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So I took my formula for a ride, just got the rear pull down motor sorted And all of the sudden a faint thumping noise form the back of the car, maybe the middle, hard to tell. Took it home and it was getting steadily louder. However engine under load the sound goes away immediately. Let up on the gas and there it is The faster I go the faster the sound, the slower, etc. So I am thinking UV joint on the drive shaft? Have to get it up on the drive up ramps tomorrow and see, Whatever it is, it doesn't sound good. Any ideas on what to look for would be great, thanks in advance!
I think your headed in the right direction, might not be a bad idea to check your transmission mount when you look under there. They commonly crap out and often. I had mine shredded and I got a clunking at various speeds but mostly when turning into the driveway. If it’s messed up they are very easy to change and there is even a write up in the how to section.
I think your headed in the right direction, might not be a bad idea to check your transmission mount when you look under there. They commonly crap out and often. I had mine shredded and I got a clunking at various speeds but mostly when turning into the driveway. If it’s messed up they are very easy to change and there is even a write up in the how to section.
Thanks will do that as well. I don't it's anything really serious. But want to get it fixed asap. Wi update after I have a look tomorrow.
So upon my first visual, nothing is standing out. The u joints on the drive shaft seem fine. No leak form the rear differential or axle area near the brakes. Bit dumb founded on what this is. Exhaust is near since last year and is solid. Not sure whatever it is came on so fast either May need to get a tech to look at it
You should take a look at the ring and pinion set, to be safe...
You might find wear on the teeth after a close inspection.
Brake Parts cleaner will help you get enough gear oil off of the gears inside the diff...
to get a descent look with a flash-light.
You should take a look at the ring and pinion set, to be safe...
You might find wear on the teeth after a close inspection.
Brake Parts cleaner will help you get enough gear oil off of the gears inside the diff...
to get a descent look with a flash-light.
Yes, that is a escalation to consider. I am going to change my u joints anyway being the are old. Then go from there. My concern is what you mention as well as any bearing used for the axle. Thanks!
Visually it would be hard to see a bad mount, when in the air, get a pry bar and check all points, TA mounts and the rear at the tranny, tranny mount, etc. Easy to do, and no mess.
Now if the rear is on stands, shake the driveshaft up and down at the rear end and at the tranny as well...see what you see/feel.
Visually it would be hard to see a bad mount, when in the air, get a pry bar and check all points, TA mounts and the rear at the tranny, tranny mount, etc. Easy to do, and no mess.
Now if the rear is on stands, shake the driveshaft up and down at the rear end and at the tranny as well...see what you see/feel.
I have the new U-joints already. Picking up a new rear trans mount tomorrow, I know for a fact the trans mount is old so I am going to just replace it Same for the u-joints, which I really think are the culprit. Years ago I had to replace them on a 71 CJ-5 I had, and the issue, noise if you will, is similar. Hopefully that will address this Even if not, replacing both of these items isnt a bad idea anyway. I want to take it on an hour away drive 1 way this fall and would feel better knowing these parts are new.
Hoping to dig into this tomorrow and will update. These responses are truly appreciated!
I have the new U-joints already. Picking up a new rear trans mount tomorrow, I know for a fact the trans mount is old so I am going to just replace it Same for the u-joints, which I really think are the culprit. Years ago I had to replace them on a 71 CJ-5 I had, and the issue, noise if you will, is similar. Hopefully that will address this Even if not, replacing both of these items isnt a bad idea anyway. I want to take it on an hour away drive 1 way this fall and would feel better knowing these parts are new.
Hoping to dig into this tomorrow and will update. These responses are truly appreciated!
If your U joints have never been replaced , and if you've never replaced third gen U joints before , look up some videos first . The factory U joint cups aren't held in with normal clips , they are glued in requiring the glue to be melted out with a small plumber's torch before the cups will move . The replacement U joints will have the normal clips to hold them in .....
If your U joints have never been replaced , and if you've never replaced third gen U joints before , look up some videos first . The factory U joint cups aren't held in with normal clips , they are glued in requiring the glue to be melted out with a small plumber's torch before the cups will move . The replacement U joints will have the normal clips to hold them in .....
