madmanperez Posted December 4, 2021 Report Share Posted December 4, 2021 A while ago I started to notice a low frequency rumble coming from the rear. It's not RPM related. seems more speed related. Faster equals louder, take the car out of gear RPMs drop sound remains. Bring the car to a stop, sounds stops gun the engine in neutral engine roars but no rumble sound. Thant's all the detail I have. As always any and all responses are appreciated. Link to comment Share on other sites More sharing options...
GoldStar Posted December 4, 2021 Report Share Posted December 4, 2021 Kinda like a growl? If so, that sounds to me like a bad bearing somewhere in the diff or the torque tube. Could also be either of the rear wheel bearings. Not sure how one could test the former, so someone can chime in there, but for the latter, one of the things you can do is find an empty stretch of road, get it up to speed where you can clearly hear the noise, then start swerving side-to-side to see if the noise changes. If it gets louder in one direction vs the other, then the side with the most load at that time has the bad wheel bearing. If no difference, it's most likely something at the diff/torque tube. Link to comment Share on other sites More sharing options...
madmanperez Posted December 5, 2021 Author Report Share Posted December 5, 2021 Noise can be heard clearly starting at about 20 - 25 mph and just gets louder after that. Never deafening but loud enough to be annoying and drowning out the radio LOL Link to comment Share on other sites More sharing options...
psu_Crash Posted December 6, 2021 Report Share Posted December 6, 2021 I would get it in the air and start twisting things around by hand. Sure sounds like a bearing. Should be able to hear/feel that by turning the driveshaft and/or wheels by hand. Might help to have a buddy to lend an ear. Link to comment Share on other sites More sharing options...
Caliber308 Posted December 7, 2021 Report Share Posted December 7, 2021 Everything that psu-crash said. I will only add that you might want to check the half shafts and the rubber boots for leaking grease. Bill Link to comment Share on other sites More sharing options...
madmanperez Posted December 15, 2021 Author Report Share Posted December 15, 2021 Thinks for all the info everyone. The only thing I can add at this time is when driving and swerving right and left no change in the sound level or pitch. Don't know if that helps narrow thing down. But I'll try to get the rear in the air as soon as possible Link to comment Share on other sites More sharing options...
Edde Posted January 4, 2022 Report Share Posted January 4, 2022 I had a set of tires that roared once. It was so unbelievable it took me forever to figure it out. I checked all the other stuff first. Link to comment Share on other sites More sharing options...
madmanperez Posted January 8, 2022 Author Report Share Posted January 8, 2022 It tock a while but I finally Got the rear of the car up. The only noise I heard was a slight scraping on each wheel which was the brake pads. Nothing else. As EDDE mentioned, The tires in the rear are new (not the most expensive rough $75 ea) I'm starting to think it could be them. Short of cracking the diff cover and draining the grease and resealing and refilling. I'm stuck. Not willing to replace new tires with more expensive ones on a hunch. I appreciate everyone's input When the rare tires where and I have to replace them I'll then look at slightly more expensive tires. Link to comment Share on other sites More sharing options...
BlueCuda Posted January 8, 2022 Report Share Posted January 8, 2022 Really sounds like a wheel bearing to me, however you said it doesn't change when swerving which seems odd. The rear doesn't see the sudden change in side loading when serving like the front does. These cars also seem to have a pretty heavy duty rear bearing setup compared to more modern stuff, at least from my browsings of the FSM. My 87 I just got running has a similar sound but it goes away when it gets driven a little bit. I have looked at replacing the rear bearings due to this and the odometer reads 192,000. The bearings seem cheap enough but I haven't been able to see if you really need a press to do them or if the FSM is being dramatic ha. Link to comment Share on other sites More sharing options...
madmanperez Posted January 14, 2022 Author Report Share Posted January 14, 2022 Thanks for the input BlueCuda. If it is in fact a bearing issue I'm kind of screwed in that I don't have any place to do that level of work and that leaves me with having to go to a mechanic (uhg🥵). Same would be true if I had to do any work on the diff. Link to comment Share on other sites More sharing options...
psu_Crash Posted January 16, 2022 Report Share Posted January 16, 2022 (edited) On 1/8/2022 at 5:56 AM, BlueCuda said: Really sounds like a wheel bearing to me, however you said it doesn't change when swerving which seems odd. The rear doesn't see the sudden change in side loading when serving like the front does. These cars also seem to have a pretty heavy duty rear bearing setup compared to more modern stuff, at least from my browsings of the FSM. My 87 I just got running has a similar sound but it goes away when it gets driven a little bit. I have looked at replacing the rear bearings due to this and the odometer reads 192,000. The bearings seem cheap enough but I haven't been able to see if you really need a press to do them or if the FSM is being dramatic ha. You could probably do it without a press. It's SOOO much easier with one though. I bought this a few years back and has worked like a charm for many jobs. I also have a normal shop press. https://www.amazon.com/Orion-Motor-Tech-Replacement-Automotive/dp/B01FLVOAZI/ref=sxin_14_pa_sp_search_thematic_sspa?cv_ct_cx=wheel+bearing+press&keywords=wheel+bearing+press&pd_rd_i=B01FLVOAZI&pd_rd_r=f29ee619-4af3-4c74-9d8a-e140fba32ac4&pd_rd_w=GgkMM&pd_rd_wg=9taxh&pf_rd_p=4ad71b32-b810-4124-8735-d02a39478d0c&pf_rd_r=3JTMYEH43EGQQNF39KEN&qid=1642350651&sr=1-1-a73d1c8c-2fd2-4f19-aa41-2df022bcb241-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExVURRQTVVU0JXUERHJmVuY3J5cHRlZElkPUEwMDc0NzY5RjVaVzdRUDAwNFAwJmVuY3J5cHRlZEFkSWQ9QTA4ODU5NjkyN1VXWk1SNk9FSjQ3JndpZGdldE5hbWU9c3Bfc2VhcmNoX3RoZW1hdGljJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ== Edited January 16, 2022 by psu_Crash Link to comment Share on other sites More sharing options...
Recommended Posts