Driveshaft balancing?

[Louisville86]

So, my '86 (2WD, 2.9, A4LD, Longbed) was suffering from an unpleasant vibration that started about 200 miles ago. It would begin at about 35 mph and get worse as I sped up. It would stop when I let off the gas. So, I correctly guessed that it was U-joints.

I took it the the gear and transmission shop a couple of blocks away (love being able to walk home from dropping off a vehicle for repairs). After diagnosis, I was given the choice of 1) just replace U-joints (front and rear), or 2) U-joints plus balance the driveshaft. I chose the latter. It's done, the vibration is gone and everything is good. But . . .

Did I need to have the driveshaft balanced or did I waste the extra $?

 

[projectnitemare]

good chance you wasted your money. The shaft is factory balanced. Unless the weights rusted off or you hit the shaft off something it will still be in balance. If the weights rusted off good chance the shaft is so rusted you can't balance it anyways. I'd say they use that to make a few extra bucks.

Matt

 

[hopster]

maybe you did maybe not. if it had been out of balance and you didn't balance it it would have taken more time and money to pull the shaft again and then get it balanced. better safe than sorry.

 

[adsm08]

good chance you wasted your money. The shaft is factory balanced. Unless the weights rusted off or you hit the shaft off something it will still be in balance. If the weights rusted off good chance the shaft is so rusted you can't balance it anyways. I'd say they use that to make a few extra bucks.

Matt

Normally they don't go out of balance in normal use, but I have seen it happen.

There is a real fun procedure called a "hose clamp balance" which is exactly what it sounds like, and is very very effective.


I may have to do a write-up on it one of these days.

 

[Louisville86]

maybe you did maybe not. if it had been out of balance and you didn't balance it it would have taken more time and money to pull the shaft again and then get it balanced. better safe than sorry.

That was my thinking; I would have had to take it back to the shop, etc. etc. But now the driveshaft is freshly-painted and looks nice if I stick my head under there. /s

Drove up and down I-25 a little bit today. It's really quiet and smooth now. I looked down and I was going 80 without knowing it.

 

[Mark_88]

When I had my drive shaft welded to match my rear plate I was considering balancing also...but didn't need it...

I did, however, discover that when I assembled the u-joint I didn't do it right and it flew apart after only 10k KM...

As others have said...it's factory balanced and unless it is severely rusted and the weight has been knocked off you're good to go...but did you test it at highway speeds?

 

[adsm08]

but did you test it at highway speeds?

He said he got it up to 80. 65 is the max in most of the states. I'd say that qualifies as "highway speeds".

 

[Mark_88]

He said he got it up to 80. 65 is the max in most of the states. I'd say that qualifies as "highway speeds".

Ah, States...not Km/hr... I guess that qualifies...lol...

But, did he do it backwards? That's the real test...highway speeds backwards will show you all kinds of quirks in your truck...

 

[Surrey]

Ah, States...not Km/hr... I guess that qualifies...lol...

But, did he do it backwards? That's the real test...highway speeds backwards will show you all kinds of quirks in your truck...

Yeah, like you hit a patch of ice, and spun around backwards....

 

[Louisville86]

Ha-ha; here in Colorado the speed limit is 75 when you are not in an urban area. So you can go north or south on I-25 just a short distance from Denver and open it up a little bit.