Replacing just the rear tires ok?
 

I just replaced the rear tires on my 01 X5 after doing some research that suggested that it is ok to have slightly different sized tires (due to older tires being up front). This is one article I read:

http://www.4x4abc.com/4WD101/diffautoAWD_AWD.html

Excerpt from that article.

"There are some AWD vehicles where it does not matter what you do. Replace one tire, replace 2 - it does not matter. Those AWD vehicles are true AWD, in the sense that they are full time 4WD or permanent 4WD powering all 4 wheels with about equal force. Most Subaru (except Impreza), BMW X5, Audi, some Toyota, Mercedes, etc. are in that group of true AWD. These AWD vehicles have a differential between the two permanently powered drive shafts. They are the ones that will survive a replacement tire that is slightly larger or slightly smaller (like when you have to buy a used (larger) tire in Mexico because nothing else is available)."

But searching around this site has made me question that decision. Any input from you guys?

With the X5, you run the risk of damage to the transfer case for pre x-drive models (2000-2003). It has shown up as damaged splines.

With x-drive models (2004 onwards), the clutch plates in the transfer case allow for some discrepancy, but if it is too large you wear the clutch plates.

With both transfer cases, you can get nuisance DSC errors due to tire size discrepancies.

BMW has the same spec for maximum differences for both versions.

If the tires are the same size and brand/model front and rear, and one end is new while the other is up to half worn, you should be fine. I would put the new tires on the front, however. You will often have higher inflation pressure on the rear due to load carried, and that helps compensate for wear differences. Apart from that, you depend on the fronts for steering and braking.

I'd put the new tires up front too...

Thanks JCL and Sprocket! I will go ahead and move the tires to the front, even though I do not carry heavy loads in my X5 (I use my pickup for that). In addition to your reasons, the fact that the rears wear down much quicker is yet another reason to put the old ones on the rear.

I did my best to measure the total circumference and I got about ½ inch difference. That still sound ok?

I did the tires 2 weeks ago, and took it on a 1000 mile road trip and I received no DSC errors, but a damaged transfer case would be scary!

How ? The planetary gear in the transfer box acts exactly like an open differential, there's no locking mechanism that will allow transmission wind up.

Due to my staggered set-up, I've done this twice (most recently about 15,000 miles ago) and have had no problems. I wouldn't waste time worrying about it.

A statement like that needs some context. What are your tire sizes?

I'm running the stock 4.4 sport package 19" staggered set-up.

I've changed the fronts tires only and the rear tires only, at different times, due to differences in treadwear b/t the front and rear.

Never had a problem.

Done exactly this with my 3.0i (06) and havent had any problems either. In fact when I bought my x5 there was a problem with one of the rear tyres and bmw changed the two rears and not the fronts. Ive since changed the fronts and never had a problem.

If you are sticking to the stock sizes then I'm not surprised you didn't have any problems. It's when you go +1 or +2 on the wheel sizes or go wider than stock that you can get into trouble since the correct tire diameters may not be available.

I don't think it is wind-up, as with a fixed part time 4wd setup, but I do think that a constant speed difference between front and rear contributes to transfer case wear. The same can be seen with a differential in an axle that is designed to allow for differences left and right, but which can wear out due to constant speed differences. Spinning one wheel can do that quite quickly.

BMW techs on the board have commented that they have seen damage to transfer cases from tire size differentials. I trust those techs. I do know the front output shaft is somewhat weak anyway, due to the limited spline engagement, but will defer to the expertise of a dealer technician.

I have personally only seen DSC errors due to the difference in rotational speeds.

I always thought you installed the new tires on the front as well if you only buy two, but I don't think that is correct.

Tire Tech Information - Where to Install New Pairs of Tires?

Here is a Michelin link. Once open, scroll down to the bottom of the page.

Replacement Tips: Tire-saving Tips: Tire Care & Buying Guide: Michelin Tires

Both those links argue that understeer is safer for most drivers than is oversteer. This is the same thinking automakers use, for liability reasons. They give up steering control on the basis that the average driver will not know would to do in the event the vehicle oversteers. It is the dumbing down of car control. I understand their logic, but I prefer to maintain control and I can do that better if I still have steering. Maintaining steering means putting the best tires on the axle that steers.

Yeah, but what good is steering the front of the car if the back comes around?

