Driveshaft u-joint replacement

[SVenable]

I just replaced the u-joints in front and rear drive shafts. The front was straight forward, I used Precicion u-joints, 235 at the front diff, 2 x 331a's at the cv joint. Besides being a pain to get the old joints out everything went back together well and no modifications were required. Now the rear...



I used Precision 330a's on a single piece driveshaft. The 330a's specs are:



cap = 1. 188 "

outside lock up 4. 187", distance between snap rings.



The factory u-joints are:



cap = 1. 188"

outside lock up = 4. 180



I had to grind the caps for them to fit properly. This is nuts. No one makes a direct fit u-joint but Maopar, (AAM), and except from reading on this forum I would not have known how to fix it readily, probably taken me several hours of pondering before I decided to grind the caps.



Why Dodge and AAM decided to make such an odd ball u-joint size and then they whine about how they have troble selling cars. There are millions, well maybe not millions, of u-joints on the market that would have met the criteria for our trucks and several are very common but Dodge cannot select a "standard u-joint". I love my truck but in the future I may get new driveshafts made with an "off the shelf" u-joint in them, all 5 the same size. Think of the fewer parts to carry in inventory. Precision hould have known better also.



I would like to thank all the submitters on this forum for your help.

 

[BenMorgan]

I replaced my rear u-joints a few weeks back with the Precision 330a's. According to the research I did before hand I expected to grind either the caps or the snap rings for a proper fit. It wasn't necessary on mine as they fit properly and the snap rings went in easily.

However,I did have a problem fitting the new u-joint in the knuckle section that slips in the transfer case. The cross section of the joint would not fit inside for assembly. It was because the new joint was a little thicker where the seal of the cap seats. The opposite side of the joint (on the forward end of the shaft) was hollow ground so the new joint slipped in fine. I carefully used a dremel grinder and hollowed out both sides of the union just enough so the joint would fit. I was worried about throwing the shaft assembly out of balance, but it has no felt vibration. I should have taken pictures of this as it would've made it more understandable.

 

[wyosteve]

I ran into the same problem about a month ago. Wanted to use Precisions, but the shop couldn't get them to fit, so they ended up using ones from Dodge. $26 a piece for Precisions, $90 from Dodge. They deserve to go belly up!

 

[pullya]

The suprising thing is that if you buy the Dodge rear U joints, you can buy a NEW rear drive shaft with the U joints already installed almost as cheap as the U joints themselves. U joints about $90 each---- the drive shaft w/ U joints about $185.

Jay

 

[Jengle]

Yeah, but when I had to get the new Dodge ones at $90/ea, they had almost no grease inside the caps, which would have led to another premature failure, if I hadn't checked.

 

[sangell]

To bring up an old thread,



Neapco part number 3-0486 has an Outside lock up distance of 4. 178".