quattro II

Hey Gentlemen, hoping some of you have experience with Bravo 1 drive clutches. Heres the skinny...My Buddies 1989 B1 drive has been producing dark oil, only problem is he has a marina do the winterizing for him and we are seing signs of them potentialy being untrustworthy, therefore, dont know what or when oil went in to it. Decided to open her up as we have nothing better to do this time of year, investigate and reseal. common suggestion for dirty oil was bearings, one person said slipping clutch because they are brass and can blacken oil if slipping... So.. to my mechanical eye, bearings are mint, gears are mint, clutches are not brass (only the fork and ring is) only thing bothering me is the inner surface of drive gear clutch which has a minor amount of scoring (10%). Cone does not look worn down.
Any educated thoughts on what clutch should look like, and how detrimental is the scoring. Should we stone it out and roll with it? Thanks guys John

FIXX

which style clutch do you have?if you look at the part thats between the gears that locks into the gears how many lines are on them? 3 or 6? 3 is old school and 6 is the updated ones..also it would not hurt to install a new fork,,would help lock it in gear harder..

quattro II

Thanx for the reply Fixall,
If you are questioning about the rings on the male part of the cone clutch, there are atleast 6 without counting them. I thought the same about the fork, but then realized that center shaft with the high helical thread is what pushes the cones together- the more torque, the more push, works in both directions. I think the fork just starts the engagement. One thought I have about the black oil is if the shifter is out of adjustment, the brass fork could be rubbing but there is not major wear. Have you had these apart and reused clutches? and what kind of wear did you notice?

JaayTeee

In regards to the black oil,
Have you taken the pinion gear off the input shaft ?

I've seen the pinion bearings loose their preload and
the washer that goes between the input shaft and the
front bearing will become loose and start to "machine" itself and and change the nice ( insert the color of gear oil you use) gear oil to black on more than 1 occasion.

quattro II

Thats interesting

Does the outer bearing race start to spin because we noticed polished marks on areas of the housing where the front bearing ( next to gear) sits. (just polished, not worn)

Mr Gadgets

That polished spot is due to the preload on the bearings going away and then front bearing is pushing on the case as the pinion gear attempts to turn the driven gear. On a LH drive the spot will be on the opposite side of the snout. Once that wear gets to a point where there is a ridge, it is hard to keep the pinion gear and bearings inline. As the preload starts to loosen up the thrust washer spins eating itself away and causing the preload to loosen more. Viscious circle..

What Fixxall was refering to was the number of vertical slots in the face of the cone. There are numerous Horizontal ridges but the old drives had cones with 3 slots around the face. The newer cones have 6 slots vertical to the horizontal ridges. If you have the old style, you should update..
They have changed the cone and shift forks and cams and springs over the years. After 2000 or so they went to the thick floored gears and use a different cone, fork, etc. They can't be used with the older style gears..
Hope this helps.
Dick