I agree that their logic is understeer is better than oversteer for the bulk of drivers on the road. It probably is. More drivers will be able to correct understeer than oversteer. Pretty much all of the tire manufacturers recommend the new tires to be installed on the rear.

Here is a quick video. There are tons more online.

It allows you to steer into the skid, while feathering the throttle, so that you can flat track it around the corner.

On the other hand, if you understeer into the corner, you have lots of spare time so that you can just hang on and enjoy the view as you sail into the trees.

Edit: I agree that a skilled driver will only be able to do so much, ie recover a certain amount. Past that, he or she is going to end up in a similar situation to the understeering vehicle. I also wasn't suggesting that the old tires would be bald, but rather just partly worn.

All of this changes somewhat with DSC. If you understeer, there isn't much it can do. If you oversteer, it can apply a single brake very quickly to help keep the car under control, within the limits of physics. It still alters the equation, IMO.

Everyone should go to (pavement) skid school. Slightly off topic, but I recall driving an overpowered Ford Sierra rally car on a dirt track, with an instructor. Halfway through the corner he could flip a switch and lock up the rears, and then watch as we got ourselves through it. Everyone should have so much fun.

so basically, if you can't drive, put them on the back. if you can, put them on the front.

I agree with jcl, driving schools are a must. i have taken many myself, they are well worth the cost.

I hear you, but I feel the tire industry recommends new on the back because most people are not as good of a driver as they think they are and that for MOST understeer is better. I wouldn't want to see the average driver try to feather the throttle to correct a skid. :wow:I am not even sure if the average driver knows that they should steer into a skid.

Now, it would have been great to be in that Sierra though. Fun in a controlled envoronment with an instructor is one thing and driving towards a Toyota Avalon that is sliding sideways around a corner while the driver is on his cell phone is another.

Which is all pretty much irrelevant as most x5`5 have different tyre sizes on the rear to what goes on the front so cant be changed around anyway.

Wear to the planetary gears, yes, quite possibly, but that's a different matter.

Commonality is not causality :) These propshaft splines are known to fail anyway, how anyone can claim it's definitely due to tyre size in some cases, but not in others I don't really know. From an engineering point of view, a small difference in tyre size front-rear will have absolutely no significant effect on the loading on this spline. IMO far more likely is a different connection - that the kind of person who fits huge blingy wheels is probably the same kind of person who drives their car hard, doing full-bore launches more often. That will shorten the drivetrain's lifespan a lot more quickly than having slightly different tyre sizes !

Same here.

No, most X5s are 3.0 gasoline models with 17" wheels.

You are assuming that the damage was exclusively to the splines. It was quoted as damage to the transfer case. I would expect that to be internal, not the splines. I should have said that there has also been damage reported to the splines, I was not suggesting that they are the only failure point. I can still see the potential for damage to the tranfer case internals due to constant relative motion, just the same as a differential experiences.

The OPs isnt and as its his thread. Your comments about putting tyres on the front or rear aren`t relevant and who says most are 3.0is have 17 inch wheels . Mine hasnt and thats the way it came from the factory. 2.55 x19 fronts and 2.85x19 rears.

The OP doesn't have staggered tires, so it is relevant. Note his location in the US.

75% of E53 models were the base 3.0 in North America, which was the largest market for X5s. BMW published sales figures every month. There was a sports option with 18" tires, but they weren't staggered. On the 4.4 there was also a sports option with 18" as I recall, and a separate 19" staggered option (depending on model year).

Yours is an exception, being in the UK. Given the price of the vehicle there, BMW put the most expensive tires they offered on it.

Since there is differing opinion here, I decided to talk to the guys at the local dealership. They were nice enough to give me a tire gauge to take home with me since I had my 540i on me at the time. They told me that they feel comfortable with 4/32nds of an inch difference between front and rear tires max. The difference for me was 5/32nds so I have decided to go ahead and replace the fronts. It may end up being overkill, but I guess I'm too damn anal and overcautious to just look the other way on this one. I'll spend the extra $350 for peace of mind.

Thanks for all your input guys!

It isn't irrelevant at all. People with staggered setups can still choose to only replace two tires at a time. Due to the fact the fronts and rears typically don't wear at the same rate, they could easily end up in a situation where they have new rubber on the front and worn rubber on the rears.

