Hi i recently purchased at t30 terex articulated dump truck. The previous owner had what looks to be the torque converter input shaft replaced. I was told the shaft brakes because the driver hasn't let the air build up to release the e brake completely. So we get the truck home and back it off the float, drive around the yard once and go to back up and the truck looses all hydraulics and forward reverse. I assume this shaft has broken again as per what the previous mechanic told me happens when the shaft brakes. It seems odd to me that such a tiny part of the shaft brakes off due to the e brake sticking. According to the last guy driving the truck he was just putting it in reverse amd th ebrake was off when it stopped moving. When I looked at the truck to purchase it there was a terrible rattle coming from the torque converter housing when the engine was at idol. When you gave it a slight bit of throttle the noise went away. Id like to believe theres something else snapping this tiny shaft. Maybe something causing this terrible rattle. Any thoughts on the issue would be great. I have not taken it apart yet, im getting to it shortly. The truck ran and drove well (other than the rattle knock noise) when I looked at it Pic of the shaft is attched. Im holding the small part that brakes off. If anyone has this shaft for sale please let me know. Thanks!
Hi greerco, I'd strongly assume the vibration damper is corroded or failed somehow. This kind of damage is typical for excessive vibrations from engine. Also the rattling noise is a sign vibrations coming through to converter drive.
It sounded like a terrible engine knock until it idoled up a few rpm.
Just a update. I did find the coupler on the back of the engine completely disintegrated I managed to purchase the rubber part but I need the rest of the steel parts. It looks to have a clutch disc type of thing and some plates. Also im curious about the small shaft that broke a few times. I since have had it welded back together but when i was re assembling the front cover (which houses the brake turbine) i was curious as to of its normal for the small shaft to "float" in the input of the torque converter. The small shaft has threaded holes but there were no bolts holding it in. It seems like alot of weight on the small splined end of the shaft that sits in the torque converter and it also drives the input shaft of the transmission to just be sitting in there, where the larger end of the small shaft goes through the end cover bearing. To me id think it should be solid not just sitting in the input of the torque converter. That's alot of down pressure So if anyone knows where I can purchase a complete coupler for the back of the engine and if someone can make sense of the shaft issue question, some insite would be great! Thanks
5 TA30 & TA300 here, and I just put a flywheel coupler in the TA300. Mine sheared completely, no output shaft movement. That coupling absorbs harmonics that can break an input shaft. This is why most light duty diesel trucks w/ manual transmissions have dual mass flywheel. Had a Cat 328DLCR shear the hydraulic pump input shaft around 1500 hours. Turns out that it had, from the factory, the wrong combination of balancer and flywheel. My serial number was *****334, and the bulletin ended at *****329 s/n. I've been doing this for over 30 years now, and that was the only excavator hydraulic pump I've had where the input shaft sheared.
Highly doubt that weld will hold for any length of time. Best get on google to find some parts hiding somewhere in the world, and yes it will take time or you'll know the eventual result. Simon C
Greerco, the flexible coupling rubber is supposed to absorb the torsional vibrations from engine, the frictions plates dampen. Terex usually fitted Centa couplings for a long time. Try to purchase a new part. Your tranny is equipped with a retarder in front of torque converter, isn't it? So the drive should look like attached pic. So, it is not clear to me where the short (welded) spline fits into input drive. I also doubt the weld will last.