New Subaru Owner, a couple Noob questions.

[Scrim]

Over the weekend i road-tripped my happy rump roast up to Michigan and bought a '95 Legacy Wagon. So far i love the car, i had to replace the front two tires and an do an oil change once i got it home, and there is one other piece of maintenance i want to do: Flush the transmission. (Auto btw.)

 

The car gives a noticable jerk when shifting from 1st to 2nd, and before i start looking at the tranny itself as the problem i want to flush it out and see if that doesn't help a bit. Now when i mentioned this plan to a friend of mine he about had a stroke and told me that under no circumstances should i flush that 14 year old tranny fluid as all the junk in there is prolly all that is keeping it from slipping. (I've heard of old motors being held together by carbon build-up, but never transmissions.) Now i have always drivin stick, so i don't claim to know the first thing about an auto tranny, so i was just wondering if anyone had ever heard of somethign like this actually being true. I am holding off flushing it out until i get some more information.

 

Now for the second bit i am curious about:

When i had 2 passengers in the car yesterday, i noticed a shudder of some sort develop once i got up to speed. A friend (the same Stroke-risk from the last question) thinks that it could be somethign in the rear end acting up, and as i have as little experience with AWD as i do with Automatics, i accept his diagnosis. Was just wondering if anyone had any input of the possible cause of this. I am goign to be picking up a couple friends from the bar tonight so i should be able to report back with a more exact description of when this happens if that will help.

 

Thanks in advance for any input:

Scrim

[Fairtax4me]

The very first thing you should do is buy two more brand new tires of the same type as the ones you put on the front. You absolutely CAN NOT have mis-matched sized tires on an AWD Subaru!!!! There is a clutch pack in the transmission that will be destroyed if the front and rear tires have more than 1/4" difference in circumference.

 

 

 

There are cases in which transmissions have died completely after having fluid flushes done. However... the damage was already done, there was not much, if any, hope for survival even if the fluid had been left alone.

 

Change the fluid. If it forks itself, throw a manual in it and be happy. There are a few threads here on the forum about changing fluid. Do some searching and you will find instructions on how to do it properly.

 

The shudder at speed. Could be a wheel bearing, a bent wheel, wheels that need to be balanced, could be a bad U joint, or drive shaft support bushing. Or it could just be crappy tires that need to be replaced, or be due to the tires being smaller circumference than the fronts due to wear. Again, 2 more new tires first, worry about the rest later.

 

Adding on to this. There is a fuse holder on the rear side of the passenger front strut tower under the hood that says FWD on it. That is there to disable the AWD system and make the car solely FWD. If I were you I'd put a fuse in that holder if you plan to drive the car at all. Any size fuse should do since all it does it actuate a relay. Best thing is to not drive the car until you get new tires on the back.

If there is already a fuse in there, then there is likely already damage to the transmission, and further driving is probably not going to make any difference.

Search for "Torque Bind" here on the forum and you will find some good threads about what is damaged and how to fix it.

Edited December 2, 2009 by Fairtax4me

[Scrim]

Thanks for the info, you've reminded me of things i forgot to mention origionally. The shudder at speed happened BEFORE i changed the front tires, so all 4 were the same. I have not had passengers since i changed them so i don't know yet if the problem is worse or better now as it doesn't happen when i am by myself.

 

The FWD fuse is definitely a cool option, i assume it was prolly put on the car for situations just like this. I just went outside and checked that fuse holder, and it is empty atm. Like i said earlier i will have a full car later tonight so I will know if the shudder has gotten any worse with new tires.

[Cougar]

I disagree with the advice you recieved about not draining the old fluid. If the current fluid is old it should be replaced. You also might try a product called Trans-X and add it to the transmission fluid. Folks here have had good results freeing up sticking valves and other transmission woes.

[Scrim]

Well as is usually the case when you ask for advice or take a car to a mechanic, the shuddering problem magically has disappeared. Last night i had 4 guys counting myself in the car, the other 3 were big dudes and the total was over 900 pounds between the four of us (the problem origionally happened with only 700 pounds of passengers). And when i got up to speed... Nothing. WTF! Don't get me wrong i'm glad it's gone, but it is just a little frustrating that the problem is probobly going to come and go now whenever it pleases. And as for the transmission, i am still pondering flushing it, i guess time will tell.

[nipper]

The fact the shudder comes and goes is a good thing.

 

With soobies-

 

 

1- Always make sure all four tires match, and preferably bought at the same time.

2- Autos LOVE tranny flushes at any times in thier lives. Tranny flushes cure many issues.

3- See rule 1

 

 

nipper