bishop93

Hey guys I am at the dual transfer case point in my yota wheeling career now and I would just like to know what years of transfer cases would be the easiest to mate up with my 93 21 spline? I know all about the 23/21 spline t cases, I just want to see the route you guys took. Plus I found a guy locally who has at least two cases from each year , 79 on up. What case year would be strongest/ easiest to install? Thanks guys

4Crawler

iTrader: (3)

You'll need at least one top-shifted, gear-driven case from a non-turbo 4-cyl. truck. The rear case needs to be the top-shifted one, the front case can be either type (easiest to be the setup that you have now).

bishop93

Ok got it. Rear case needs to basically be my stock top shifter, and then I can sandwich either or between the tranny and top shifter case. Will two 21 spline cases be ok? What is a better option considering 21 and 23 spline. Can I convert my rear case to 23 and leave my front case 21 because of the trans 21 spline? Thanks guys, I'm doing a lot of research right now, but I figure you guys can help me with some stuff.

4Crawler

iTrader: (3)

If rear case is a top shifter now, then the 2nd case needs to be as well (or converted to top shift) as your tranny won't work with a fwd. shifter:
- http://www.4x4wire.com/toyota/tech/topshifter/

I believe you can have a 23 spline conversion in the rear case, helps with the added torque it sees, or you can run it with 21 splines.

SpecialScottie

You can convert the rear case to 23 spline if you order the 23 spline dual adapter.
I run dual 21 spine cases in my runner and havent had any problems

bishop93

Ok so ill just grab another top shift to make things easier for myself. Then grab a marlin adapter and then the fun begins lol. Hey thanks for the help bud, much appreciated.

bishop93

Right on, I'm just gonna run dual 21's also. Thanks for the input.

bishop93

Ok guys great stuff. Let me ask you this, do you guys mostly run 2.28's in both cases? Should I just throw in a 4.7 in one case and leave the 2.28 in the other case? I really like the idea of this, and since ill be rebuilding one of tbe cases, why not throw in a 4.7 anyway.

BigMike

If this is a 1993 4cyl 5spd setup, then it in fact has a late model (short) forward shift style transfer case. Top shifting gear drive transfer cases were last used in 1988 (or '89 4Runners). In addition to Roger's link, you can also check out our Transfer Case Bible. bishop93 has a Type 6-B transfer case behind a W56-E transmission (transmission application table).

Modern-day dual case adapters require a top shifting transfer case, there is no way around this. The Dual Case Crawl Box (what goes between your transmission and transfer case), should be configured to match your transmission, however this is not required.

When sourcing donor cases, it is a good practice to find newer t/cases because they are more likely to have fewer miles and have not been sitting around collecting dirt/rust.

Here is what you will have:

W56-E transmission with a 21-spline output > 21-spline Crawl Box input > late model forward shifting Crawl Box > dual case adapter > 21-spline dual case coupler > 21-spline t/case input > top shifting t/case.

Take note that there are two different types of forward shift styles: early 1984-88 "long-rail" style and 1989-95 "short-rail" style. The difference is that the short style has a forward shift offset 1/2-inch less than the long forward shift style. Again consult our bible on this.

Since you already have a short style forward shifting t/case (your stock '93 t/case), you will want to use this to build your Crawl Box. Then all you have to do is find a complete top shifting transfer case to mate behind the dual case adapter plate. For this I recommend the 1985-88 top shift style since it has an improved gear set and will most likely have fewer miles than the 1979-83 top shift style, however any top shift case will suffice.

Regarding converting to 23-spline, this would be nice but not necessary. It will definitely strengthen the main weak link of the dual case setup, but it will cost you more $ for the 23-spline input gear. These gears were only made in 1986 and 87 (Turbo 4cyl models), which are rare enough to find, so we make a Total-Spline 23-spline stock replacement input gear that is much, much stronger than the stock Turbo input:

http://www.marlincrawler.com/transfe...ine-input-gear


Not only do we use Total-Spline technology to maximize couple spline contact and remove the factory fuse, but we also make these from Chromoly steel!

SpecialScottie said it perfectly: You will have to use a 23-spline dual case coupler in conjunction with a 23-spline transfer case input, however for most 4-cylinder applications this is considered overkill....but it's always great to have that extra bit of piece of mind / insurance. It all comes down to user preference. I am running a W56-A 21-spline transfer case and Crawl Box but with a 23-spline transfer case. I decided to pay the extra $$ so I can just build it once and never have to worry about it again.

