drjive Posted August 14, 2004 Share Posted August 14, 2004 Hi- I'm new to the site- didn't know something like this existed. I have a '95 subaru legacy wagon and I was wondering if anyone out there knew if having rear and front tires with different tread but circumferences/wear within specifications could cause drive train problems/ locking? I have two new front tires that were put on in June- but the tread wear was within the 1/4" circ difference according to my garage. This past month the car was locking with acceleration- brought the car into the subaru dealer while on a trip- was told the differential plate needed to be rebuilt. I then brought my car to my local subaru dealer who says it impossible to tell until I have four identical tires on my car because having different treads front to back can cause locking. My car is currently in FWD (from the info I got from this site- Thanks!) to prevent any further damage... Thanks Angela Quote Link to comment Share on other sites More sharing options...
THAWA Posted August 14, 2004 Share Posted August 14, 2004 I assume it's AWD, and yes different tread (which automatically means different types of tires, which means they have different properties) can cause damage to the AWD system. You should ALWAYS replace all 4 tires at the same time. If you absolutely can't do all 4 #1 you shoudlnt be driving an AWD vechicle and #2 only replace two on one side at a time. At least that way the drivetrain sees the difference as two of the wheels on the same side are moving faster or in essense it thinks the car is turning, which isnt nearly as damaging on the center diff as it constantly trying to slow down one axle. You will have to get all 4 new tires, or get 2 more of the same tires you have on the front and get them shaved down to the exact thickness as the ones in the front. Where did you go to get the tires mounted in june? I wonder why they didnt notify you that you needed to get all 4 new tires. Also I wouldnt leave the fuse in for FWD, as that's only supposed to be a temporary thing, for towing and whatnot. Quote Link to comment Share on other sites More sharing options...
drjive Posted August 14, 2004 Author Share Posted August 14, 2004 I assume it's AWD, Where did you go to get the tires mounted in june? I wonder why they didnt notify you that you needed to get all 4 new tires. Also I wouldnt leave the fuse in for FWD, as that's only supposed to be a temporary thing, for towing and whatnot. Yes- its AWD, actually asked my garage about changing all four instead of two- they said two was all I needed to do- they still say that if the circumferences are similar it shouldn't make a difference. My local subaru dealer told me to leave the fuse in until they can take the car and then end of the week... is that really bad? Quote Link to comment Share on other sites More sharing options...
drjive Posted August 14, 2004 Author Share Posted August 14, 2004 they just charged me $400 to have the crank pulley replaced (new pulley and labor) which they said was caused by the other garage not cranking it down properly when they replaced my timing belt. Then told me they can't check/fix the drive train until next week and told leave the car in FWD until then that it would not be a problem... They say if it is the differential plate it'll cost about $1500 including labor (plus the tires). Quote Link to comment Share on other sites More sharing options...
THAWA Posted August 14, 2004 Share Posted August 14, 2004 What "garage" is this, and why are they giving you false information? You NEED all 4 tires to be the same and have tread within 1/4" or maybe it's 2/32". If it was me I wouldn't take it to that "garage" since they didnt torque down the crank pulley either. Which by the way if it fails is quite an expensive repair. Trust what the dealer is telling you, and leave the fuse in, if you end up destroying someting the dealer will have to fix it as they told you to do it (but actually is sounds like they're going to be fixing it anyway so it shouldnt matter. At anyrate, best of luck to ya. Quote Link to comment Share on other sites More sharing options...
WGBlasdel Posted August 14, 2004 Share Posted August 14, 2004 I just bought a AWD 95 Legacy Wagon with two tires worn bald on the outside of the tread by underinflation, thinking that I could just replace the 2. After spending many hours on line and tracing down threads at this site (and not liking that everyone said I had to replace all 4), I came upon a fellow that quoted from the mysubaru.com web site: From mysubaru.com: All-Wheel Drive (AWD) vehicles, it is extremely important that the rolling or outer circumferences of the tires be within 1/4 inch of each other. This means that you must physically measure the size of the tire. This is best done with the weight of the vehicle off the tire and at the tread centerline. Also be certain that the tires are properly inflated since this can affect your readings. If you need to replace just one tire, the same holds true. The measured difference in circumference between the replacement tire and the other tires on the vehicle cannot exceed 1/4 inch. Depending on the vehicle mileage, it might be better to replace all four tires. If the vehicle mileage is low and the tires have been rotated and driven at the proper inflation pressures, then you may be within the allowable 1/4-inch difference in circumference. If the difference between the new/replacement tire and the current tires is within this 1/4-nch maximum, then the tire should be compatible. If it is not, then other tires will need to be replaced to conform to the 1/4-inch rule. Exceeding this 1/4-inch difference in tire circumference can place unnecessary wear on drivetrain components, possibly causing them to wear out prematurely. Still not liking what I was reading, I checked at mysubaru.com in the technical advise section, and learned that the above was an exact quote. Basically, the price we have to pay for AWD and going anywhere in any kind of weather is to do 4 tires at a time. Some people get 5 and then rotate them to keep them at the same wear level, then you still have 4 if a rock rips out the sidewall on a tire. I think that I will just have to spend the money. Quote Link to comment Share on other sites More sharing options...
SevenSisters Posted August 14, 2004 Share Posted August 14, 2004 QUOTE: "Basically, the price we have to pay for AWD and going anywhere in any kind of weather is to do 4 tires at a time." Any car with properly rotated tires will require that all be replaced at the same time. Our Subarus are no different. A 5 tire rotation yields the same tire cost per mile as a 4 tire rotation but gives the added safety of having a proper sized replacement in the event of a non-repairable tire anomaly. Tires are relatively cheap. People used to pay about the same as we pay now for a 60K radial for a 15K bias tire. Replace 'em all and get a full size spare. Quote Link to comment Share on other sites More sharing options...
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