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[monza789]

Hello all..........My 97R 2.5V6 estate has just had a donor engine fitted as the other blew its head gasket....

To cut a long story short....the flywheel was taken from mine and put on the 'new' engine (which incidentally was from an S Reg i believe)

I kept my clutch and refitted it as a new kit costs approx £225 incl a new concentric hydraulic cylinder, and right now my original clutch looked reasonably ok for a while.

Anyhow, Ive been running it for a day and all seemed good.....except I notice a vibration when the engine is running thro a speed band of around 70 mph coming down to about 60mph With the throttle lifted, like when you are entering a slip road after a motorway jaunt...it feels like it's alot as I can feel it thro' the car and in the back of my seat....its obviously under me somewhere gearbox /propshaft area...it goes away when this speed band has been through.

I noticed that if i ride the clutch pedal slightly during this vibration it kills the problem and it goes away especially if i dip the clutch altogether while the car decreases in speed in this way.

Any ideas guys?.....anyone had the same maybe?

cheers

monza

[Marks DTM Calib]

Was the donor from a manual or auto?

[monza789]

hi mark,

i think the donor was a auto......reason i say this is there was no flywheel on it when it arrived but on the output was a small disc with a spigot shoulder on it....which mine didnt have...

we fastened my flywheel straight onto output shaft and discarded the spigot ring as mine didnt have this item anyhow

the vibration only seems to occur during rundown through speed range with throttle lifted.....also it goes away when clutch depressed so i am stumped as i first thought of propshaft inbalance..

monza

[TheBoy]

Engine and gearbox mountings all ok?

[Marks DTM Calib]

Did you not fit a manual gearbox spiggot bearing into the end of the crank (an auto does not have one) to support the end of the gearbox input shaft?

[RonaldMcBurger]

Mark is spot on. The autobox'd engines dont have the spigot on the end of the crank, but the manuals must! Otherwise the end of the input shaft will wobble and give vibration - just like you are getting. I do seem to recollect Mark mentioned this to you BEFORE the job was done. Good advise!

the other likely candidate is if the clutch isn't aligned properly.

[monza789]

Hi Guys,

Have checked out the spigot baering issue with VX ...the workshop manager told me that VX stopped fitting the roller spigot bearing in question some years ago as the bearing was doing nothing more than causing transmission drag...!
He said it doesnt need a spigot bearing and the only bearing is the needle bearing which would be in the engine anyhow as it would be noticably absent. He told me that the flywheel bolts directly up to the engine which is what was how mine was when we took it apart. I noticed when i looked at the supplied engine that everything was flush at the crank- flywheel end ie there were no apparent recessed diameters which look like needing any items..just a pattern of tapped holes for the flywheel mounting.!

The spacer disc with a boss in the middle that was supplied with the new engine is apparently for when an auto is used and fitted when the transmission is attached. It has a pattern of holes which locate with the flywheel mounting bolts.

He said the vibration points in the direction of the propshaft and that is where he would look first as I am using my clutch and gearbox and flywheel so he said there should be no real probs there ...however never say never...!!

Any more thoughts on this would be very welcome guys.....Im getting the guy who fitted the engine to take a look on saturday....

PS Ronald McB......THE PLUG WELLS were full of oil in the new unit which has supposedly covered a mere 58k ??  I have put my cleaned out breather box on it and cleaned my flexible pipes again...then fitted new VX Rocker seals....hope it lasts a while...(Does the mileage sound suspect with oil filled wells to you?)

monza

[sassanach]

as already stated your spigot bearing is missing from the end of the crank,it cannot be your propshaft as dipping the clutch does not stop the propshaft  from rotating,also an old saying of mine, if it wasnt broken until you fixed it ,then whatever fixed it must have broken it(roughly translated -changing an engine will not knacker a propshaft but leaving out the spigot bearing will very quickly knacker a gearbox).

