Pls Help, Severe load related vibrating, got trackday on sat!!!

[msisleman]

Guys,

Bit of an emergency this one. Last weekend I did 620 miles in the 172 and a vibrating began. Not vehicle speed related, only load related. So that instantly said to me CV joint as it wasn't really coming through the steering wheel and was shaking the car quite "melodically" (not in a good way!). Not engine related as all the engine mounts are brand new and when you hold the revs in neutral at different rpms its fine.

Slowly but surely this week started to get worse so I changed the drivers side driveshaft this evening as this is the only one that the CV boot has been off at any point, at the end of last year, so assumed it'd worn. The replacement driveshaft came off a 172 with only 7k on the clock and looked and felt noticeably better when looking at them both together, so I was still happy this was the problem.

Got it on, no problems, pulled out easily after moving hub out the way and the new one just pushed in. Bolted everything back up and checked twice.

It has made it worse!!!!! Now it does the same but is more violent, but more noticeably when cornering it only does it round left hand corners!!! It didn't do it at all when cornering before!!

What on earth is it? Might have to take day off work to sort this tomorrow as I've got a trackday at Snett on satuerday!!!! Nightmare...... All I can think is wheel bearings but this wouldn't make sense with it being load related and no whining or grinding noises to speak of, just vibrating.

GGrrrrrrrrr!! Please help!!! :S :S

 

[msisleman]

Gearbox/diff bearings???

Please help!

 

[ditz]

could well be the engine mounts adusted wrongly, if the engine is "leaning" on a shaft due to it being one way or the other it would do that being load related points to something mounted flexible ie rubber mounted...
doubt its gearbox if it does it in all gears

 

[msisleman]

could well be the engine mounts adusted wrongly, if the engine is "leaning" on a shaft due to it being one way or the other it would do that being load related points to something mounted flexible ie rubber mounted...
doubt its gearbox if it does it in all gears

Well this would be a huge relief if it was. I'll try adjusting the dogbone mount tomorrow. Or shall I drive with it taken off just up and down the road to see if this makes any difference? How do you adjust the engine mounts correctly, sorry I think there's a guide isn't there, I'll search now.

Something I found a little strange was after reading peoples experience of taking o/s driveshaft out, I expected it to be fairly stuck in its roller bearings in the diff, but it came straight out, no fuss. And the new one slid straight in with very minimal force, after making sure the spline was correct etc. Does this sound right?

 

[Fred@BTM]

yeah the passenger drive shaft will come out easy peasy

got your PM, but without seeing the car i´m stuck

 

[msisleman]

yeah the passenger drive shaft will come out easy peasy

got your PM, but without seeing the car i´m stuck

It was the drivers side that came out easy peasy, haven't touched the passenger side. I'm so confused. After some research on the forum I'm maybe thinking towards diff bearings?? Can these be replaced easily or is it a new box job?

No trackday for me on sat. Gutted, was first one in my 172 too.

 

[msisleman]

could well be the engine mounts adusted wrongly, if the engine is "leaning" on a shaft due to it being one way or the other it would do that being load related points to something mounted flexible ie rubber mounted...
doubt its gearbox if it does it in all gears

Ok after thinking this through thoroughly, I am actually now confident this is what the problem is. It makes perfect sense, what a relief that will be if it works. Basically what made me realise just now is that when we refitted the driveshaft, it was a very, very tight squeeze between hub and diff. This therefore means theres no play whatsoever between hub and diff, hence the knocking round left hand bends (engine centripetally being pushed against shaft, against hub) and then under load the the engine naturally moves due to the torque effect, hence vibrating straight through the shaft to the hub again.

Thanks a lot ditz, hope this works, I'll let you know. I have faith though as you were the person who diagnosed the problem with my g/f's Ka, changed the wishbones and it transformed the car! Best £30 I've ever spent that was!

Maybe I will make Snett on sat....... just maybe.

 

[LegoHead]

could well be the engine mounts adusted wrongly, if the engine is "leaning" on a shaft due to it being one way or the other it would do that being load related points to something mounted flexible ie rubber mounted...
doubt its gearbox if it does it in all gears

I also had all brand new engine mounts and really bad vibrations and exhaust hitting subframe. I removed all the bolts on the upper mount, pulled the engine as far forward as possible still allowing bolts to go back in and bolted it all back down.

It was fine for 500 miles then I think the engine mount must have moved as the vibration is slowly coming back. I am gonna look at a ktec mount or see if I can stop it from moving again.

Does anyone know the correct torque for the bolts on the upper engine mount?

 

[msisleman]

I also had all brand new engine mounts and really bad vibrations and exhaust hitting subframe. I removed all the bolts on the upper mount, pulled the engine as far forward as possible still allowing bolts to go back in and bolted it all back down.

It was fine for 500 miles then I think the engine mount must have moved as the vibration is slowly coming back. I am gonna look at a ktec mount or see if I can stop it from moving again.

Does anyone know the correct torque for the bolts on the upper engine mount?

http://www.cliosport.net/forum/showthread.php?t=349543&highlight=engine+mounts

Yeah, really hope this does the trick. That engine mount is 62Nm by looks of it.

 

[LegoHead]

http://www.cliosport.net/forum/showthread.php?t=349543&highlight=engine+mounts

Yeah, really hope this does the trick. That engine mount is 62Nm by looks of it.

cheers, I can go and play with my new torque wrench now!

 

[msisleman]

Ok, just adjusted the top left and right engine mounts into much better positions, pulling the engine away from the drivers side driveshaft. Now much, much better, so this was obviously the problem. However it is still noticeably doing it, slight knocking from drivers side wheel (like running over cats eyes) when turning left, then perfect when turning right. Still got the rumbling/vibrating under load between around 3-5k, but much, much more mild then before.

Other then the top two engine mounts, is there any others that I should be adjusting? Because its still not right, I'll have a crack at the track day tomorrow. Dogbone can't really do anything can it? Gearbox mount?

Cheers ditz for helping, its 80% cured which means I can track it tomorrow, even if I will only do maybe half of the day.

 

[msisleman]

Anyone any fix ideas for me for trackday tomorrow to keep my engine to the left of the engine bay??!

Pack something into my drivers side top engine mount to restrict its movement to the right (when looking from drivers seat)?? Bloody annoying considering they're all brand new engine mounts and brand new suspension to mounts. Sh*te cars.... have to bodge them just so they can be used.

 

[msisleman]

Well it looks like only me reading this thread! But I might as well close it with the answer.

I had the wrong driveshaft on, I had a Cup wide one!!! I rebuilt the tripod in my old inner cv and put it back on at the trackday and the car felt amazing. Finally!!

 

[ditz]

i was close then, lol

 

[msisleman]

i was close then, lol

well the engine was "leaning" on the driveshaft...... feels so nice now

 

[LeeJSA]

Well it looks like only me reading this thread! But I might as well close it with the answer.

I had the wrong driveshaft on, I had a Cup wide one!!! I rebuilt the tripod in my old inner cv and put it back on at the trackday and the car felt amazing. Finally!!

Just as a matter of interest.....whats the difference then - different lengths?

 

[msisleman]

Just as a matter of interest.....whats the difference then - different lengths?

Yes the length, 5mm per side I think.