Nothing wrong with that.

You aught to learn to read the thread properly . It was talk about switching tyres from front to back that I said was irrelevant. Not just changing fronts only or rears only.
With a staggered set up the fronts stay on the front and the rears stay on the rear. Therefore talking about putting the new tyres on the front and the old on the rear is irrelevant if you only need rears.

:rofl: ass.

You aught to take your own advice. As JCL said, most of the e53's sold here were non-staggered setups, where moving tires from front to rear or Vice Versa is possible, so your post about it being irrelevant due to the fact most X5's came with staggered setups was completely inaccurate. I also included those videos just to show what can happen with worn tires on the rear and new tires on the front, not necessarily moving worn tires from front to rear or rear to front. Once again, I was also trying to show people with staggered setups that they may want to consider going with 4 tires if they have a staggered setup instead of getting themselves into a situation where they end up with new rubber on the fronts and fairly worn rubber on the rears. This is a very possible scenario if you just replace two at a time.

You ought to use the correct word, or it will all be for naught.

Yea JCL had already answered with a relevant response . Didnt need any help from you . Some tossers just cant help but interfering though

You still don't get it. Good luck with everything buddy. :thumbup:

RPH74, you made the right decision by replacing all four, good piece of mind having good rubber all around. I was in the same situation a few years ago and just replaced the rears which ended up being fine for my situation - I have 117K miles now and no damage to the tranny or transfer case as a result. This past winter the fronts were getting a bit thin and were noticeable in the bad winter we had in the Northeast, the start/stops in the snow were just not very good. This spring, I replaced all four just to get back to a good rubber baseline even though the rears were just fine. I kinda felt bad about tossing out two good tires, but my wife drives our X5 alot with the kids, so I felt a few hundred $$$'s is worth it. Keep us posted on your ride!
:thumbup:

@JCL, your point regarding the x-drive models (2004 onwards) being afflicted by using differing tire size, mine (a nov 2004 built 3.0d) is not a xDrive no mention of this anywhere on 'packet' or manual, had a case over the last few years where left side tires were substantially more worn over the entire circufmerence of the tires than the right so rotated them (they werent directional), never had a dsc error popup, just be good to know if there is any hard fast empirical data for the e53 where owners have used mismatched tires (as you say most had 17" stock rear andt front) and has lead to transfer case failure and the like.. Reading online today have seen that some of the much newer bmws are more susceptible, but for our X5s is this something as I mentioned in another post that would just go kaput on the highway or would we get a warning?

Why make you say your 3.0d is NOT xDrive? It almost certainly is.

You have a "facelift" (LCI) E53 X5 and they all have xDrive. The xDrive driveline was fitted to all LCI E53 X5 produced, starting in late 2003.

And so yes, tyres are important. You need to keep the rolling circumference of all tyres with a couple of percent of each other or you risk wearing out the clutch packs in the transfer case.

Documented evidence of this happening...? Dunno. :dunno: But I don't want to risk it... ;)

So i found this:

That works out to just about 4/32" difference in tread depth allowed front to back. I don't believe the 3% of OE for overall size as long as they fit and are all the SAME size or within 1% rolling circumference.

That is for x-drive. i think the pre LCI can have up to 3% difference front to back axle.

Spoke to my mechanic and he confirmed seeing it (drivetrain issue) on X3s with mismatched tires, so gonna go get em changed today

Im late to the party here but here is my situation. A coworker gave me two tires for the front, Pirelli P Zero Nero 275/40R20. They are slightly used and were taken off a different car that got racing tires. So I looked up that same size tire for the back but found that Pirelli does not make any in my size. I ended up getting two Pirelli Cinturato P7 315/35R20 for the rear, although I haven't installed them yet. My concern after reading this thread is that my tires are 2 slightly used in the front and two new in the rear. Also the tire models are different. I thought it would be fine since my E53 has a staggered setup from factory and the tire sizes are already different. Also the tires are all made by the same manufacturer, although have different thread patterns being that they are different models. Should I just buy two new tires for the front and keep those other ones as spares or will I be fine with what I planned to do? I also really want to use Michellin but I am kinda stuck with the Pirellis since that is what my coworker gave me and I don't want to be rude if I don't use them. If I get new Pirellis in the front, maybe he won't notice that they are not the same ones he gave me.

