Vibration at 45MPH ?

Post by **JustinMinor1000** » Tue May 16, 2006 2:34 pm

So .. Pod runs fine (and quite quietly) up to 45MPH then there is a whole heap of vibration .. up to about 65-70 MPH and then it falls off ..

It's not the front tyres (nothing comes through the steering) .. I inspected the probshaft today and it seems OK ....

Anyone got any ideas ?

Post by **rayofleamington** » Tue May 16, 2006 6:20 pm

My first guesses would be propshaft or gearbox.
Is there any cross-axial play in the prop where is sits in the bush at the back of the gearbox?

Post by **JustinMinor1000** » Tue May 16, 2006 6:52 pm

rayofleamington wrote:My first guesses would be propshaft or gearbox.
Is there any cross-axial play in the prop where is sits in the bush at the back of the gearbox?

Ok .. I'll just change the propshaft ..

Post by **bmcecosse** » Tue May 16, 2006 9:52 pm

You could try just turning it 90 degrees on the diff flange - but if you have another handy, may as well try it!

Post by **bigginger** » Tue May 16, 2006 9:53 pm

180 degrees, surely? I think they only fit on two ways.

Post by **Cam** » Tue May 16, 2006 9:54 pm

Yes, the holes only allow 180 degree change.

Post by **bmcecosse** » Tue May 16, 2006 10:01 pm

Ages since I messed with props and diffs - you are probably right!

Post by **bigginger** » Tue May 16, 2006 10:04 pm

A week since I did - DEFINITELY right

Post by **Willie** » Tue May 16, 2006 10:13 pm

I had this vibration after changing a diff and found that the prop shaft flange
was bent! The vibration commenced at about 48mph and was so violent that
it was impossible to 'drive through it'. If you cannot feel any play in the UJ's
you could try a jubilee clip large enough to clamp round the prop which you
move around it to see if things improve. I would not recommend that you
continue to drive with the bad vibration as, if it is in the drive train, you could
seriously damage the tail end of the gearbox.

Post by **rayofleamington** » Tue May 16, 2006 11:14 pm

Tail end of the gearbox might just be worn out due to old age - this allows the prop to spin off centre

There is a press fit bsh in the tail end of the gearbox which costs less than a tenner (probably about £15 including a new rear seal). The downside is that it needs to be reamed to size after fitting!

I'm sure there's an opportunity for a trader to offer this complete assy on an exchange basis... Most people want to be able to bolt the bits on, rather than press and machine before they can use them.

Back to topic - the front of the prop is located in this bush in the tail of the box, so if there is any play in the prop (in front of the UJ) you need to investigate further.

Post by **JustinMinor1000** » Wed May 17, 2006 10:52 am

rayofleamington wrote:Back to topic - the front of the prop is located in this bush in the tail of the box, so if there is any play in the prop (in front of the UJ) you need to investigate further.

What is slightly odd is that there does not seem to be a huge ammount of vibration coming through the gear stick ..

As I have one handy .. I might as well change it ..

if that doesn't work then it's the gearbox as well .. Fortuantly I have oneof those too ..

Post by **rayofleamington** » Wed May 17, 2006 12:34 pm

Ok - back to the obvious - are all the wheels balanced ok?

Post by **JustinMinor1000** » Wed May 17, 2006 1:02 pm

rayofleamington wrote:Ok - back to the obvious - are all the wheels balanced ok?

The obvious is always usefull with me

I suspect they are and I guess it would be the back ones (as nothing comes through the steering) .. it also happened when the car had the minilites fitted ..