XSeries-forum

After 3 months having a new transfer box and all new front diff fitted http://xdrivers.co.uk/forum/https://xdr ... 9#msg85059 I finally got the X5 back. The fiasco involved the new global BMW parts and delivery system called ATLAS which got it's knickers in a twist when it went live around June time and has affected BMW share price. I was getting different delivery dates every day, when they really had no idea what was happening.

What's interesting is the price of the diff. The second hand price from specialist breakers and ebay is only about £100 off the price of a new one.

It's cost me a fair bit, but the driving experience is now very nice. Smooth, no judder and just as it should be. However I'm missing the 730ld M-Sport loaner which was an awesome car. I tried for a trade in, but they wanted too much. They are having trouble selling those long wheel base cars and to be fair, they do stick out by about a foot when you're in a car park.

Congrats on getting it sorted it sounded like an epic adventure.

The parts system is certainly taking on farcical proportions.  I'm still waiting for parts ordered in July.

Glad you are now able to enjoy your X..

Richard

The plot thickens....

After I had the new transfer box and front diff replaced, the car was good, but having put the Alpina wheels on, it drives extremely really well now. Very smooth, no jerking or juddering at all speeds under load or just cruising. It's a pleasure to drive slow or fast.

When I had the original V-Spokes on it felt somehow - uncomfortable. I'd describe it as squirreling under heavy acceleration like the traction control wasn't able to cope. Also, when pulling away in the wet there was a very slight lurch.

The answer is so obvious and it was eagle eyed Raj that spotted it. When I bought the car it had the wrong size tyres on the front 275/45/20 rather than 275/40/20 and that's a 3 inch difference in rolling radius between the back and the front. I missed it and 2 BMW garages missed it.

I think a set of cheap, part worn tyres was thrown on the car before I bought it to save a bit of cash.

If the transfer box was on the way out, that's sure to have contributed to it's demise. I don't think this was the diff issue though. When the brand spanking new one was fitted after the 4 month delivery time,  it wasn't from the same supplier. Obviously BMW source their OEM stuff from various suppliers and the original 3.91 diff is known to be not up to the power of the 4.8.

Anyway, another lesson learned. Always check tyre/wheel sizes are correct when buying a car particularly on  4x4s.

275/40/20 buddy...

but yes it certainly will have been a contributing factor to the issues you were having.

I now spoken to 3 reliable sources who have all said the original front diff fitted to the 4.8 was never up to it.

[quote="DaveB"]
I now spoken to 3 reliable sources who have all said the original front diff fitted to the 4.8 was never up to it.
[/quote]

Still need to try a full wheel swap to see if it is the tyres/wheels causing my vibration issues.

Any chance of swapping diffs to rule that out LOL