Fuller AT1202 1880 yoke

[m16ty]

I’ve picked up a Fuller AT 1202 auxiliary trans for my RD822sx. The trans came with 1710 yokes, but the Mack has 1880 driveline. I can’t find a 1880 yoke anywhere to fit the Fuller AT-1202. My local driveshaft shop says the only thing he knows to do is make up 2 driveshafts with 1880 joints on one end ( to fit the main trans and rear end) and 1810 joints on the other end of the driveshaft to fit the auxiliary.

Anybody got any other ideas?

[AZB755V8]

I don't think that a 1710 yoke will work with a 1810 yoke in the first place. The across cap dimension are 6.094 and 7.547 respectfully. An 1880 is 8.094 across. Get the 1880 on one end and a 1710 on the other end of each driveshaft would work. Doing so would just have a much lower torque rating for the 1710 u-joints. Maybe the Aux Trans has a lower torque capacity as well. 

[Freightrain]

I went through this with my little 6041 box when I put it in my truck.   1510 and 1710 if I recall? 

Anyhooo, I had the driveshaft shop swap some ends around that was given to me with the box(was given a short shaft with 1510 ends on it).  Took my original 1710 put on one end of the front shaft, 1510 on the other.  Then the second 1510 on the front end of the rear shaft(original drive shaft from truck cut down).  Tube sizes were the same, so the ends fit without fuss.

[m16ty]

22 hours ago, AZB755V8 said:

I don't think that a 1710 yoke will work with a 1810 yoke in the first place. The across cap dimension are 6.094 and 7.547 respectfully. An 1880 is 8.094 across. Get the 1880 on one end and a 1710 on the other end of each driveshaft would work. Doing so would just have a much lower torque rating for the 1710 u-joints. Maybe the Aux Trans has a lower torque capacity as well. 

I guess I wasn't clear in my first post. The auxiliary came with 1710 yokes, 1810 yokes are available for the auxiliary. The torque rating for the AT1202 is 35,700 lb-ft, the highest rated auxiliary I could find.   

Looks like I'll have to do what Freightrain mentioned, have the driveshafts made up with the original 1880 yokes on one end, and 1810 yokes on the other. I've got a couple of more phone calls to make to people that work with these transmissions a lot, before I cut anything up. 

Are 1880 joints that uncommon on large trucks? It's the first ones I've seen, but it's also the first RD800 I've dealt with. They list the Fuller AT1202 as a factory option on the RD800 series, so you'd think somebody would make yokes to fit it. It just seems kind of counter-intuitive to add a auxiliary trans to increase torque, and then weaken the driveline.   

Edited November 3, 2018 by m16ty

[AZB755V8]

I did see the Eaton website on the torque rating for that trans. That seems incredibly high capacity compared to anything else they offer but they would know. I do have 1880 universals back to the first rear then 1810 between Rockwell rears on my Superliner. I don't think mine came that way but was beefed up for heavy pulling. I don't think the 1880 parts are that common or at lease any more. Saw one CL713 with that big of driveline once doing Texas oil field work.