you could look for a diff from an R-Spec or a Track and get the LSD, it's worth it. Regardless, all that is different diff to diff is the internals, the axle stubs are the same for all versions and model years so you don't need to worry about that.
 

·
Registered
Joined
·
70 Posts
Discussion Starter · #3 ·
You'd need a pumpkin from a BK1 2.0T manual for a 3.91 FD, most of the BK1 autos will be 4.10. Knowing that, you could look for a diff from an R-Spec or a Track and get the LSD, it's worth it. Regardless, all that is different diff to diff is the internals, the axle stubs are the same for all versions and model years so you don't need to worry about that.
Sounds good. Going from 3.54 to 3.91 and the tros potent booster added to this 3.8 should really wake it up. I know that dropping a tooth on the front sprocket of my crotch rocket changed its personality as well and really was quite noticeable. Will going to 3.91 throw my speedometer out at all?
 

·
I'd rather do it myself
Joined
·
19,453 Posts
Sounds good. Going from 3.54 to 3.91 and the tros potent booster added to this 3.8 should really wake it up. I know that dropping a tooth on the front sprocket of my crotch rocket changed its personality as well and really was quite noticeable. Will going to 3.91 throw my speedometer out at all?
How accurate is the speedo now? My track LSD had a fast speedo from the factory and I added bigger tires to get it much closer to the GPS readout.
 

·
Premium Member
Joined
·
797 Posts
You'd need a pumpkin from a BK1 2.0T manual for a 3.91 FD, most of the BK1 autos will be 4.10. Knowing that, you could look for a diff from an R-Spec or a Track and get the LSD, it's worth it. Regardless, all that is different diff to diff is the internals, the axle stubs are the same for all versions and model years so you don't need to worry about that.
BK1 auto are mostly 3.91, only a handful of 2010 had 4.10
 

·
Registered
2013 3.8 Track White Pearl
Joined
·
3,107 Posts
I may have had that swapped in my head but I thought I remembered it being the other way around, regardless it's still worth looking at manual diffs so an LSD is a possibility.
 

·
Registered
Joined
·
396 Posts
As far as the gear ratios go, you can choose it based on your preference.

To answer the question about automatic and manual, it will make a difference if you are swapping the whole pumpkin. The manual axles are bolt in, and the automatic axles are slide in.

AT BK2 owner here that swapped the base open differential to the OEM LSD. I did the swap myself, and kept the same ratio of 4.18
 

·
Registered
2013 3.8 Track White Pearl
Joined
·
3,107 Posts
To answer the question about automatic and manual, it will make a difference if you are swapping the whole pumpkin. The manual axles are bolt in, and the automatic axles are slide in.
That's only BK2s and you can still pull out the bolt up stubs and use the non-bolt up axles.
 
1 - 8 of 8 Posts
Top