Hello 
I’m sorting a 2013 AWD auto Kuga for my friend which the transfer box had lost the top bolts and snapped in half ! 
Any way whilst removing the transfer box from the auto box a metal ring fell out which I can see it was from on top of the gearbox output seal and around the splined adaptor collar .
Tried tapping it back in place but it’s out of shape , the main seal inside is perfect .
Only reason I can see it being there is May be when they are built the splined adaptor not fall off .

Or is there another reason for it ? 
Had a quick look on eBay and afew came up but they have an outer lip and slightly different .

also is it possible to use studs and nuts on top of transfer case ? If so what size do I need to order .

Help any one if possible ? As only want to do this job once lol 
Photos enclosed Thankyou .

Sorry I can't  help you with query about ring but was wondering  how you got on as I'm  doing the same. I'm  putting studs in top 3 bolt holes and fitting a replacement  ptu gearcase as mine has snapped off bottom portion.  How did you tighten top bolt as for the life of me I  cant get a spanner or socket near it?

Hello bud

I was a mechanic in fire service 30 years and I decided to leave that very top bolt out as like said it’s impossible.

Only way you will get to it is to remove the turbo !!

Or by leaving the heat shield off the top of the transfer box , then you could get a long extension onto it .

But reason for shield is because earlier ones used to cook the oil from heat off turbo .

I used loctite on all bolts .

I rechecked all the bolts recently after he has done 5000 miles and it’s all perfect .

I was not going to risk snapping bolts off in turbo charger on a 12 year old car and opening a can of worms .

I believe these bolts need to be checked every service any way .