Mister Fab Posted August 14, 2020 Share Posted August 14, 2020 Hi all, I just bought my first Riviera, which is also my first V8 American car. I have been restoring front wheel drive cars for many years, but the V8 world is a new world to me. There are a lot of little problems I want to fix on my Riviera. The first one is that I felt vibrations when I was driving home for two days. I have been driving all the way between 55 and 60 mph Some vibrations came from the back, like a little shaking, all the time And some other came from the front, amplifying above 60mph The engine is working perfectly with no wobbling. The first thing I will do during the weekend will be to take the wheels off and make them controlled and balanced by a professional. But if the wheels are OK, where can the vibrations come from? and what can I do about it? What is the next step to eliminate progressively all the suspicions? The previous owner gave me the two volumes of "67 buick chassis repair" that I already started to read, but any advice is welcome Link to comment Share on other sites More sharing options...
PWB Posted August 14, 2020 Share Posted August 14, 2020 (edited) Upper control arm bushings are first to wear out then the brake reaction rod bushings as they are rubber. After you have ruled out wheel balance and potential front end issues you might want to investigate the drive shaft as Rivieras have a unique phase that most driveline shops fail to recognize. The Buick manual shows the correct phasing. Edited August 14, 2020 by PWB (see edit history) Link to comment Share on other sites More sharing options...
R8RS Posted August 14, 2020 Share Posted August 14, 2020 balance the drive shaft Link to comment Share on other sites More sharing options...
JZRIV Posted August 14, 2020 Share Posted August 14, 2020 Vibration can be very difficult to identify via forum but there are some basics. Check the driveshaft carrier bearing and mount. The bearing can fail or the rubber than is vulcanized to the mount dries out and breaks. Vibration can result from worn CV joints in the driveshaft or often if the driveshaft is rebuilt by an incompetent shop it will cause vibration. Less likely but easy to check is rear wheel bearings. Link to comment Share on other sites More sharing options...
Mister Fab Posted August 17, 2020 Author Share Posted August 17, 2020 Thank you for all your answers. I'll start to check all of this as soon as possible. I have been driving the car during the weekend, and I noticed a squeak, coming from under the car in the center. It happens only when the car accelerates and decelerates, and no noise while cruising at a constant speed. No noise either while on neutral position. I have greased the joints, but the noise still remains. Link to comment Share on other sites More sharing options...
moran75 Posted August 17, 2020 Share Posted August 17, 2020 (edited) I have the same thing re squeak and also only under acceleration....and slight but noticeable vibration briefly at 30mph - ish...I’m pretty sure squeak is coming from worn out single ujoint where prop shaft joins transmission yoke...if I turn rear wheels by hand then cv joint clicks as it rotates. Rear Wheel bearings seem Ok. Also a lot of rust coloured dust which I believe is symptom of failing CV joint. anyway I going to have my theory tested this week and if correct the single ujoint replaced ( I have a ‘65) and have also purchased a new centre bearing and support bracket just in case it turns out to be shot when prop shaft is out. re the new parts....from past bad experience I’ve bypassed ‘cheap’ places like RockAuto and in this case I have gone straight to Classicbuicks.com . I live in UK and don’t want (again) to waste time/money going back and forth with non-buick specialists... I have also noted other posts re correct balancing of a prop shaft for a 65 - apparently quite unique - so will be making sure my garage is aware of that. Will be giving them the manual! is a ‘67 ‘unique’ as well? Don’t know - but all info is in the manual somewhere. The consensus is don’t assume your local shop knows this info..... ill keep you posted if all this cures my squeak.... probably barking up wrong tree and it’s the rear wheel bearings😀 kev Edited August 17, 2020 by moran75 Incorrect terminology (see edit history) 1 Link to comment Share on other sites More sharing options...
Seafoam65 Posted August 17, 2020 Share Posted August 17, 2020 On 8/14/2020 at 2:37 AM, Mister Fab said: Hi all, I just bought my first Riviera, which is also my first V8 American car. I have been restoring front wheel drive cars for many years, but the V8 world is a new world to me. There are a lot of little problems I want to fix on my Riviera. The first one is that I felt vibrations when I was driving home for two days. I have been driving all the way between 55 and 60 mph Some vibrations came from the back, like a little shaking, all the time And some other came from the front, amplifying above 60mph The engine is working perfectly with no wobbling. The first thing I will do during the weekend will be to take the wheels off and make them controlled and balanced by a professional. But if the wheels are OK, where can the vibrations come from? and what can I do about it? What is the next step to eliminate progressively all the suspicions? The previous owner gave me the two volumes of "67 buick chassis repair" that I already started to read, but any advice is welcome In my car repair shop 90 percent of vibrations at high speed are out of round tires.......never a balance problem...just tires out of round due to sitting too long with all the weight on one spot (very common with old cars that sit a lot) or just tires with tread separations, or just cheap tires that won't hold their shape. Take a jack and jack one wheel off the ground at a time and spin each tire while holding your thumb up to the tread....if the tread gets closer then farther away from your thumb as you spin the tire, the tires are out of round. also while doing this you can check the run out on each will as you spin it as you could have one or more bent wheels. In 99 per cent of cases if you have a driveshaft problem the vibration will go away when you let off the gas and coast then start up again when you hit the accelerator. 2 Link to comment Share on other sites More sharing options...
