Mikeb44

What is the difference between top shift transfercase and forward shift?

AxleIke

Well, exactly as it sounds. One is top shift, one is forward.

Top shift uses a shifter mount that is physically on top of the transfer case.

Forward shift has long shift rails that come out of the tcase and into the transmission. The tcase shifter is physically attached to the transmisssion.

richf

pretty much sums it up. Check out marlin crawlers website under the rebuilt trannys you can see exactly what he is talking about. The w56A & B are top shift the others C,D&E are forward shift.
http://www.marlincrawler.com/transmi...built-complete

Are you trying to twin stick a single transfer case or something?

xxxtreme22r

Top vs Forward Shift

In both photos the transmission and transfer case have been separated to show where one ends and the other starts. It also helps show the shift forks on the forward shift setup. The left photo shows a top shifting transfer case and transmission. Notice the tcase shifter comes out of the top of the tcase. The transmission has just one shifter. Notice there are no forks on the front of the tcase. The right photo is a forward shift transfer case. Notice the block off plate on top of the case. This unit is shifted through two rails that connect to the transmission. A forward shift transmission like this one has two shifters, one for the tranny and one for the tcase. Click photos for larger image.

The block off plate of a forward shift style tcase can be seen from under the vehicle. From under the truck on the driver side look up at the transfer case to see the block off plate..

Top Shift


Forward Shift

Mikeb44

Cool thank you I understand now.

Mikeb44

Which is better to have forward or top shift

4Crawler

iTrader: (3)

Either one is fine, depends on what you have now and what you want to do in the future. If you have fwd. shift now, then the shifters and holes in the floor are set up for that and that is what would be best/easiest to run. Same w/ top shift. Only "advantage" of top shift is that if you ever convert to dual t-cases, then the rear case *must* be a top shift unit:
- http://www.4x4wire.com/toyota/tech/topshifter/

R.DesJardin

iTrader: (1)

They are the same except for how they are shifted, but don't get confused with forward shift chain drive cases. You need gear drive cases as shown in the pics above for practical duals and gear and shift improvements/modifications.

Mikeb44

do i need to put the 4:70 gears in the rear for it to work the right way?

4Crawler

iTrader: (3)

If doing dual cases, then yes, best to put the lower gears in the rear case. Why? Torque. With the stock 2.28:1 in the forward reduction box, you already have 2.28 times the original toque coming into the rear case input. If you were to put a 4.70 gear in the front reduction box, you more than twice that torque on the rear input shaft, good way to break things.

Mikeb44

ok thank you again,i have forward shift what do i have to do to have duel cases? as you can tell im new to these duel cases to im just trying to get all my ducks in a row before i start all this.

R.DesJardin

iTrader: (1)

Go to Marlins website and search around the store and forum for info. I did a lot of reading before ordering al lthat I needed just to be sure I bought the right stuff.
So you need either to get a top shift transfer case or another forward shift and then buy a top shift conversion kit for it. The figure out what gears you want, don't forget to make sure all your spline counts on your shafts match. I did 23 spline on mine. There is so much more but really it would help you out if you checked out the websites of the adapter manufacturers. Then you would probably narrow down your questions to be a little more exact.

Mikeb44

Ok I will do thank you.

THEMAN

Old thread I know but just wanted to say thanks. As this answered my question as well, and I didn't have to post a new question just search and revive a dead thread. Thanks again.

tonetone

i agree with THEMAN, awesome thread and got a lot of info i needed quickly. will dig in the marlin website forums for more specifics.