[89on35s]

I drive an 89' pick up with 35's and stock drivetrain. The last 2 times I went 4-wheelin, I broke a u-joint. The first one on the back shaft at the diff, The second one at the front shaft at the diff.
I only run a 4" rancho lift in front, including front degree shims, and add-a-leafs in the rear, so the angles are not that extreme.
My first thought is to upgrade to driveshafts from a 3/4 ton to get bigger u joint crosses. I know that my NP-241 t-case was available in 3/4 ton trucks, as was my Dana 44 front diff, so getting yokes for these is no problem. Where I run into trouble is at the 9 1/4" rear diff. Will I be able to find a 3/4 ton size yoke to match the pinion on this 1/2 ton diff?
Also if I can find a 3/4 ton 4x4 at a wrecker, I think that the front driveshaft will work as is, and the back one should be able to be shortened to match thi original.
Any thoughts on this would be greatly appreciated
Cley

 

[ddart]

for a long time dodge has used the same size joints in 1/2 and 3/4 tons. what kind of joints do you buy? with u joints you get what you pay for. in the past year or so some mfgs have come out with really strong new joints. i would look in some 4wd mags to find a manufacturer. it would probably be cheaper and much easier than changing yokes for bigger joints.

 

[89on35s]

I guess I never looked at 3/4 ton u-joints, but I would think they would be bigger than those puny things on my 1/2 ton,

 

[ddart]

yeah its kinda sad how small they are and actually some one tons have the same joint. you have to get a dana 60 in a 1 tn to get the bigger joints but they are hard to come by and are expensive! what kind of wheelin do you do? (when you break them)

 

[89on35s]

The first one broke climbing a hill and stupid me should have let off the gas and didn't. The other one broke on a muddy back road by my buddy's farm. The second one really cheesed me off cause I was just getting started.

 

[ddart]

do you know what kind of shape they were in when they broke cause if you keep them greased they should last quite a while. they dont usually break in the mud unless you've got big tires sunk down in a big hole

 

[89on35s]

Guess i'll hafta try good quality u-joints, until I can upgrade to D-60's. Maybe I should pay better attention to the little stuff that i've got, in hopes it will last longer.

 

[ddart]

i was just curious but have you looked under that new hemi?
what rear does it have and are they the small joints too?

 

[89on35s]

I dont know, but that is a helluva good place to look, as soon as the wife gets home with it

 

[RXT]

OK heres a few thoughts.

If you buy greasable U-joints, there is a right way and wrong way to install them. The grease fitting hole actually becomes a weak spot for the u-joint, and if it's on wrong, it's most likely to crack starting at the grease fitting.

This will be hard to explain but looking at the rotation of the driveshaft, the grease fitting should have compression on it, which makes the grease fitting area stronger.

You can avoid that potential problem with life time lubricated u-joints which do not have grease fittings, but then these are more prone to over heating and failure because you cannot purge out old grease especially if the grease becomes contaminated with water.

Ed

 

[Bogie]

Yea I have to agree with first buying quality U-Joints

 

[mad dog]

I have a dana 60 in my pw it also has the small u-joints and I break them so often that I carry 2 spares.The diff is out of a 74 I don't know when they went to a larger size,but I am going to machine my yoke flat,machine a plate w/4 3/8 bolt holes and one large enough to allow access to the pinion nut, weld it up and use some military shafts that use external full circle snap rings and a 4 bolt flange on each end.I'll post how it turns out

 

[lost1]

Buy the good u-joints and carry spares. At least its the $30 joints and not the $600 diff that is crapping out. It is a good thing to have a cheap, accessable weak spot.

 

[Guest]

I agree stick with Spicer or Neapco joints

 

[89on35s]

I checked the Hemi, It looks the same as the 89'. I'm still going to look further into bigger crosses, and custom shafts. I know my diffs must be stronger than these cheesy joints.

 

[MudFlap]

I ONLY use Spicer U-joints. Lessons learned the hard way. The school of hard knocks is an accelerated curriculum.

 

[Smokey]

I know this is not what you want to hear,... but shorter tires and a lighter foot would ease some of that breakage...

 

[KThaxton]

I know this is not what you want to hear,... but shorter tires and a lighter foot would ease some of that breakage...

Smokey! BACK TO YOUR ROOM! And don't come out till you think about what you said!

 

[Smokey]

LMAO. I'm old ya know. I get to say such things with impunity !

 

[Guest]

Whew, I'm glad Smokey said it before I did. Your 35's, in my opinion, put you right on the edge of what your stock truck can handle. The axles will hold up fine, but, as you already know, the yokes and the u-joints are the weak link. You don't mention your gear ratio, if stock it's 3.21 or 3.55. You are woefully over geared for those tires. That also puts a strain on the drivetrain. I too would consider either smaller tires or taller gears.