Transmission chain omission no more..

N

Naranja

New member
Location
Sweden
As I have no idea how old my triplex is I ordered a new one and opened the left panel and entered… Well inside I found that the oil pump gear had lost one tooth (1) since last years inspection. The marks on the big chain gear (3) I knew already . Question is if these (1 and 3) are normal wear or signs of something that need to be corrected? For example, the axial play (2) is about 0,35 mm. Not sure if this is critical. I also tried to check for free play in the rubbers behind big gears. It’s about 1 mm at the apex when holding the clutch drum and moving the big triple gears which doesn’t to me seem to be very much. Anyhow, greatful for your cunning inputs.

Also, my impact wrench is fixed to 450 NM would that be too much for tightening the crank nut ? I guess so but still hope it would be bearable. 🥶

Thanks
Axel
 

Attachments

  • IMG_0887.jpeg
    IMG_0887.jpeg
    172.2 KB · Views: 161
No impact wrench! A tool to hold the front sprocket can be made from scrap metal and a few bolts. And no I don't mean a tool to put between the sprockets which can break things. And find the missing sprocket tooth before you put it back together.
 
Pump gears shouldn't loose teeth. What happened to it?
Clutch rubbers need changing as they are still original.
Spring link on the triplex!
It needs taking to bits and checking by somebody competent.
Paul
 
I would dismantle the entire drive.
- open jesus nut (rattle drive is ok - but don't block crank on opposite side!)
- grind off the rivet heads and carefully remove the rivets once the clutch chainwheel is on your workbench
49859950463_a0587dbfc2_c.jpg


- change rubber dampers
- thread the rivet holes and use hex bolts w/o washers but with loctite instead

49860486141_156538f947_c.jpg

- check and change oil-pump gears (though why is a tooth missing is interesting enough)
- install your new chain and put back everything together

49886913773_be3b38d744_c.jpg
 
Last edited:
Enlargening your image Axel, shows there is not only a tooth missing from the pump gear, there is quite a large piece missing from the gears' circumference to the lightening bore. The markings on the clutch sprocket may have been caused by the chunck of gear lodging itself between chain and sprocket. The oil pump drive gear on the crankshaft also needs to be closely inspected, it's a wonder the pump turned at all...

piet
 
the chain is in almost every case (99.9%) endless and certainly when new exfactory, there is no real reason why you cant have a split link, as on some Tridents or Commandos, but the spring link realy must be on the correct way around, yours is not! (both those chains are much cheaper than from Laverda sources, and will fit the Laverda if you are competent enough to shorten them, because as supplied for Trident or Commando they are too long, (so you can retain triplex if that is your desire) most people are now using duplex on the inner two rows of teeth, two single chains have (largely) been proved inadequate.

and Jo!!! green gaskets??? and rivet heads ground off in situ???, please tell me that didnt happen, and if you cannot get dark grey gaskets, mail me and I will send you one FOC (one favour always deserves a return of the same)
CLEM
 
CLEMTOG said:
and Jo!!! green gaskets??? and rivet heads ground off in situ???, please tell me that didnt happen, and if you cannot get dark grey gaskets, mail me and I will send you one FOC (one favour always deserves a return of the same)
CLEM
Click to expand...

Hi Clem, yes, grinded in situ. Of course everything was carefully covered beforehand, worked perfectly. Green gasket was the old one, it was replaced. Pictures are from early 2000, now everything should stay as is (hopefully) a long time! But thanks for your offer anyway!
:D
 
Last edited:
Been using 2 single chains for many years, no issues. What's wrong with green gaskets? never had any problems with them.

Gerald
 
twin single chains do not wear at the same rate, so you could be driving on only one chain as the tightest one will take the load, and when one breaks, you do not stop but carry on spreading the swarf/metal from the broken one into and throughout the engine, I have seen three RGS engines that "lost drive" when the second chain broke, how long before that the frst chain broke is anyone guess, but for sure they didnt both break at exactly the same time, carnage was evident in all cases. (sorry about the pun)
CLEM
 
CLEMTOG said:
twin single chains do not wear at the same rate, so you could be driving on only one chain as the tightest one will take the load, and when one breaks, you do not stop but carry on spreading the swarf/metal from the broken one into and throughout the engine, I have seen three RGS engines that "lost drive" when the second chain broke, how long before that the frst chain broke is anyone guess, but for sure they didnt both break at exactly the same time, carnage was evident in all cases. (sorry about the pun)
CLEM
Click to expand...
Largely academic Clem.

There's loads of high mileage 1000SFC and RGS that have run individual chains on their special primary sprockets without issues from day #1. I'd wager on lack of maintenance or fitment of unsuitable chains causing premature failures. Both cannot be blamed on the actual design. The change interval of 25000km (for all types!!) seems to be largely ignored far and wide... just like oil change intervals.

Two individual chains actually have a slightly higher minimum breaking load than a duplex, 2 x 8900N vs. 16400N (06B-1 and 06B-2, both conforming to DIN8187).

piet
 
Paul Marx said:
And where are the missing bits of oil pump gear?
Paul
Click to expand...
Actually, that’s the first thing I noticed, hmm that little piece below the clutch drum looks somewhat familiar..Now back to its origin. Perfect fit (see pic) and I now look for some though glue 😁.

Thanks everyone for input, especially to Jo for an excellent tutorial. Pictures says more than words - very true. However, how did you get the rivets out of their hole after grinding?

Axel
 

Attachments

  • IMG_5797.jpg
    IMG_5797.jpg
    169.8 KB · Views: 56
Punching the rivets out.... Piet's recommendation is without doubt worth the trouble.... drill a hole down the middle out of the rivet, thus relieving the hold and forces between rivet and casting - making damage much less likely.
 
You must log in or register to reply here.
Back
Top