Hi,

I've been lurking on the forum for sometime now, there's already so much valuable information here but I thought this thread might be useful to someone out there.

After a long search I bought a 2003 blob eye wagon earlier this year, as it had a tasty list of upgrades including STi turbo/intercooler etc...albeit with a 5 spd box. A few months in to ownership I developed a whine....my initial reaction was that it was something to do with radio interference, those of you who have run aftermarket sound systems may know the weird alternator type whine you get from faulty RCA cables. After a few tests, it was clear it wasn't anything to do with the stereo, the whine sounded like it was coming beneath the gearstick area.

My next thought was it was a bad front passenger side driveshaft, as the boot had split and shed some grease. I replaced this, but the whine remained. Next step, I got the car up on ramp and used a stethoscope which confirmed the whine was coming from the rear of the gearbox in the diff housing.

Doing some research, this thread was VERY useful: https://www.scoobynet.com/drivetrain...-2006-wrx.html

So, having sat on my hands most the year I started planning the job and sourcing parts. I didn't want to do this on my drive, so I found a garage with ramp hire, I'd highly recommend these guys: http://ramphigher.co.uk/ - really friendly chaps in Gravesend, Kent and had some very useful tools including bearing pullers. Here's photo of the parts,



35047AC030 UJ JOINT GEAR SELECTOR
806322080 ROLLER BEARING
806330120 ROLLER BEARING
806230170 BEARING - BOLT ON TYPE
806255010 BEARING - CENTRE DIFF FRONT
806735210 GEARBOX PROPSHAFT SEAL
33179AA030 GASKET TRANSFER CASE REAR
ST35036ST000 BUSH - GEAR LEVER STAY
633046020 SPRING PIN-BOSS JOINT

All of the above came in at £242 delivered from ICP. I also ordered some Prothane uprated shifter bushings for good measure. Also, note the different thickness m50 x 62mm shims I purchased. As Subaru modified two of the shaft bearings/races I previously read that you need to remeasure the distances (in thread above, or here + here) a few people had mentioned needing a thinner shim so I got a range just in case, turns out the 0.5mm shim was perfect.

So first step was to drain the gearbox oil (they had a raised catch can) , remove the exhaust, mounts, shields, propshaft, all pretty straight forward:



Then undo the shift linkage:




Rear casing off:



The last person used some sort of silicone instead of the OEM gasket, so it was a real pig to get the cover off after undoing all the bolts. You can't get anything in to pry the casing apart as it's a machined finish so have to very careful. Our approach was to bolt the downpipe hanger bracket back on, and hit this in the direction of the rear of the car. It came apart, but be ready with a catch can to hold the diff - it's heavier than I thought it'd be. You're left with this:



At this point, I was starting to wonder if it was these bearings causing the whine as they felt pretty good. No metal bits in the oil or signs of failure or significant wear. There was however some play on the main diff bearing itself - I haven't read about many of these failings but I'm pretty sure it was my issue.

So next was to remove the bearings+race, this was made much easier by Ramp Higher's tools + vice:





Suspected cause of my whine


New propshaft seal installed using a 36mm socket to tap it in:



Knocked this old race out, you can get good access from behind it. It has a shim behind it which replaced for a thinner 0.5mm version:



The race left on the car side is very easy to pull out, I was fearing the worst but very simple.

Next cleaned off oil, old silicone and gunk with a light abrasive scotch pad:





New bearings pushed on, mainly using the old bearing inner races to tap them on. Make sure you don't forget the shim under the diff itself. Give everything a spin to make sure it sounds/feels good:



Put the diff back in the car once I'd cleaned the silicone off the other mating surface:



Bushings and gear lever stay installed:




Case back on using the OEM gasket, and new UJ joint gear selector installed too. Getting that bloody pin back in is probably one of the hardest things on this job!



Refilled the gearbox, using a funnel and some tube with Motul Gear 300:




All in all, thanks to all the amazing information kicking around on the forum we did this in about 3-4 hours. Made much easier by the ramp and borrowed tools - I would not want to do this job on axel stands!

