Great dyno numbers but too bad about the lsd. Are you going to do a full engine overhaul this winter or just pull it to get the tranny out?

Yeah, I was pretty depressed last night, but I think I'll try to lift the engine and trans by unbolting large bits of 'accessories'. If its too complicated, it will have to wait till winter.
Engine will not be opened then as there seems no need for overhaul. No smoke, no noise, no compression loss, no valve adjustments, it all seems just fine still..

I will however replace it over winter anyways with a 1200 type 1 turbo EFI I'am building as a project :cool:

Pulled my finger out of my.... and put some work into it and raised engine-tranny combo a bit.
That proved just enough to pull the diff out :)

http://i174.photobucket.com/albums/w...1.jpg~original

Hi Wally

That doesn't look like much fun, I'm sure you will be pleased with the results.

I've just been offered a new Quaife for a G50 for about 1025 Euro or $1354 Au, I'm thinking that might get it.

Do you have any experience with Quaife as far a drivability is concerned?

Steve

No personal experience with Quaiffe, but usually when somebody says quaiffe, they mean their Torque biassing diff or TBD.
That is a whole other type of diff then a limited slip diff. Not better or worse by type, but it react different. I hesitated long, but think I prefer a LSD for my application.
I am sure you know, but I thought mentioning it anyways.

Less progression and no overrun locking with tor-sen types, they are either locked or they're not, plate types are more tunable, with different drive and overrun ramps available, but all at a price. Torsens good for drags.

Fantastic #'s Wally !

Really looking forward to your updates with the LSD installed. Judging by the pics, it looks like you'll be installing this yourself.

I'm at the cross roads as well right now ... body about to be installed but no LSD in the G50 and a 915 still sitting on the shop floor :o

Sandeep

I had quite a few email exchanges with Paul Gears and finally got some of the GT disks in my hands. They are such a difference, just feeling what their surface is with your fingers, that I would not want to ever run a original ZF diff without them.
So, either full GT diff or original and change out the disks for GT ones would be my advise.
I hope the diff measures out so I don't have to do more complicated stuff to install it properly...

I hear ya.

While that diff is out, do you happen to have the part # handy for the 100mm output flange ? :idunno: I'm at odds with the local Porsche dealer and don't want to order something I cannot return.

Thanks

Sandeep

I'm very interested in how you get on with this as I have an LSD sitting on the shelf for my G50 too! Did you find any god reference material on rebuilding it and installing it with the correct tolerancing?
Rich

Maybe even better, I think I still have an extra set I once bought for the 412 which I was thinking of converting to G50. Bought a complete G64 front diff for it ;)
Also looked at the subs, but they are a casting without any numbers on them.. At www.mittelmotor.de you can however chase down most all numbers for original porsche parts in their catalog and order them at the same time if you feel like it ;-)

Rich: not sure what there is to rebuild as only the original brass disks can and do wear, even if they seem original thickness. Learnt this from Paul.
See pics on former pages, its quite simple once you see the inside.

Just removed the ring gear and bearings so both could be compared in detail.
All the important measurements that would impact ring-gear distance are extremely close (beyond my accuracy anyways), for all practicle purposes I would say they are the same. Lets hope I am correct...

The only thing I really need, is a set of new ring-gear bolts ($$ no doubt) as the flange of the LSD is 2mm thicker (to the direction that doesn't impact ring gear distance of course ;) ).

http://i174.photobucket.com/albums/w...1.jpg~original

Thanks for that. I used the www.autoatlanta.com website to confirm the part #, but the local dealer believes the swap will not work.

No issues though ... used G64 front diffs are going for ~$200 on EBay, going to try another local source first.

Good luck with the swap !

Sandeep

Exactly! Shipping it overseas would not be cost effective for such a part.

I am still looking for the correct new (longer) bolts I need for the swap over of the ring gear. Its a M12 x1.25 bolt in 12.9 grade, but would be nice to have the part number. Mittelmotor don't list inner diff parts. I'll look at auto-atlanta in return ;)

If I'm looking for Porsche part numbers I just go to the Porsche online PET rather than via a 3rd party.

http://www.porsche.com/uk/accessorie...artscatalogue/

I had an issue accessing the 996GT3 catalogue but the 996 catalogue list two possible options for the ring gear bolts (with LSD).

999 217 152 01 or 996 332 276 00 depending on which diff (can't quite read the full number in your photos).

The GT2 catalogue lists the 999 217 152 01 bolt for use with the 996 332 083 9B (40/65% GKN) diff. The bolts are M12 x 1.5 x 22,5

Hope that helps.

oh..... and the front diff axle flanges from a 964 C4 are "964 332 209 01", if you need that number.

Interestingly, the gears inside that front diff (which I guess the subs splines attach to) have a 950 part number and are straight from a G50 box (plus 928 & 968)

Thanks Bruce, that helps surely, but I looked into the catalogue also and the 999 217 152 number seems to be the partnumber of the regular open diff (although a pic of a lsd was used, the general title of that section is 'Differential') as opposed to the 'Limited Slip Differential' section, where the 996 332 276 00 number seems to come from...
You wrote 999 332 276 00 but I am sure you meant 996 as first 3 digits for this one.

I could open de 996GT3 as well as the 996GT2 and both list the same pic and part numbers for that 9B diff..

I do indeed have that GKN diff however, so I am a little confused now which one I need... Could you check if your assesment is still correct, pls?

The 996GT3 catalogue is perhaps clearer (i got it to open at last).

http://www.porsche.com/all/media/pdf...T3_KATALOG.pdf

Like the GT2, it lists the LSD (the only diff) as part number 996-332-083-9B. It is hard to read from your photo the last two digits but could this be your diff (or does it end "00" or "01").

