Replacing diff with Q2 myself

This is a great post, and excellent pictures.....tells me what's happening to mine.

Sounds like all that you describe could happen if the diff goes in a big way is what happened to my GTA. I'm looking forward to getting it back with the Q2 diff and new box fitted.....

see the attached..... http://www.alfaowner.com/Forum/alfa-...on-my-gta.html

Thanks again - keep the pics coming

Originally Posted by 156GTASW

This is a great post, and excellent pictures.....tells me what's happening to mine.

Thanks again - keep the pics coming

That goes for me too. Would make a good sticky when the job's been done.

I see you have taper roller bearings on the diff. In order to set it all up corectly, do you have to bolt it all up, measure end float then open it and set a pre-load with shims or what (I need to find a manual for this car)?

Being a bit of a newcomer to the Alfa world, could someone enlighten me on the advantages of the Q2 diff?

Originally Posted by Tanuki

Being a bit of a newcomer to the Alfa world, could someone enlighten me on the advantages of the Q2 diff?

reliability, reliability, and reliability.

together with improved traction and less torque steer, which makes for much improved drivability; particularly with off-the-line acceleration, and flooring the accelerator out of corners. it should just GOOOOOOOOooooo, without the ASR kicking in, and not having to fight the steering wheel and without any nervessness.

This has been posted before, but
I couldn't find it in a search, so:

http://www.youtube.com/watch?v=Y_WzamjD4w8

http://www.youtube.com/watch?v=5DDmo-1Lr2Q

http://www.youtube.com/watch?v=suRYFCPcnzE

From the pictures that i saw i can see that the metal of the teeth shows all the signs of lack of lubrication. If the teeth didn't break they would have frictionwelded themselves. What was the oil level like before this happened?
By the way, impressive work to tackle on your own, well done.

Originally Posted by newalfisti

From the pictures that i saw i can see that the metal of the teeth shows all the signs of lack of lubrication. If the teeth didn't break they would have frictionwelded themselves. What was the oil level like before this happened?
By the way, impressive work to tackle on your own, well done.

Havn't had a chance to do any more at the moment....a few things have come up taking priority.

I don't hink lubrication was an issue here. She dropped the full amount of oil she should have, and it was clean as a whistle despite the bits of crap flying around inside the housing. I'll be able to tell the state of affairs much better when the old diff is dropped out (fingers crossed the internal housing is intact). The casing I removed had a small indent from being struck by a piece of gear. Luckily it didn't penetrate far and has no burrs or loose bits.

how much is the Q2 coming from EB Spares ? Did they ship in France ?

thanks a lot

I think it was about 240 squid plus 20 for the bearings and another 20 for shipping to Australia. Yes they will ship anywhere. I didn't realise at the time, but I think they offer a discount for AO members? (I should have told Kevin I was). Anyways, the parts were in my hands 4 days after ordering.....very inpressive.

Nathan - great thread & thanks for posting This is so going to be an upgrade on the GT once the warranty is out

@ Nev - great vids

can you PM me with an email address and i can send you a copy of mine.

Originally Posted by Cuore_Sportivo_155

correct ad nearly complete it's also to reduce unsprung weight of the right driveshaft. torque steer and excess torsion can be countered by making the longer driveshaft thicker

For info, actually it cant, torque steer is mainly due to the different angles in the joints, which creates a steering moment, made worse by mcphereson strut front ends, double wishbone is generally much better.

Sorry it's been a while since I posted.....I did get the diff out by splitting both driveshafts. The right side driveshaft wasn't that bad a job, though a ratcheting spanner with adjustable angle head helped a lot.

Unfortunately when the diff was removed there was a nasty big hole in the bellhousing. The clutch and all of it's components were perfectly intact though.....phew!

That meant that the gearbox and bellhousing had to be dropped from the car. There are some really nasty bolts to access on the rear of the gearbox, and you really need a hoist to do this. That meant rthe car was dropped in to the workshop as I don't have that sort of equipment yet....bummer.

Anyways, the crown gear was intact, but it ground up the bits of gear that were spat out into the housing. The filings from the gears made their way into the gearbox making the job a whole lot bigger too. The gearbox is being stripped down and cleaned out to remove all the metal filings. All the internals were fine.

My advice to anyone considering a diff change is to do it as soon as you're able to. I could have replaced the diff no problem myself if the extra damage hadn't happened, but that's not how things went down.

In regards to the end float issue that someone mentioned, I have been told that yes you do need to make sure that it is carried out, but the same value can be used on the Q2 as the original item. I heard someone say that no preloading is required on a torsen2 diff....while this theoretically may be fine, it's not good to allow the diff excessive horizontal movement. If you did allow this, you would get a knocking sound everytime you go on and off the loud pedal.

I had to oder extra parts for the job too. You will need new driveshaft seals and gaskets (rubber O-rings inside seals).

Because of the damage, I also had to order new gearbox input shaft seal. The damage on the bellhousing cost $60 to weld up (nice job done too). This was a lot cheaper than $800 for a new bellhousing.

good to hear the update. did you end up trucking it to an alfa dealer, or an independent workshop?

so, is it now back on the road? better than ever?

Originally Posted by AussieNath

Sorry it's been a while since I posted.....I did get the diff out by splitting both driveshafts. The right side driveshaft wasn't that bad a job, though a ratcheting spanner with adjustable angle head helped a lot.

