as i understand the 68 and up Dana 18's are larger than the pre 68 Dana 18's. And i have a 1961 Dana 18 that i want lower gears in. My question is.... are the two Dana 18's bolt patterns the same?? and do the 68 and up Dana 18 have the output shaft parking brake as they do on the pre Dana 18's?:confused:

Yes on both questions. The '68 and up has a larger intermediate shaft (1-1/4") and a larger input hole.

The bolt patterns are the same (also same as a 20). they also had the brake if I'm not mistaken.

make sure you kep track of the bull gear for the tranny output shaft, they came in different spline counts. and the 1.125" shaft D18 can be bored to accept the 1.25" shaft. the gears are the same, the bearings are different.

You can also use an 18 out of a Willys wag or truck as they use the big shaft case. The wag/truck case also does not have a parking brake.
:cool:

Originally posted by 64Trvlr
The wag/truck case also does not have a parking brake.
:cool:

That's a good point. If you're looking to get away from the parking brake assembly you can also use a Scout Dana 18. They don't have them either.

i want to keep the parking brake, so, if i find a newer t-case, i could just blot it right in, replaceing the old one, the outputshft for the Tranny is the same for both?, does it mount the same?:question:

Originally posted by peeJ
i want to keep the parking brake, so, if i find a newer t-case, i could just blot it right in, replaceing the old one, the outputshft for the Tranny is the same for both?, does it mount the same?


Which newer case are you talking about?

If you are talking about the Willys wag/truck it is older but will bolt right in.

I'm sure you can put the parking brake on the wag/truck case.

I'd rather have the big 1 1/4" shaft over the parking brake anytime. Good luck.....
:cool:

Originally posted by peeJ
i want to keep the parking brake, so, if i find a newer t-case, i could just blot it right in, replaceing the old one, the outputshft for the Tranny is the same for both?, does it mount the same?:question:

I'm not sure if the shaft is the same, but if it's not, you could use your old shaft and output housing. It should work just fine in the new housing. A bigger concern is the mounting hole. Your 61 would be the small hole version and the '68 would be the large hole version if it came from a V6 Jeep. I think you'd still be able to use it, but you would have to get a different bearing retainer. If you're doing this swap to get lower gearing, you should be aware that the gearing is the same. The only real benefit is the larger shaft and I'm not entirely sure you don't have the big shaft already. Here's some more info on the Dana 18.

http://www.jeeptech.com/xfer/d18.html

ob both the Dana 18's (any model), there is a place to mount on the crossmember?

will i just be able to bolt it up? or will i have to fab up more and diffeent crossmembers? what kind of case do i want to look for to bolt in?

when i say what, what kind of case to look for, i mean out of what vehicle..

Speaking of dana 18 anybody know if the bearing for the front output is standard. Id like to just go to the parts house and pick this up. This would be the bearing in the shifter housing that bolts to the front of t-case housing.

Just to contribute to this thread you can use a 20 case with your gears I think. What is your reasoning for getting a newer case?

arndog

front output bearing is a Timken SET 14. any parts hous should be able x-ref that.

Yes, you can use a Dana 20 case with your Dana 18 guts, makes for an easier install of a low-gear set, less grinding on the Dana 20 case.

thanks sundowner

arndog

any1?

peeJ, just what is it you're hoping to accomplish? Based on your first question, you want lower gears. '68 and later D18s have the same gear ratio. The case is the same externally (no mounts except for the foot on the front output like you already have) It will bolt up with the possible exception on the index hole size which I already mentioned. Since it's all the same externally it will bolt up in place of your current transfercase and use the same mounts. However, there's not much to gain by doing so. The only advantage would be if you have the 1 1/8" intermediate shaft (which I don't think you should have). Even then, it would be easier to have your current case machined for a larger shaft. So once again, what is it you're trying to accomplish?

i want to put 3.15 gears in it......will a CJ-5 model have the parking brake

Ahhh, now we're getting somewhere. You should be able to put 3.15 gears in your current case, it just requires some grinding. The later D18 and D20 cases are supposed to be thicker and don't require as much grinding. The cheapest way to go about this is to get a D20 and put all your D18 guts in it as well as your output housings and parking brake. That's what I did. The only modifications to the case I did was the filler hole. On the D20, the filler hole is on the rear of the case. It interferes with the output housing on the D18. I plugged it with a flush mount plug and drilled a fill hole on the side where it was on the D18. Other than that everything from my D18 bolted up. Don't know what tranny you're running, but if it's a T-90, you will have to deal with the indexing hole problem I mentioned earlier. I think you can get a different bearing retainer to take care of that. In my case, I needed the large index case to go with my transmission swap.

ok.....i have a t-18, so i can put the dana 18 gears in the dana 20 to make the dana 20 case offset correct.......since i can put the 3:15 gears in the dana 20 case, cant i buy some 4:1 gears for the dana 20 and swap the gut around in the dana 20 to make it offset,

my cuurent case is the 1 1/4" shaft. so you saying that the newer case is also 1 1/4" shaft, i should be able to put the gears in with a little grinding...?

You have a T-18? Do you know if your current transfer case is large index hole or small index hole? Both index sizes were available with the 1 1/4" intermediate shaft so you can't tell from that. If it's large hole, you probably already have the later case. If it's small hole, you're going to need a different adapter to run the large hole case. (should be easy to find)

If you swap, then yes, you put the D18 gears, shafts and output housings on a D20 case and it will be offset. I assume since you said 3.15, you're talking about the Teralow gears. The Teralow gears for the D20 are the same 3.15 ratio. In fact they should be exactly the same gears as the D18 with one additional gear. There are lower gearsets available for both the D18 and D20 from Jack O'brien, but they're a lot more expensive. I think his go down to 4.86 and cost around $1500.