Sorry for rambling, also forgot to mention I have an 06 E53 with the 4.8is engine.
Thanks

Since you say they came from a car, replaced with racing tires, I'll suggest to first check on the load rating of the tire. Not sure about your '06 4.8is, but my '01 3.0i specifies 103V in the front and 107V in the rear. The V speed rating means any of V W Y Z will work. And 103 or higher will work in the front, 107 or higher in the rear.

Ok, any clue where I can find the load rating that I’m supposed to have? Is it in the manual?

Should be. It might also be on the plate inside your driver's door jamb, along with the recommended inflation pressures. And of course the tires will have it on the sidewall.

Im gonna chime in here, and don't want to spread undue stress, cos I had the same query a while back having different brand/tread tires front and rear and was specifically told that the actual tread pattern had to be the same rear and front or you risk transfer case issues...be good to finally know the truth here

I'm not sure if anyone has suggested that tread patterns make any difference or can put your transfer case in peril but (just like the old saying), size certainly matters, at least in terms of matching the rolling circumference front to back.

Hey Wpoll hope all well, it was to do with the traction control side of things and that one axle could possibly be overworking to compensate for the difference in tread/surface are contact with the road leading to " the issue" dunno will dig up the old post if i can , sure its here...

I guess that's possible but isn't that what xDrive does - varying the drive to each wheel depending on the traction available? ;)

I'd be VERY surprised in all the other variables (gravel on the side of the road, mud, snow etc.) we not a greater factors than the very slight difference in traction a different tread pattern would make. :dunno:

All good here - getting ready for winter and lower traction.... :rolleyes:

Yeah you are right come to think of it.....tire place i went to a while back was adamant that i would f up the transfer case running different fronts to rears....
we are getting ready for summer.....come early its 30C today pile of dust and sorry to hijack this post..ps if i find the replies i got re the trans.case i'll add em

here is my old post and some replies

https://xoutpost.com/bmw-sav-forums/...g-trouble.html

I believe that the 2004+ xdrive only engages a clutch back in the center differential which sends torque to the front wheels when the rears are slipping. I think it may selectively brake individual wheels but I doubt it does that except in heavy cornering. Saying it "sends torque selectively to each wheel" is not untrue, but it's not a particularly accurate statement either. Either way, unless you are driving very aggressively or driving on a slippery surface such as ice or gravel, I doubt it is doing much.



But to answer the question about tread, the tread pattern shouldn't matter at all UNLESS the tires have worn differently such that the circumference changes. If you put an aggressive summer tire on the front, and a crappy 100k-mile all season on the rear, not only with the front be much stickier (which is dangerous) but it will also wear out much faster, and after putting some miles on, the difference may be enough to start making your center diff unhappy. The treadwear rating should be similar or the same if you are going to do this, unless it's just for a short time.



Like I said in your old post, omodos, putting stickier tires on one axle than on the other can tend to be dangerous, and should only be done with caution.

Even with DSC to control wheel slip there is good reason to keep the more grippy tires on the rear axle.

I don't believe different tread being a problem for x-drive for a minute.

You can always actually measure the tire circumference with a tape measure turned inside out. Mark the overlap with tape and read where tape is. Rolling circumference will be a little different I think that's part of why BMW specs 39psi back when loaded.

1200/32=37.5 in.² front and 1600/39=41 in.² contact patch for my car

If I had 32 in the back: 1600/32=50 that will for sure mean different rolling circumference.

01 e53 doesn't care about these things all open dif and must take more wheel to wheel difference to care.

X-drive From my understanding and the feedback from driving at 328xi Is that the front axle is completely disengaged when you’re not moving and after the launch it kicks in the front drive but it always kicks on some amount it doesn’t die wait until their slippage. I think the ratio is roughly 2/3 back 1/3 front. X Dr. can put 100% of the torque to a single wheel by locking the slipping wheels with the brakes.

I’m about to test drive 50i x5 and and I’m really hoping that I can’t feel the front axle kick in like the 328.

Returning from tangent: If you wanna compare your rolling circumference squeeze a piece of crayon Into the trade of the front and a back tire and dryer’s and then measure the distance between the two marks

appreciate all feedback and sorry jumped in post.....so rolling circumference is key and ideally similiar 'type' summer all round or mud and snow all round....PS NOV 2004 x5 3.0d, i dont think has x-drive , all the notes you mention still apply to non xdrive

Good man much appreciated clarification.....

