+++balancing driveshafts+++

[I.C.]

Lets see if anyone can help out....
Vehicle:2000 chevy silverado
Problem: vibration between 45-70mph though the whole truck.

Not too long ago,i had to rebuild my tranny. Upon taking it out, the adaptor which bolts to the end of the tranny had cracked & broken on the top right sides. The mechanic who re did my tranny said he had the same prob & had checked, THEN REPLACED his driveshaft. Before the tranny rebuild, the same vibration occurred at the same speeds.
My problem: I'm calling different places about balancing & they say "Is it aluminum? We can't balance aluminum shafts. You need to replace with a steel shaft". Is this true? My current shaft HAS WEIGHTS &i swear I haven't dropped or done any damage to it! Why would I need to REPLACE with a steel shaft instead of balancing the current one???

[stunt305]

Disconnect and turn 180 degrees if there are no defects in the shaft that may be it. In regards to Steel vs aluminum I'm almost 110 percent you can balance either

[I.C.]

yea i rotated it,but.... im getting it looked at next week. thnx bruh

[dlish]

wtf would a 180 rotate do?
if it didnt toss a weight & has never been dropped its prob ok. poss diff or axle issue???

[dlish]

also is it a stick or auto?

[stunt305]

Quote:

Originally Posted by dlish wtf would a 180 rotate do? if it didnt toss a weight & has never been dropped its prob ok. poss diff or axle issue???

its not a dumb fucking suggestion im not even going to reply im sure im not the only one one here who knows thats a first step in driveline vibration concerns

[dlish]

Quote:

Originally Posted by stunt305 its not a dumb fucking suggestion im not even going to reply im sure im not the only one one here who knows thats a first step in driveline vibration concerns

how? the drive shaft isnt balanced with the output shaft of the trans or diff yoke? so even if there was a balance issue with the drive shaft simply changing its position with its end points(output shaft/pinion yoke)shouldnt change anything. Im not trying to belittle you at all man, just dont see how that would work? explain to me how changing the shafts position would effect balance?

[stunt305]

My bad for coming off as an ass. I know moving your U-joints into another position will often cause vibrations. If you take the driveshaft off at the U-joint, you have to mark everything to make sure you get it back on in the exact orientation. If not it will be out of phase. I think that most likely the problem is the shaft was not balanced properly to begin with.

-chris

[drew"db"beck]

dlish Ive heard of the 180 fixing it before...

[Rummel Autosport]

Quote:

Originally Posted by stunt305 My bad for coming off as an ass. I know moving your U-joints into another position will often cause vibrations. If you take the driveshaft off at the U-joint, you have to mark everything to make sure you get it back on in the exact orientation. If not it will be out of phase. I think that most likely the problem is the shaft was not balanced properly to begin with. -chris

+1

you can balance either steel or aluminum, all they do is weld a weight to it. if it is an aluminum shaft and they dont have a Tig, or a Spool gun for aluminum they can just find a suitable spot on the ends to weld a steel weight to. I don't recommend that, but I have seen it done, and it worked fine.
Most likely it wasn't done properly, or it looked like a good weld when it was on the bench, but the weight flew off first time it got a jolt.
That does happen sometimes.