Topic: Dual Cases with a forward shift rear case?

[Evilwhitey]

I picked up a 4.7 marlin case six months ago for my 93' 4cyl pickup and it's worked perfect! Thanks Marlin. Now I want to run a doubler infront of my 4.7 case. Can I do it using my forward shift case? Thanks!

[Hottrod81]

You cannot use a forward shift case in the rear but you can use it for the crawler box.

[79coyotefrg]

yea,  you can get a topshift crawl box from Marlin already clearanced for the 4.7 gears  and swap the 4.7's to that box and use the crawler portion of your forward shift  between the tranny and the topshift

or just run the 4.7 in the front case

[Evilwhitey [OP]]

Ok, so correct me if I'm wrong but I need to find a top shift t-case to throw my crawl box on and then I can put a doubler infront of that? What does that all entail? Is it very difficult? Thanks for your help!

[Evilwhitey [OP]]

I just saw that marlin has a top shift conversion kit. If I use that kit can I then bolt up a doubler in front of that?

[Hottrod81]

It goes the crawler box, adapter, then the transfercase.  It sounds like you probably shouldn't try doing this.  The best advice I can give you is to buy all of the necessary parts and have Marlin assemble them.

[854RUN]

OK, do you have a Donner case for the front box yet if not get one with a top shift and What you can do is use the forward shift rails, forks, and stuff on the first box. So you need to get a case that is a top shift and take it apart. #1 Take the shifter, shift forks, and shift rails out of your Donner Case #2 tack your case with the 4.7 gears and open it up. Pull the forks, rails, shifter and put it in the front case then take the top shift stuff and put in in your full t-case. bolt it all together, bolt it to the tranny cut a hole in the floor for the shifter and shorten the rear driveshaft and lengthen the front, oil and you are crawling.   on the tech page on the web store there is a good right up on tacking your t-case apart if you are not to comfortable and it has good pics with it on every step :   http://www.marlincrawler.com/htm/transfercase/crawler_installer/crawler_inst.htm  http://www.marlincrawler.com/docs/470install/installation.htm

hope that help and not confuses

[BigMike]

The only way to run a forward shift transfercase in a dualcase setup, would be to run the MC01 or MC03 dualcase adapters, both of which were discontinued in 1995.

I just ran out back to our Trophy room and took some pictures of a prehistoric MC01 twp piece adapter. Take a look at these relics:

[Rocksurfer]

Wow those are old! Doesn't look like they came from no trophy room.

[BigMike]

That MC01 adapter was 12 inches long and accepted either a top or forward shifting t/case behind it.

But as soon as Marlin wanted to run Triple Cases, he knew he had a problem, so he redesigned it to the MC03, which was about 9 inches long, and then the MC05, which is just 6.5 inches long.

So today, because we want to make these dualcases as short as possible, we require the rear transfercase to be top shifting only.

I recommend you convert your 4.70:1 case to a top shift and run that behind the MC07/08 adapter.

Please, whatever you do, do not use the 4.70:1 gears in the Crawl Box unless you are using a 23-spline rear transfercase.

BigMike