Mud-club
Vehicle & Technical => Discovery => Topic started by: jnoshea on October 28, 2007, 22:30:47
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My 300Tdi has developed a vibration which is getting worse. I was thinking of taking off the front propshaft to narrow it down a bit. Is it ok to drive around the block a bit with the propshaft off? At least then I should be able to see if it's coming from the front or rear of the system.
In terms of the vibration itself, it is only under power (i.e. much less when cruising). There is a very noticeable 'single' shudder when taking up the drive from a standing start. It is definately worst at 2000rpm in 3rd (around 30mph) but also if the revs are a little too low in 4th you can almost hear a growning sound. Basically accelerating hard feels like something is about to break.
Cheers
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You can remove the front, or rear, propshaft and drive the vehicle normally with the difflock engauged. :wink:
Check for play in the U/Js, once you've removed the propshafts and also check for cracks in the rubber U/J on the rear propshaft. Also make sure there's no play in the centre splines of the props and that they move in & out smoothly.
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Jamie, sounds to me like a UJ is on it's way out.
Budgie is perfectly right, on your motor you can safely drive round on 2WD indefinitely as long as you remeber the car might handle differently in the wet.
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Thanks guys. That's my weekend sorted :D
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Well I got under the truck this afternoon. There is some lateral movement in the front propshaft UJ, but much more noticeable is that I can rotate the propshaft by a good 10 degrees. I don't know how much (if any) slack there should be, any ideas?
When I rotate the front prop, it obviously turns the gears a bit in both the transfer box and the front diff. Also, when turning it I can here a click near the hub. I'm not sure if this is normal as I guess this means the slack is somewhere near the front wheel hub. I know almost nothing about the drivetrain as you can tell, since nothing has ever gone wrong in this department before :D
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Some degree of backlash is normal, you have play in the differential that is an essential part of it's design, then there's going to be play in the splines of the inner halfshafts, their outer ends into the cv, wear in the cv by now I'd imagine, then wear on the splines inside the drive flange. 10 degrees, not unheard of at the front.
Go to say, one of my UJs was toast and I couldn't tell until I started to remove it from the car though :? Got to say it's still the most likely suspect unless you've done something particulary rough to your transmission, you'd remember doing it though.
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Thanks, that's reassurring. I'm certainly hoping that it's the UJ, as anything else is a lot more work to sort out. [-o<
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The lateral movement in the prop is what you need ot look at. I'd expect a tiny amount of sideways play inthe output of a B-W box like mine, with high miles on it, but not a massive amount and IIRC not so much on your LT230.
Anyway, I'm sure you have a Eureka moment on your horizon :)
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Prob is requiring new UJs - fairly cheap.
If your motor is lifted and gets a fair bit of (ab)use off road, then consider UJs almost as 'service items' due to the extra strain of lift and larger tyres, etc.
Additionally, if it's 300Tdi, it's got that "rubber donut" (3-bolt flange) on the rear diff end - ditch it, replace rear prop with a 200Tdi and change output flange on diff to 4-bolt type ........... much more reliable for a lifted motor.
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Just to let you all know that the problem turned out to be rubber coupling on the rear prop. It was so badly worn that bolt heads on the diff side were scraping on the prop flange! All done now and unsurprisingly much better to drive :D
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point to note:
if you suspect a propshaft fault, then removing a prof to isolate the cause is ok, but dont forget you are then putting twice the stress on the remaining prop.....
food for thought :wink:
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Jamie, did you check the state of the rubber bush in the end of the prop? it's the one the spigott goes into to locate the propshaft.
If not you might find as I did that the rubber doughnut doesn't last very long before it's vibrating again.