Let's Talk Front Driveshafts........

From: Kyle Kozubal (grndak4x4@home.com)
Date: Mon Jul 10 2000 - 17:11:45 EDT


Well with the leaking diff cover fixed and the transfer case fixed......let
us move on to a new episode: Fixing the noise coming from under the cab
portion of my truck; which sounds like, if I may quote Jon Smith....."the
little man hitting with floorboards with a hammer." And this is what is
sounds like too! Remember now, the clunking noise ONLY occurs when
acceleration, hard or soft, from a dead stop; basically when the initial
load is put on the drivetrain. It first occured around January, and only
made this noise once every month. Now, it will clunk typically on every
acceleration and will ocassionally clunk even 2-3 times per acceleration. I
have also noticed when I put my truck in reverse, I get a good clunk when
the tranny engages and puts the initial load on the drivetrain.

I have checked the motor mounts, transmission mounts, tie rods, ball
joints.....and everything is in great condition. I have also ruled out the
rear driveshaft, as it is extremely tight with no slop at all. So this
basically leaves the front driveshaft and its 3 universal joints as the
culprit, right? At the front of the front driveshaft, where it connects to
the front axle.....there is 1 ujoint. I noticed a good amount of
'grease-gun' type grease flung around the general area where this front-most
ujoint is, and I cleaned it all off while putting on a new rubber fuel line
hose this past weekend. So possibly this front ujoint needs replacing since
it is leaking so bad. Now onto the rear part of the front driveshaft, where
it goes into the front of the transfer case. There are 2 more ujoints back
here, since the front shaft uses a double cardan style ujoint system. There
really is no grease or visual leakage back here, but these ujoints are
sealed, and I dont think they have any grease fittings. So maybe these have
dried up and need replacing also, since I do have 125,500 miles on my truck.
*****Another question is, what is the zerk fitting for in the middle of the
front driveshaft? Is this for the 'slip yolk", which allows the front shaft
to expand out(lengthen) and contract(shorten)? Could the splines on this
slip yolk be worn and clunking as it skips over the the next 'tooth'? If so,
I think this could be a pricey fix......but hopefully the driveshaft shop
will tell me if it is ok.
*****The ujoint clamps, which hold the joints and really the driveshaft to
the axle yokes.....should these be replaced or can they be reused?
I called around, and the best deal I found for a front driveshaft rebuild
will cost me $115. This will inlcude 3 new ujoints(all greaseable this
time!), installation, shaft balance, grease, and a new socket ball/retainer.
This place is the same place which I took my front axle cj joints into to
get rebuilt. I want to definately get this fixed this week and hopefully be
done with repair work for a while. The shaft rebuild would only take 2-3
hours, and looks like it is pretty easy to remove the shaft from the truck.
Thanks for any and all info.
Kyle
93 Dakota 4x4 V6



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