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**Guest** · 25 March 2004, 14:45

Originally posted by bensonsnuts

Had a niggling rattle for a couple of months thats been driving me crazy

Finally discovered the rear u/j was on it's way out. As the bolts had been tightened by KingKong with a jackhammer I had to take it to the garage to get it removed.
It wasn't till I took it to the specialist I found out that the garage should not have split it without marking where it originally fitted together. They warned it could well vibrate worse than ever if refitted incorrectly.
They were right .....it did.
I undid the rear end & turned it 180 degrees. This was a vast improvement..but there is still a shudder from about 15 -25 mph . Unfortunately this makes it horrible around town.
The garage aren't much help & reckon there should be no difference on such a short shaft.
Somebody else told me there could be 16 combinations...i.e. 4 x 4 ....which is the number of bolts on the u/j at each end.
I can't face fitting and removing it another 14 times...especially as its lashing down outside

Now I know they are balanced..but surely balanced means as long as it is aligned...there shouldn't be a top or bottom etc.
I shouldn't need to try each u/j in each position ,isn't it just the interior spline that needs adjusting ? How many positions does that have ?
Anybody know ??

Geoff.

There are lots more than 16 combinations - sorry to be the bearer of bad news. Because the shaft is nore than one piece (i.e its the shaft, plus the UJs (2 parts each) and there are also probably about 20 positions on the spline and four positions each end, then the combinations are immense/ The problem is that the unit is balanced from the factory with the UJs fitted. When you change a UJ, if it is at all out of balance compared to the old one then that can cause vibration. Also if the splines are fitted in a different position that can cause a vibration.

Generally in 8 out of 10 situations you will get away without marking it however if they have fitted the Yoke 180 degrees out from it's original position this can also be a problem (actually increasing the possible combinations from 4 to 8 each end.

Have a look at the propshaft, you will often find balance weights attached to the outside of the shaft. You may be able to find where one has come off. This can often be a reason why the UJs fail apart from dirt, lack of grease etc.

Your best bet is to get the garage to have the propshaft balanced as they didn't do the job correctly.

Hope that all made sense.

Cheers

**TonyN** · 25 March 2004, 20:34

you should be able to get it balenced locally, shouldn't be expensive, I'd renew the UJ's anyway, they are only �10ish from Milners. A good prop shop will recommend they are changed before balencing anyway. Then you know its OK.

and move on to the next when the vibes are stil there......

**macca** · 2 May 2005, 12:50

New Ujs but still shaking

I just had the rear uj replaced but in my haste to get it done f**kn forgot to mark the shaft. If anyone could help with identifying where the propshaft weight is in relation to the front uv grease nipples as this would greatly reduce the options. As i presume they are going to be similar when they leave the factory.If this fails i guess ill be up for a ballance.
cheers, grant

**JimL** · 2 May 2005, 22:52

http://www.pirate4x4.com/tech/billav...ft/index2.html

Hope that helps.

**macca** · 3 May 2005, 12:35

Thanks

Thanks jiml that has given me a few ideas to try and fix my problem, very muchly appreciate your help.now all ivr got to do is get out there and undo the bolts again and spin it round a few degrees and ill be well on the way to less vibrations. Thanks again, Grant

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