Vibration when accelerating after driveshaft replacement

[tmulsund]

Hello, experts

This problem was originally posted on the Transit Custom board a while ago, but as it's a bit complicated to diagnose I was advised to ask here as well to benefit from your extensive knowledge and experience.

I have a 2013 left hand drive Tourneo Custom (L2H1) with motor code CYFF that has recently passed 240.000 kilometres.

Two years ago I had the right side driveshaft replaced because it made noises when turning hard to the left. When the job was done, I could feel a vibration in the car when the engine worked hard to convert force to speed. Typically in the second gear when exiting an intersection while applying pressure to the accelerator to gain speed. No explanation was found under the car, everything seemed as tight as it should be, so I just left it at that. It did not get worse during those two years, so I assumed no bearings were being eaten.

Three weeks ago I had the left hand side driveshaft replaced because it had for a long time been making noises when turning hard to the right. It turned out the rubber cover on the knuckle was gone, so no mystery as to the cause. But now I get a rather violent vibration when the engine applies force to the moving parts. It can't be good and I can almost feel that a major part of the horsepowers are wasted on making the vibration instead of turning the front wheels.

All included new parts were used, so everything should be nice and tight. The center nut at the end of the driveshaft was tightened to at least the recommended 250 newton, I've asked the mechanic.

Both driveshafts were made by the same vendor, supposedly new and marketed under the brand Triscan. They were purchased two years apart from a major supplier of aftermarket parts in my country, and the same brand is offered by several major suppliers here. It should hopefully mean the quality is good.

Since my original post, the car has been checked again by the mechanic who replaced both driveshafts and by a Ford garage. Neither of them can find any reason for the vibration and there is no unexpected room for movement at either end of the driveshafts.

Possibilities listed in the other board was clutch, gearbox or DMF (or wheelbearings), but replacing driveshafts should be a quite straightforward job and shouldn't likely cause any major damage to bearings or anything else. Right?

Does anyone have any theories on what could be the cause of the vibration? Any help is appreciated.

[metalworker0]

Well i actually said the mk6 ; 7 forum is where the concentration of knowledge was.

Did you drop the gearbox oil and check for glittery stuff?

if it never had a DMf or clutch in all those miles ..you cant rule them out.

Bad tyres or dented wheels is worth a look at..jack up .. and hand spin the wheels,,, look for off centre wobbling on both sides of each wheel....this will also detect bad maybe bent hubs.. resulting from pot hole damage.

These people from the garages must be lacking, if they haven't found the fault. Or missed things to check

A few other things worth looking at
...The crankshaft damper ..this is a lump of rubber in the middle of the crankshaft pulley ..it is quite common for these to wear out ...there will be cracks etc ..

Another thing to look at is the auxiliary belt together with the tensioner pulley and all items it drives...alternator , power steering pump, air con pump .etc

Belt will have to come off ..so you can physically hand spin some of these accessories to hear rumbles in the bearings etc.

all the best.mark

[tmulsund]

Sorry about that. I was uncertain because both forums cover 2013 models. Any Admin is welcome to move the thread to MK6/MK7.

Yesterday I had the car at the Ford garage to replace some parts to cure a sound that has been building up over time. No apparent relation to the violent vibration, as that was suddenly there only after the last driveshaft replacement. They replaced a tension pulley, a belt set and two other pulleys. It didn't cure all of the sound, there is still a fast ticking noise at the low right hand side of the engine compartment that I think I recognize from when the dynamo had to be replaced two years ago. It did however surprisingly cure most of the violent vibration. It doesn't happen quite as often as it did, and is less noticeable. It must be quite a coincidence that it started when it did.

Mark will of course notice that this is according to the last advice in the previous post, so thanks for that. I'll keep looking into the others, unless you guys have any strong suggestions based on the new information.

[metalworker0]

all i can say is don't replace anything unless its actual worn or failed.
i wrote a bit about disks up there in another post about vibration ,..that may hold a few clues.

you don't replace a disk though ..just because you suspect it...get a dial gauge on it and see if there's anything there to show its warped.

like so