Hello everyone my name is Alex Crowell I live in Gallatin Tennessee and I'm the used to be proud owner of a survivor 68 Riviera. I say used to be because recently this thing has been a pain in my arse and my wallet. It all started a month ago as I had my mechanic put new body mounts and shocks on it as it's been riding like a log wagon for the past several years. It has had a vibration in it for quite some time which I attributed to the body riding on the frame as the four main mounts located on front of the cabin had completely disintegrated. So got all that done and picked it up and it did ride much better but the vibration was not only still there but was even worse now. I noticed when I put it in neutral and coasted that the vibrations seem to disappear but when put back in gear would start to happen again. So I called my mechanic and told him what was going on and he said from my description that it sounded like it could possibly be u-joints going bad and unfortunately on that car there was five of them and two CV joints, and that could be a major issue because he had worked on a Cadillac once before around that era that had bad CV joints in it and the owner spent a lot of time and money and had to look out of state for a new one or to have it rebuilt, he also told me there was no drive shaft shops in the Middle Tennessee area at all. He told me I could bring it in a couple of weeks later and we could take a look at it and maybe rebuild it, but it could turn into a can of worms. So I did some research and ordered five new u-joints and the ball seats from CARS and from reading one of the post here on the forum I was sure to get the u-joints with the recessed center. So got the car back to him and he rebuilt the drive shaft and fortunately he said the balls in the CV joint were still in good shape, had very minor scoring to them which he polished in his lathe and said they were good to go. He also said that it was definitely time for the u-joints to be replaced, that the needle bearings weren't falling out of them yet but they were definitely worn. He said there was still a little vibration around 45 mph but once you got it up to about 60 or 70 it smoothed out and that I might need to get the tires balanced or maybe it just needed driving for a while to wear everything in and make it smoother which kind of made sense to me. So, I went to pick it up and it was driving much better but like he said around 45 mph you'd get a little vibration but get up past 55/60 it seemed to ease up. I live about 15 miles away from him and by the time I got home it seemed like it was getting worse but after I got home I decided to take the family out to dinner in it and again it seemed to be about the same or worse, unfortunately most of the time when I cruise around town it's around 35 45 mph so I thought maybe that's why it seems so bad. So the next morning, Saturday morning, I decided to drive it into work as I work a half day on Saturday at my shop about 12 miles away from home. I noticed then that the vibration seem to be happening at a higher speed as well, around 55 60 it was vibrating pretty bad. I had to take some trash off to the local convenience center so I stopped by the shop first to pick up the trash there and it took about 15 minutes to open the shop and get things rounded up then I proceeded to drive to the convenience center and when it shifted out of second gear the engine just reved up and I didn't have any second gear at all, so I stopped the car put it in neutral and shifted it back down into drive and I could feel it go back in gear so I took off and it shifted into second just fine. I thought maybe I had accidentally knocked it out of gear since I usually rest my hand on the shifter and I may not have locked it into gear good. When I took off onto the main highway from the cross street it did it again no second gear when it shifted so at that point I did a u-turn pulled off to the side of the road once again put it in neutral then shifted back down into drive and headed back to my shop which was about a mile away. From that point back to the shop it drove just fine it shifted into second and then also shifted into third no problem but I just took it back and parked it and was fairly discouraged at that point. Over the weekend I did some research and thought about it a bit and concluded that maybe the shift linkage was loose and wandering due to the vibration and maybe that's what caused it to not shift properly. On Monday (last monday) I decided to warm it up and take it for a test drive and see if I could tell if there was any slop in the linkage which there didn't seem to be any and I couldn't really get under the car to check it out physically but I decided to take it for a test drive again so I drove it around the block and at first it drove just fine except for the vibration but then sure enough it again started losing second gear when it shifted so took it back to the shop and parked it and called my mechanic and told him what was happening with the transmission and asked him if the vibration could be in the transmission and he said that typically isn't what happens with the transmission it just slips like what it was doing. He