PatGalvin
Jedi Warrior
Offline
Hello everyone:
Well, a few of you may remember that I blew out the TR3A rear end last September and had it rebuilt locally. I re-installed and all seemed wonderful, for a while. But it seemed like I was bottoming out (scraping) more frequently, so I had the muffler raised up tight under the body. But, scraping persisted. Hmmm, what could it be? Took a trip last weekend to the Foothills and the scraping was awful. It sounded like the tires were scraping up in the wheel wells on every bump. But there was no paint scrapes under the wheel wells.
But then I noticed that the scraping sound persisted when I was climbing up hills under significant load, regardless of road bumps and dips. That got me worried. I got the car up on jack stands and inspected all and couldn't see anything that was scraping. Today, I got under the midsection and examined the front driveshaft U-joint flange connection to the transmission nose piece. And voila, the nyloc nuts on the transmission nose piece flange are hitting the gearbox mounts when the shaft extends forward, when the rear axle travels upwards (like over a dip in the road). The noise I'm hearing was the nuts being ground away against the gearbox mount. Then, I went back and noticed that I've got clear scraping where the rear end axle tube scrapes against the steel loop axle check strap. My theory is that the strap is forcing the axle forward, as it travels upward in its suspension travel, causing the driveshaft to move forward and thus causing the driveshaft nuts to scrape on the mount. This is odd, as I didn't modify the axle travel check straps in any way, just reinstalled them.
I wondered if maybe I installed the axle incorrectly, but I can't see that is the case. It really only goes in one way and it sets upon the springs, at which time you put the "u" shaped bolts down to mount the axle tube to the spring. I have about 1300 miles on the new axle install.
Fixes? Well, I can pull (muscle) the travel limit strap back a bit with the intention of preventing the scraping between the strap and the axle tube and allowing the axle tube to move freely through its desired travel. I'll need to order new nuts and bolts for the driveshaft where it mounts to the gearbox nosepiece.
I am running the HVDA Toyota 5-speed gearbox conversion so I suppose I can also remove the driveshaft and shorten it, as the Toyota conversion has a driveshaft collar that makes the driveshaft a fixed length (because the gearbox nosepiece slides in and out of the gearbox so driveshaft must be fixed length). I need to go check the HVDA conversion instructions for the driveshaft length and check that against my current install. Maybe the driveshaft slipped and lengthened itself? If so, I risk damaging the rear seal on the gearbox and the nosepiece will be driven into the back of the gearbox.
This all seems very weird to me. Let me know if any of you have any other ideas about what might be going on here. Or any hints on how to properly remedy this. I hope these photos illustrate the problem. You can see the scrape on the axle tube, the check strap orientation, and the ground driveshaft nuts. Thanks very much
Pat
Well, a few of you may remember that I blew out the TR3A rear end last September and had it rebuilt locally. I re-installed and all seemed wonderful, for a while. But it seemed like I was bottoming out (scraping) more frequently, so I had the muffler raised up tight under the body. But, scraping persisted. Hmmm, what could it be? Took a trip last weekend to the Foothills and the scraping was awful. It sounded like the tires were scraping up in the wheel wells on every bump. But there was no paint scrapes under the wheel wells.
But then I noticed that the scraping sound persisted when I was climbing up hills under significant load, regardless of road bumps and dips. That got me worried. I got the car up on jack stands and inspected all and couldn't see anything that was scraping. Today, I got under the midsection and examined the front driveshaft U-joint flange connection to the transmission nose piece. And voila, the nyloc nuts on the transmission nose piece flange are hitting the gearbox mounts when the shaft extends forward, when the rear axle travels upwards (like over a dip in the road). The noise I'm hearing was the nuts being ground away against the gearbox mount. Then, I went back and noticed that I've got clear scraping where the rear end axle tube scrapes against the steel loop axle check strap. My theory is that the strap is forcing the axle forward, as it travels upward in its suspension travel, causing the driveshaft to move forward and thus causing the driveshaft nuts to scrape on the mount. This is odd, as I didn't modify the axle travel check straps in any way, just reinstalled them.
I wondered if maybe I installed the axle incorrectly, but I can't see that is the case. It really only goes in one way and it sets upon the springs, at which time you put the "u" shaped bolts down to mount the axle tube to the spring. I have about 1300 miles on the new axle install.
Fixes? Well, I can pull (muscle) the travel limit strap back a bit with the intention of preventing the scraping between the strap and the axle tube and allowing the axle tube to move freely through its desired travel. I'll need to order new nuts and bolts for the driveshaft where it mounts to the gearbox nosepiece.
I am running the HVDA Toyota 5-speed gearbox conversion so I suppose I can also remove the driveshaft and shorten it, as the Toyota conversion has a driveshaft collar that makes the driveshaft a fixed length (because the gearbox nosepiece slides in and out of the gearbox so driveshaft must be fixed length). I need to go check the HVDA conversion instructions for the driveshaft length and check that against my current install. Maybe the driveshaft slipped and lengthened itself? If so, I risk damaging the rear seal on the gearbox and the nosepiece will be driven into the back of the gearbox.
This all seems very weird to me. Let me know if any of you have any other ideas about what might be going on here. Or any hints on how to properly remedy this. I hope these photos illustrate the problem. You can see the scrape on the axle tube, the check strap orientation, and the ground driveshaft nuts. Thanks very much
Pat