Good to know! I am tackling this tomorrow afternoon. I believe...they were replaced back in the lat 90s but I will find out. If not they are original and either way getting replaced!
Some sort of clip breaking off the u joint. See below The shaft seemed ok, no play in it, just this metal piece hanging I had to burn our the plastic pins. So they are original 31 years old. Burn out was pretty easy. But I cant get this stupid thing to press out.
Any help on our to get these old u joints out would be appreciated. I just bought that c clamp tool from Harbor Freight for 60 bucks and its hardly moving it. HELP!!
not sure this is the correct way, but you got to use what's available in the garage sometimes, I just used some sockets, one a little larger on the underneath of the bottom cup, one a little smaller on the top cup, and hammered away. not as easy a job but get's it done.. Sure all the glue is melted out, it should squirt out if I remember correctly, been a decade since I did one last.. . I'm sure you'll get a more knowlwdgable answer soon..
Edit: Is the C clamp large enough on the static side to let the cup slide thru?
Last edited by Camaro86IrocZ; Sep 26, 2020 at 07:40 PM.
not sure this is the correct way, but you got to use what's available in the garage sometimes, I just used some sockets, one a little larger on the underneath of the bottom cup, one a little smaller on the top cup, and hammered away. not as easy a job but get's it done.. Sure all the glue is melted out, it should squirt out if I remember correctly, been a decade since I did one last.. . I'm sure you'll get a more knowlwdgable answer soon..
Edit: Is the C clamp large enough on the static side to let the cup slide thru?
Yes it shot out like a worm. But it looks like there might be some still in some of the holes.
The c clamp does have a large enough hole on the other side but it it moves when I tighten it.
Gonna try the socket and hammer routine tomorrow
Now the fun part...getting the new u-jonts in. what I did was discovered a video on YouTube to heat these up and then take a sledge hammer and whack them from the back end. Funny thing is there was still more plastic inside When I first heated them up yesterday a ton came out on all of them. But another ton came out again. 2 of these actually popped and the cap popped up.
Now...how to get them back in without messing up the roller bearings.....
Ok can ANYONE tell me what are the right replacements for this stupid drive shaft? I just put a new ujoint in thinking the locking ring need to go in the slot where the plastic is. So I tapped it in level with the knuckle, then installed the other side. But as I put them in, the caps cant go down that far. The width of the cap is the same on the new Moogs as it is on the factory. So now I have it in tight and the u joint can barely move. WTF?? How do fix this without messing up the new u joint? As well as do I NOT use the locking ring on this? Just press them in?
This is absolutely stupid, using plastic to hold the factory ones in.
OK call me MUD. So these are the inside C Clip kind of ujoints. Not the outside one. DUH!!! I fixed it. Its all coming together now. But first the rear tranny mount get a replacement. That to is 31 years old.
Well bad news is the noise is still there and getting worse. Its something in back for sure. It sounds like a piece of metal on the drive shaft is scraping up against another piece of metal, or whatever turns when the car is in drive. I only hear it when I let off the gas and it slows down as the car slows down. No sound in reverse and I can hear it slightly when I drive slow. I give up. I may have to moth ball it until the spring.
Well bad news is the noise is still there and getting worse. Its something in back for sure. It sounds like a piece of metal on the drive shaft is scraping up against another piece of metal, or whatever turns when the car is in drive. I only hear it when I let off the gas and it slows down as the car slows down. No sound in reverse and I can hear it slightly when I drive slow. I give up. I may have to moth ball it until the spring.
It was surprisingly warm in the area of NY that I live in today (NYC)...
You still have time before is gets really cold (unless you live in the mountains, northern, or western NY).
This may sound stupid... but I would double-check that none of the heat-shields under the car are vibrating, making the noise you hear.
I have found some really weird noises that were produced by things that seemed completely unlikely.
Also see if the noise stops/ changes by raising the tires off of the ground, and driving the power-train forwards.
