I had u joints done on my 69 a few months ago and last week I had to remove the driveshaft front u joint in order to replaced my flywheel. I noticed that the 2 cups for the u joint appeared to be different lengths. The diameter was the same and they fit nicely into the output shaft recess,but the fact that one is slightly longer (.25") concerns me . Did the shop misplace a halfshaft cup for a drive shaft cup ? I can't help but think this would cause a driveshaft out of balance issue. There is a small vibration @ speed but nothing severe. Should this be rectified?

 

Something has been changed on your driveline. Either the driveshaft or a flange. You have a conversion joint. One side is a 1330, the other is a 1310. This is a factory joint for other GM cars. Nothing to worry about.
Mike

 

What concerns me is that the mismatched cups are on the same portion of the joint ( ie. 3oclock and 9 oclock with bearing on bench),both on the are on the transmission output yoke. The 12 oclock and 6 oclock positions are both equal to one another.

 

That is how they should be. You have a 1330 trans yoke and a 1310 driveshaft. Or at least you should have. The 1310 driveshaft should be stock for your 69. What trans do you have?
Mike

 

Muncie m 20 , so the u joint has 3 cups of one length and 1 that is .25" shorter?

 

I'm about to replace my driveshaft u-joints as well, and although I have NOT removed them from the shaft yet, I did notice they are different on each end...

I've got a '95 LT1/4L60e tranny w/ the stock '76 rear end... anyone got the numbers I need for my situation (I'm sure the teenage punk at the parts counter will be clueless!)

Let me know if more info is needed...

Thanks!

p.s. are these part numbers for Spicer or another brand?

added pic:

I'm using the aluminum as shown below (steel is the original for the TH400 tranny)
[IMG]

 

No,
All 4 caps are the same. The trunion on the u-joint at 3 and 9 oclock will be .6 longer than at 12 and 6 oclock. I have a step away from the computer for awhile. Give me a call 214-717-8379.
Mike

 

Something is wrong, you should not have 1 odd cap.

 

Why do you have that giant "flywheel style" slip yoke on there? Kinda defeats the point of going to all aluminum and reducing rotating mass when you put a 10 pould slip yoke on, doesnt it?

btw - skip the parts house since that pimply faced kid is going to ask you "what year car are you working on sir". Go to your local drive shaft shop and ask for spicers.


bigredbrad

 

DR76,
The are the series numbers, not the part numbers. Give me a call also.
Mike

 

I had my u- joints replaced and the mechanic found that the previous owner had lost the spring clips so he SPOT WELDED the u-joints in! the mechanic had to cut them out..it was a nightmare...and just a couple days ago

 

Mike, found my original invoice for the driveshaft and it listed parts SPICER-5-786X (1310 for aluminum) and Neapco 1-0134BF (1310/1330)

I've got a "rolling" sound inside my driveshaft that seems weird to me (unless it has something to do w/ the balance of it???), so going to bring it by the driveline shop and see what that's all about...

THANKS SO MUCH for your assistance!

 

I just replaced all of my u-joints and end caps should be same length. Does the u-joint fit into the u-joint holder? There should be small notches on the ends of the mating yokes that hold the joint together. I had the same problem on one u-joint when I started, as I was greasing the end cap I did not notice that a bearing had slipped out and was caught between the end flange and the end cap and that was about .025 longer until I figured out what it was,I could not get the end spring clip to catch in the grove, that may be your problem also, did you look inside your end cap to see if one might be stuck there and held with the grease?
Sorry I just re-read your post and it seems that your u-joint does fit into the output shaft , so your cap is just a little larger than the other ones. Should not be a problem as long as you are sure it is a good fit and it fits into the mating flange it may have been a replacement cap, sometimes while installing them with a hammer one may chip a cap in the process. As I mentioned as long as its a good tight fit , like the others it should not be a problem.

 

Dr76,
The 5-786X is no longer available. It's the same as the 5-785X (1310series) but had a coating on it to prevent corrosion. The Neapco is the Spicer 5-134X conversion joint (1310 to 1330). It's a standard u-joint used in many of the other GM models. Unfortunately it's not available as a SpicerLife solid due to the unequal lengths but it is still a strong joint. The 5-785X is a solid joint.
Good talking with you on the phone.
Mike

 

We found the problem on Vintage-racer's. For some reason the person who installed the joint had put a mis-matched cap on. He had 3 matching caps and one oddball.
Mike

 

Hey Mike(tracdogg2), Thanks so much for all your help with the diagnosis. I contacted the shop which did the work today and they offered to replace the joint if I drove the 80 miles round trip. I countered with them sending me a replacement u joint and replacing it myself. It really sucks to pay someone you have trusted w/ your suspension work for years and then have to go back over their work w/ a fine tooth comb fearful that something else isn't tight or correct. Oh well....I guess I'm back to doing all of my own labor again. This was the 2nd incidence of poor workmanship on this work order.