Mister Fab Posted August 18, 2020 Author Share Posted August 18, 2020 17 hours ago, Seafoam65 said: In my car repair shop 90 percent of vibrations at high speed are out of round tires.......never a balance problem...just tires out of round due to sitting too long with all the weight on one spot (very common with old cars that sit a lot) or just tires with tread separations, or just cheap tires that won't hold their shape. Take a jack and jack one wheel off the ground at a time and spin each tire while holding your thumb up to the tread....if the tread gets closer then farther away from your thumb as you spin the tire, the tires are out of round. also while doing this you can check the run out on each will as you spin it as you could have one or more bent wheels. In 99 per cent of cases if you have a driveshaft problem the vibration will go away when you let off the gas and coast then start up again when you hit the accelerator. All the tires are brand new Toyo, and I checked them yesterday. I also checked if the wheels weren't bent. I didn't find anything wrong Link to comment Share on other sites More sharing options...
Mister Fab Posted August 21, 2020 Author Share Posted August 21, 2020 (edited) I have taken out the driveshaft yesterday. Is there a way to control the CV joint visually, or do I need to disassembly to check inside? And if I disassembly all the U joints, do I have to install new ones or can I reinstall these ones after checking? Edited August 21, 2020 by Mister Fab (see edit history) Link to comment Share on other sites More sharing options...
DAVES89 Posted August 21, 2020 Share Posted August 21, 2020 Maybe an idea to check it would be to take it to a machine shop and have them turn it on a lathe. They can run the RPMs up high and see if there is any vibration. 1 Link to comment Share on other sites More sharing options...
Seafoam65 Posted August 21, 2020 Share Posted August 21, 2020 You've never stated if the vibration changes when you coast versus stepping on the gas.....unless a driveshaft is coming completely apart, they don't usually vibrate when not on the accelerator. Link to comment Share on other sites More sharing options...
Mister Fab Posted September 13, 2022 Author Share Posted September 13, 2022 Hi all, I am reopening that discussion as I still have vibrations, even after replacing the CV joints I went to a machine shop, but it is complicated in france to find a place where they have the good adapters to install the shaft. The problem here is the front channeled part. I would need the same part as the rear, with a 4 screw plate to temporary replace the channeled part and install it in the machine. Has someone got that part as spare I could buy? Shipment would be to texas as I visit my family in 2 weeks Link to comment Share on other sites More sharing options...
EmTee Posted September 13, 2022 Share Posted September 13, 2022 It sounds like you're trying to balance the driveshaft, correct? Have you inspected the universal joints? Have any been replaced? Note that the angular relationship between the front and rear halves of the driveshaft is critical and it must be assembled in the same relation as when disassembled. Changing the relationship between the two will cause vibration. Refer to the Buick shop manual for the assembly details. My experience has been that if the U-joints, center bearing and its mount are good, and the relationship between the two shafts is as specified, there should be no reason to re-balance the assembly. It was balanced when it was manufactured. Make sure the shafts are not bent and none of the factory balancing weights have been lost. Link to comment Share on other sites More sharing options...
Mister Fab Posted September 13, 2022 Author Share Posted September 13, 2022 Hi EmTee, I have already replaced, one year ago, all the U-joints, and the center bearing because of that problem. It starts to vibrate at around 60mph The problem doesn't come from my wheels, they've all been replaced and balanced. I made marks on each part before to replace the U-joints to be sure to keep the right phasing angle, and I even checked if it was correct using the chassis repair manual. I didn't see any missing weights. What else could cause vibrations? Link to comment Share on other sites More sharing options...
EmTee Posted September 13, 2022 Share Posted September 13, 2022 Tires? Wheels? Try swapping the rear wheels and tires to the front (same sides). If the vibration moves from your seat to the steering wheel that tells you it is a tire or wheel problem. Link to comment Share on other sites More sharing options...
Mister Fab Posted September 13, 2022 Author Share Posted September 13, 2022 (edited) Wheels and tires are new, just balanced and checked. No problem there. And I don't feel any vibrations in the steering wheel. I feel it like shaking all the car. I don't know what has been done on the car by the previous owner. The engine is supposed to have been rebuilt, but there's no vibration if it is on neutral even if I take it at 1500 rpm Edited September 13, 2022 by Mister Fab (see edit history) Link to comment Share on other sites More sharing options...
RivNut Posted September 13, 2022 Share Posted September 13, 2022 Might not be in the driveline. An engine will develop a vibration at certain RPMs if a piston is broken or a bolt has dropped out. Check to make sure all of your torque converter bolts are in place. 1 Link to comment Share on other sites More sharing options...
EmTee Posted September 14, 2022 Share Posted September 14, 2022 If tires and wheels are good then It's probably time to check the pinion angle. The center bearing and rear axle link bushings should be checked. The front U-joint behind the transmission yoke is new, correct? Has the output bushing in the transmission been checked? Link to comment Share on other sites More sharing options...
Mister Fab Posted September 14, 2022 Author Share Posted September 14, 2022 I have changed the pinion angle already after I changed all the U-joints. As the car has been lowered by the previous owner, the angle was bad when I bought the car. I have to check the documents I have to see if something has been done in the transmission by the previous owner. I did not check anything on it for the moment. The engine is 66000 miles, so must be the transmission. Any particular things to check? Link to comment Share on other sites More sharing options...
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