I know we have discussed this before - but a Nov. 2004 should be X-Drive. :confused:

Why don't you check and answer this question once and for all? Climb under the car with a flashlight (or a torch as we say down-under!) and look at the transfer case. If you see a small electric motor and wiring on the side of the transfer case, you have X-Drive. ;)

X-Drive transfer case (ATC500)..

https://encrypted-tbn0.gstatic.com/i...iYuDQ&usqp=CAU

non-X-Drive transfer case (NV125 or LWC500)..

https://www.picclickimg.com/d/l400/p...Box-X5-E53.jpg

This is a comment from me today in the tire forum on xoutpost ...

Wow I should have checked this forum instead of the general e53 forum as I had the same question as OP.

I JUST installed new Mich Latitude Tour HPs on the front late last summer and now the rears are toasted BUT Michelin no longer sells the Latitude Tour HPs in the 315 size... So I reviewed internet lore and consensus (based on tire company, vehicle.manufacturer & testing) was the same tread pattern SHOULD be used on AWD vehicles, as having different tread patterns could cause different traction. slippage of one set of wheels compared to the other axel set would cause AWD system to work harder or sometimes malfunction, at the extreme.

I have a great Indy Mech who never steers me wrong so I called them and asked their thoughts and I was told essentially the same thing. They said there are a few factors at play. Not just tread pattern but rubber compound, similar sidewall feel also count. He said he would sell me a set of just rears that were closely matching my Lat Tour HPs but once I told him I could buy 4 new Nokians for just a few hundred more than just 2 Michelin's... He said don't be stupid and just.buy the 4 new Nokians.

So I JUST dropped my PERFECTLY washed wheels (even removed every wheel weight and any road tar or old wheel weight stickers with Good Gone and the inside is brand new again) Even the tire dealer complimented on cleanliness of wheels (it's actually so I can see if they scratch my wheels up)...anyhow I am getting a new set of Nokian Z Line tires installed for JUST a little more than buying JUST 2 rear Michelin Pilot A/S 4's.

And I can sell my new Front tires I just installed last late summer.

Even the tread difference between the Lat Tour HP and new Pilot A/S 4 is quite different so I didn't want to chance anything.

I hope to have a review of the Nokian Z Line in a month and

6 months and

a year of ownership.

Apparently they have a 65k km warranty and width is 0.2" wider than Mich Pilot A/S4 so a BIT more wheel protection and they are 11/32 as opposed to 10/32 of many other tires. That's a few more days of driving safer [emoji4]

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hahahah thanks Wpoll, i'll give it bash when i can squeeze under as had a mishap yesterday preventing me from doing much, ok so there will be no cowling etc hiding this ...this is the spec as per BMW mail to me, not sure if there would have been a ref to it being xdrive here



Fahrzeug Details WBAFB72090LX10326


Produktionsdatum

E-Reihe

Motor

Getriebe

13.11.2004

E53

M57/TU

AUT



Länderausstattung

Type

Leistung (KW)

Antrieb

EUR

X5 3.0D

160

ALLR


Lenkung

Variante

Hubraum



RL

GEFZG

3.00







Türen

Motorsteuerung





5

DDE


Produktionsstätte

Lackierung

Motor-Nr.

Getriebe-Nr.

Werk 75 SPARTANBURG

TITANSILBER METALLIC

29705784





Modellzyklus

Polster





01.10.2003 bis 30.09.2006

LEDER DAKOTA/SCHWARZ

It won't mention X-Drive specifically - see this PDF on your actual car for a full list of fitted options.

https://www.dropbox.com/s/nlo7o0u6lz....work.pdf?dl=0

No, there is no cover over the transfer case itself - you should be able to peer in under the left rear door, looking forward and see it. It sits just behind the transmission under-shield...

You have X-Drive, BTW. ;)

Hahahaha amazing thanks for pdf .....

gonna live with X5 long as I can its showing its age things are started to sag the inner headliner puffing up here and there, the panoramic sunroof usual issue and haven't got round to trying to disable the 2 clips on either side at rear of the guide rails for the sunroof, so at least it can work half way.......

Like all things needs maintenance.....