U-Joint Replacement. I have no flex disc.

[BimmerBro]

Apparently I have a Driveshaft with no flexdisc in my 1986 325es auto. Just U-joints at each end. This is not to unusual from what i've read on other forums.
Today I was trying to replace the centermount bearing (which is a common cause I hear for that "thump" as you pull away from a stop) and my rear u joint is completely froze up and in need of replacing. The mechanic I was doing this with says these u joints could be replaced. I found on pelican parts "replacement u joints" part # 26-11-7-518-304-M158. However it claims its for verts only AND vehicles equipped with replacement style U joints (thats me). My question is does anyone know where to find replacement u joints specific for my car or will these work out.

[Aptyp]

you need to find a local driveshaft shop. They can all be replaced, but they have to be rebalanced as a whole...

[BimmerBro]

My mechanic is fortunate enough to have the whole set up including a machine shop at his place where we work. Will this be enough? As for rebalancing as a whole, is this a PITA? Any tips, I'd like to just replace instead of buying a whole new one and my guy say's it's plenty possible.

[BimmerBro]

Alright we have the Center Mount Bearing in and we replaced one of three u joints and it took FOREVER. We got it all back together and it runs. The new Center Mount got rid of that damn thump when you pull away from a stop. However I have a new sound that sounds like a "wah wah wah" in a rotational fashion. It's not there all the time, usually when it shows up is right when i start it up and drive. Does anyone know what that sound could be? We're planning on taking it to a driveshaft shop later this week or next to do the remaining two joints and driveshaft balancing. Can this be done?

[BimmerBro]

....

[Aptyp]

not too many machine shops can balance a 2 piece driveshaft... not too many guys with tools, who've never done this before can do this... but hey, you have all this under control...

[BimmerBro]

I'm alittle bit more optimistic then that.....plenty of people on R3V have done what i'm doing.

oh btw your really cool.....8)

[clorey]

I've done a few 2 piece driveshafts and didn't have any problems but a couple things i have seen is not "phasing" the shafts(marking them to make sure they are alinged) before splitting the two,they are balanced as a whole and if you put them back together one turn off it does make a difference.I have also seen damage from a vise or hammer on the shaft itself from u-joint replacement,you should never damage the area below the weld seam as this will effect balance also.You should also make sure the u-joint you do replace moves freely before install,i've seen them pinched so tight they were not moveable by hand.

any one of these factors could be your sound.

[Jean]

So your driveshaft really doesn't have a Guibo or flex disc? That's a first.

[graphikg]

Sorry to ressurect this, but dont get mad at me for searching. How much does balancing usually run?