'Rs' rear diff, do I still need the pump for acd?

[D1andonlyantman]

Hi. Months ago I bought my evo which apprently had a rs rear diff. Once I got ontop of a few other small issues I started looking into that. After getting under the car and having a look, it looked like the pump had just been removed and the diff blocked off. There were no signs of the diff being removed from the car or anything like that. Since then I've bought an ayc pump and had it rebuilt because it wasn't working, and I'm due to get it fitted to my car in the next few days. Just last night I stumbled across an old thread of the previous previous owner advertising the car and he mentioned the RS diff in his advert too. I messaged him basically asking if it had really got an RS diff because I've got no receipts for it, and he said when he had the car he had receipt for the diff work (which id have to assume was a mechanical diff in the standard housing),but he can't guarantee it has now because obviously he doesn't know what the guy I bought it off of done. What I'm wondering is do I still need the pump if it has got a mechanical rear diff, can I just get it fitted and bled up and let it do it's thing, not knowing 100% what's going on in the rear diff and the pump will handle the acd, or do I need someone to get inside the diff and see what's going on?

Sorry for the essay and thanks for any replies

 

[liffy16]

what model evo do you have?4/5/6 evos dont need an ayc with a rs diff as they dont
have an acd either. 7 onwards do have acd

 

[D1andonlyantman]

It's a 9 mate. Even the specialist who worked on my car said he'd bet it was the standard rear diff just closed off and I just need to get a new pump (which I have),but now it's looking like it could possibly have a mechanical diff inside, and I've just spent a proper wedge of cash getting this pump all sorted, so I'm just hoping it's still of use to me if that's the case

 

[D1andonlyantman]

Thought I'd finish the thread. I got the pump fitted today. The mechanic said the best idea is to just throw on the pump and bleed it and it should still be ok even if it's an aftermarket diff. He turned the wheels before putting on the pump and said it felt like an open diff, and it seems to be working properly, so so far so good

 

[liffy16]

glad its worked out ok hopefully!just repaired my pump and made a new soleniod
pretty straight foreword with the bleeding tool aswell great for testing pump on
bench before fitting!

 

[D1andonlyantman]

Ah you're the guy who's thread I read about making a new solenoid. Good work. At the moment I've just got a driveway, not even a garage, but I look forward to the day I have my own garage so I can get good and stuck in!