Drive Shaft With Busted Teeth

[Steve S]

Mike,

 

This gear on the end of the shaft just slips into a coupler attached to one end of the pinion gear and is lubricated by the hypoid fluid in the final drive. That's why there is a seal to hold it in the coupler.

 

Rick

 

OK... I am now TOTALLY confused (which is a natural state for me).

 

If the gear on the rear of the shaft runs in hypoid oil, why is it reccomended to remove the shaft every tire change and coat it with a good coating of Moly grease that never comes off???

 

 

The hypoid oil constantly being circulated in the shaft coupling would make it a better lubricant. Adding a heavy grease in this area would deter the movement of hypoid oil to this component creating heat build-up. It seems to me that this would be self-defeating.

 

Somebody SAVVVEEEEEEEE MEEEEEEEE...

[KiteSquid]

The splines on my drive shaft has have shown signs of Gear Lube on them, just grease.

[Neil86]

Venture rear ends since 86 have used the rear end oil to lubricate the rear driveshaft spline....thats why theres an oil seal on the shaft. If you are greasing that spline, you'll block the oil holes as its a gravity feed.

Ventures from 83-85 relied on greasing of the rear shaft splines to prevent wearing out.

[Jinksy4]

Rick - Thanks for the input. The final drive was not making any noise, that I could tell, before disassembly - that's what is making this episode so weird. I can see some wear marks on the pinion, but it doesn't look bad. I am going to try and get some pictures of the gear coupling wear tomorrow - doubt that I can get a good shot of the pinion. It rotates smooth with no binding or grating, but probably wouldn't make noise without a load.

 

Is your concern with just the condition or wear of the pinion or a combo of things in the drive?

 

Here are the pictures (see below):

 

I have to change my observation about the spline wear on the pinion end of the drive shaft. The nearly new shaft (less than 100 miles) has machine finish on the top of the teeth and in the root. I thought they might have been ground when new and that would make the wear appear even worse, but some of the wear comes from wearing off the top of the machine marks. What I thought was cracking on top of the tooth is actually the original finish. I think the original drive shaft is suffering from tooth wear only - it wore past the heat treat depth into the soft flesh - no cracks - still junk though.

 

The pinion looks pretty good - I could not see any cracks, knicks, noise before disassembly, or deep wear depth in tooth face. It is wore to a shine on the tooth only. Need to know what a new one looks like to make sure on the wear, though.

 

The coupling looks good also. It appears to have even wear, if any, with what I can see. Many have stated that you should put a light coat of Moly 60 on the teeth and with mine at disassembly, it looked to have a heavy coat of grease that could have plugged the lube holes in the back of coupling - causing the drive shaft spline wear.

 

Any thoughts about any of this - from anyone?

[KiteSquid]

NOTE: all numbers listed below are the reference number of the part on page E2 of the parts catalogue available for free download from this site.

 

 

I don't think the holes in the rear of the Gear Coupling #10 is for Gear Oil to get into the Gear Coupling to lubricate the splines at the rear of the drive-shaft.

 

This part spins and centrifugal force would spin the Gear Lube away from the splines. Also if you look at the diagram, there is a bearing #8, bearing retainer #6, o-ring #7 and oil seal #9 between the gear coupling and the splashing gear lube coming off of the ring gear.

 

 

When I removed my drive-shaft for the first time, all that was on the rear splines and in the gear coupling was the, IMHO substandard lithium soap grease that Yamaha installed in the factory, now replaced with Honda Moly60 Paste. The slot like holes in the rear of the gear coupler were open and clear upon dis-assembly and I used a light coat of Honda Moly60 Paste on the rear spline, so I don't think the holes will become fouled by the Honda Moly60 Paste.