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CLR Project Leichtbau: adding lightness to the tune of 250kg

Thanks guys you have confirmed exactly what I was thinking. Regarding the taper roller bearings they sit on top of these shims as follows and are sided as follows:

LH: 99905906400 is a 50x90 (20x large rollers)

RH: 99905906602 is a 50x80 (smaller rollers and more of; around 25)

These were fitted correctly.

Now I've just checked the other side and the shim on that side appear to be much thinner, around 1mm:
26896745439_553ffa2dcf_h.jpg


However on the previously fitted diff the markings kind of indicate a much thicker shim was in use before.

So going forward I need to speak to the guys who fitted the diff again and try and establish exactly what they did. I then also need the procedure for how you do the installation set-up for a new diff.

The LSD housings are slightly different in places however the critical mounting surfaces for things like these shims bearings all appear to be the same as the OEM LSD, so my thinking is the previously fitted shims should be just about right for this new LSD give or take a few 0.05mm.

The main issue I really have is nobody really gets involved with this type of work. All OPC's would most likely outsource gearbox work, the likes of Manthey the same. The only company I know and trust with this are 'Sport and Classic' (Mike) but they are in the UK. I have lost pretty much the whole driving season last year due to this, so this winter I need it resolved so that I can crack on and get this finished.
 
I'm ready to be shot down on this but could the issue be back lash between the helical gearing?
Just a long shot!
 
bakerboy4s said:
I'm ready to be shot down on this but could the issue be back lash between the helical gearing?
Just a long shot!

It will be partly the pinion and ring gear backlash being slack with the diff being loose in the housing due to the shims not keeping it all tight and together.

Been looking at diff installation procedures and it seems reasonably simple to work out what shims you will need but will take more time in a transaxle.

Making sure the pinion and ring gears are tight and run without any slack or binding then measure what shims you need each side to fill the gaps, contrary to what I said previously there is a chance that both sides may actually be different thicknesses as yours is.
You do need to speak to the guys who installed it and get them to install correctly, I assume they should know how to do it, if not ask OPC who they use for gearbox work as it looks as though its a fairly bog standard job for someone who rebuilds these all the time.
There are a few videos on Youtube to explain the basics of a diff installation.
 
infrasilver said:
bakerboy4s said:
I'm ready to be shot down on this but could the issue be back lash between the helical gearing?
Just a long shot!

It will be partly the pinion and ring gear backlash being slack with the diff being loose in the housing due to the shims not keeping it all tight and together.

Been looking at diff installation procedures and it seems reasonably simple to work out what shims you will need but will take more time in a transaxle.

Making sure the pinion and ring gears are tight and run without any slack or binding then measure what shims you need each side to fill the gaps, contrary to what I said previously there is a chance that both sides may actually be different thicknesses as yours is.
You do need to speak to the guys who installed it and get them to install correctly, I assume they should know how to do it, if not ask OPC who they use for gearbox work as it looks as though its a fairly bog standard job for someone who rebuilds these all the time.
There are a few videos on Youtube to explain the basics of a diff installation.

Just an small update, I said last time I'll never removed the gearbox without ramps again but for what must be 5 times now in the last year, I had to drop the box again :frustrated: Not recommend!!!

38064382094_64c38a17f9_k.jpg


Having looked into setting up the back-lash and bearing pre-loads; very fine tolerance, 0.03mm I think it was. I decided to take it to Manthey Racing. They have a dedicated race team set up away from the road car showroom, where they do all the engine and gearbox work. So hopefully next week it should finally all be sorted.
 
Hi ELA- I'm in the middle of swapping to the Cup wheel but I can't get the horn to work as the column (which the horn wants to use as the earth) isn't earthed. How did you resolve this?
 
Hi Dammit, please send me a pm with your email and I'll send you a guide ;)
 
ELA said:
Just an small update, I said last time I'll never removed the gearbox without ramps again but for what must be 5 times now in the last year, I had to drop the box again frustrated Not recommend!!!

Having looked into setting up the back-lash and bearing pre-loads; very fine tolerance, 0.03mm I think it was. I decided to take it to Manthey Racing. They have a dedicated race team set up away from the road car showroom, where they do all the engine and gearbox work. So hopefully next week it should finally all be sorted.

Hopefully they sort it once and for all, did you remove the gearbox every time you wanted to remove the diff because you can remove the diff in situ, I know it needs to be removed this time though to get it set up.
 
I've personally removed it 5 times now due to LWFWx2, Clutch, complete overhaul, then this this time now due to LSD set-up. 4 other times have been just the LSD removal with gearbox left in.
I really have my fingers crossed this time that Manthey can produce the goods. I lost practically all of June-now because of this problem; having to cancel video reviews and approval process...
I still have a lot to be cracking on with so once this issue is resolved, it will be a massive headache finally resolved.
 
Finally a meaningful update; to be brutally honest, the last 6 months have been a bit of a disaster and I seriously considered throwing in the towel: Costs spiralling massively out of control, development issues (LSD, suspension components, power loss, NVH...). Well the good news is the major stumbling blocks are now resolved (or in the process of redesign/manufacture).
Custom LSD issue was due to incorrect set-up. Now set up to 0.08mm bearing preload and 0.15mm crown-pinion backlash. Whilst the gearbox is removed I've also thrown in the powerflex mount bushes (I was sent the old design so had to modify these).
Regarding the suspension, I am now on the fifth 'and final I might add' design. The LCA's are in manufacture as I type but I have a few fabrication pics below. New adjustable castor arms done and new adjustable front tie rods due any day now.
38315713895_9b7113b777_h.jpg

38315712905_cfdc45d3b3_h.jpg

38484735544_0a1c4dede6_h.jpg

39191839851_723779559c_k.jpg

39191834071_265f7f9ac7_k.jpg

27415298109_177dd6a1e0_k.jpg


All being well, I am now on track to have this project complete by spring, TUV approved and ready for review :D
 
ELA said:
All being well, I am now on track to have this project complete by spring, TUV approved and ready for review :D

Looking forward to seeing it at Dinslaken. :thumbs:
 
I was just saying to my mate Craig last night that there isn't much car stuff happening at the minute. My cars away, there are no decent bits popping up on eBay and not many good threads popping up....

So it's great to see an update on one of the best 996s out there. Glad you're getting there after the set backs. The parts are looking really good. 8)

Have a great Xmas Rich and hopefully swap the R&D for some R&R. :thumb:
 
Those suspension components look much beefier (and more gorgeous!) than the initial ones, were the first redesigns just to test the required geometry for the test drives?

This project is awesome, just awesome, thanks again for sharing its progress.
 
Well done Rich.
:mechanic:
:worship:
 

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