240sx/rb20 driveshaft issue

[91boosted240]

hey guys ok so i have a 91 240sx with a rb20 im having an issue with my U joints breaking happend 2 times in the past month and a half. i have a ka24de transmission mounted and i have a custom single piece driveshaft. its hard for me to believe that my u joints would break that fast and easy anyone have any ideas or suggestion on why it would be breaking that much and that fast?

[Promise Land]

who made the custom driveshaft? Have you contacted them about the issue?

[91boosted240]

this local company called driveline services. about a month after i had it made by them it snapped both u joints the one by the yoke and the one by the pumpkin, i mean it snapped so bad it dropped out from under my car. i took it back to him and said uh i dont think this is suposed to happen and he said hes never seen that before and asked are you running alot of power i was like if you consider 300hp alot. anyway i payed him to put new u joints in got it back in the car and noticed that same day i was feeling vibrations at about 55mph or so and humming like the driveshaft was outa balance, called him up again and said hey did you balance it and he said no he forgot and wanted me to pay 100 bucks for him to do that when he forgot so i said i cant afford that right now. well that was 3 weeks ago and now my rear one snapped again 3 weeks later. to me and several other people i had look at it today said they must have not done it right or not balanced it that well because the u joints shouldnt be going out once a month for casual driving with the ocasonal getting on it. be a different story if i was at a drag strip all day launching it. so idk if its something on my part that im doing wrong or if its something that the driveshaft place is doing thats causing them to fail so fast.

[compactfean]

Ive put more power than that on my 2 piece driveshaft! Lol. I would check your trans mount. If there is alot of flex in the trans mount, on acceleration the angle at which the drive shaft is rotated, changes. Which will put stress on the u-joints. Check your invoice to see if you were charged for a balance ....if so than I would demand service redone for free......I've never heard about a custom driveshaft that you have to pay extra For a balance.I'd try to be civil but in the end I think. At minimum he balance it for free...I would do my own u-joints.