Hot rear differential

[Beau-Kat]

Has anyone felt their rear differential after a ride to see how hot it gets.

 

I've never really paid attention to mine in my Millenium. I see that some of the older diffs have cooling fins on them, but the newer ones don't.

 

My issue:

 

I put a 2008 Venture rear (the whole pumpkin - after machining the hole in the boss for the shock and plugging the speedo sensor hole) into my 1998 VMax to lower the rpms. Seems to work well and I like the 500 or so lower rpms at highway speed. Gas mileage is better too.

 

But the diff seems to get pretty doggone hot to the touch after a ride. Now I know that I live in the south and it has been really hot lately. But I've had this bike since '99 and I didn't notice that heat with the original set-up. Could have been hot too, just never boticed it. I hear no cracking or creaking going on back there.

 

Do you think I have something discombobulated?

 

Any ideas?

[Beau-Kat]

O.K. As a follow up, I read some posts on a VMax forum.

 

Most of the guys talked about hot rear diffs on their VMaxs.

 

Many considered the specified rear axle nut torque to be too high and lowered the torque (some by quite a bit) and think their diffs run much cooler now.

 

Every time I have changed a rear tire on my VMax or Ventures, I stick with the recommended 110 ft/lb torque. Do y'all think that is too tight?

 

Any of you ever use a different spec for your rear axle nuts?

 

Rusty

[dingy]

Does your real wheel spin somewhat freely when off the ground & in neutral?

 

Gary

[Beau-Kat]

Yes:thumbsup2:

[dingy]

Yes:thumbsup2:

 

Everything should then be riding on the two bearings as intended.

 

Yes, 110 ft/lbs is a bunch of torque.

 

For giggles, you could try backing of the torque a little and see if the wheel spins any easier.

 

It's only going to cost you a cotter pin to see what effect it has.

 

Gary

[Squeeze]

The huge Torque is somewhat needed. If you look at all the Bearings involved, you'll see it's absolutely necessary to tighten the Combination of inner Races and Spacers together. If you ride with a loose Axle, the Bearings can't work as they should and it will cause premature wear and tear to the Bearings.

 

Riding in hot Weather at higher Speed for a longer Period of Time can cause the Temp to rise up to 160 F. Above that (Infrared Thermometer) there's a Problem Which you need to address. I'd recommend the Yammi final Drive Oil(9079E-SH001-00). It's not cheap, but it specifically designed to run with a high Power Engine and in hot Environment.

[dingy]

The huge Torque is somewhat needed. If you look at all the Bearings involved, you'll see it's absolutely necessary to tighten the Combination of inner Races and Spacers together. If you ride with a loose Axle, the Bearings can't work as they should and it will cause premature wear and tear to the Bearings.

 

 

Squeeze is absolutely correct in saying not to ride it with a loose rear axle.

 

My point in saying to loosen the axle a bit and see if it changes the rear wheel drag was related to the problems I had when I put the FJR rear end in my bike. The rear wheel would start to bind as I tightened the axle down. For a short period of time I put my stock rear end back in until I was shown what the problem was after posting on here about my struggles with it..

 

 

Gary

[Beau-Kat]

Squeeze is absolutely correct in saying not to ride it with a loose rear axle.

 

My point in saying to loosen the axle a bit and see if it changes the rear wheel drag was related to the problems I had when I put the FJR rear end in my bike. The rear wheel would start to bind as I tightened the axle down. For a short period of time I put my stock rear end back in until I was shown what the problem was after posting on here about my struggles with it..

 

 

Gary

 

So what was your problem when you installed the FJR rear end?

[Beau-Kat]

The huge Torque is somewhat needed. If you look at all the Bearings involved, you'll see it's absolutely necessary to tighten the Combination of inner Races and Spacers together. If you ride with a loose Axle, the Bearings can't work as they should and it will cause premature wear and tear to the Bearings.

 

Riding in hot Weather at higher Speed for a longer Period of Time can cause the Temp to rise up to 160 F. Above that (Infrared Thermometer) there's a Problem Which you need to address. I'd recommend the Yammi final Drive Oil(9079E-SH001-00). It's not cheap, but it specifically designed to run with a high Power Engine and in hot Environment.

 

Thanks Squeeze.

 

I don't have an infrared thermometer (yet...my birthday's next week.....

 

It's 70 degrees out this morning. I'm about to take about a 40 mile ride then see what the rear feels like when I stop.

[KiteSquid]

I would recommend using a GL-5 gear oil containing molybdenum disulfide.

 

Liqui Moly and Moltu are two brands I have seen.

 

 

http://www.liqui-moly.de/liquimoly/mediendb.nsf/gfx2/1516_200_100.jpg/$file/1516_200_100.jpg

 

 

http://shop.edoperformance.com/images/gearbox_80w90_small.jpg

[dingy]

So what was your problem when you installed the FJR rear end?

 

 

It was missing the about 2" long spacer that slides over axle.

 

On Vmax & FJR rear ends it is not pressed into housing like it is on Ventures, so I didn't get it when I bought rear end.

 

Gary

[Beau-Kat]

Aaahso, I can understand that. Spacers can be a very good thing.

 

Well, after my 40 mile ride this morning in 70 degree weather, my differential still feels hot.

 

Imma keep on researchin'

 

Thanks folks.

[Beau-Kat]

I would recommend using a GL-5 gear oil containing molybdenum disulfide.

 

Liqui Moly and Moltu are two brands I have seen.

 

 

http://www.liqui-moly.de/liquimoly/mediendb.nsf/gfx2/1516_200_100.jpg/$file/1516_200_100.jpg

 

 

http://shop.edoperformance.com/images/gearbox_80w90_small.jpg

 

Looks interesting. Where do you buy it?

[KiteSquid]

Good motorcycle shops (I am still looking for one)

 

 

OR online....

[Beau-Kat]

Thanks Squid