Sudden drop in rankings after 301 redirect

[snorkel]

We recently merged our old webshops to one big webshop. The new webshop is mutlidomain/multilanguage so the English version is at the .com extension and the germand version at  the .de extension etc. etc.

We redirected the 2 best old webshops to the .com extention  with a htaccess 301 redirect. The other old webshops we divided over the other extensions.

We redirected the 200 most importent pages with a page to page redirect and redirected the other indexed pages to the new index page. (300K)

Everything went well and the new website started indexing. All extentions are doing well and even the .com version had very good rankings for a few days.

After a few days we almost lost all rankings to the .com version. We did always clean seo, had 100% unique content written by our own writers and translated by our own translators.

Our old webshops have very good branche related backlinks and i can`t find anything else then the 300K redirects to the homepage that might be the problem.

Hope somebody will help us, or know someone we can hire to check our webmaster account, and check everything we did.

[snorkel]

We now removed all 301 after 2,5 weeks and replaced them with a custom 404 page. Only the most important pages are now redirected. But i guess something happened already.

The .com version is very badly indexed, and it shouldn`t because we directed the 2 most important old webshops to this domain.

All other versions, like the .nl and .de etc. are doing fine.

[kellymandingo]

If i have read correctly then i would not have let the old pages over to the new site just to 404 them, also never redirect a whole site to the index

Have you thought about 301 the important pages to their closest match on the new domain, rather than just push all the old site to the index push them to the closest match possible so as you don't waste any of the old link juice.

How long ago did you do the 301?

also noticed hardly any of the new pages have more than 1 or 2 word in the titles,

[snorkel]

We changed our tactics and instead of 301 the 300K links we let them run into a 404 page. I think its not the meaning of a 301 redirect to push old pages to the index page.

But now the main question is. Should we have the 404 pages on the old or new domain.

www.oldoldold.com/custom404.php

or

www.newurl.com/custom404.php

If we use the old domein we can put a text on the page that says we are moved to the new location. Google will have the 404 errors in the old webmaster account for the old webpage

If we use the new domain we can use a custom 404 page with links to different pages on the new webshop. But in this case Google will receive the 404 errors in the webmaster account for the new webpage.

I don`t know if Google penalize us for this.

What is the best and most natural way so solve this problem? At the moment we dropped from 2500 organic a day to 400 organic a day.

[kellymandingo]

Post your URL , you will have a lot more chance of people responding, as its hard to see without looking at the site and running a few tests