th400 and np208 t-case

[dixiechevy01]

I have a th400 with a np208 t-case behind it in my k5, both output seals on the t-case are leaking and I'm probably gonna be raplacing them soon. The transmission takes a little bit of fluid every once in a while so I was thinking maybe the front t-case and rear trans seal might be going out, so I checked the t-case fluid and it wasn't even up to the fill plug. Does anyone know the proper level for the 208 and what type of fluid to use in it?

Also does anyone know if there is way to rebuild the front driveshaft slip joint or do you just have to replace the whole driveshaft?

 

[diesel4me]

The fluid should be up to the filler hole plug ,the NP-208's use ATF,so at least if your trans is leaking fluid into the transfer case it wont hurt it,but running the tranny low will!..

You can have a front driveshaft re-splined at a driveshaft shop or machine shop,but it would probably be cheaper to just get a good used one or a rebuilt one..sometimes the yoke wears out the most ,not so much the splines,maybe just replacing the yoke will tighten it up,but maybe not too..

 

[dixiechevy01]

Ok thanks for the info. I thought I read in another forum awhile ago that the fluid should be like right below the fill plug maybe I read it wrong though? Well are the t case input seal and trans output seals 2 seperate seals and have you ever done these seals before?

And the driveshaft mainly has play at the slip joint. Which yoke were you talking about, the cv part of the shaft coming out of the t case? I've heard of those going bad before. Probably my best bet is just get a new or used one.

 

[diesel4me]

I haven't had to separate the Th-400 and NP-208 in my pickup,so I cant say what type seals it uses in there--someone here will know though..there may be more than one seal or different arrangements depending on the year too..

The fluid level,I usually just ensure its full enough for me to feel ATF if I stick my finger in the filler hole,most shops will fill it till some pours back out and they let it drain until it stops..

The slip yoke at the diff end of the front shaft is the yoke I was refering too--the other end at the t-case has a ball and socket joint between the 2 u-joints,if there is wear there your better off just getting a good used or rebuilt shaft since it requires some machine work to fix that part of it..