Split boot for outer CV axle 10k success!

[MarkM]

Had my outer pass front CV boot fail. It had just happened so all the grease was still on there and no water.


After doing some measuring and then research I found the proper speedi boot for our 10k outer CV shafts. Quick install and repacked with grease provided. I like these speedi boots better than some others out there. Hopefully it will last and I believe it will. Very well thought out even down to the screws and nuts as the un-threaded shank keeps you from over tightening. Speedi boot #03662. Paid $26 bucks.

Mark

 

[Mogman]

Just make sure you have enough clearance, those things grow while spinning a bazillion RPM. I would expect that one to be out of balance in the exact wrong place where it would grow where you have the least clearance, these run almost twice the RPM as a "regular" half shaft , run it down the highway for a while and report back!!

 

[MarkM]

The pumpkins are a reg ratio in the HMMWV the portals rev up the system to handle the tall tires. With these diesels maxing out most of the time around 3k the boots should see a lot less rpms than boots in a car reving to 6k.

Mark

 

[Mogman]

The half shafts are turning twice as many RPMs as the tires, most vehicles the half shafts turn the same RPM as the tires has little to do with the engine RPMs
I have ripped up many half shaft boots on the ball joint stud on my DuraVee

 

[Coug]

The pumpkins are a reg ratio in the HMMWV the portals rev up the system to handle the tall tires. With these diesels maxing out most of the time around 3k the boots should see a lot less rpms than boots in a car reving to 6k.

Mark

engine revs are not directly related to the half shaft speed. half shaft speed is tied directly to tire rotation speed.

Doing a quick comparison, a 2001 honda civic tire (I picked a random small car for comparison) tire is about 24.5" diameter. It spins at 825 rotations per mile.
The 37+ military tire spins at 545 rotations per mile.
The geared hubs are about 1.9 to 1 ratio, so the halfshaft spins at 1035 rotations per mile.

So at identical speeds, the HMMWV halfshaft will be spinning at about 25% higher RPMs than it would be on a small passenger car.

 

[frauhansen]

For heaven's sake! Now they bring such a RedNack bungle as a legal product on the market. Where do you buy this shit in the States, at Wallmark next to the yogurt, extra cheap, the latest shit from China.

Sorry, I could not help myself now! The ball was in front of the goal!

 

[Mullaney]

For heaven's sake! Now they bring such a RedNack bungle as a legal product on the market. Where do you buy this shit in the States, at Wallmark next to the yogurt, extra cheap, the latest shit from China.

Sorry, I could not help myself now! The ball was in front of the goal!

.
I was pretty excited myself...
Until I saw the Made In China part.

Don't know why... Might be that they would love to kill us all. Could be a certain virus maybe?

 

[frauhansen]

This is not a virus. This is just classic botch. Packed with a barcode on the side!

 

[patracy]

The half shafts are turning twice as many RPMs as the tires, most vehicles the half shafts turn the same RPM as the tires has little to do with the engine RPMs
I have ripped up many half shaft boots on the ball joint stud on my DuraVee

55mph with a tire of 36" tall means 514 rpm. 514 x 1.92 gearboxes = 987 rpm for the half shafts.

That said, remember there's still the 3rd member between the half shafts and the transmission/engine. So I'll just use the base 2.41 ratio for the first trucks. That means the driveshaft/engine (without OD) would be 2378 at that speed. If you had 3.08's that would mean a driveshaft speed of 3040rpm. But the halfshaft speeds aren't nearly what the engine/driveshaft speeds are.

 

[MarkM]

55mph with a tire of 36" tall means 514 rpm. 514 x 1.92 gearboxes = 987 rpm for the half shafts.

That said, remember there's still the 3rd member between the half shafts and the transmission/engine. So I'll just use the base 2.41 ratio for the first trucks. That means the driveshaft/engine (without OD) would be 2378 at that speed. If you had 3.08's that would mean a driveshaft speed of 3040rpm. But the halfshaft speeds aren't nearly what the engine/driveshaft speeds are.

Forgetting the tire and the portal for a moment at 3k engine rpm and with the transmission in 3rd 1:1 and now we add in a 2.56 dif would not the CV shaft speed be 1172 rpms? I only simplified this as 3k would be the max rpm and given this the maximum rotational speed of a standard M998 with the three speed. Am I wrong here?

Mark

 

[patracy]

You are correct. I had it in my mind that 2.41 was the base ratio for the diffs. But it's 2.56. (There's also 2.73 and 3.08 )

But back to the half shaft speed, no, that wouldn't change. The gearboxes are 1.92.

 

[MarkM]

Thank you. I fail to see that our half shafts are running any faster than a reg trucks half shafts.

Mark

 

[MarkM]

If you add in the portal gearing you end up with a final ratio of 1.92:1 you end up with a final ratio of just less than 4.46:1. With 37" tires the math all works out.

 

[TOBASH]

Guys, differential gearing does not affect half shaft speed in this case.

Tire RPM gets multiplied by 1.92 to identify half shaft RPM. Diffs only affect engine/tranny/transfer case RPM.

Or am I missing something?

 

[MarkM]

With the engine ONLY at 3k rpms the CV shaft speed is around 1200 rpms. That is the only number I have been looking for. If you change the difs gear ratios the CV shaft speed will also change given the constant 3k engine rpm. The portal and the tire are after the fact as I was just looking at CV shaft rpms given the above parameters.

Mark

 

[Mogman]

I am just talking about experience not math, if you swing that shaft around I think you will find it is pretty close to the ball joint stud and that will change with the relatively high RPMs they spin at, might work just fine, why I asked for a test and report, that boot is obviously heavier on the side with the split so centrifugal force will drive that side, which has the least clearance outward farther than the rest of the boot.

 

[Milcommoguy]

If it gets him down the road who cares? In a pinch ?? OK ??

It's a band-aid with screws, CAMO

 

[frauhansen]

In the end, the speeds don't matter at all. Unbalance or not.
The stuff will never be leak-proof. And so it's a quick fix for on the road, but never a clean job that you would offer a customer.
And what I would not offer a customer as work I would never accept for myself.

 

[MarkM]

Never said this is a permanent fix for a broken boot. If a reg boot is good for 80k which seem to be the standard then even if I get half of that or even a quarter of that it would last me years. If it fails I will replace the shaft. Not trying to reinvent the wheel here as I was just looking for options of a quick adequate fix.

Mark

 

[frauhansen]

In this case, I'm with you. Even if I would never do this with me so. Because it will leak at some point. If necessary, it will never be tight.
But interesting to know that there is such a thing at all. I had never seen before.