Important parts issue. (cross post from Samba)

[raygreenwood]

I thought this thread might be important to those type 4 owners who do not occasionally visit the Samba.

Ray


http://www.thesamba.com/vw/forum/viewto ... 59#6676359

[doc]

Nice post. Hope those with skin in the game find it.

doc

[raygreenwood]

Thanks....This is a REAL problem. Of the three 004 gear boxes I have on hand...this one has the most "damage". Its fixable but also its worth destroying if need be... to find the last ins and outs and documenting them for others.

I am not actually doing the rebuild until July. I am sourcing parts and bearings right now. I am photgraphing everything...and will post it online in e-zine/flip page fashion.

The two important keys to get across to people concerning these transmissions are:

1. If there is any even moderate wear to either of the pinion bearings...you must replace both of them. Why?...because of the opposing nature of the two bearings and their location within the cast steel pinion carrier....unique to this transmisson and rarely found in any other type....you cannot remove either without damaging the other to some extent....unlessyou have a lareg amount of specialized equipment. And..with the rarity of these units...it would be foolish to leave a bearing with wear in a transmission this hard to find.

2. Unless I can find an answer or a cross match to this bearing....we will have to live with the specialized bearinsg that it came with.....which are not maufactured....have not been maufactured for maybe 30 years.....and will only be available by lucky finds on old dusty shelves.

I am exploring having the pinion gear shaft end lapped. I can do that between a set of live centers. That would allow the poinion gear end to use the more standard bearing....readily available. It needs to be lapped down by about .0018".

However...the bearing opposite cannot have its shaft poistion lapped down...because there are four sets of splines between the shaft seating position of this bearing and the end of the shaft it slips over.

So i am exploring having the inner bore of the bearing precision lapped or grund with a diamond. hone. It would suffice to have .0018" removed....and like the other end....could now use the readily available bearing that comes with the race normally.

Bear in mind that the bearings are hardeneded..and teh shaft is case hardened.

I might repost the whole thread here so people dont have to jump around.

Ray

[raygreenwood]

This is a very worthwhile PDF from Timkin....all pictures....showing diagnosing tapered roller bearing damage. I am also photographing the collection I have to show what should be replaced and what should be reused.

http://www.timken.com/en-us/products/ma ... s/6347.pdf


Ray