Additional oil way for small block bevel drive

[Skiwi39]

I'm in the middle of replacing the pinion shaft bearings and have come across a few images and mentions of the suggested supplementary oilway that can be drilled in the bevel drive casing. There is plenty of mention of Check from Indiana's excellent article about it but I'm unable to find it on this site.

Can anyone post the link here? The inner bearing was showing definite wear, and the race had some minor, but visible pitting, so I'd like to do the mod.

Thanks and apologies for lack of website nouse!

JS

[Dirk_S]

From David Richardson’s Guzziology (worth the purchase for any Guzzi owner, but especially those with older models, available on Amazon and I believe on David’s own website), under the chapter Early small-twin lubrication update:

Early rear drives suffered premature pinion bearing wear. Guzzi revised the housing to alleviate  the problem in 1987. Your housing can easily be modified to emulate the factory improvement.  With the rear drive drained and removed, pull out the pinion carrier that when in place couples  to the driveshaft (The part that looks like a thick black steel spacer between the swingarm and  rear drive). It may be stuck but can be pried out. Any free movement fore and aft of the pinion  shaft in the carrier indicates pinion bearing wear. You must replace the outer races as well as  the bearings themselves. Usually there is no need to re-shim the engagement of the ring-andpinion gear set (although it’s best to make sure) but the shaft’s end float must be checked. There  should be virtually no end float in the shaft but no bind either. This is determined by removing  one shim at a time from between the bearings until it’s perfect.  The housing must be drilled at point A to 5/16” (8mm). The spinning ring gear will then be able  to drive lube through this hole to the relieved area between the two bearings in the pinion carrier.  Drill so that the forward end falls into the area between the bearings.  Practically, it’s impossible to make the hole come out too far forward,  so aim as far forward as you can and it should come out all right.  The update is completed by modifying and repositioning the shim  between the rear-drive housing and its cover. The shim (B in the  illustration) is flipped over so that the wide area previously used for  sealing the breather chamber (Arrow C) at the top now faces forward.  This is done to help direct the gear lube into the new hole. The gasket  between the housing and the shim is positioned as before so as to seal  the breather chamber at the top. Using the housing as a pattern, the two  holes in the shim designated in the illustration as D must be enlarged to  align with the bolt holes.

Make sure to send David a dollar for the knowledge…or buy his book :)

Amazon link: https://a.co/d/gKEaupv
David’s website: https://www.daverichardson.biz/

[guzzisteve]

It IS on this Forum, I just got this info from Chuck cause I couldn't find it. He did the mod on a rebuild.  I also was doing this mod in 80's & 90's and had a paper on it that I could not find recently for another guy on GTM forum. I'll go get the thread Chuck sent me.

Here ya go----------------------

https://wildguzzi.com/forum/index.php?topic=99910.0

Thanks Dirk for putting info up from Guzziology

[Antietam Classic Cycle]

https://wildguzzi.com/forum/index.php?topic=89034.msg1410129#msg1410129  Unfortunately, all of the photos are gone. Here are a few of mine.

Passage drilled.






Shim flipped around to catch the oil and funnel it down the passage. A few of the bolt holes need to be altered.

[Kev m]

My bad, in my foggy morning getting I read this as modern smallblock....

[John A]

Another part of it is when using the level hole to check oil level, have the swingarm level. I just hang the rear from the ceiling or put the front wheel out the door where it’s lower .