Blown head gasket 8.9 liter near knoxville,TN

[Hellcat]

Great news glad your back on the road.

[NoGas]

That’s good news Paul. Missed this thread till just now. Went back and reviewed all…

Every year I run many of the highest mountain passes in the US in our M380. Yes, I use my Engine Brake (EB) and it’s NOT a Jake Brake! I prefer to think of it as a wimpy Jake. However our travel down those long-steep grades without using it would be extremely hazardous to the air brakes. Every year I inspect the brakes right before we leave on our Summer trip and every year I find little to no additional wear. Shortly after purchasing our M380 I discovered that its brakes had severe heat damage: https://www.wanderlodgeownersgroup.c...ad.php?t=39664 Post #2 has a link to my earlier 2015 WOG Brake Thread. The damage was heat caused. Lesson learned was one needs to minimize the heating caused by going down long grades. How I do that is described at the 30 sec point of this video: https://youtu.be/1PPCS8gb_9Q?si=5ZI0qyBLjIAn7Q37

I change my engine coolant every other year (24 mo schedule) as it does not accumulate enough mileage to use a mileage interval. I switched to basic NAPA Green a long time ago. Have you seen this video on switching?: https://youtu.be/aioolI-uxCs?si=kcUYWzHfRy3XMmUj DIY and my Maddox coolant changeout device from HF makes it a simple process - https://www.harborfreight.com/coolin...kit-64985.html

My coach had a full $22K engine rebuild at Salt Lake City UT Cummins shop by the PO, for a blown head gasket failure - just before I bought it. Was that due to 4th gear engagement at high speed? Who knows? But considering what he managed to do to the Brakes, it’s possible. Seems a pricy rebuild, but I have his 4 page work order to prove that’s what he did/paid. One of the first things I did on purchasing the coach was to have the Auto 4th gear function of the EB changed to 6th gear instead. The change wasn’t expensive. Sixth gear engagement made sense to me because most of the time I will already be running in 6th, and can then manually manage the down-gearing to keep my RPMs within desired ranges as my speed slows. For grades steeper than say 6% I use the Randy D technique at the top and start down SLOW in 3rd or even 2nd. The steepest grade this past year was 12%!

[golfster]

Originally Posted by Randy Dupree

the S60's would over rev the engine too,down shifting into 4th gear was not smart.
(before charm school i would have said "stupid")

I agree. I just went over Mounteagle, and the jack took it up to 2300 RPMs. I need to get it adjusted to drop to 5th instead of 4th. Does anybody know how to do that?

[Hellcat]

Badandy did mine at WOG 5th is so much better than 4th.

[Bikeboy57]

I know I don’t have a Wanderlodge, but my experience with the S60 and Allison 4000 may be pertinent.

I have been over and down Monteagle a number of times which I mention because it seems to be a common denominator in this thread. I have also descended Hwy 550 in Colorado into Ouray from Silverton.

Here is my learning. If start the top of the grade in 5th and on the jakes it will build speed that I have to scrub off with the service brakes. The key, as Randy has said, is to start at the top in the right gear. For example, on Monteagle, I start down in 3rd. It will not build speed in 3rd on the Jakes that it will build in 5th.

I came down into Ouray in 2nd. I never exceeded 20 mph. I touched the brakes twice to negotiate the two hairpins.

The point is that the lower gears keep the coach from building speed and over revving.

[Hellcat]

Originally Posted by Bikeboy57

I know I don’t have a Wanderlodge, but my experience with the S60 and Allison 4000 may be pertinent.

I have been over and down Monteagle a number of times which I mention because it seems to be a common denominator in this thread. I have also descended Hwy 550 in Colorado into Ouray from Silverton.

Here is my learning. If start the top of the grade in 5th and on the jakes it will build speed that I have to scrub off with the service brakes. The key, as Randy has said, is to start at the top in the right gear. For example, on Monteagle, I start down in 3rd. It will not build speed in 3rd on the Jakes that it will build in 5th.

I came down into Ouray in 2nd. I never exceeded 20 mph. I touched the brakes twice to negotiate the two hairpins.

The point is that the lower gears keep the coach from building speed and over revving.

I’m confused by your last statement. Wouldn’t a lower gear going down hill result in higher RPM’s? After my program change when the Jake is on in 5th my RPM’s are less. Just trying to understand.

[golfster]

It is a good point. I should start in 4th and let the jack hold the speed. I get that would work when I know mountains like Mounteagle, but when I don't know the hills, and I want the jack, I think it would be nice to have it drop to 5th instead of 4th. For the people who have it dropping to 5th, does that still hold your speed? If I dropped to 4th at the top on Mounteagle and had the Jack on high it would hold me at 45 MPH without hardly touching the brakes.

[Bikeboy57]

Doug,

It isn’t exactly intuitive. When I start in a lower gear at the top such as 3 or even 2, the speed never climbs and therefore the RPMS don’t climb.

But IF I start a 6% downhill grade in 5th, the speed will slowly climb to uncomfortable. Of course the RPMs climb with the speed, and I have to apply the brakes.

To get all geeky on you. Think of it this way. It is easier to think in terms of acceleration. The lower the gear ratio the more the torque is multiplied to the rear wheels. So lower gear means the torque the engine is producing is greater at the wheel. Assume the engine also has a maximum negative torque when the jakes are on maximum. So the lower the gear, the more negative torque is transferred to the drive wheels for braking.

[Hellcat]

Originally Posted by Bikeboy57

Doug,

It isn’t exactly intuitive. When I start in a lower gear at the top such as 3 or even 2, the speed never climbs and therefore the RPMS don’t climb.

But IF I start a 6% downhill grade in 5th, the speed will slowly climb to uncomfortable. