Identify 915 Gearset; count teeth? - Page 2

wprater · 05-12-2016, 08:55 PM

While I was checking out the bearing races in the differential cover, I looked inside and the flanges looked like they had some repair work done on them? What is that white epoxy on the sides (on either side of the "5")?

Matt Monson · 05-13-2016, 07:37 AM

Can you get a better picture from the side? I can't tell at all what is going on there.

KTL · 05-13-2016, 07:49 AM

That area by the 5 inside the diff housing is where the differential side bearing resides. What you're seeing there is the speedo sender "tone ring" that's mounted on the differential underneath the tapered roller bearing. That tone ring rotates around inside the diff housing and the epoxy you see there is what holds little magnets into the tone ring.

Matt Monson · 05-13-2016, 09:25 AM

Quote:

Originally Posted by KTL

That area by the 5 inside the diff housing is where the differential side bearing resides. What you're seeing there is the speedo sender "tone ring" that's mounted on the differential underneath the tapered roller bearing. That tone ring rotates around inside the diff housing and the epoxy you see there is what holds little magnets into the tone ring.

Aha. Thank you Kevin. I see it now that I am at my computer and not on a little phone. I didn't realize that the differential had not been pulled out of the gearbox.

Wprater, you will want to pull the diff out of there and inspect its bearings as well as the condition of the ring gear.

wprater · 05-13-2016, 10:27 AM

Quote:

Originally Posted by Matt Monson

Aha. Thank you Kevin. I see it now that I am at my computer and not on a little phone. I didn't realize that the differential had not been pulled out of the gearbox.

Wprater, you will want to pull the diff out of there and inspect its bearings as well as the condition of the ring gear.

I can check today. Was about to seal it up after this WEVO was in, just got my replacement gaskets.

I've seen using curil-t, copper sealant spray, and silicone sealant (no gasket). Thoughts from other experienced 915 gurus?

Been reading Zimmerman's tutorial again and I've had a hard time figuring out what year my gearbox is; making torque specs difficult to decipher.

wprater · 05-13-2016, 10:28 AM

Ah, realized I torqued down the shafts to diff housing already. Can I remove the flanges and inspect with them already installed?

Matt Monson · 05-13-2016, 10:38 AM

I wouldn't worry about it. I looked at your pinion and it looks pretty good. Usually the pinion goes bad before the ring gear. I just usually put the differential in and seal the sidecover last. Makes installing all the rest of the stuff simpler.

Earlier you said 80 sc. That's something like a 915/61. It is clearly aluminum. Just use the specs for 78-83 and you are fine.

Regards,

Matt

wprater · 05-13-2016, 10:41 AM

Thanks again for your input. I said 80SC as it matched that gear set. However this is a 78 SC RoW, kinda doubt it's a matching gearbox tho.

Matt Monson · 05-13-2016, 10:46 AM

There will be production dates on your gears. I thought that was how you figured 80 SC. Regardless 78 SC and 80 SC will have the same basic gearbox.

wprater · 05-13-2016, 02:16 PM

Got it. Looks like mine is an '81

Matt Monson · 05-13-2016, 02:55 PM

Most likely. That would be March of 1981 your mainshaft was made.

0396 · 05-14-2016, 10:43 AM

Not to question your expertise, but I can see 81, but where's the 3 hiding?

Matt Monson · 05-14-2016, 06:04 PM

Quote:

Originally Posted by 0396

Not to question your expertise, but I can see 81, but where's the 3 hiding?

Its a 10 , in front of the trademark. It's the week of production.

Matt Monson · 05-15-2016, 08:41 AM

I've been privately reminded my pm that while the transmission castings use a pro date with week and year the gears are month and year. That's an October 1981 gear making this a 1982 gearbox. Doesn't change anyymthung technical but I always want to make sure in giving accurate info for future readers.