realdiehl Posted October 22, 2012 Report Share Posted October 22, 2012 i have a 1970 datsun 510 that i am trying to figure out a vibration issue with.this car has a l18 with a 4speed transmission.you can feel the vibration even with the car just ideling throu the floor,seat,steering wheel and then as speed increases it seems to get a little worse.i also noticed when i turn the car off the whole car kind of shakes.the motor mounts and transmission mounts appear to be ok as far as i can tell with very little movement when engine gets revved up. Quote Link to comment
datzenmike Posted October 22, 2012 Report Share Posted October 22, 2012 If vibing when sitting still you can eliminate the drive line and suspension right there. Check that the exhaust pipe is not against the body anywhere. Muffler and pipe supports should be flexible or they will transmit vibration. Is the hood tight against the air filter? Shouldn't be with a stock carb but you may have a weber and air filter. Make sure the motor is not in contact with the crossmember same with the transmission and the rear crossmember. The motor and transmission should be supported on rubber. Pry on them with a 2x4 and be sure they are free to move back and forth. Motor shaking can be several things including one or more bad cylinders. Instead of a nice smooth idle 123412341234 you have 123 123 123 The missing cylinder or part cylinder will be felt as a gap in the smoothness. A spark plug could be fouled, a bad wire, a burnt valve, an over tight valve, a blown head gasket, carbon fouled from a stuck choke. I would check/clean the plugs/wires rotor and distributor cap. Look for plugs that abnormally black When the ignition is assured set the valve lash. Now check/set the ignition timing. Last set the idle mixture and speed. Quote Link to comment
realdiehl Posted October 22, 2012 Author Report Share Posted October 22, 2012 thanks datzenmike i will check those other items. Quote Link to comment
realdiehl Posted October 23, 2012 Author Report Share Posted October 23, 2012 UPDATE!!!!!!!!!!! i found that the bolts holding the transmission isolator pad to the crossmember were touching the crossmember causing the bad vibration while idling.i also replaced the plugs,plug wires,distributer cap and rotor and now most of the vibration is gone however at speed if i depress the clutch the vibration completely goes away.anyone have any ideas on that one Quote Link to comment
banzai510(hainz) Posted October 23, 2012 Report Share Posted October 23, 2012 motor to trans bolts tight? Mine have come loose before Quote Link to comment
realdiehl Posted October 24, 2012 Author Report Share Posted October 24, 2012 yes. i had actually found 3 bolts missing when i purchased the car Quote Link to comment
datzenmike Posted October 24, 2012 Report Share Posted October 24, 2012 If the tranny mount was loose and you found three bolts missing, the thing to do now is obvious. Quote Link to comment
Ratwagon1600 Posted October 24, 2012 Report Share Posted October 24, 2012 If the tranny mount was loose and you found three bolts missing, the thing to do now is obvious. Yep, apart from replacing them, grab a handful of 10, 12, 13, 14, 17 and 19 mm spanners and sockets. Start from the front of the car and work towards the back. Tighten/ check everything. Just be careful you don't over tighten things. Stripped or broken bolts are a lot more annoying than loose or missing ones (trust me I know from bitter experience) Quote Link to comment
Stoffregen Motorsports Posted October 25, 2012 Report Share Posted October 25, 2012 You might have to clarify for him what a "spanner" is. 1 Quote Link to comment
ggzilla Posted October 25, 2012 Report Share Posted October 25, 2012 at speed if i depress the clutch the vibration completely goes away At speed, in gear or at speed in nuetral -- does it make a difference? One possibility is that the flywheel bolts are loose. When you depress the clutch pedal, it forces the flywheel towards the engine (which is opposed by the thrust bearing). Be sure to torque the flywheel properly as too tight and the bolts can break. Quote Link to comment