Unfortunately when the diff was removed there was a nasty big hole in the bellhousing. The clutch and all of it's components were perfectly intact though.....phew!

That meant that the gearbox and bellhousing had to be dropped from the car. There are some really nasty bolts to access on the rear of the gearbox, and you really need a hoist to do this. That meant rthe car was dropped in to the workshop as I don't have that sort of equipment yet....bummer.

Did you remove the subframe to gain access to the diff housing or were you able to remove it without taking it off?

Dropping the gearbox is a real PITA! I'm pretty sure you have to remove the rear exhaust manifold to get at the bolts that hold the starter motor on so that you can remove the box.

Originally Posted by AussieNath

Anyways, the crown gear was intact, but it ground up the bits of gear that were spat out into the housing. The filings from the gears made their way into the gearbox making the job a whole lot bigger too. The gearbox is being stripped down and cleaned out to remove all the metal filings. All the internals were fine.

My advice to anyone considering a diff change is to do it as soon as you're able to. I could have replaced the diff no problem myself if the extra damage hadn't happened, but that's not how things went down.

In regards to the end float issue that someone mentioned, I have been told that yes you do need to make sure that it is carried out, but the same value can be used on the Q2 as the original item. I heard someone say that no preloading is required on a torsen2 diff....while this theoretically may be fine, it's not good to allow the diff excessive horizontal movement. If you did allow this, you would get a knocking sound everytime you go on and off the loud pedal.

I found the shim in my 2.5 box was exactly the right size when I replaced my diff with a quaife torque biasing jobbie too.

Originally Posted by AussieNath

I had to oder extra parts for the job too. You will need new driveshaft seals and gaskets (rubber O-rings inside seals).

And new bearings for the diff. They're not automotive specific and any decent bearing supplier should be able to provide a set. They're 20+vat each at alfa. I paid less than half that for mine.

Originally Posted by AussieNath

Because of the damage, I also had to order new gearbox input shaft seal. The damage on the bellhousing cost $60 to weld up (nice job done too). This was a lot cheaper than $800 for a new bellhousing.

Nicely done. Not cheap are they?

Well, I got the car back. I ended up giving it to a local european car specialist. Problem was he hadn't done any work on a GTA before. Promised it would be done in a couple of days for roughly $700. I ordered the parts and organised the bellhousing repair.

Well, we had to wait on the driveshaft seals for a month as they were on back order. This wasn't their fault, so no problems there.....

The problem was when I was going to pick up the car they wanted $2600.........ouch! I refused to pay that amount as there is a slight difference between $700 and $2600. There was extra work involved because of the gearbox being stripped and cleaned, but an extra $1900? I don't think so.

The problem was the hours that they said that they had put into the car. I told them that because it was a first time on a GTA for them I shouldn't have to pay for it......not when I was assured they could handle the job without any problems.

So I ended up paying $1580 which I was happy with.....In hindsight, would have been better to get a car and trailer and take it to an Alfa specialist in Sydney.

Drives beautifully now though.

Next.....brakes and rotors......

good to hear it's going well now.

but you would have thought they'd ring and explain it will cost more BEFORE pushing on!

Good to hear is all sorted out and drive beautifully.

I think I was really lucky with the labour charge of my Q2 diff.

Great to see it back on the road. I hope you can help with a few more details, as I am looking to do mine myself as well.

What was the final story with the preload or lash required, or is it just a mattter of shimming everything back the way it came apart? And lastly, the parts list for an undamaged car should be:- the diff, the 2 bearings, driveshaft seals and gaskets?

Thanks,
downunder

Hi AussieNath, have just read the Q2 diff thread - interesting stuff. How did you get on with the completed job? The thread runs out where you are trying to remove the right hand drive shaft. I have recently purchased a secondhand GT and have ordered a Q2 diff from EBSpares - I am not game to put my foot down while on left/right lock at the moment!!!! Too many pain stories on the forum. I will do this changeover job myself so am interested on your end result. I wonder if anyone would be interested in a standard diff (unbroken of course!!!!). Thanks....Bill

Any point in undertaking this kind of project with a GT JTD?

Yes, the parts required to replace an intact diff include....

1. Q2 diff
2. 2 tapered bearing sets
3. driveshaft seals (they are different on left and right and the right side is double the cost of the left).
4. loctite 510 or similar (no gaskets required)
5. new gearbox/diff oil.

I would encourage anyone with decent mechanical experience to have a crack themselves. You will need a decent amount of tools to do the job. I found my adjustable head ratcheting spanners a godsend for some of the difficult to access bolts. I would also recommend a large and good quality set of car ramps plus car stands. Access to a hoist would be superb.

The job takes a day to do if you know what you are doing, obviously a lot longer if you don't. I found the CD workshop manual was practically useless.

When looking at preload, you can set it back to the original factory spec. With preload, what you are trying to avoid is lateral movement of the diff.....this causing a clunking/banging noise every time you go on and off the accelerator. It can also damage the bearings over time. It is also important make sure the preload is noe too high otherwise you put too much pressure on the bearings and they will be damaged after only a few thousand k's/miles.

In regard to the feasability on a JTS, I wouldn't bother. I've not personally known of anyone with a JTS to blow a diff. If money was no object and you wanted LSD, then sure.....but if money was no object, you would probably own a Zonda or something