OK, so I just bought this '03 evo from a local dealership. It had 20xxx miles on it when I bought it on the 29th of December. I know for a fact that it was highly modded by the previous owner because one of my friends knows him and saw the car a while ago. He returned it almost to stock before trading it in for a IX. All that was left was the roll cage.

Because of this fact I opted to get the car certified for the 10yr/ 100k warranty. Well I'm glad I did because after 1500 miles the rear diff started to get louder and then it began to grind. So the dealership replaced it without incident. Well about 1000 miles and its about cooked agian. It had just started to make a little grind and I took it to the dealer agian. This time they said it is a normal sound. The whine from the thing is painful to the ears at about 62 and when the weight of the car is neutral, its grinding worse and worse everyday. I'm going to take it to them for a third time and hopefully they replace it agian.

On a good note, they haven't given me any trouble and I don't think they will this time either. And just to be clear, Im not new to the manual awd cars, I owned a 92 3000gt vr4 for about 4 years and had a 5 speed impreza for 2 before that. I'm not a pro or anything, but I have never had problems like this.

Any ideas what could cause this? I know the engine was out of the car at one point. I've never pulled an engine, but could a mount be installed wrong. Maybe the drive shaft is out of phase? I don't here any strange clunks so I dont think its a worn mount. I'm just glad I seem to have found a good dealership.

thanks
John

 

Damn man. First I'm glad to hear the dealer is being good to you. I do have one suggestion for you. Keep your car stock for a few thousand miles to ensure other problems dont arise after modding. I have never heard of this problem b4 and I'm sure thats what many people will say on this forum. Good luck with it all.

 

hmm, might sound like a stupid question but are the rear tires the same size?
i had a friend who destroyed his differential in his jeep cherokee cuz he was dumb and got 2 diff size of tires in the back.
this is just a thot but check it out, i dunno what else could be the problem to kill the diff.

 

hmm that sucks havent a clue what it could be i wonder if they put diaqueen in the rear end

 

Well I know all 4 tires are the same. The dealer had put brand new ones on all around. I would assume they used the diaqueen, as the tech that works on the evos owns one himself so i would hope he would be putting in the right fluid.

 

Double check to make sure they are actually using the spec diaqueen fluids...

 

On the service report it says "Installed 3775610 : oil, lsd (4 liters)" I would assume that is the diaqeen correct as it is a lsd rear.


Oh on the tires, They are cheapies that they put on. They are "generals" its not possible for there to be enough variance in them to cause the problem is there? I would hope not anyway...

 

^^^^ Good suggestion. If the tires or rims are of a different diamater from front to back, this will definitely do your drivetrain harm. Also make sure your not leaking gear oil anywhere. Are you driving the car very hard? Make sure they are using the approved fluid as well.

 

I wouldn't say I have been driving it hard. The hardest I have driven it was on the test drive. Its a bit snowy in new york to be pushing too hard. I havent been above 75 and its only seen 6k rpms a couple times. I have never launched it and I'm always careful to get the clutch to the floor. My VR4 didnt care much for a bad clutch foot so im pretty well versed in that. Seeing as though I bought this directly from a Mitsu dealer, and they have even replaced it once, I would hope they are using the right fluid. From what I have seen this is a pretty reputable dealership and I have confidence ther are using the right stuff. It has the stock wheels and as I said, brand new tires all around.

 

You can check phasing easily, Place a str8 edge across each of the yokes and see if they are parallel. It's kinda using ur eyes to tell. Or get a angle gauge from someone or the dealer. Not quite sure what the prob could be but I hope you find it out

 

This is a very strange problem. I have not heard anything about their being chronic problems with the rear diff, and for you to go through two of them in such a short time period just makes no sense. Maybe the two differentials just happened to be defective...doesn't seem likely. It is a long shot but I would try to contact the previous owner somehow and see if he has made any changes or repairs internal to the tranny (any aftermarket differentials). If he did something wrong with the center differential this could cause damage to the rear differential. Again this seems highly unlikely but its the only thing I can think of that would toast the rear differential. If he was racing the car it is possible he could have installed a rear biased center differential to change the torque split to something like 20/80 (%80 of the power going to the rear) which could cause problems.

 

do you think that a DS out of phase could cause a problem like this? I honestly have no idea. I can usualy get away with fixing my car myself but I'm no mechanic

 

well I think that is more plausable in my case than it would be in your avg. evo. It does have a rollcage after all. I'll talk to the salesman, as he sold a 06 rs to him the same day i picked mine up. Actually Sam(salesman) said that Bab(prev owner) was going to give him a card to mail me. Sam said he has a ton of parts for evos. I dont know if he's a vendor or what, but racing it, isnt out of the realm of possibility.

 

Maybe you have a diff with the wrong axle ratio - Mitsubishi make a number of different ratios for rallying, but you must use the same back and front. To test, jack up all four wheels and check how many turns of the engine are required to move the front and then the rear wheels one revolution.

 

Yea doubt its nething with the driveshaft or u-joints as u should have felt a vibration or heard something way b4 ur thing went whack. Possibly two bad diffs. Did you get a brand new dif after the first one went bad or did they just rebuild your old one?