1977 GMC pickup front driveshaft

[wild03]

Well I 'm sure I have a np203, the truck has front locking hubs, not sure about the part-time mod. since I'm having problems with the levers....(see previows thread)

This question is regarding the driveshafts and again is something chilton doesn't mention.

both driveshafts on the truck have some sort of sleeve that allows the length of the shafts to vary, they have a grease fitting to pump grease inside the sleeve. the front sleeve has a lot of play, like the shaft is too small for the sleeve, If they have bearings inside, they are GONE, the rear sleeve is solid.

Well how do I servise the front driveshaft? is it a complete driveshaft replacement, just the sleeve? bearings?....chilton only covers CV joints and shaft removal and installation, nothing on the sleeves!


Thanks!

[roundedline]

Has the truck been lifted?  I would verify that the splined shaft is going into the sleeve far enough first.  How much of the splines are exposed when the truck is resting?  The only service to the driveshafts are the U-joints and the lubrication of that sleeved joint, there are no bearings in there.  The sleeve allows for axle droop and compression.  If it hasn't been lubed, it has been rubbing metal to metal contact and that could be the "loose" feel you are getting.  BUT, I can't decipher what loose means to you.  I am imagining A LOT of slop in the front driveshaft.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com

[wild03]

Thanks Chris,

Yes the truck is higher than normal, I can see 3" or so blocks on the springs.
I will double check how much of the splines are exposed,
There's slop on the driveshaft, it feels like the sleeve is too big for the driveshaft.

The 203 was running locked all the time with the front wheels hub locks unlocked, one of the levers was not connected and the 203 was left on the lock position, I assume this aggravated the situation,

If it turns out the 203 has a parttime kit, I will be running it on 2wd all the time, and will only use the 4WD when pulling the boat out of the ramp. I will have to make sure than the shaft does not spin on the sleeve.
I will take it out for a closer inspection.

Thanks again

[wild03]

I pumped soome grease with a grease gun and it seems a lot metter now.

The 203 doesn't have a part-time kit, so that makes the locking front hubs useless unless I run the case locked all the time, I'll definetly won't be doing that, I locked the front hubs, and I'll be looking online for a part-time kit.

Thanks again