Discussion in 'Tech/Mech General' started by Parapilot, Jun 1, 2018.
exactly my thoughts to much backlash
@Parapilot any further forward ?
A phone call to this guy may shed some light. He has a strange accent South African, but the best axle and diff man I know.
No help whatsoever to the OP but I have similar problem with engine starting been to mercs 4 times and numeryother gges without the slightest bit of difference but over £4000 lighter :-(. So just live with it now.
Good luck with your problem and like everyone else on here wish you luck mate in your search to get it fixed once and for all. Will be following post
Try this stuff. It is fantastic. I had a shuddering autobox on my 2007 discovery, put one of these in and it disappeared with a couple of minutes and has never returned. I cannot recommend it highly enough and it is cheap and easy to put in so even if it doesn't work it was worth a try. I suspected prop shaft, centre bearing, gear box, all sorts but this stuff fixed it. Give it a go!
From experience it take it you are talking about this stuff.
Hi , I gave your problem to a retired Jaguar engineer and these are his comments.
I’m no expert but two things worry me about that film. The first is the amount of backlash at the diff drive flange. Unfortunately there are quite a few comments saying that that amount of backlash is normal but, to my mind, it looks more than I would think is normal. Secondly, during the road drive I noticed the splined central joint expanding and returning quite a bit……..However, the problem with that fixed camera position is that you can’t see what the rear suspension is doing. If the rear axle was crossing some surface bumps etc then the longitudinal movement of the central splines would be expected.
I can also say that I have some experience of diff problems on an Escort Mexico that I owned back in 1973/4. I bought the car brand new through the Own a Ford scheme that applied to Ford employees at the time. There was, right from day one, bad back axle noise. In the course of the warranty attempts to repair I had three brand new diffs and three reconditioned ones and still the problem wasn’t cured, or even altered. I asked the dealer to change the whole back axle and not just the diff but they said that the Ford warranty rep wouldn’t agree to it.
This story illustrates that just because you’ve had reconditioned diffs fitted it doesn’t necessarily mean that noises can be cured.
My gut feeling is that it is the diff but I would do some more testing first which is slightly dangerous but the only way that I can think of to identify the source. My method would be to lie underneath and listen to the components through the handle of a long screwdriver with the blade pressed against each component in turn while a person was replicating that stationary drive engagement/disengagement. Where you get the loudest noise, and bear in mind that such a clonk will transmit down prop shafts etc, that should identify the problem area. Obviously you would only be able to do this with the vehicle stationary and the drive engaging/disengaging as in the very first part of the film. It isn’t going to be easy to do on the prop shaft itself but could be done with care. If you worked your way up from the diff forward to the gearbox using that listening screwdriver tool with the handle pressed against your ear you would definitely pick out where the loudest noise was. The fact that the problem only really happens under very light load is a certain indicator of a mechanical lash problem rather than one of the suggestions that it might be the gearbox ECU for example. The OP confirms that the noise disappears if you boot it and load the driveline so, again, this confirms backlash to me. I just reckon that the dealers and repairers haven’t really identified the source properly.
I did want to expand the exploded diagram of the diff assembly but the site won’t let me do that unless I am a member. It might be something that you have access to though.
Not much help but it is what I would do.
Really hope you get to the bottom of the problem. Obviously as I have the same chassis on our Concorde I have a vested interest,
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