I have a Euro6 DAF XF 510. When the engine is under load between 1000 and 1200 revs there is a severe vibration. Happens in various gears and therefore speeds so isn’t a wheel balance problem. Once above 1200 revs it stops. Only occurs when the engine is under load. Any Ideas, as the dealer hasn’t any!!
You are probably onto a loser with this one, if the vehicle is low mileage then unless someone strikes lucky, or the dealer doesn’t know about an identified problem then it could mean days and days in the workshop and a lot of your diesel used for road testing. The list of possibilities is as long as your arm. The factory field service engineer will have all sorts of ideas, some of them absolutely crazy. Consider getting shot and giving someone else the headache.
cav551:
You are probably onto a loser with this one, if the vehicle is low mileage then unless someone strikes lucky, or the dealer doesn’t know about an identified problem then it could mean days and days in the workshop and a lot of your diesel used for road testing. The list of possibilities is as long as your arm. The factory field service engineer will have all sorts of ideas, some of them absolutely crazy. Consider getting shot and giving someone else the headache.
Bit too new to sell only done 9700kms. Will have to see what DAF come up with.
Unfortunately it would be unwise for you to start making suggestions to your supplying dealer about potential causes since they may take the line that they have done the work you requested and become unwilling to do any more to resolve the issue. This is the dealer and DAF’s problem to resolve, several contributors will enjoy pondering on the problem and suggest possible causes, but it would be best for these to be kept for your personal interest.
The one thing that you as the owner can do usefully is to make a few enquiries. Try to find out an exact manufacturing date, where it was stored and for how long in each location before you took delivery, and if possible what the weather and ground conditions on site were like at the time. New vehicles, or any vehicle for that matter, parked in the open for any length of time, particularly if not on clean concrete or tarmac will suffer from damp penetration. This may seem irrelevant, however what you find out may well turn out to be very useful for investigations.
The natural frequency of the engine at certain revs can affect items which would appear to be only road-speed related, or even seemingly totally unrelated parts of the vehicle. This may not have any mechanical cause at all but be instead incorrect sensor data or the ECU’s interpretation of it. It can be an eye opener just how long some new vehicles have been hanging around outdoors before they are registered. The newer the vehicle the more difficult finding the cause is likely to be since wear will not be a factor normally.
If it was my vehicle I would not be troubling the service department with this line of enquiry, but I would be giving sales absolute hell. Fling it back at them, demand a demonstrator on permanent loan until yours is fixed to your satisfaction and make sure that there is practically no fuel in your vehicle when you take it in.
I managed fortunately never to get involved in a similar issue at the dealer I was working for some 30 odd years ago, but I do recall the number of times the vehicle returned with the problem unresolved but the dealer packed up before it was sorted. IIRC the vehicle had various parts substituted including the fan, the injection pump, the engine mountings, the clutch and the propshaft. It even had the rear engine mounting brackets redesigned to alter the angle of the driveline at the behest of the field service engineer, but all to no avail.
Surely at that mileage it is still brand new. Personally I would hand it back and say, truthfully, it is not fit for purpose!! Which it isn’t! As has already been said, I wouldn’t get involved in suggesting possible causes or places to start looking for causes. Just hand it back, and tell them to fix it so as it is fit for purpose.
bullitt:
Surely at that mileage it is still brand new. Personally I would hand it back and say, truthfully, it is not fit for purpose!! Which it isn’t! As has already been said, I wouldn’t get involved in suggesting possible causes or places to start looking for causes. Just hand it back, and tell them to fix it so as it is fit for purpose.
Handing a vehicle back isn’t as simple as you make it out to be
bullitt:
Surely at that mileage it is still brand new. Personally I would hand it back and say, truthfully, it is not fit for purpose!! Which it isn’t! As has already been said, I wouldn’t get involved in suggesting possible causes or places to start looking for causes. Just hand it back, and tell them to fix it so as it is fit for purpose.
