nin478 Posted June 22, 2023 Share Posted June 22, 2023 Hello, I recently towed my LS400 and now it seems to have a malfunction. Before towing I disconnected the driveshaft carrier bearing and the rear bolts to the diff then slid the driveshaft forward off of the diff then tied it off so it wouldn't move. After getting to our new location I bolted everything back then took it for a drive. At about 20-30 miles the driveshaft seems to be vibrating pretty bad. As soon as I put it in neutral to coast the vibration immediately stops. Anyone have any thoughts? Quote Link to comment Share on other sites More sharing options...
paulo57509 Posted June 22, 2023 Share Posted June 22, 2023 Before you unbolted the driveshaft from the differential, did you mark both sides of the flange so that it was bolted back in the same orientation? Did you replace the adjusting washers in their proper locations between the body and center support bearing? Quote Link to comment Share on other sites More sharing options...
nin478 Posted June 22, 2023 Author Share Posted June 22, 2023 I did not mark them. Could that be the issue? I did put the washers back where they were supposed to go on the center support. Quote Link to comment Share on other sites More sharing options...
paulo57509 Posted June 23, 2023 Share Posted June 23, 2023 The service manual wouldn't specify replacing everything in the same orientation that they were removed if it wasn't important. I have no idea how you recover from this oversight. The replacement attachment is FYI. PR-3 Propeller Shaft Assembly - Removal.pdf PR-9 Propeller Shaft Assembly - Installation.pdf PR-6 Propeller Shaft Assembly - Replacement.pdf Quote Link to comment Share on other sites More sharing options...
nin478 Posted June 23, 2023 Author Share Posted June 23, 2023 Looks like I need to start moving the shaft around the drivetrain holes... Doh! Thanks for the insight. Quote Link to comment Share on other sites More sharing options...
scbuckeye Posted June 23, 2023 Share Posted June 23, 2023 Having been a mechanic for some 50+ years, it is always a good practice to chalkmark the locations of any moving part so as to put it back together the exact same way.. This was crucial in the older days when wheels were balanced ON the car. This type of balancing made it near impossible to rotate the wheels as the wheels were balanced on a certain axle side Quote Link to comment Share on other sites More sharing options...
nin478 Posted June 24, 2023 Author Share Posted June 24, 2023 Fixed! Put the transmission in neutral, took off the bolts and rotated the driveshaft. Tightened everything down and drove it and it was connected back the right way. Thank you to everyone for your help! 2 Quote Link to comment Share on other sites More sharing options...
fondu Posted July 6, 2023 Share Posted July 6, 2023 Did you rotate it 180 Degrees? Try each different position on the rear flange? Or did you get lucky the first go around? Quote Link to comment Share on other sites More sharing options...
nin478 Posted July 6, 2023 Author Share Posted July 6, 2023 I would say I got lucky. The flex plate was stuck to the driveshaft so I only had 2 other positions to try and the first one fixed it. If you're having trouble I'd recommend trying the other spots on the driveshaft. Quote Link to comment Share on other sites More sharing options...
fondu Posted July 6, 2023 Share Posted July 6, 2023 When you say flex plate do you mean the rubber piece at each end of the shaft? (guibo) These driveshafts only have one proper orientation, each end is 180 degrees opposite of each other (in phase). However it would make sense that the diff and trans flanges could have high or low spots hence the need to rotate them to find the "right spot" if they are not marked during removal. This would also ring true if one was to replace the original driveshaft with a used one and a vibration occurs. Thank you for sharing your experience as there is very little knowledge outside of the repair manual on these specific driveshafts. Quote Link to comment Share on other sites More sharing options...
nin478 Posted July 6, 2023 Author Share Posted July 6, 2023 Yes that is correct! The flex plate (guibo) would not release from the driveshaft. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.