Getting the x5 Going! Tires/Front Diff/Other Minor Repairs

[SeanIngstrum]

Ok, so I'm trying to dust myself off and jump in this thing. I'm getting a used front differential, but first I need to make sure I'm getting the right one. Everything points to the 3.64 ratio so I know that is the one I need, but I am just going to pull the old one first and compare. I think that will let me see what other damaged parts I am in deep for. I also have a coolant leak that seems to be coming from the adapter plate past the heater block next to the radiator. I don't know if seals blew inside or what? The other thing is a broken inner boot on the front driver's side. I can rebuilt during the front diff switch out. The thing I'm worried about is the tires. They had the wrong size (P255/50 R19 107H) on all wheels. On top of that, the back wheels were switched to the front and front to the rear. The reason the front diff went bye bye in the first place at high speeds on the freeway along with the not wide enough tires on them. I realize this is my fault and I should've taken into have it inspected. Idiot confirmed, lesson learned. I know the wheels need to be switched back obviously, and tires removed completely. The rear rims are wider diameter. I'm having trouble figuring out how wide my particular rims are. Certain sites say one thing than the other. If I had to guess, I would say,
Front: 255/50 R19 103v
Rear: 285/45 R19 107v
Again, that is a guess.
Any help or info or suggestions or even your expert opinion on how I can pull any of this off would be awesome and greatly appreciated! Just FYI, I am a DIY'r and do all the maintenance on my Volvo. Not that, that is saying much, I am not familiar with BMW. Thank so much!

[wpoll]

Rim dimensions should be cast into the centre near the hub bolts.

For the 19" wheels the rim sizes are likely to be: -

Front - 8Jx19 ET30 - tire 255/50R19
Rear - 10.5Jx19 ET30 - tire 285/45R19

HTH...

[SeanIngstrum]

Fantastic! Thank you kindly!

[wpoll]

I'm surprised the tyre mismatch destroyed the front diff - it's more likely to have taken out the transfer case (on the rear of the transmission), as that's the device the connects the front drive train to the rear one. I wonder if the diff had other issues...

BTW, sorry to read of your troubles and good on you for getting the X5 back on the road - much kudos to ya!

While I DO like the look of the staggered set up on the V8s I'm glad to have the simplicity of the 18sq.

[SeanIngstrum]

Thanks a lot! I appreciate it very much! I'm sure it did, a lot of wear I'm sure. I'm probably just in the start of things to come for sure, but it'll be fine I think. It's a nice ride!

[upallnight]

Originally Posted by wpoll

I'm surprised the tyre mismatch destroyed the front diff - it's more likely to have taken out the transfer case (on the rear of the transmission), as that's the device the connects the front drive train to the rear one. I wonder if the diff had other issues...

BTW, sorry to read of your troubles and good on you for getting the X5 back on the road - much kudos to ya!

While I DO like the look of the staggered set up on the V8s I'm glad to have the simplicity of the 18sq.

If all four tires were the same size, the circumference of the tires should have been pretty close so that shouldn't have destroyed a front diff. Why do you think the front diff. needs to be replaced?

If the front wheels are not turning when you step on the gas, the most likely candidate is the transfer case.

[wpoll]

Originally Posted by upallnight

If all four tires were the same size, the circumference of the tires should have been pretty close so that shouldn't have destroyed a front diff. Why do you think the front diff. needs to be replaced?

If the front wheels are not turning when you step on the gas, the most likely candidate is the transfer case.

While the tires are all the same size, they are mounted on staggered rims, so it's anyone's guess (or a smart person's calculation!) as to the effect of this arrangement.

The 255/50R19 tires mounted on 10.5 rims (on the front!) would have been stretched somewhat.

[mam4.6]

Subd for your progress on getting it sorted...

[David.X5]

I second the why? What points to a bad diff?

The TC and front driveshaft splines are much more common failures.

[squidzilla]

Hopefully it is only the transfer case. You can rebuild those on the X5.
I think 200-300 in parts get the whole thing done if you DIY. And you can decide if you want to replace the existing drive shaft with one of the slightly longer ones you can find ebay for less and here in the USA for more.