Teleport

My 1999 2.5 Auto has recently developed a whurring noise at the front.
The noise occurs only when accellerating (foot comes off accellerator - noise stops) which leads me to think the front differential is worn and not meshing correctly.

What I need to know is how easy it is to get at the front diff and what, if any, special tools I would need?
Has anyone had similar symptoms? How did you cure it?
Budget is limited so I'd rather DIY unless anyone knows how much dealers charge (I will be getting a quote but dread to think what the labour might be).

I have replaced the diff oil and even put some ZX1(friction reducer) in the mix.

Any advice of diagrams would be appreciated.

Thanks

scoobyslut

Are you sure it is the front diff and not the torque converter? Especially as you say it only occurs under load, maybe wrth investigating further before laying a spanner on it and possibly creating more work.

beryllium

to reach front diff,you must remove and open the gear box.
good luck

Teleport

Thanks for both your replies.

Scoobyslut, I didn't even think of the Torque converter.

It seems to be constant and unaffected by gearchanges. I'll have a closer look/listen and get back to you.

Cheers

Teleport

Upon having a closer listen.

The noise "speeds up" as I accellerate and the only time I hear it when I decellerate is just as I go from 10mph to 0mph as I stop. The noise sounds as if it is spinning down slower than the car is stopping.

Would this be a worn Torque Converter (Gearshifts are smooth)? As I would think the diff would spin relative to the speed of the car so it couldn't be the diff right?.

I've asked at Subaru and it looks like a new Torque converter would be £600. WHAM. I don't even want to think what the labour would add onto that.

So I need to find out how easy it is to replace a torque converter myself. Anyone have any idea or instructions/diagrams?

Thanks again

Teleport

Finally got round to taking the car my local Subaru dealer..

After about 10 seconds of driving the technician said it was the front pinion bearing. He had it running on the ramp and hooked it up to the computer to verify there wasn't an electrical fault aswell.

Aparently there is a fault with pinion shaft oil seal between the Front diff and the Auto box. Apparently when the seal goes the oil drains from the front diff into the autobox causing damage to the bearing. Whether the seal goes because of the bearing or vice-versa I don't know.

We couldn't find any evidence of Diff oil in the auto box, probably because the transmission fluid had been replaced just before I bought the car and I replaced the front diff oil myself.

So we've just taken the gearbox out using a trolley jack, some BST (Blood, Sweat & Tears) and a few manuals downloaded from Subaru.

Just need to open the box confirm the fault, see what parts are worn, buy them and put the whole lot back together. I'll keep you posted.

Has anyone else experienced this phenomenon with the oil seal? As the part's must be used on other Subarus someone must have experience of this.

The dealer recommended a complete gearbox replacement and said the diff oil may have got into the bands in the box. But there's no slippage or other gear probs so I'm going to try this cheaper option first.

Wish me luck...

Teleport

Update.

Well we've opened up the box (with some help from a Subaru Technical guide purchased from ebay for £10) and it was indeed the drive pinion bearing causing the noise.

Upon breaking open the bearing you could clearly see the hardened surface or the outer race was breaking up for about a 5th of the circumference.

Teleport

Well we've fully refurbished the gearbox and put it back in the vehicle.
It's like a new car

Hope this thread can help someone in the future.