NP205 input shaft

[dzlpwr]

I am in need of some advice from anyone who has done this. Here is the problem. I have an auto transmission and NP205 tcase in my 92 pulling truck. All the shafts in the auto are billet but I keep breaking the input shaft of my tcase. Currently it has the 23 spline input shaft in the tcase and the autos are all 23 spline output shafts. I am curious if the 29 spline tcase input shaft is any bigger then the 23 spline shaft. It it is, does anyone make a 23 to 29 spline coupler to go between the transmission an tcase? I could have one made if need be but i didn't know if the newer 2nd gen trucks used a 29 spline tcase input and used a similar coupler. I appreciate any feedback.

 

[Mopar_Tim]

i have got a 29 spline case in my garage, if you want me to i can go measure for you.



i think ... . think being the key word that the second gen manual trans were also 29 spline in and out.

 

[dzlpwr]

That would be great if you would measure it for me. Would you be interested in selling it? Just curious as it would save me some time from modifying mine to upgrade to the other input? Just trying to weigh my options.

 

[HRDROKN]

I s this correct... all auto's/NP205 23 spline?

 

[Mopar_Tim]

i measured the coupling inside diameter... . b/c the case is buried under some other stuff and all i could get to was the coupling



i got about 1. 5 inches give or take a 1/16



as for selling it possibly but not for a while and i have already got one guy interested in it, i bought it for my first gen swap in case i end up what an automatic transmission truck i will need it for when i swap in an nv4500. but if i get a 5 speed truck then i will probably sell it.

 

[dzlpwr]

Thanks for measuring that for me. My 23 spline measures 1 1/4 inches so I would gain a 1/4 inch by swapping to the 29 spline. I got ahold of a 29 spline shaft and did some research and found a bearing with a larger ID so I won't have to machine my case. There is a machine shop that builds alot of my custom drivetrain parts for me and he said he can cut the other side of my coupler for the larger 29 spline diameter no problem. Ill keep you guys posted on how this works out.

 

[Mopar_Tim]

i think now your just going to break the output of the transmission

 

[BHiggins]

If you get stuck, try this guy: www.partsmikeparts.com

He's been helpful to me in the past, and he has all kinds of adapters and parts for the NP205.