D18 intermediate shaft interchangeability

I've currently got a D18 in my jeep with the 1 1/4" intermediate shaft. I broke the case and chipped a bunch of teeth off of the gears, so I picked up a spare D18 for cheap. The old case already has a hardened novak shaft in it, but the new case has a 1 1/8 inch intermediate shaft. I know novak can machine it to work for like 75 bucks, but im trying to go wheeling in a couple days and don't want to wait for shipping.

Can I just get the 2 holes in the case opened up locally at a machine shop and be good to go? Will I run into any other problems running the 1 1/4" shaft and bearings with the gears out of the 1 1/8" case? Does anyone happen to have an accurate size for the holes in the case when using a 1 1/4" shaft? Thanks for your help.

 

75 to have it machined? Just order a hardened 1 1/8 shaft and be done with it!

 

He said he needs it in a couple of days.

I don't know but I would assume the middle gear that goes over the intermediate shaft corresponds with the size of the intermediate shaft. If this is not the case, then there would have to be two differenct size needle bearings; one for the 1 1/4 and one for the 1 1/8. If the gears all the same size, then there would be a spacing difference between the shaft and the inside of the gear. Plus the 3 spacers that go around the needle bearings. I would think the other two bearings are the same. I would measure the size of the needle bearings and the inside diameter of both gears. If you expand the size of the case holes, I would make real sure they get it symetrical, otherwise it would turn out of balance and who knows, "Kaboom." The only other thing I can think of is you might have to grind the key that holds the inter shaft in down, or get the one off the other case.

Oh by the way, I am rattling on because I just rebuilt my D18 on Saturday and can still visualize what you are talking about.

I would also pay attention to which way the other bearings face when you take them out. They only go in one way. Took me a while to figure that one out

 

hey i've asked some of these q's in just the last couple days. This is novak's interchange chart
http://www.novak-adapt.com/knowledge/transfer_case_gears_grid.htm
the gear id is the same between the gears so they must just take different bearings. as for the hole in the case i am sure any quality machine shop could do the work if you know what size the holes need to be which i do not know

 

Ok, so it sounds like as long as I use both the bearings and the shaft from the 1 1/4" case I should be home free.

The only thing that seems weird is that looking at novak's chart, the tooth count varies on the individual gears, even though the overall gear ratio is the same. So I'm thinking as long as I swap all the gears over, not just the ones I broke, I should be ok. Just out of curiousity, does anyone know the reasoning behind them being different?

 

$75 is kinda high to have the case machined. I did one for Jason (neptco19) for about 1/2 that or so. There are 2 different gear ratios for the dana 18, one is 2.43 the other is 2.46. I would think that you could have your case if clean, machined at a local shop for about $40-$45 and have it back the next day.

 

I got the donor transfer case mostly apart, but ran into a slight problem. After knocking one of the bearing cups out and removing the snap ring on the main shaft, you're supposed to be able to slide the shaft out of the case and then lift the gears out. Only one of the gears was really tight on the shaft for some reason, and if you put a D18 in a press the case will break in half with next to no pressure on it. oops. Looks like I'm in the market for another D18.

 

If you get desperate, try J&W Dismantlers http://www.jwjeep.com/ I'm sure they'll have a case, but it won't be cheap. They are located just outside Sacramento, near Roseville. You can do a parts search at their site.

 

Well, if you do get another one, I'm in the market for a rear output housing...the type for mounting an e-brake to.

 

I have an extra case if you need one.
Give me a call
858-274-5395 hm
858-614-1146 wk
Ray