Topic: Transfer case ratio question???

[93REDCRAWLER]

So I'm currently running duels  2.28 in the crawl box 4.7 in the transfer case with the upgraded 23 spline input . This is on a 4 cylinder so the crawlbox has the 21 spline input . Could I run 4.7s in both cases with 21 input in the front and 23 in the rear? Is anyone running this setup now? Or is t just going to brake? Thanks for the help in advance

[blackdiamond]

I doubt that it is a guarantee that it t would break but I know Marlin Crawler has a strong preference for having the 4.70 gears in the rear case in a dual ultimate setup.

The real question is why you think going that low is necessary?  I also run the dual ultimate gearing and can't see a real value for lower gearing. If you truly do have a need then do it right. If not then don't waste the money. 

The reason BigMike runs triples is that having the 2.28 gears is valuable and you'd be eliminating seversl useful gear ranges by only having 4.7 and 4.7 x 4.7.

2.28 and 2.28 x 4.7 are of far more practical use than 4.7 x 4.7 will ever be.

[93REDCRAWLER [OP]]

I doubt that it is a guarantee that it t would break but I know Marlin Crawler has a strong preference for having the 4.70 gears in the rear case in a dual ultimate setup.

The real question is why you think going that low is necessary?  I also run the dual ultimate gearing and can't see a real value for lower gearing. If you truly do have a need then do it right. If not then don't waste the money. 

The reason BigMike runs triples is that having the 2.28 gears is valuable and you'd be eliminating seversl useful gear ranges by only having 4.7 and 4.7 x 4.7.

2.28 and 2.28 x 4.7 are of far more practical use than 4.7 x 4.7 will ever be.

Thanks black diamond  for some info!  Some things I haven't thought about yet. 

[T-Revv]

Marlin called the box with a 2.28 and 4.7 the Dual Ultimate for a reason.  He truly believes it is the ultimate gear ratio.  (wheeling with him last week he told me his favorite for most situations is dual ultimate 2nd gear, and going into dual ultimate 1st when he really is looking for that slow crawl).  Marlin ran all 4.7 gears for awhile but it wasn't worth losing that 2.28 factory low.  So now he runs triple cases 2.28, 4.7 and 4.7.  Just show he can demonstrate different gearing options to people, but when hes wheeling you'll never see him drop below dual ultimate 1st gear.  Same with Big mike, in his 81 he has triple cases with 2.28, 2.28 and 4.7 for demonstration purposes but mike is usually in single 4.7 or dual Ultimate. Riding with Mike in his Tacoma on the Rubicon this last weekend was the same.  There is no need to go dual 4.7 Overkill box, and is definitely not worth losing the factory low.

[T-Revv]

As far as running a 21 spline with a 4.7 in the crawl box, it should make no difference if that is 21 or 23 spline.  It has to be whatever your transmission is to match the female in inside your transmission.  You're not applying anymore torque to the input shaft on the front of the crawl box by changing the gear ratio inside, it will always be the amount torque coming from the trans being applied to that part.  It is after the crawl box where that torque is multiplied, so you would be putting double the stress on the 23 spline input between the two cases. There is a much higher risk of breaking that 23 spline with that much torque going to it, which is why it is suggested to  run the 4.7 in the back.  But its been done plenty of times with no problems.  That's why marlin makes his total spline input with no neck down spot like other companies.

[YooperYota]

The best part about dual ultimate imo is that you have 3 low ranges. More options. Going to double 4.7s would remove a low range, less versatile.

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[redneckcustoms13]

I have a single 4.7 in one of my rigs and a dual 2.28 on another. I prefer the dual 2.28 over a single 4.7 because it is much more useful. A single 4.7 is often too low (I know it doesn't sound right lol). A 2.28/4.7 would be amazing in my book. A set up like big mike is running would truly be the best of all possible options.