Horrible Whirring noise after tyre change

[bongobazza]

Hi everyone,

We have only had our Bongo 4WD AFT for a couple months and although the tyres passed the MOT they didn't have much life left in them. Given the recent weather I decided it would be a good idea to get some fresh rubber on.

I got the sizes from the old tyres, which were as follows: Front 195/65/15 - Rear 215/75/15.

I phone my local garage for a price and they sorted me out with some nice chunky ones (the rears alot chunkier than the fronts) tyres as per the sizes I've written above.

I have just taken it out for spin for the first time since having them fitted. All seemed fine until I reached about 50mph then a horrible and very disturbing loud whirring noise started. Also the steering appeared to become very light, almost as if I was partially losing grip. The noise sounds like it is coming from the the transmission area. This noise does not change with engine revs, only with the speed of the van. If you come to a stop then start again, the noise has gone until you reach 50mph then it all starts again.

I have just dropped it back at the local garage but thought I would just seek the advice of all you experienced Bongoers!

Any advice appreciated, thanks.

[BongoMTBer]

Mine made a whirring noise when I had the front tyres changed recently. Not loud, but I knew it wasn’t the same as before. I have run the same size tyres all round since I purchase it, but I am guessing the difference in rolling circumference of new vs. old gave a different rotational speed from front to back, hence putting a load into the 4wd trans. I am therefore guessing in your case, the difference in tyre size will give you a marginal discrepancy in rolling diameter too. All I can say is now that my front tyres have bedded in, the noise has diminished. You may also find that after a few hundred miles it fades away. In the meantime, ensure your diffs are appropriately filled with the correct oil, as they will be working harder than before.

I will be getting the back tyres replaced soon. The new ones will go on the front and front (nearly new) will be transferred to the rear. In future, I will transfer all tyres from front to rear on occasion to give even tyre wear. I will then replace a 4 at once, still with the same size.

[munroman]

The front and rear tyres should be different profiles, to ensure that they have the same circumference, so travel the same number of turns per mile.

Standard front tyres are 195/70 x 15 - are you sure that the old front tyres were 65 profile and not 70 profile?

The tyres you have are mismatched by 4.1%, which is very bad.

The standard tyres are within 1%

You should not drive the car until you have properly sized tyres on it, basically you are driving the interconnected front and back wheels at different speeds and you will cause serious and expensive damage to the drivetrain!

The weird feeling in the steering is because the front tyres are, in effect, being twisted because the rear wheels are travelling further, and they might be slipping on the road.

[Jaws]

Many users will point out that the tyre sizes as supplied from the factory should be 195/70 R15 at the front and 215/65 R15 at rear.

I think it's fair to say nobody is really sure why the front and rear tyres have different profiles but it is quite clear that the rolling diameter of front and rear tyres should be pretty much the same on a 4wd Bongo (within 1%).

Try putting the tyre sizes you have into a calculator e.g. http://www.1010tires.com/TireSizeCalcul ... &reset=yes

If the front/rear diameter is out by more than 1% then you might have the explanation for your problem. i.e. transmission not happy to accomodate differing front and rear rotation speeds!


Ah somebody got there first

[scanner]

Yes (if that is indeed the size) the rear tyres are the wrong size - they should be 215/65-15.

4.1% difference is way too much.

[daveblueozzie]

A lot of people put the same size tyres on all four wheels without any problems.

[mister munkey]

got the sizes from the old tyres, which were as follows: Front 195/65/15 - Rear 215/75/15.

70s are what you need. If its been running previously with 75 profile tyres some damage could already have been done to the drivetrain side of things. If yours is a 2WD this is unlikely to be a problem though.

Take it back pronto unless thats a typo error. One set of wheels turning constantly at a different speed to the other can cause a minefield of headaches on the Viscious Coupling on a 4WD.

[munroman]

The front and rear tyres should be different profiles, to ensure that they have the same circumference, so travel the same number of turns per mile.

Standard front tyres are 195/70 x 15 - are you sure that the old front tyres were 65 profile and not 70 profile?
Standard rears are 215/65 x 15.

The tyres you have are mismatched by 10.9%, which is very bad.

The standard tyres are within 1%

You should not drive the car until you have properly sized tyres on it, basically you are driving the interconnected front and back wheels at different speeds and you will cause serious and expensive damage to the drivetrain!

The weird feeling in the steering is because the front tyres are, in effect, being twisted because the rear wheels are travelling further, and they might be slipping on the road.

Edited because 75 profile on rear makes % difference even worse.

[dandywarhol]

got the sizes from the old tyres, which were as follows: Front 195/65/15 - Rear 215/75/15.

70s are what you need. If its been running previously with 75 profile tyres some damage could already have been done to the drivetrain side of things. If yours is a 2WD this is unlikely to be a problem though.

Take it back pronto unless thats a typo error. One set of wheels turning constantly at a different speed to the other can cause a minefield of headaches on the Viscious Coupling on a 4WD.

65 on the back NOT 70 - Jaws is right MrM

[mister munkey]

Apologies, not paying attention.

BUT the point I was trying to make was - 75 profile tyres on a pair of 15" rims, mismatched with a different size at the other end is not the way to achieve long term happiness.

[Tripewriter]

phone my local garage for a price and they sorted me out with some nice chunky ones (the rears alot chunkier than the fronts) tyres as per the sizes I've written above.

I have just taken it out for spin for the first time since having them fitted. All seemed fine until I reached about 50mph then a horrible and very disturbing loud whirring noise started. Also the steering appeared to become very light, almost as if I was partially losing grip. The noise sounds like it is coming from the the transmission area. This noise does not change with engine revs, only with the speed of the van. If you come to a stop then start again, the noise has gone until you reach 50mph then it all starts again.


I had yhis problem with Goodyear Tyres and I think the answer to your problem is "nice chunky ones". The goodyears looked as if they had real grip while most other tyres are fairly smooth having just a few grooves. However the goodyears wore unevenly (I don know why) and lead me to thinking all sorts of things were wrong. However my mechanic took a brief look said your tyres are "castling" get some new ones. Fitted Kumho tyres problem vanished.

I run the same size tyres all round and the Kumho just need replacing after 3 years about 25000 miles. Slightly more wear at front.

[Lewy]

I always used to run with the different tyres front and rear and I used to get very uneven wear and castling on the fronts - this doesn't seem to be a problem anymore now I've swapped to same size all round - and it means you can swap tyres round fronts to rears to get a nice even wear in all four corners, tyres are lasting much longer.

[mikexgough]

Mines a 4wd ......same size all round for me..... that's my 15" wheels for winter and the 17" wheels for the summer...

[bongobazza]

Tyres are all now the same size and the problem has gone away.

Thanks again everyone for help. Invaluable as ever!

[downward dog]

Amazed at this! We are picking up an import 4x4 this weekend (snow permitting) I noticed all 4 tyres were the same size and following the advice on here said that was wrong, and the dealer said it didn't matter,and it has come from japan with same size tyres.....looks like he was right ? ....maybe too much research on BF leads to honorary membership of confused.com ? Aaaaaarrrrrghhhh!