Certainly you will LOVE your new Crawl Ratio and will be super amazed at how your truck will wheel regardless of which spline count you use!! Get er done and start CRAWLING!!!!!!!!

Good luck with everything,
BigMike

BigMike

Perfect!

Ohhhh man it's gonna be saaa-weeeeeeeeeeeeet!!!!!!!!!!!!

That is what we all had to ponder at some time or another... "I'll have everything torn down anyway so why not just go all out?"

Again, it's purely user preference.

With the dual case setup, you will be converting your truck into an 15 speed setup (forward gears). You'll have a three speed 1.00:1, a 2.28:1, and a 5.20:1 transfer case setup.

With the dual Ultimate case setup (2.28 & 4.70), your truck will have 20 different forward gears thanks to a four speed t/case setup: 1.00:1, 2.28:1, 4.70:1, and 10.72:1 ratios.

The nice thing about first going dual cases is that you get all of the hard stuff out of the way. You get your drive lines modified, your 4WD indicator lamp harness lengthened, and your floor board shifter modifications all completed. Then, if you ever decided that you want to go even lower, you can just simply drop your t/case, install a 4.70:1 gear set, and you're done.

So I say if you have ample free time and access to good tools, then maybe it won't be such a big deal to swap in some 4.70s at a later date. But if you really want to CRAWL like the best rigs on the trail and don't want to have to drop your drivetrain down again, then go with the 4.70s.

Yes the Ultimate setup is, well, the Ultimate setup, but I guarantee you will be blown away with even just the 2.28 & 2.28 gearing. No matter which route you take your truck will graduate into an amazing Crawling machine for sure!

Regards,
BigMike

bishop93

Hey bigmike thank you for clarifying. Awesome help and info!! Ok NOW I got it lol. So my late model forward box will be the first box, then comes the marlin dual adapter, then a top shift box and t-case. Awesome. Id like to leave the 21's in both. Ok I was thinking backwards basically.

bishop93

Lol I appreciate this info incredibly bigmike. Ya I'm pretty sure just leaving the stock 2.28's will be amazing. Like you said if I find I need them later on, it will be simple to just plop em in a case over the weekend. Thanks mike ill keep ya posted on progress.

BigMike

Bingo! Also you'll have it made in the shade with the 21-spline setup, it will work great!

Sounds great, so then we are both looking forward to it!

Mike

bishop93

Ya Im picking up an 84 straight axle and that top shift t-case that Ive purchased tomorrow, so I can get rolling on it! If I have any questions Mike Ill let you know. THANKS A BUNCH BROTHA

BigMike

SpecialScottie

Ive got dual 2.28s with 5.29 gearing and 35's and its plenty low. Plus if you ever want to go to 4.7s in the future you can just pull the rear tcase and regear it

bishop93

ya im sure it will be less of a headache once I know everything is fine and it all fits.

bishop93

Ok I got my top loader case home today and it seems ok.
Now all I need is the adapter. Wat symptoms should I look for to see if my 84 top loader t case needs a rebuild? IE-play, anything sticking?

BigMike

You probably have either an 83' or an 85' top shift t/case. These t/cases are built really well with very few parts that last a very long time. Really, the only thing I would be super concerned about is if it has any rusted components. You're gonna tear it down and can easily clean out dirt/grease/etc, but the rust can pit away and ruin metal parts.

Other things to check are the shifter base bolt hole ears (they can break if the case is dropped), cross member mount bolt threads (many people over-tighten and strip these out), and for cracks along the bottom of the reduction housing and the front output section of the #2 housing.

Be careful when removing the mechanical speedometer sender because sometimes it gets frozen in place and it's easy to break it's aluminum housing. Also the sender uses a nylon gear that can wear out of completely strip out if the previous owner had a broken or damaged speedometer unit or cable.

There are other issues, such as worn shift forks and shift collars, but it is very rare to find these (happens when the previous owner rests his/her leg on the shift handle causing constant shift fork-to-shift collar contact).

The only tricky things to watch out are how the shift detent spring and balls are arranged, and the two .25" mainshaft balls. Don't loose these!

In case you don't have it, here is the 28-page Transfer Case section of the 1985 Toyota Hilux service manual. Have fun!!

RF1A Service Manual: http://www.marlincrawler.com/guide/FSM_1985_RF1A.pdf

BigMike

bishop93

Thanks mike. Awesome. Hey not to hijack my thread, but real quick, I'm ordering my sas through allpro so for a 35 or 37 would you recommend 4" with 1" shackle or 5" leaf? Thanks