Jump to content
Click here if you are having website access problems ×

Drumming vibration in fifth gear


stevemersey

Recommended Posts

Hi all,

I have just bought a nice old 7, 92 vintage with 1800 Zetec and five speed box. I have been pleasantly surprised at how few rattles and gremlins this car has for its age, and it drives really well - but it does have one problem.

 

In fifth at steady motorway speeds there is a drumming vibration like driving over a rough road surface, you feel it rater than hear it. It disappears if I change down. So it is not related to road speed. Similarly, there is no vibration at the same rpm in another gear. The car is sweet and smooth all the way through gears 1 to 4.

 

Any thoughts on where I should start looking to sort this problem would be gratefully received.

 

 

Link to comment
Share on other sites

Not about the TV show then 😬

 

Welcome to BlatChat *wavey*

 

Don't know where you are based. If you think the problem is in the box and can remove the gearbox, you could take it to a transmission specialist like Road and Race near Sevenoaks in Kent. Others are available round the country.

 

 

 

Edited by - Stationary M25 Traveller on 10 Jan 2012 19:34:38

Link to comment
Share on other sites

The bridge is rarely a problem unless they have coned the lanes, though last year there was one occasion when coming home they were shutting it for 30 min then running convoys each way.

 

I know Grassendale well, lived in St.Michaels-in-the-Hamlet when I was at Uni.

 

 

Link to comment
Share on other sites

My guess is propshaft but your tests are slightly contradictory. If it were a propshaft/driveshaft/UJ problem then it would be speed related, changing gear would have no effect. Equally if it were engine/box related it would be revs related and roadspeed independent. But it's neither, apparently.

 

Propshaft troubles are usually obvious and the vibration comes and goes at various speeds. It's a very heavy vibration as you describe.

Link to comment
Share on other sites

  • Leadership Team

Hi Steve, welcome to the fold *thumbup* As John says get along to the MADS meeting at the end of the month and we'll do some tyre kicking for you and give you at least 10 possible faults/cures that may fit the bill! No seriously, I'm sure someone will be able to identify what's wrong!

We meet at the Ring'O'Bells in Daresbury village, just off the M56 - usually there's a few of us there from around 7.15pm to sample the pubs food as well as beer *thumbup* Also we have an email list running to circulate useful info and if you'd like to be included on it send me your details.

 

Stu.

Link to comment
Share on other sites

Thanks for more constructive ideas. I am going to eliminate the easy ones. I will get the wheels balanced in the next couple of days and have another look at the tyres, and nipple greasing is always fun.

 

I have a tiny cheap video camera that I thought I might be able to fix in the transmission tunnel to see if I can see anything obvious in the prop shaft, and if I can identify the frequency that should give me clue.

 

Link to comment
Share on other sites

Also experienced vibration issues at aroun 70 mph which felt like unbalanced wheels but was fixed by replacing the engine mounts during other upgrades. Could be a cheap fix.

 

Found the nearside mount to be quite loose and the bracket to the engine the same, so I met yet have found the problem. Also one wheel bearing was a bit sloppy. I love this car already, so much play value. *wink* Just need the chance to road test.

Link to comment
Share on other sites

Just an update.

 

During an overall examination of the car we found a slight misalignment of the gearbox and engine. After rectifying that and tightening some loose differential bolts, the vibration has been all but eliminated. I do not think I would notice it now if I was not looking for it.

 

I suspect the barely perceptable residual vibration is due to uneven wear at the clutch caused by the misalignment, and it remains to see if this will get better or worse as everything settles in to it's correct alignment. Either way, the car is running beautifully and at worst might need a little clutch work at some time in the future.

 

Let the farkling commence!

 

Link to comment
Share on other sites

The former...the bellhousing was tight to the engine at the top but not quite snug at the bottom. Missing bolts being the cause.

 

Fingers crossed there is no damage to bearings or gearbox as a result. All feels pretty good and quiet now it is tightened up, but if I do get any problems later on I know where to start looking.

 

 

 

 

Link to comment
Share on other sites

An update and request for more specific help.

 

Quick recap. I have recently acquired a 1992 7 with Raceline Zetec 1800 and 5 speed box. It runs very nicely apart from a drumming vibration in fifth gear only at motorway speeds. I reduced this effect, but have not eliminated it, by tightening up differential and engine mountings and replacing missing bolts in the bell housing.

 

I have now found what may be the cause. There is significant play where the propshaft enters the gearbox. Grabbing the U joint and wiggling results in visible movement and a knocking feeling suggesting the rear gearbox bearing is worn.

 

I intend to take the gearbox out and replace the bearing as soon as possible, and replace or repair anything else worn in the drive train but cannot get onto this for a week or so.

 

So my questions are.

1. Is this a common problem? I cannot seem to find a reference to it in search.

2. I have had motorcycle boxes apart before, but not a car. How tricky are they to rebuild yourself?

3. With the engine and gearbox out, will the prop shaft be removable with the diff in place?

 

 

Link to comment
Share on other sites

In your original post you state that the drumming happens in 5th at motorway speeds but not in other gears. If this is the case then it MUST be the gearbox. The other bits and pieces that you have found and fixed might have amplified it, but if it's not roadspeed dependent it has to be upstream of the propshaft, if it is not engine-speed dependent then it must be downstream of the clutch.
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...