SOT having some fun with driveshaft balancing

[2002iii]

I've seen driveshafts with a stack of washers welded on to balance them. It's the cheap and easy way to balance a driveshaft. Most driveshaft shops make their money off speed and volume, so it's a lot easier than taking the whole thing back apart.

 

Also I would assume the quality of the parts has a lot to do with it. A lot more parts are being made in China and other countries that don't have as good quality control. The old saying "you get what you pay for " is still true. 

 

@PatAllen You are a brave man making your own driveshaft balancing machine and running it at 5000rpm without any safety loop/cage. I would suggest at least 2 steel driveshaft loops, 1 over each section of the driveshaft. If anything happens at 5000rpm that driveshaft could kill you.

[PatAllen]

the thing is, i am not cheap. i bought like 1000$ worth of used driveshafts just for the purpose of the test and learning. Shafts that i will probably never use, + the ones i had already from remain cars and collection.

 

i want exactly to avoid staking up washers on balanced shaft, ie, i want to know how and why this is needed (no i know).

altought one shaft can be well balanced in such ways it proved me that it stresses up the ujoints a lot and generate a lot of audible noise...i have many shafts with heavy weights and they do not perform well at all no matter what, especially at high speed. well, not to my standards...factory shafts, stock, and some supposedely rebuilded by "experts".

 

Noted on the loops. i did only 1x 5000rpm run and to be honnest it was scarry. i keep my tests around 3000rpm where there is a harmonic and where it is the most audible/feelable into a car.

[PatAllen]

would you ride this ?

same for a driveshaft. it just hides something wrong.

[2002iii]

2 minutes ago, PatAllen said:

the thing is, i am not cheap. i bought like 1000$ worth of used driveshafts just for the purpose of the test and learning. Shafts that i will probably never use, + the ones i had already from remain cars and collection.

 

i want exactly to avoid staking up washers on balanced shaft, ie, i want to know how and why this is needed (no i know).

altought one shaft can be well balanced in such ways it proved me that it stresses up the ujoints a lot and generate a lot of audible noise...i have many shafts with heavy weights and they do not perform well at all no matter what, especially at high speed. well, not to my standards...factory shafts, stock, and some supposedely rebuilded by "experts".

 

Noted on the loops. i did only 1x 5000rpm run and to be honnest it was scarry. i keep my tests around 3000rpm where there is a harmonic and where it is the most audible/feelable into a car.

I wasn't calling you cheap, I was just pointing out why most shops do it that way. They're more concerned with money then quality these days it seems to me.

 

I totally agree putting extra weight on anything rotating is usually not good, unfortunately not everyone else does. Most newer cars have enough sound deadening to get rid of those annoying noises, so people don't notice. The way cars are built these days is to be cheap and disposable, so they take shortcuts and put bandaids on problems instead of fixing them properly. The standards for quality and dimensional tolerances seem to be getting looser and looser.

 

Add up the hours it took you to balance a shaft without adding weights, then multiply by $100 and you'll get approximately what it would cost at a driveshaft shop. If it's under $500 you might have something.

 

Even at 3000rpm I would still suggest the safety loops. Safety first, it only takes one mistake to severely injure or kill you. There is a reason the driveshaft is underneath the car in a metal transmission tunnel.

[PatAllen]

1 hour ago, 2002iii said:

I wasn't calling you cheap, I was just pointing out why most shops do it that way. They're more concerned with money then quality these days it seems to me.

 

I totally agree putting extra weight on anything rotating is usually not good, unfortunately not everyone else does. Most newer cars have enough sound deadening to get rid of those annoying noises, so people don't notice. The way cars are built these days is to be cheap and disposable, so they take shortcuts and put bandaids on problems instead of fixing them properly. The standards for quality and dimensional tolerances seem to be getting looser and looser.

 

Add up the hours it took you to balance a shaft without adding weights, then multiply by $100 and you'll get approximately what it would cost at a driveshaft shop. If it's under $500 you might have something.

 

Even at 3000rpm I would still suggest the safety loops. Safety first, it only takes one mistake to severely injure or kill you. There is a reason the driveshaft is underneath the car in a metal transmission tunnel.

i understand your point you didnt called me cheap i know.

i am just not one of thoses shop nor i ever will.

 

i do this all for my own purpose wathever it cost. its my learning course.

 

fwiw i paid 1200$ my E36 DS in 2008, and it was bad. very.

 

Edited February 25, 2021 by PatAllen

[PatAllen]

i have this tool too to pinpoint rapidly sources and severity of vibration, but at the levels i am at now it doesnt measure anything at all....0.00 or 0.01 wathever it means on its scale.

 

Edited February 25, 2021 by PatAllen

[2002iii]

17 minutes ago, PatAllen said:

i understand your point you didnt called me cheap i know.

i am just not one of thoses shop nor i ever will.

 

i do this all for my own purpose wathever it cost. its my learning course.

 

fwiw i paid 1200$ my E36 DS in 2008, and it was bad. very.

 

I feel your pain on having to deal with BS from shops.

 

I applaud you for doing it yourself and educating yourself. Like they say "If your want it done right sometimes you have to do it yourself". 

 

Wow $1200 for a good driveshaft sounds like too much to me. Was it a brand new driveshaft?

 

If I paid that much for a driveshaft shaft and it was bad I would take it back to whoever I bought it from and demand that it be made right or a full refund.

[PatAllen]

i am not the only one to be completely nuts about DS

 

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/950986-balancing-and-phasing-new-driveshaft-components.html

 

Toyotas lexus uses various weigth bolts on the guibo to finish proper balancing ON CAR...and they do balance guibo as well...pffff

 

found out also that most if not all DS i am playing with have common problem, the center bearing is not 90 deg perfect to the front section causing a tangent vibration. it is like 5-6 thou, once machined on a lathe near 0, that vibration is almost gone....

 

I found out too that on the 3 DS from E60 i am playng with, it appears that the front section IS balanced WITH the guibo....so as soon as you change the guibo, it becomes out of balance.....loool