bishbosh Posted October 22, 2009 Share Posted October 22, 2009 I am getting a very loud "rumble" in the interval between "drive" and "over run" on my 200TDi auto 90. It only happens (noticably) above 50mph and is only there when the drive train is more or less unloaded i.e. if you are cruising on the motorway and ease off the throttle slightly to control your speed or distance etc. So far I have tried: - Spare rear diff - New propshafts front and rear - Spare t-case - Driving with no front prop None of these have made a blind bit of difference. The noise sounds like it is coming from the rear of the truck. Half shafts are one piece jobbies and the bolts are all tight. All rear axle bushes are in good condtion and the ball joint is fine too. Wheel bearings are all new on the rear axle. Oils are as they should be. Frankly I have run out of ideas. Help!! (please ) Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 22, 2009 Share Posted October 22, 2009 Does it have a lift? I had a similar problem on my Discovery when the diff pinion angle was wrong due to a suspension lift. Pete. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 22, 2009 Author Share Posted October 22, 2009 1 1/2" max lift. Props are both wide angle (one GKN, the other Propshaft Clinic) Never had this problem on the RR with a much bigger lift Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 22, 2009 Share Posted October 22, 2009 Halfshaft splines? Worn stub axle? Loose brake caliper? That's the only three other bits I can think of... (was two, then I thought some more ) Do either of the wheels rock at all when they are off the ground? Quote Link to comment Share on other sites More sharing options...
Les Henson Posted October 22, 2009 Share Posted October 22, 2009 Have you tried different tyres - swapping them front to back perhaps? A slightly deformed tyre will rumble at a certain speed. Les. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 22, 2009 Author Share Posted October 22, 2009 Tyres - same noise with simex pattern or AT pattern. 1/2 shafts looked ok. I could try my spare set though... Caliper bolts - would hope not! would also expect a clunk when braking but I will check Stub axles - one is new ish, the other not so, but looked OK when I changed the bearings.... I shall check bearing tightness again too.. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted October 22, 2009 Share Posted October 22, 2009 V8_Freak had a rumble at 40mph - it was front prop yokes ouf of sync. He moved it one spline and the rumble was gone, Les. Quote Link to comment Share on other sites More sharing options...
white90 Posted October 22, 2009 Share Posted October 22, 2009 Mine was the Front Prop Charles I replaced: front Diff Transfer Box Prop for a wide angle variant bushes mounts etc etc then fitted the DC front prop and away the issue went. the R/R being longer I guess did not suffer the issue. you are welcome to try my prop if it will fit. It uses standard T/B Flanges. ps have you checked the distance wheel centre to wheel centre each side to see what the axle alignment is like? or possibly a bent prop? Quote Link to comment Share on other sites More sharing options...
V8 Freak Posted October 22, 2009 Share Posted October 22, 2009 Building on what Les said..... I was told a while ago by David Ashcroft that the front prop UJ's should be one or two splines out of line. I had replaced my front prop with new, the UJ's were aligned. I moved them so out of line by one spline but I neglected to check the direction of rotation. The initial judder went away but got a "rumble" noise at around 40 and then noticably at cruise speed on Motorway. Recently we split the front prop again and made sure the front UJ was one spline out of line in an anticlockwise direction. (While looking forward to the prop) Rumble totally gone at low and higher speeds. Neil Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 22, 2009 Author Share Posted October 22, 2009 Thanks for all the input folks. I am reasonably sure it is not the front prop as it makes the same noise when there is no front prop fitted. I shall add the other suggestions / checks to my list Any more for any more...? Quote Link to comment Share on other sites More sharing options...
daveturnbull Posted October 22, 2009 Share Posted October 22, 2009 My first thought was propshaft out of line. I've not got enough fingers to count the number of times I've had to keep turning the damn things round a spline or 5 after changing a UJ and forgetting what orientation the two halves were in - for the exact symptoms as you describe. Why not take the rear prop off and go for a drive? Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 22, 2009 Author Share Posted October 22, 2009 I have tried two different props on the back - both are high quality wide angle units one brand new, the other less than 5k miles old with no change to the noise. However, as I am at my wits end, I shall try anything now! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted October 22, 2009 Share Posted October 22, 2009 Hmm, pinion bearing/nut loose? Though I suspect you wold have noticed that, as you've  changed the props... Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 22, 2009 Author Share Posted October 22, 2009 Changed the diff too... Quote Link to comment Share on other sites More sharing options...
will_warne Posted October 22, 2009 Share Posted October 22, 2009 Something caught in one of the brake calipers??? Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted October 22, 2009 Share Posted October 22, 2009 Its a gremlin hiding but you can hear it moving about. Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 22, 2009 Share Posted October 22, 2009 The reason I asked about the suspension lift was because on mine it altered the pinion angle of the diff which effected the phasing of the rear prop as it had changed the relationship between the 2 prop flanges (t/box and diff) as on mine it had rolled the diff nose upwards. I had also tried a couple of propshafts ( one standard & one wide angle) to no effect. I cured mine by adjusting the length of the trailing arms with a packing washer. Pete. Quote Link to comment Share on other sites More sharing options...
bishbosh Posted October 25, 2009 Author Share Posted October 25, 2009 The reason I asked about the suspension lift was because on mine it altered the pinion angle of the diff which effected the phasing of the rear prop as it had changed the relationship between the 2 prop flanges (t/box and diff) as on mine it had rolled the diff nose upwards. I had also tried a couple of propshafts ( one standard & one wide angle) to no effect. I cured mine by adjusting the length of the trailing arms with a packing washer. Pete. Pete, you are a genius!! (I think ) Your posts got me thinking - the noise appeared suddenly and could have been after I fitted new springs, but I couldn't recall the precise timing. Anyhow, this afternoon I had a bit of spare time so I had a quick measure of the spring seats and reckoned the front of the seat was higher than the rear, which would make sense due to the lift. So, off with the trailing arms and on with a 5mm packer. Quick test drive up the dual carriageway and I think the noise has gone! :D I say think because I couldn't get to motorway speeds, but I am pretty confident it has gone as I could produce the noise on the same stretch of road previously. Yippee!!!! :D Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted October 25, 2009 Share Posted October 25, 2009 Glad, I may have helped . It took me ages and some help from the forum to fix mine so I hope it has cured yours. Pete. Quote Link to comment Share on other sites More sharing options...
MJIbex Posted October 25, 2009 Share Posted October 25, 2009 Thanks for all the input folks. I am reasonably sure it is not the front prop as it makes the same noise when there is no front prop fitted. I shall add the other suggestions / checks to my list Any more for any more...? As others have said the rear prop is shorter - try changing the phasing on this by 1 or 2 splines at a time. Mark Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted October 25, 2009 Share Posted October 25, 2009 Hopefully you've solved your problem. If you're still struggling, and you're willing to try anything, it could be a relationship between the two propshafts. You'll sometimes find that the front prop, with the different angles across the UJs, can excite a harmonic across the (open) centre diff, which reflects rotationally off the uncorrected middle section of the rear prop - before the second UJ corrects the speed. Solution: remove both props. Problem goes away completely. Quote Link to comment Share on other sites More sharing options...
JST Posted October 26, 2009 Share Posted October 26, 2009 Hope the issue is sorted now i was going to suggest run without a rear prop for a while. out of interest are these two related? my 200TDi auto 90. I couldn't get to motorway speeds, Quote Link to comment Share on other sites More sharing options...
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