The GT3 & GT2 use the 999-217-152-01 bolts (only option listed).

(also corrected the part number above for the other bolts, as you mentioned)

Thanks Bruce, the diff number ends with 9B, so its spot on.
I'll order the 999.217.152 bolts then ;)

It will be fun to later couple a 1200 T1 engine to a 996GT2 equipped diff with a Gears Transmission friction plates upgrade :lmao:

Bruce,
By any chance, do you also know the correct torque setting for these bolts? I did came across it once, but didn't save the info then...:-(

Hi

Does this help?

Steve

Steve:
From what I can gather, that is the "street" LSD.
Wally's LSDiff is the motorsport version which is tighter than an inappropriate simile.


Wally:
For the torque settings, I think the safest plan would be to send another email to Guard. I'm sure he will spare 2 mins for a customer. Internet chatter suggests 50ftlbs+90degrees with locktite for a standard diff but I wouldn't trust that spec without confirmation from a reliable source such as Guard.

:lmao:
Well, I am no customer really. Paul send me a few old used disks from his own old stock as a favour to try out in my bug. He has sold most of the company a few years ago, but carries still his name. I did already send Paul a message of course from my new email adress. Hope he receives it as he probably knows this value by heart. So cool he wants to help a bugger out!
Hope to be able to pick up the bolts tomorrow afternoon as they were in stock at the central porsche dealership over here.

Wally, sorry for changing the topic, but could you detail the modification you did to the oil filter pressure relief ball/spring setup? I was surfing the keversite.nl forums with google translate, but it's not that good :P
Thanks!

Easy: drill 5.0mm hole in top above ball-spring, tap with M6 tap and install M6 bolt with lock nut. Install with loctite ;)

These are/were the original bolts: 22.0 mm shank length. I need 2mm more (i.e. 24.0-24.5mm).
http://i174.photobucket.com/albums/w...1.jpg~original

I do hope the ordered bolts are the correct length, but how could they not be?

Hi Bruce

I thought that he was after the part number for the bolts.

Steve

Hi Steve,

I looked in the same place as you, the 996 carrera catalogue but the optional LSD for the 996C is different from the "motorsport" LSD used in the GT3/GT2 and the bolts specified for each are different.

Hopefully, the bolts will fit with the G50 Crown gear. It is difficult to see how they wouldn't.

Hi

Its a shame that Porsche don't have a "Lack & normal tellie" section like VW where you could look up bolt and other part numbers by description.

Steve

Picked up the correct bolts for exactly my differential and got a mail from Paul to use 120 lbs.ft and a drop of red Loctite.
There is a difference in length, but not exactly as much as the difference of the flanges.
Anyway, it will do fine I think.

http://i174.photobucket.com/albums/w...2.jpg~original

Just reassembled everything and very happy I got the spacers and bearings pressed on again without any trouble. Ring gear was extremely nice and tight fit on the much later dated diff housing. The machining on these parts is amazing!

http://i174.photobucket.com/albums/w...1.jpg~original

After a lot of work pulling the engine forward far enough to get the thicker diff back in, I got the engine back in its place again. Filled tranny with new synthetic 75W90 Valvoline and reused the O-ring n the side cover (even though I still have a new one from the gasket set). If you turn one wheel, the other one turns in the same direction as it should with a LSD :D It turns nice and smooth by hand.
Got the engine running again and went for a test drive.

No extra noises, all seems just fine and dandy. Did a deliberate lighting of the tires in second gear (cold and damp road) and that felt different somehow, more aggressive in a way, but not out of control.
Car is still stupid fast and seemingly effortless at doing so.
At home, tranny is still bone dry as before.
All in all, this was relatively easy sailing, though I didn't know that up front..
Gotta love orginal parts ;)

Hi,

Nice job but before you go any further, are you sure about the oil you put into the tranny?

Usually in a 911 with LSD (old ones), oil is something like 75w140 (not sure about the exact values but sure about the range). I can check if you need the exact values.

Seb

Well done Wally! It will make a world of difference I´m sure!

Hi Sebastian,

Yes, very sure: besides the fact that this is not an old tranny 911 type with porsches' own syncro system (which indeed needs a different oil), its actually counterproductive to use thicker oil or specially formulated LSD oil:
The latter usual has friction modifiers, which reduce the effectiveness of the friction plates. In that sentence alone, you can see/read how weird this is...
Those 'special' lsd gear oils were made because they reduce noise of the friction plates (in slow corners or in the parking lot), which is very liked by the typical Porsche owner who wants a comfortable a relatively quiet car.
I just want performance ;)

Good luck with the diff!

I wouldn't go too crazy with the burnouts though. Replacing the clutch pack with "cup spec" (not the crappy road clutches) costs over £600 from Porsche.

If you hadn't noticed already Bruce, I now have a Guard Transmission clutch pack in there, that's supposed to be better then even the 'cup-spec' clutch disks :D
Both in performance as in duration ;)

:D

Bet you can't wait to get it on the track :)

You got that right! I also changed my front springs to 'very stiff'...: I thought I had changed to 350 lbs springs in the past, so I now ordered some +50 lbs ones (400). Turned out they were still 300 lbs... (very nice ride quality, but for track could do with a bit harder), so the difference is a 'bit' more then anticipated LOL.
Also re-installed my self-adapted 'wing' for extra downforce.
Indeed curieus what it will all do/mean on the track.

You will see a big difference in your lap times. The car must be amazing now.

Thanks for the intel, I'll pass it along to one of my friends who doesn't really care about noise (1983 RUF SC) and I'm glad I was wrong but I'd rather be wrong than hear about a broken lsd...

Have fun on the track...

Seb