I took the red'99, Forester(4eat) for routine brake job today. When I picked the car up the mechanic said he noticed something I have a noticed as well- a light vibration in the drive train. It is most noticeable in second gear, and then almost completely goes away in the others, though I still sense it. He was concerned enough to recommend it be checked. Its done for so long, that I hardly notice it. Mechanic seems to think its in the, " Transmission," because in his view the prominence is only in one gear. This guy is really awesome and does not do this kind of repair, thus the referral.

Does anyone have any thoughts on this? If it is the tranny ,what would be the issue, Torque Converter or other? If this this the case, how much would that cost, and can the average Transmission shop do this, or would it be wise to go to the dealer? The tranny itself, shifts like a brand new car.

 

Thanks in advance for any tip!

While in second gear, does the vibration go away on trailing throttle and come back when you step on the gas again. If so, this is pretty typical for a bad DOJ on one or both of your axles. Check the boot for tears; if it's torn on one side that could likely be your problem. Too early to really decide whether it's the tranny or not. Even replacing both axles will cost less than replacing the tranny. Good luck.

While in second gear, does the vibration go away on trailing throttle and come back when you step on the gas again. If so, this is pretty typical for a bad DOJ on one or both of your axles. Check the boot for tears; if it's torn on one side that could likely be your problem. Too early to really decide whether it's the tranny or not. Even replacing both axles will cost less than replacing the tranny. Good luck.

No it does not go away with throttle. Axles checked,look perfect and no tares.

Thanks ed.

Check the drive shaft, the carrier bearing, and the universals.

 

How many miles on the car?

 

nipper

Check the drive shaft, the carrier bearing, and the universals.

 

How many miles on the car?

 

nipper

I will Check these, but the mechanic thinks if is one of these that the shake would persist (similarly) through all the gears.

145K on the clock

I will Check these, but the mechanic thinks if is one of these that the shake would persist (similarly) through all the gears.

145K on the clock

 

No it wouldnt. They usualy start out as having a sweet spot where they first appear, and it can stay like that for a while. Remeber that the driveshaft isnt really under a lot of load like a rear wheel drive car is. Since subarus vary the load to the rear from 10-50% split, there may only specific times that the shft is loaded or unloaded that allows for the vibration.

 

It can be decieving, but its a good and simple place to start looking for mysterious vibration, and easy enough to rule out.

 

nipper

PS: You can safely rule out the tranny. Its super rare for the 4eat to produce this issue.

 

 

Just for kicks, put in the FWD fuse and see if it changes (after inspecting the driveshaft)

 

 

nipper

PS: You can safely rule out the tranny. Its super rare for the 4eat to produce this issue.

 

 

Just for kicks, put in the FWD fuse and see if it changes (after inspecting the driveshaft)

 

 

nipper

Good Idea, hadn't thought of that. Where is this mysterious fuse? I assume the fuse box under the hood

Good Idea, hadn't thought of that. Where is this mysterious fuse? I assume the fuse box under the hood

 

Under the hood, passenger side, by the wiper motor. It should be markes FWD. Any fuse higher then 10 amps can go in there.

 

nipper

Under the hood, passenger side, by the wiper motor. It should be markes FWD. Any fuse higher then 10 amps can go in there.

 

nipper

There is spare 20amp in the box, this will work?

Thanks

There is spare 20amp in the box, this will work?

 

Yes................

 

You almost have to pull the drive shaft to check it. The needle bearings in the U joints take a "set" rather than wear out, because the shaft travel is so limited, there is not really "wear".

There is spare 20amp in the box, this will work?

 

Yes................

 

You almost have to pull the drive shaft to check it. The needle bearings in the U joints take a "set" rather than wear out, because the shaft travel is so limited, there is not really "wear".

Ok Put the fuse in and test drove it. Same shake, no change.

There is spare 20amp in the box, this will work?

Thanks

 

Yes. All that ciruit does is send a signal to the TCU to disable the AWD. I just want to rule out the begnings of torque bind.

 

Speaking of, when was the last time the tranny fluid was changed

 

nipper

Yes. All that ciruit does is send a signal to the TCU to disable the AWD. I just want to rule out the begnings of torque bind.

 

Speaking of, when was the last time the tranny fluid was changed

 

nipper

It has been changed 3 times over the past year-just to get really good and clean.