said if it was slipping that was for sure a transmission problem but didn't know if the vibration would be caused from it as well. He recommended a transmission guy to take it to which I have set up to take to him next Monday. I then quizzed him about the drive shaft causing the vibration and reluctantly asked him if he was sure he got it all back together right and that the timing wasn't off on the drive shaft. He assured me he had marked everything and it went back together in the car just like it came out except with new CV and universal joints but he couldn't say for sure that the drive shaft was in balance but that it should be as he didn't notice any missing weights or it being bent or damaged in any way and once again reminded me unfortunately there's no drive shaft shops in our area. It has a 400 turbo tranny in it so I'm just curious if anyone has run across this before. I'm really hoping the vibration is indeed coming from the transmission, if so problem solved, but if I get the tranny fixed and I still have a vibration from the drive shaft, I may drive it off a cliff. first of all are these dang drive shafts known to get out of balance like that? Does it sound like maybe the CV ball joints have gone bad even though they may not look like it? Can an out of balance drive shaft be severe enough to cause a transmission problem? Until last Monday I've had no problems with it shifting or slipping, but like I said at the beginning of the post the vibration has been in there for quite some time. I would really appreciate any words of wisdom or any guidance from experience on this matter but it definitely seems like I've got to knock the transmission problem out first. a few pix:
There are several things that can cause vibration. But I will address the issues with the transmission. Yes, if bushings are worn, a transmission can vibrate. A bad converter can vibrate/shudder. Badly worn shafts where they ride in the bushings, or splines worn can cause vibration. Slipping is typically low fluid, worn fluid, low pressures, worn/burnt clutch discs and or steel plates, bad lip seals, cracked pistons spools sticking and other internal issues. A good transmission shop can pretty much tell where the problem lies. Multiple piece shafts can be a bit harder to diagnose, but runout should be checked. If the phasing was not correct when you got the car, (as you thought the ride and vibration was due to bad shocks/body mounts) and work was done, it can change "where" the vibration is, and if anything was off and not addressed (not sure if your mechanic is a "driveshaft guy"). If he knows his stuff, I would have a good tranny shop look at the car. You could have bad engine mounts, transmission mount, suspension issues, warped brake drums/rotors, rims or bad tires. Proper and fully diagnosing the issue before spending a lot of time and money in several shops is the thing to focus on. I am sure there are people near you that know of good sources you can take the car to. Hard to diagnose vibration problems when you have the car in front of your and very hard to guess from the other side of the computer. It's a good looking boat, I wouldn't be so quick to scuttle it yet. So, here's a hollar out to middle Tennessee, Lower Kentucky folk. Jump in.
Cjay thats very good to know, hopefully that snot the problem, I suppose I'll find out next week. Trunk monkey, a lil more info on this ride which may shed more light on the subject. I bought this car around 30 years ago and it only has 61k miles on it, buuut it has done a lot of sitting in its life. When I first bought it it floated like a battleship and it was kind of a daily driver for a couple of years then I parked it for several years but would still start it and run it every few months. Then i got married, had kids, got cancer, bought a business and I neglected it for 20 years and it only got started once every 6 mo -yearly and brakes went bad so i never drove it much during that period, also before that it had a similar life I'm guessing because my stepfather actually bought it at an estate sale from the original owner and it was in pole barn with several other classics and a couple of wood hull chriscraft boats. He put a lot of work in it then before he sold it to me a couple years after that. In 2017 we had to move and luckily the kids were getting older, and I had more disposable income to put in it to get it back in running order. Redid all the brakes wheel cylinders, shoes, hoses, etc and a few other items and she was road ready once again, then........ One day when going for a joyride the tranny started puking fluid through the fill tube. But as far as I can remember it was still riding smooth and wasn't having any shifting problems. I then took it to my mechanic and he pulled it n sent it to a tranny guy who fixed it, I believe he said the priming valve had to be replaced if I remember correctly. Well it never puked fluid again and for the next few years it was my sunday driver and Ive made sure to drive her around at least once a month, during cooler weather I try to drive her to church at least every other week if not every week. The ride has been getting worse and my attention was drawn to the body mounts 2-3 years ago when i could hear and feel a very rough creaking directly under my left foot under the floorboard which is where 2 of the body mounts were. I guess thats why I attributed it to the body mounts. As far as I know the drive shaft never been out of it, although I guess it probably had to be pulled when the transmission was pulled. I do trust my mechanic, he's a drag racer and during drag racing season he's gone a lot to different events, he's got quite the nice alcohol rail car and actually makes money doing it. He's a long time hot rodder and works on lots of classic cars so I know he's got the knowledge and skills, however time is another story, but he's never given me a reason to doubt his work, he's also worked on just about all my vehicles at some point in time. He's a straight shooter and I trust him and in todays world its hard to find an affordable and trustworthy mechanic that won't try to sell you a bunch of stuff you dont need. With that being said Im not so sure about the guy that worked on the tranny 6+ years ago, perhaps thats been the source of the vibrations getting progressively worse although the body mounts, shocks and driveshaft are things that needed to be done anyway and have definitely improved the ride minus the vibration. One last thing about the drive shaft, I forgot to mention I also replaced the center support bearing too and there wasn't a damper ring on it although service manual shows one so not sure if its supposed to be one there or not, and if that could make a difference with vibration. The old support bearing had come apart. I hope im not too long winded for the forum lol.
That's a good history and helps. The "puking fluid from the fill tube", can be caused from plugged vent tube (mud daubers and other critters can pack them). I have no idea what a "priming valve" is. But I think it may have been the pressure regulator since it covers the following tasks and could have been the cause of the "fluid dump". The pressure regulator moves when the pump creates pressure and as it moves, the converter feed is charged, then the lube circuit, and the valve will "dynamically" operate in the correct range. If the valve was sticking in or near closed position, extreme line pressure, lack of converter charging and no fluid return to the suction side, could cause fluid to puke, especially if the converter has drained back (from car sitting and not running for a while). I think maybe that was what was repaired by the transmission guy. Let us know what more you find out.
No mention of the carrier bearing in the center of the drive shaft. Most common thing for a drivetrain vibration. A slipped harmonic balancer will also cause vibration. Another thing to consider is the 2 piece rear tube. Theres a rubber bushing inside that can wear or slip causing it to be out of balance. The shop I used for that is located in Jacksonville. Had them install a 1 piece solid tube. Car has always had a slight vibration which I have never completely removed. Have been through 4-5 different wheel and tire combos as well.
TM sounds like you must be a tranny guru for sure, and yes I remember now when I first told my mechanic about the puking problem that he also thought It could have been a pugged up vent tube as well, but unfortunately that was not the case. it could have been the pressure regulator, maybe some folks call that a priming valve? Did you say that it feed the converter, could that be considered priming? anyway that got me thinking so I let her warm up today and reved the engine up while in park and putting my hand on the valve cover and revving the engine it was smooth as could be, sitting in driver seat and revving I could once again feel a vibration at high rpm guessing 3000-3500 rpm, not sure it that would point to something or not. Briz, at the end of my last post I did say I also replaced the center bearing and the old one had actually come apart. Im not sure what condition the ruber seal was in, but I was unable to find a replacement for it. also there was not a damper ring on the shaft either, curious if your 68' had one on it either? I'm surprised that you can make that connection a solid piece because I thought that was a splined slip yoke to move with suspension travel? does anyone know of a source for this seal for the front driveshaft where the splined yoke mate?
That in itself is considered a vibration damper It does not move in and out. Only the slip yolk into the trans and the splined part that slips into the center of the shaft.. Even after 2 go a rounds with having it professionally balanced I still have a slight vibration. I just live with it. My car is far, very far from stock so it could be anything.
I have a vibration in mine as well. Minor and annoying at times at different speeds. I have had my driveshafts rebuilt, trans mount replaced, engine mounts replaced carrier bearing and mount replaced etc. I live with it, and I have felt the effects of each one of those things listed failing starting with there rear drive/propeller shaft rubber melting! I think you are on the right track, get that trans looked at. Then go through everything again to assure all is installed properly. good luck.
