How long will these splines last?

[mossy173]

I cracked open the final drive of a fix-up project '87 K75, and the splines are definitely showing some wear. 

In the experience of folks here, how many miles are left on these splines?

[orforester]

I am by far not in a position to tell you how long they will last, but they look pretty worn out.  Makes me wonder what the clutch splines look like?  And driveline?  I would say it is time to search CL or FleaBay for a replacement and carry it handy.  Johnny always seems to have final drive spares and failures! 

[johnny]

when whacking the throttle on a regular basis something is gonna wear out...  tiors drive shafts final drives...

i gotts 2 sets of spare wheels with new tiors... 2 full spare drive shafts... 2 spare final drives... all ready to go...

i say lube it up and commence to whacking and have spares ready to go...

j o

[TX brick]

My 91 75RT had 30,000 miles when I bought it. The splines looked like yours. I started lubing the splines with Honda MOLY 60 every time the rear wheel was off. At 60,000 miles they were worse and I sent them off to Bruno for repair. I have since used Guarddog 525 grease.

[TimTyler]

i say lube it up and commence to whacking and have spares ready to go...

Yes.

[mossy173]

My 91 75RT had 30,000 miles when I bought it. The splines looked like yours. I started lubing the splines with Honda MOLY 60 every time the rear wheel was off. At 60,000 miles they were worse and I sent them off to Bruno for repair. I have since used Guarddog 525 grease.

Gosh, if that means I have 30,000 miles on these splines left I'll be a happy camper.  Will I know they're on their last legs, or does this sort of thing tend to fail suddenly and completely, stranding me wherever I am?

[TimTyler]

....stranding me wherever I am?

Yes.

[mossy173]

Ok, I'm good to go.  Thanks, this is very helpful!

[mw074]

What does the driveshaft look like? It may be to your advantage to fix it now.

[mossy173]

What does the driveshaft look like? It may be to your advantage to fix it now.

I haven't had it out yet.  What are red flags, other than these splines?  Play in the U-joint?

[kioolt]

I think you will wear out at least two new rear tires before those splines fail.  I say lube it and go.  Check it at every tire change.  That's what I do with my 91 K100LT.