GRiSO 1100 Drive with metal fragments inside

Finally got the spare parts and builded some tools for reassambling.

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Tomorrow i will start fixing the Pinion and the Crownwheel.
I checked a bit how much i can tighten it up without using too much force.
What can i say, its millimeter-work between good and blocked.
Will keep you guys up to date!

Good night

I see you have rocker cover gaskets as well. Those ones you've got are useless and will fail in a very short time. Buy a pair of Valpolini gaskets, they last pretty much forever and won't fail. They are a coated metal gasket similar to those used on a variety of Aprilias and other applications by Guzzi. Why anyone is still selling those ones is beyond me?

Its done, the Crownwheel got 35 Nm, the Pinion 22Nm and turned very easy.

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Furthermore i secured both with Loctite 2701.

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After reassambling,  i can hardly turn it by hand, but maybe because its not oiled yet and needs kind of a short warmup-run.

One question regarding the main-seal.
It is 1-2 mm deeper than before, it somehow slipped a bit deeper during the final mounting.
How bad is that and do i need to bring it up a bit?

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I tend to think those figures are a bit too high but you'll soon find out.

The seal should be OK as long as it isn't pressed right into the bearing.

I will complete my GRiSO and will check temperature as discussed.

Will keep you up to date, the next few weeks!

Thx Pete, you are great, and i am really grateful for your help!

Hi guys,
almost ready for a testride, maybe i can manage it this weekend!

No leaking so far and the Wheel turns as well as my brothers Stelvio, which makes me confident.

I will furthermore build a temperature sensor, that measures the oiltemperature from the inside and sends an Alarm to my Phone, if its getting too hot.

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First 25km ride, the drive gets hot, but we are talking about 50-60°C oil temprature.
I will try another run these days.



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Greetings
Havli

Hi again!
Next update, i rode 180km with one longer break and measured 3 Times.
I never had more than 60°C, mostly it was around 55°C and it was a hot day with 30°C airtemp.

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After the ride I filled in new oil for the drive; there was a lot of “metal sand”, but that is probably normal as the tooth flanks are running in.

Do you have any experience with this, Pete?

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Greetings
Havli

When you say'Metal sand'? What do you mean and how much detritus? Any pictures of the oil? Or the magnetic drain plug?

I have to say I'm uneasy about this. As I said before I fear your tightening torques are too high and there might be a backlash/mesh depth issue.

Unfortunately I don't have a real photo of it, I didn't think about it.

1) Before Rebuild:

When I drained the oil, a fine metal abrasion about 2mm high was attached to the magnet.

I put the oil in a glass container, where after a few days 1mm was deposited at the bottom as well.
I suspect because the driveshaft was loose.

2) After rebuild

After I rebuilt the drive and drove about 200km, this happened again.

Here is a symbolic image, but its very similar to what it looked like.

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It's like scrapings from 800 grit sandpaper, no coarse fragments.
I will make today a photo of the old oil, i´m sure there will be again 1mm deposit at the bottom.

And just fyi, i used always new oil, in order to compare it for exact this case.
Its not possible, that fragments from old oil were already inside.
Maybe there was also some abrasion from the drive, that i couldnt clean up properly.

Hmmm.

I'm not entirely happy. There are few bits that should shed filings in a bevelbox. In a gearbox, with multiple ratios, there are engagement dogs and rapid acceleration and deceleration forces at work as gears are changed. In a spiral bevel set? Not so much.

Once the gears are run in there should be little more wear.

Keep an eye on the oil and change it frequently. If it's colour or smell changes markedly or if you continue to have a high particulate build up in the oil or on the plug you'll need to go back in.

I still feel you have applied too much torque to the nuts but that shouldn't cause wear to the gears.

Im 90% happy, but i agree with you!
I will keep monitoring temprature and check the oil every 200km in order to have a comparison.

If its not getting better, i need to check the drive again.

Honestly i´m a bit afraid of using less Nm for the nut, the 35 at the Crownwheel are exactly the same as it was from the factory.

The 22Nm from the pinion are really on the bottom side of a pinion-nut, but IAM NOT EVEN CLOSE AN EXPERT LIKE YOU!

Most bevelboxes, and differential drives, that use a spiral bevel or hypoid gear system use a collapsible spacer between the bearings of the pinion to establish preload. Torque the nut down, when the spacer is applying the correct preload? Click goes the torque wrench!

With this system there is a cross drilling in the pinion shaft that facilitates lubrication of the nose bearing of the pinion. Can't have a spacer due to that I imagine but what would I know?

Therefore preload is dependent on a light torque and a lockwasher.

Do I like it? No! I think it's shite! But it's what was worked out by the Aprilia engineers and the cost/benefit analysis obviously worked for the accountants so it's what we're stuck with.

Could someone reverse engineer something better? Once again, I have no idea! I'm just a dumbfuck motorbike mechanic! But I do know that if you take a few, sensible, precautions to overcome the general lack of interest in assembly the damn things are virtually indestructible.

I'm very grateful for your willingness to experiment and persevere as im likely to learn a lot from it.

I checked the Oil, not so much metal-dust, it looks good!
Furthermore  i finally installed the temerature-measurement-system!

It will send the data to my phone during the ride, i will get an alarm above 90°C.

Looking forward to test everything :-

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I drove 40km and measured even with 130km/h never more than 68°C inside the drive.
The last 15km were in the city with 80km/h max, i recorded some statistics, as you can see.
The temprature was never above 60°C and dropped very fast when i slow down, or stop.

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A fun tool, in my view

Update for the drive!
After a bit more than 400km, i checked the Lockwasher and if everything is still tight.
Looks good so far, nothing got loose

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Furthermore i checked the Oil of the drive again after 210km and still got some metal dust on the magnet.

@Pete, this time i made pictures.
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The oil looks btw. darker, because of some additives i put in.

Greetings from Vienna
Havli

As I've said before, I fear your torque on the peg nuts is too high but where the metal filings are coming from and what, if any, damage is occurring I really can't say, or anything I did say would be guesswork.

I see your point!
Still hoping it will get better after a few km more.
If its still after 1000km, i will tear it down again and use less Nm.

Hope its okay, that i will post status now and then.
Maybe it can help someone else as well.

THX Pete!

Greetings
Havli