Diff whine has completely gone and my gear shifting feels so much better. Not sure if it's the oil change, uprated bushings or new gear selector joint....but I thought I might as well do these other jobs whilst under the car in that area and it has worked a treat. The car used to crunch in to first + second when cold, now goes in smooth like butter!

I'm sure there are loads more useful images I have, if anyone has any questions please shout.

As the pictures above show, rust was also something I needed to tackle which I did whilst I had access to the ramp for the day. Another write up coming soon!

Thanks,
Sunny

 

Excellent how to. Thanks

 

I've been planning (i.e. putting off) this job for months.. mainly because it was such an issue to source the shims. Reading this:

..has confirmed I'm going to get someone else to do it!

 

Haha! I'm sure it can be done on stands, but is so much easier with the car in the air. Can you find a ramp hire company, like ramp it up or ramphigher? It's a very straight forward job and rewarding. How much would a garage charge for this job?

Just so you know, I did not use the Subaru shims. I sourced my own off an engineering firm. I have a few of these spare, and I also have an brand new (in packet) unused genuine STI group N gear lever support bush as I ended up using the aftermarket poly version that came with shifter bushings. Let me know if you're interested in these?

Thanks

 

Great stuff.

 

Thanks!

I did just post another thread about sorting the rust under the car but for some reason it didn't upload

In short, wire brush/flap disc, treat, paint + under seal:

 

 

This virus has given me enough time to attempt this (on my driveway, with axle stands - as per your advise not to!). All good so far, but would you mind explaining why you replaced the adjusting washer with a thinner version? Am I right in thinking this is because the new bearing was thicker?

I'm so jealous of how clean your gasket surfaces are - I've been trying to clean off 27 year old gasket for hours!

 

Because the new bearings need the correct clearance/preload to work and keep working.
Attached pdf document should give you some idea of what is involved in checking this.(page 6 of 8)

 

Thanks Don - I have referred to that guide (as a part of his document) but am getting confused with the diagrams and part numbers; the section/pages you quoted seem to show the Phase 2 Centre Diff, whereas I have the Phase 1. Is it just that the adjustment washer ("Thrust washer") part numbers are the same regardless of phase of diff? I've tried to confirm this to no avail (opposedforces.com hasn't cleared it up).

The answer, however, could be a moot point - the old bearing and washer are xx.6mm and 0.6mm respectively, whereas the new bearing is xx.9mm (i.e. 0.3mm wider) and the thinnest washer available is 0.5mm (803050060). It seems like I have no choice but to fit the 0.5mm washer? I realise I could reassemble it and check for sufficient fore/aft movement in the output shaft but am waiting on replacement dowels to alignment the rear extension with the transfer case (I don't realise you weren't meant to knock them out..!).

 

The washers have the same part numbers for both generations of box.
I hope you realise the "guide" and most of the manual sections in this thread refer to later 5MT boxes that have taper roller bearings fitted to the output shaft compared with the earlier models that have radial ball bearings (taper roller bearings will be "thicker" than radial ball bearings)
This is the section from a 1995 manual
1995 5MT Transmission and Diff pdf

Output shaft bearings required for earlier box (MY97 and earlier) are 806230130 and 806222120 superceded by 806222060
http://opposedforces.com/parts/impre...llustration_2/

 

I did acknowledge the different type of bearings but certain part number similarities and an apparent absence of info on the earlier box led me to make certain, desperate (and incorrect) assumptions. That 1995 manual is exactly what I'm after - many thanks for the umpteenth time!

 

I know this is an old thread but i am doing this to my 1995 wrx and the pdf link is not working. Do I need to shim between the diff, it doesnt show one on the opposedforces illustration and there isnt one fitted to my car but i know the centre diff was replaced and an awful rattling sound off throttle led me to believe the bearings need doing but now im not sure if its due to missing shim?

 

Early classic 5MT transmission

 

WRT the shim, it depends whats actually fitted


The shim was only fitted to the 95 on WRXRASTI with DCCD

 

I dont have dccd, mine is the 4kg early diff, so no shim then thank you. hopefully the off throttle rattling is bearing (10), which i should have in a day or 2