axles

[Big Jake 18]

Will the axles from a GT14 rear fit in my C120 8 speed this is a project I think the axles are longer and that's what Iam looking for thanks Jake

[rmaynard 14,865]

Don't take this as gospel, but in my opinion, since both axles are 1-1/8", and both connect to the same part number inner gear with a c-clip, I don't see any reason why it wouldn't work. I would however wait for others to chime with their opinions.

 

[stevasaurus 22,229]

I think this is an interesting question.  After looking at some manuals, here is what I found.
1. the axle gears are not the same...GT-14 uses # 8053 axle gear...C-120 uses # 101889
2. the GT-14 uses the 10 pinion, limited slip differential...the axles are not the same length.  I think the RH axle is 3/4" longer then the LH axle.
3. the C-120 uses the 8 pinion differential and the axles are the same length.

Choices and speculation::
The axle gears may fit on any and all of your axles...if the spline is the same,(and it probably is) but you will have to use the axle gears that were in the C-120.  I suspect the difference in the gears are the number and size of outer teeth, because they are engaging a different number and size pinion gear in the differential.
It may be possible to take the whole differential and the 11/44 tooth gear and interchange both.  There is a Service Bulletin showing what to do to get rid of a 10 pinion differential and put in an 8 pinion differential.  You should be able to go the other way.  This option would ensure your axles stick out the same distance. 
Jake, I went back and verified the axle lengths for the 10 pinion differential...one is 11 1/4" and other is 12". 

Edited October 28, 2015 by stevasaurus

[rmaynard 14,865]

@Stevasaurus -  There are a lot of assumptions in my response. But since Big Jake did not mention what year the donor GT-14 was, and he did not mention what year C-120 the recipient was, I selected a C-120 which uses the 8053 gear. Then I looked at C-120 axles from 1974 through 1976 and found that they all used the replacement axle service kit 99-5359, which lead me to assume that the spline is the same. That is unless the kit included side gears with different splines. Sort of a convoluted way to get from A to Z.  I have been known to be wrong before. 

[stevasaurus 22,229]

You may not be wrong Bob.  Jake did not say what year those horses were.  I got involved in the transmissions, because I was interested in what is really possible as far as switching things around and what may be possible.  Knowing such things would make it possible to save many more transmissions.  I hope, if Jake gets into this and opens both of them up, he will continue in this thread and let us know what he finds.  This has the makings of becoming an important thread., and a valuable learning experience...of course...pictures are required.
BTW Jake...what year are these horses?? 

[Big Jake 18]

Not sure on the Gt14 I had the rear and hydro given to me the C120 is a 1977.What Iam up to is I got a Case 444 with 16" rear wheels and like it a lot. Like to put 16" rubber on a Wheel Horse like to make the C120 a little wider. I thank the axles in the GT rear are longer. Thanks

[953 nut 51,541]

 If you plan to use larger diameter rear wheels and tires you may want to consider using the GT-14 trans axle. With the C120 gearing and large tires it would go a bit faster than you want (unless that is your objective) and will probably be a bit under-powered. The final drive on the GT-14 compensates for the larger tires.