Thanks for the replies. Had a chat with the service Department today to see if there was any feedback from DAF. DAF suggested wheel balance issue, which we both felt was incorrect as fault occurs at different road speeds and if the engine isn’t under load there is no vibration at the same speed. (Hope that makes sense). They also wanted dealer to check propshaft and centre bearing. I need to add at this point it had it’s first 6 weekly under the R and M contract a week ago and they did a road test and agreed there was a vibration problem. Got finished a bit early this afternoon so popped into the dealer to have the aforementioned checks done. Was in the pit with the service manager and technician when he found one of the four centre bearing carrier bolts with no nut on it and the bolt next to it loose!! Service Manager said he would be having a word with the technician who did the work last week!!
Will let you know tomorrow if this has cured it, but I seem to think it will have. Perhaps I should have laid under it myself to have a look, but that is one of the reasons I bought a new tractor so I don’t have to spend my weekends working on it!!
Unfotunately one clown can put you off a dealership …I think you should get a good will gesture of some sort from the service manager…At least it is sorted
norb:
Unfotunately one clown can put you off a dealership …I think you should get a good will gesture of some sort from the service manager…At least it is sorted
The service manager and I go back far more years than I care to remember. He has always been good to me since I started working for my self.
As a coincidence I have been struggling the last few days to source a propshaft centre bearing for a 50 yr old bus which has been exhibiting almost the same symptoms: ie vibration when pulling and in this case noise, the quietest place being in the cab! This bearing sits in a greaseable cast housing with oil seals each end to keep the grease in and the damp out. However it spent years parked outside on rough farm ground. The bearing shows very little sign of wear, but a lot of corrosion damage to the balls and tracks.
Bad news still have the vibration so the loose carrier is a sympton not the cause. Now back to the dealer but I am also going to start talking to the sales department following the replues on here.
Just a thought but are all the yokes on the propshaft lined up?
^^
Easily missed especially when there is a centre bearing involved. The set up rearward of the bearing depends on the actual type of shaft fitted. I would be yellow paint-marking those bearing carrier mounting nuts because I have a sneaking feeling that they may well have been tight when looked at.
To give an update, back into the dealer tomorrow morning as it has thrown the grease out of the sealed for life centre bearing and grease is starting to come out of the sealed for life UJ’s!! At present dealer won’t give me a demo as a replacement as it is out with another customer.
Just noted that there is a comment on the prof section of the forum about DAF units suffering from vibration and things rattling and cracking. Returning to this being engine speed and torque related I would want to be having a very close look at the crankshaft vibration damper. A fault with this is so obvious that I would have expected it to have been ruled out during the very first dealer investigations. However with issues now reported with the propshaft, which may or may not be the primary cause, I would be looking again since vibration will be transmitted right down the driveline. The centre bearing is located at the point where the angle of the driveline alters hence this is the point where the shaft will be experiencing the greatest whip.
The dealer is in a fortunate position with this since unlike any other repairer they can swap parts over from another vehicle without having to purchase anything.
I had a marine ■■■■■■■■ V8 that had a severe balance problem with the vibration damper so much so that it tore out the coupling between the engine and gearbox and knackered the crankshaft, my main problem was we was 35 mile off the African coast and about 150 miles south of the Canary Islands when it all went bang ! After a 30 hr wait wallowing in the Atlantic swells we were towed by a salvage tug to Las Palmas where we spent a long terrible 42 days waiting for the repair. I had the damper checked by a firm that did turbos who told me it was 50 grams out of balance which they rectified with a weighted chewing gum like substance. I asked would that make much difference and was told to tie my packet of tobacco on the end of a one and a half foot long piece of string and wizz it around at 1700 rpm and experience the centrifugal force.
Actually the 42 days in Las Palmas were the best ever but cost me a bloody fortune 
Have they had the prop off and sent away to be balanced?
At present they are replacing the centre bearing. The props have been balanced when manufactured as there are weights on them, and no signs of any having come off. If the new bearing doesn’t cure it, perhaps they will go down that route.
If vibrating at same revs in different gears then Id have thought its an engine rather than transmission problem. Vibration due to prop etc is more likely to be present at the same road speed in whatever gear surely?
We`ve just had a DAF 510 demo for a week. That had vibration about 1100 to 1200rpm when under load. Being a demo, and one would hope properly set up, you can draw your own conclusions…