GoldStar Posted October 29, 2022 Report Share Posted October 29, 2022 Alright, so my Quest has been making some rear end noises for some time now, and it's about time I took care of it. To preface, by axles are the 4-bolts, so I think the axles, differential, and torque tube are original to my 87. One of the noises a clunk I get sometimes when getting on/off the clutch, or when alternating between light accell/decell when cruising. Got it in the air and this is what I found, definitely seems to be related to the torque tube: https://i.imgur.com/X1DWBoW.mp4 So I pulled the torque tube and had a look, below are a couple of pictures. I am seeing some wear on the splines, but I'm not sure it's enough to cause the play I'm seeing/hearing. Does this look like normal wear?: The other noise I'm hearing is a whining/groaning during decel, but only in 4th and, to a much lesser extent, 5th. It does go away abruptly once I slow down enough or if I accelerate at all. Kinda sounds like a transmission with straight-cut gears, but mine's not a race car yet, and this noise seems a bit too situational to be the transmission. Considering it's loudest in 4th, my hunch is the differential. While I had the torque tube off, I checked for play at the differential flange, and I am able to feel a little bit of play in the diff, but not near enough to get on camera. For the moment I was planning to top off the diff fluid to see if that helped, but is a little bit of play expected in a healthy differential? Link to comment Share on other sites More sharing options...
techboy Posted October 30, 2022 Report Share Posted October 30, 2022 Lucky for you your TT appears to be in good shape. Definitely needed to be regreased. Link to comment Share on other sites More sharing options...
GoldStar Posted October 30, 2022 Author Report Share Posted October 30, 2022 14 hours ago, techboy said: Lucky for you your TT appears to be in good shape. Definitely needed to be regreased. I brake cleaned the TT splines so I could get a better look at the wear. I've actually pulled this not too long ago just to grease it, but I didn't put any grease in the TT pocket. I will definitely be doing that this time around. Today I put a new bearing in the tube, and was just about to reinstall the torque shaft when I noticed these "stretch marks". Is this normal? Link to comment Share on other sites More sharing options...
BKB94 Posted October 31, 2022 Report Share Posted October 31, 2022 Pretty sure mine looks like that. I’ll snap a picture and post mine when I get home. Link to comment Share on other sites More sharing options...
obsolete Posted October 31, 2022 Report Share Posted October 31, 2022 I think the marks you're talking about (at least where the picture is focused) are from a weld that's been turned down in a lathe. The torque tube cup is welded to the shaft, you can see the heat affected zone on either side. My '88 has the same annoying drivetrain lash on/off the throttle that you've described, and about the same amount of movement at the driveshaft as your video. I haven't taken my torque tube apart yet, but I noticed that when I took my axles apart to replace the boots, the CV joints had a noticeable amount of slop in them. I think your torque tube splines look pretty good. I've definitely seen worse. But they all get sloppy over time, it's a bad design... Link to comment Share on other sites More sharing options...
GoldStar Posted November 1, 2022 Author Report Share Posted November 1, 2022 15 hours ago, obsolete said: I think the marks you're talking about (at least where the picture is focused) are from a weld that's been turned down in a lathe. The torque tube cup is welded to the shaft, you can see the heat affected zone on either side. My '88 has the same annoying drivetrain lash on/off the throttle that you've described, and about the same amount of movement at the driveshaft as your video. I haven't taken my torque tube apart yet, but I noticed that when I took my axles apart to replace the boots, the CV joints had a noticeable amount of slop in them. I think your torque tube splines look pretty good. I've definitely seen worse. But they all get sloppy over time, it's a bad design... Huh, didn't think that cup was welded on. Not claiming to have any metalworking experience, but I thought the whole thing would have been manufactured as one piece. To me, it just looked to me like this car had seen too many 5k RPM clutch drops in it's life. I guess we'll really see how much of a problem it is when I get this MPI swap done and dialed in. Link to comment Share on other sites More sharing options...
BKB94 Posted November 2, 2022 Report Share Posted November 2, 2022 Just the way they look 1 Link to comment Share on other sites More sharing options...