H5WAGON Posted October 26, 2012 Report Share Posted October 26, 2012 At speed, in gear or at speed in nuetral -- does it make a difference? One possibility is that the flywheel bolts are loose. When you depress the clutch pedal, it forces the flywheel towards the engine (which is opposed by the thrust bearing). Be sure to torque the flywheel properly as too tight and the bolts can break. Pull the trans & check clutch and flywheel bolts....!!! I ruined my first motor this way at 17...stripped the crankbolt threads... :( Quote Link to comment
banzai510(hainz) Posted October 26, 2012 Report Share Posted October 26, 2012 "One possibility is that the flywheel bolts are loose." clutch bolts also I thought of saying this. But the last owner coundnt be that bad and do this do another person Quote Link to comment
datzenmike Posted October 26, 2012 Report Share Posted October 26, 2012 ..... and now most of the vibration is gone however at speed if i depress the clutch the vibration completely goes away.anyone have any ideas on that one Yes.... what happens at speed if you shift into neutral and let the clutch out????? Quote Link to comment
banzai510(hainz) Posted October 26, 2012 Report Share Posted October 26, 2012 jack the car up on all 4s and then rev it up and feel for vibration 1 Quote Link to comment
RatVonDude Posted December 24, 2014 Report Share Posted December 24, 2014 I'm having a similar problem with my 521. Very heavy vibration at around 35mph, its gotten soo bad that I finally just took it to a mechanic up the street and now he can't figure it out. Heres all the stuff I've checked 1. Shocks, all good 2. Tie Rods, motor mounts, new u joints all good. 3. bushings are kinda old but NOT the problem 4. vibration is NOT from un balanced tires.........although nobody believes me. 5. Doesn't seem like a mechanical issue because it would vibrate in neutral 6. No way a loose exhaust system would cause this amount of vibration I'm guessing its something in the drive train Quote Link to comment
MikeRL411 Posted December 24, 2014 Report Share Posted December 24, 2014 I'm having a similar problem with my 521. Very heavy vibration at around 35mph, its gotten soo bad that I finally just took it to a mechanic up the street and now he can't figure it out. Heres all the stuff I've checked 1. Shocks, all good 2. Tie Rods, motor mounts, new u joints all good. 3. bushings are kinda old but NOT the problem 4. vibration is NOT from un balanced tires.........although nobody believes me. 5. Doesn't seem like a mechanical issue because it would vibrate in neutral 6. No way a loose exhaust system would cause this amount of vibration I'm guessing its something in the drive train Upper "shock tower" wear and tear on the front struts? Quote Link to comment
RatVonDude Posted December 24, 2014 Report Share Posted December 24, 2014 Upper "shock tower" wear and tear on the front struts? Thats a new idea. I'll check it out Mike. Feels like the issue is in the front of the truck. Going to have a friend fallow me when I drive it to see where the shaking is coming from. Wish I didn't get involved with this mechanic its been about 3 days of bullshit. Just can't seem to locate this issue Quote Link to comment
datzenmike Posted December 24, 2014 Report Share Posted December 24, 2014 Spin all tires by hand. Do the tire treads have a lump or raised area in them? Does the tread wobble side to side... bent rim? Inspect the drums for breaks and missing metal. Spin the driveshaft by hand. Inspect the complete surface for any damage or strikes. Does it visibly wobble? Quote Link to comment
RatVonDude Posted December 24, 2014 Report Share Posted December 24, 2014 Spin all tires by hand. Do the tire treads have a lump or raised area in them? Does the tread wobble side to side... bent rim? Inspect the drums for breaks and missing metal. Spin the driveshaft by hand. Inspect the complete surface for any damage or strikes. Does it visibly wobble? done almost all that except spin the drive shaft by hand. could be a bent rim, but it is a problem that slowly has gotton worse, not an immediate damage related issue like hitting a pothole. Quote Link to comment
datzenmike Posted December 25, 2014 Report Share Posted December 25, 2014 Swap the tires to the front. See if it feels different. Some tires can come apart inside even though they stay balanced. Had a tire with a palm sized raised lump that made the car rock side to side coming to a stop sign. Quote Link to comment
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