vibration at around 1500-2000rpm

[Super Birthday Snake 11]

Been getting a vibration on my car at around these revs, don't get it when the car is stationary.

 

Recently changed the clutch, hoping it's not that? Gears change fine and no noise when doing so. My engine is a 302 EFI from an 89 and I also took the prop off this and had it lengthened and balanced as well as the bearings replaced.

 

My guess would be something to do with the prop shaft but no idea where to start with any sort of diagnosis. Any ideas?

[Rsanter 152]

So you put a late model engine in....

What flywheel and what trans are you using?

 

Did you drive the car before the engine swap? I'd it do it then?

 

Bob

[Super Birthday Snake 11]

So you put a late model engine in....

What flywheel and what trans are you using?

 

Did you drive the car before the engine swap? I'd it do it then?

 

Bob

 

Sorry Should've said, t5 and the 50z flywheel, did it before the clutch replacement I'm pretty sure but had never driven the 69 before as it didn't have an engine at all.

[Brian Conway 264]

Gotta ask; what's a prop shaft ? Brian

[Brian Conway 264]

So if the prop shaft got lengthened and balanced. The drive shaft ? Still don't know where the new bearings would go ? A clutch pressure plate with a balance problem could be your vibration source. Brian

Edited September 30, 2014 by Brian Conway

[Rsanter 152]

I have had pressure plated balanced before and have been shocked at how far out they have been

 

Bob

[barnett468 418]

hello;

 

does it get worse the faster you go.

 

if it is not in the engine, put the rear on jack stands

 

block the front wheels,

 

put it in gear and rev it to 1500 for a few seconds then 2000, then 2500. if it does not vibrate it is likely your tires having flat spots or bubbles.

 

if it does vibrate, remove the rear wheels then put nuts on the hubs to secure them then do the test again.

 

if the vibration stops your wheels are bent and/or out of balance.

 

if it continues, it is your driveshsaft or you have a bent yoke in the pumpkin.

.

Edited September 30, 2014 by barnett468

[Super Birthday Snake 11]

So if the prop shaft got lengthened and balanced. The drive shaft ? Still don't know where the new bearings would go ? A clutch pressure plate with a balance problem could be your vibration source. Brian

 

Yeah, sorry Drive Shaft. Bearings is the wrong word , was the needle rollers. Didn't know the clutch pressure plate could be off balance, absolutely loathe to drop the tranny so will be my last check :)

 

hello;

 

does it get worse the faster you go.

 

if it is not in the engine, put the rear on jack stands

 

block the front wheels,

 

put it in gear and rev it to 1500 for a few seconds then 2000, then 2500. if it does not vibrate it is likely your tires having flat spots or bubbles.

 

if it does vibrate, remove the rear wheels then put nuts on the hubs to secure them then do the test again.

 

if the vibration stops your wheels are bent and/or out of balance.

 

if it continues, it is your driveshsaft or you have a bent yoke in the pumpkin.

.

 

It's pretty consistent at all speeds when hitting the same revs. Doesn't sound like it's the engine to me seems more like coming from under the driver seat around that area so I'm assuming it's around the tranny/drive shaft. Some good advice to test out will give that a go.

Edited September 30, 2014 by Super Birthday Snake

[barnett468 418]

Didn't know the clutch pressure plate could be off balance, absolutely loathe to drop the tranny so will be my last check :)

 

It's pretty consistent at all speeds when hitting the same revs. Doesn't sound like it's the engine to me seems more like coming from under the driver seat around that area so I'm assuming it's around the tranny/drive shaft. Some good advice to test out will give that a go.

 

i find vibrations that way all the time.

 

when on the jackstands, brake slowly so the sudden stop of the wheel doesn't jerk the car. i have never had a prob.

 

you can straighten a coat hangar, put an 8" loop in it so it will sit on the ground then put then other end next to the driveshaft and turn it and see if the gap gets bigger then smaller etc.. if it dies your shaft us off center or the yoke in the diff is bent. if the u joint does not fut tight in the rear yoke, it is the wrong one and can cause probs.

 

you also hear something?

 

if you have not done this then try it. in your driveway, put the car in neutral, hold the rpm at 1500 for 10 seconds, then 2000 for ten then 2500 for ten then 3 for ten. if it makes the same vibration it is the engine or flywheel or pressure plate.

.

Edited September 30, 2014 by barnett468

[Super Birthday Snake 11]

i find vibrations that way all the time.

 

when on the jackstands, brake slowly so the sudden stop of the wheel doesn't jerk the car. i have never had a prob.

 

you can straighten a coat hangar, put an 8" loop in it so it will sit on the ground then put then other end next to the driveshaft and turn it and see if the gap gets bigger then smaller etc.. if it dies your shaft us off center or the yoke in the diff is bent. if the u joint does not fut tight in the rear yoke, it is the wrong one and can cause probs.

 

you also hear something?

 

if you have not done this then try it. in your driveway, put the car in neutral, hold the rpm at 1500 for 10 seconds, then 2000 for ten then 2500 for ten then 3 for ten. if it makes the same vibration it is the engine or flywheel or pressure plate.

.

 

Yeah it sounds like the vibration is originating below me when I'm driving if that makes sense, like I can hear the source of it 'shaking' whatever it is.

 

I haven't done that no, I'll give that a go to see if I get the vibrations at a standstill.

 

Thanks again!

[barnett468 418]

Yeah it sounds like the vibration is originating below me when I'm driving if that makes sense, like I can hear the source of it 'shaking' whatever it is.

 

I haven't done that no, I'll give that a go to see if I get the vibrations at a standstill.

 

Thanks again!

ok, cool, let us know.

[70769 18]

A lot of good info in this thread... keepin it for later

[Super Birthday Snake 11]

Ok put it in neutral, rev'd it up for ten seconds at 15k, 20k, 25k and 30k and the vibration wasn't there, so least it's not the engine or clutch. Will do the tests with the back up at the weekend.

[barnett468 418]

Ok put it in neutral, rev'd it up for ten seconds at 15k, 20k, 25k and 30k and the vibration wasn't there, so least it's not the engine or clutch. Will do the tests with the back up at the weekend.

 

thats great news. the other fixes are dirt cheap.

[Super Birthday Snake 11]

thats great news. the other fixes are dirt cheap.

 

Yip, delighted it isn't that. Thanks again for all your help, will let you know how it goes over the weekend.

[barnett468 418]

yup, glad it eliminated the worst possible prob and put your mind at ease. now you can drink a few beers because you want to and not because you "need" to, lol.

 

also, put it in drive and watch the wheels rotate from directly behind each one. if they wobble much, it will also cause probs and is either the rim or a bent axle.

[Super Birthday Snake 11]

yup, glad it eliminated the worst possible prob and put your mind at ease. now you can drink a few beers because you want to and not because you "need" to, lol.

 

also, put it in drive and watch the wheels rotate from directly behind each one. if they wobble much, it will also cause probs and is either the rim or a bent axle.

 

Will check that out as well, cheers!