BlueCuda Posted November 4, 2022 Report Share Posted November 4, 2022 (edited) I'd say that has for sure been welded on, its unlikely that much heat could generate from a splined coupling. My car has the same gear whine you have mentioned. The odometer reads 194K so some gear whine would not be out of question. My car appears to have been abused at one point in its life and despite that the diff fluid was clean and clear. Changing it did nothing for the gear whine. I have another assembly from a car with 116K on the odometer that I am going to go through and swap in. Edited November 4, 2022 by BlueCuda Link to comment Share on other sites More sharing options...
Contsi Posted November 5, 2022 Report Share Posted November 5, 2022 (edited) On 10/29/2022 at 1:11 PM, GoldStar said: Alright, so my Quest has been making some rear end noises for some time now, and it's about time I took care of it. To preface, by axles are the 4-bolts, so I think the axles, differential, and torque tube are original to my 87. One of the noises a clunk I get sometimes when getting on/off the clutch, or when alternating between light accell/decell when cruising. Got it in the air and this is what I found, definitely seems to be related to the torque tube: https:// Please post back if you figure out exactly what is causing the clunk noise. Thanks Edited November 5, 2022 by Contsis Fat finger Link to comment Share on other sites More sharing options...
GoldStar Posted November 12, 2022 Author Report Share Posted November 12, 2022 The repair manual said to fill the cup, so I did: I've put some more miles on it since I did this, and it seems to have nearly eliminated the clunk. It does still happen sometimes, but as I learn how to actually operate a manual, and get used to this lightened flywheel, I anticipate I won't hear it anymore. This, and topping of the diff fluid, didn't make a difference with the whining I'm hearing though. I presume after 160k+ miles of unknown abuse it's time for the differential to be rebuilt. Link to comment Share on other sites More sharing options...
Contsi Posted November 13, 2022 Report Share Posted November 13, 2022 (edited) Normal driving does not cause any noise; I can recreate the clunk by popping the clutch or come off the gas at high rev. I would have to go to a shop to remove the torque tube and fill with grease, not sure what that would cost. Where in the factory repair manual did you find that instruction? Another edit: can you recreate the clunk consistently? Doesn’t seem like that grease would eliminate it Thanks Edited November 13, 2022 by Contsis Link to comment Share on other sites More sharing options...
GoldStar Posted November 13, 2022 Author Report Share Posted November 13, 2022 1 hour ago, Contsis said: Normal driving does not cause any noise; I can recreate the clunk by popping the clutch or come off the gas at high rev. I would have to go to a shop to remove the torque tube and fill with grease, not sure what that would cost. Where in the factory repair manual did you find that instruction? Another edit: can you recreate the clunk consistently? Doesn’t seem like that grease would eliminate it Thanks I was able to recreate it by very lightly accelerating/decelerating while cruising prior to this, or by doing what you described (usually accidentally). I believe this was due to me not putting enough lube on the splines when I first pulled the torque tube. Could be the same for you if yours has never been pulled; that grease doesn't last forever. Check page 3-32 here: http://www.starquestgarage.com/manuals/service/conquest/1988/88_conquest_service_manual_-_group_03_-_rear_axle.pdf For the record, the splines are not a very tight fit. I believe there's play in there by design, hence the grease to prevent metal striking metal. If you're going to have someone pull yours, that would also be the best time to replace the bearing. Kev's got the details here, it's not hard at all: Link to comment Share on other sites More sharing options...
Contsi Posted November 13, 2022 Report Share Posted November 13, 2022 Thanks Mine was never pulled, I’m the original owner. I was aware of the rebuild thread but I’m not equipped to do it. Link to comment Share on other sites More sharing options...
Mech Posted April 12 Report Share Posted April 12 The extension shaft cup splines, and the pinion coupler spline mesh together very precisly when they don't have wear. I pulled them out of my 88 140k miles on it, that was never beat on, and there is zero play. Link to comment Share on other sites More sharing options...
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