Check the fluid level in the diff at the very least, easy and quick to do.. When I take my '86 out after long extended sit times it takes awhile to get the outer axle bearings to quite down. I've learned to corner it hard to get the diff. oil to flow out to them. Also, could it be a sticky brake in the rear or are the pads at the wear indicator?
Yes its been nice in NYS lately. I will continue to troubleshoot. going to lift it again and service the differential. Also an obvious one...check if the lug nuts are tight. Thanks Vorteciroc
Mark this problem MOSTLY resolved! It turned out to be loose lug nuts on my wheel adapters. My fault, I only tighten them with my air tool. Should have checked by hand as well. I figured it out because I got a recommened video on YouTube. Guy with a rice burner had the issue. Made the EXACT same sound. It was also suggest here by you guys too.
Now there is a rattle noise, but I am not as concerned. Just glad this wasnt the rear diff.
So it looks like the heat shield is causing the new noise. when I bang on it not to hard I hear it hitting metal, but I can find where. Its bolted on tight so I am lost on why this is happening all of the sudden. Should I just pull it out and see if that is the source of the rattle?
Sorry to laugh... this reminds me of a nightmare that I had once with heat-shields on a convertible 3rd gen...
Those cars flex sooooooooooooooo much, it is crazy.
Intermittent random noises galore!
As I mentioned in a post above... check all the heat-shields...
One this one car, I had to eliminate all of them... as well as the cross-bars in-front of the radiator/ A/C condenser.
Hopefully for the rear-end noises; you raised the rear wheels off of the ground... and drove the rear wheels.
HAHA, yes they do flex for sure!
I fixed the scary noise, it was loose lug nuts on my wheel adapters. Now the noise is something is loose and it bangs when I hit bumps, rough road, etc. Coming form the very back of the car. The exhaust is new and tight. But something is rattling back there and its VERY ANNOYING. Just cant figure it.
Well the sound is coming form the right side rear. I thought it may be the spare tire and jack I put back in. When I checked they were loose, but no. the sound is still there. This weekend I will look underneath.
I am having the same issue as well.. its like a thump, thump, thump just crusin around in drive, when i floor it, the sound goes away, then when i go back to cruise and slowly hit the gas the thudding comes back.. I thought the driveshaft was out of balance, so i took it to a driveshaft shop and they balanced it and put all new u joints in.. still have the thumping. I replaced the gears in the back.. same sound.. New panhard bar and torque arm, still there.. New BMR transmission mount for the TQ arm, still making that dam sound.. Tranny flush, new filter, larger pan, and cooler.. yup still there.. Motor mounts are good, tranny mounts are solid.. i am stumped!!!!!
Negative on the hatch.. I had a issues with the rear hatch not closing, turned out a mouse chewed on the wires and got zapped.. had been dead for awhile.. so i replaced the whole assembly while i was back there.. still having the issue.. its good to know that i am not the only one that is having this problem.. it seems to not just be a singular problem!!!
Hey Hawkeye.. Any updates or resolution yet?? No Luck Here...
The original scary noise for me was my rim adaptors/spacers were loose. But the new rattle down can't figure it out. Thought it was my spare tire, nope. Definitely from the right rear. Rattle hard to tell if it's metal on metal or not
I am having the same issue as well.. its like a thump, thump, thump just crusin around in drive, when i floor it, the sound goes away, then when i go back to cruise and slowly hit the gas the thudding comes back.. I thought the driveshaft was out of balance, so i took it to a driveshaft shop and they balanced it and put all new u joints in.. still have the thumping. I replaced the gears in the back.. same sound.. New panhard bar and torque arm, still there.. New BMR transmission mount for the TQ arm, still making that dam sound.. Tranny flush, new filter, larger pan, and cooler.. yup still there.. Motor mounts are good, tranny mounts are solid.. i am stumped!!!!!
Does it speed up and slow down when you do the same with the car itself?
If your U joints have never been replaced , and if you've never replaced third gen U joints before , look up some videos first . The factory U joint cups aren't held in with normal clips , they are glued in requiring the glue to be melted out with a small plumber's torch before the cups will move . The replacement U joints will have the normal clips to hold them in ..... 