[monza789]

Thanks sassanach for your reply.......can you clarify the spigot bearing we are all talking about........is it a small needle roller bearing ?.....and is the end of the crankshaft 'counterbored' (for want of a better term).....to house this needle bearing?......and then is the gearbox input shaft passing through this bearing when it locates on the spline in the engine?

Sorry Im being a bit dense here but the terminologies that folk use is a bit different im afraid.......spigot in my engineering terms refers to a raised boss on a surface ie a shoulder that protrudes that locates say in a female recess for example.

Now here im coming to think we are talking about a standard type roller/race bearing in a cage which is housed in a machined recess in the end of the crankshaft which when fitted in then makes the end of the crankshaft flush. The gearbox drive shaft then passes through this bearing and is engaged on spline......am i right so far?.  If its this item...then VX call it a needle bearing...yes??

cheers for all he help so far guys.......anyone got a photo of this little bearing???

monza

[Kevin Wood]

Sounds like you're on the right track. They normally are a small needle roller bearing that presses into the end of the crank.

The spline on the input shaft engages in the clutch driven plate and the tip of the input shaft is machined down to a rod which locates in the spigot bearing. I'm sure this is why you are seeing this vibration. The clutch driven plate and input shaft are not held securely in place without it. Shame it's a gearbox out job to fix

Kevin

[Marks DTM Calib]

The service manager is talking bull.....just checked with my source, they all have them and always did.....

[Andy B]

The service manager is talking bull..........

Surely not!?!?        

[Marks DTM Calib]

The comment I got was....'daft bugger'

It turns out that when Vx supply an exchange engine to a dealer, it comes with no flywheel or spiggot bearing.

How ever, this is because the engine can be fitted to auto or manual and if fitting to a manual, a spiggot bearing should be fitted.

So god knows how many power plants that useless sod has had fitted without spiggot bearings in!

As for transmission drag....whats he on, its a roller bearing for christ sake.

[monza789]

Hi guys.......the help you are giving is much appreciated .......its a mine field out here with the info i am getting from the dealers and the guys who sold me the engine.

I just roadtested the car up a dual carriageway to try and see what's going on...!

I found that the car really vibrates alot when engine revs are at about 2500 rpm.......and it is not felt quite as bad under acceleration but is annoying on run down thro this range.

I feel that the clutch has a different feel to it as well which i find strange as it was ok before.......its heavier and has less travel now and when i get this run down vibration, if i dip the clutch then the problem is not there....!

Mark.....Would this vibration be caused by the omission of this spigot/needle bearing so much?.....and...
Does the input shaft really need supporting at the end as its already located in the spline on the clutch ?......have you come across these symptoms before
The guy who gave me the engine was also adament that the bearing made no difference and said he's fitted 100's of the V6 engines and some have the bearing and others havent had one in....without further problems (he used to be VX Technical he said)
As you may have gathered I am just trying to nail any other reasons for this problem before i get down to fetching the box off again.
Can the clutch be causing this problem?......
could it be fitted incorrectly without realising??
and why does the problem cease if the clutch is dipped at the same road/engine speeds

I have bought a needle bearing today from VX at an amazing £3.50 cost...!!!

monza

[Kevin Wood]

Does the input shaft really need supporting at the end as its already located in the spline on the clutch ?......have you come across these symptoms before

Remember that the clutch driven plate is only sandwiched between the flywheel and pressure plate. When you press the clutch pedal the pressure on the clutch plate is removed and it is loose between the two, so it is vital that the gearbox input shaft remains accurately located as this is holding the driven plate central.

Can the clutch be causing this problem?......

I guess it could if there was a missing spring or something. Having said that with a dual mass flywheel the driven plate may be mounted solid. Either way it needs to be removed to check, unfortunately

and why does the problem cease if the clutch is dipped at the same road/engine speeds

This will release the force clamping the driven plate. If it wasn't entirely central when it was engaged I guess it could centralise when running at speed as it will be acting like a gyroscope.

Kevin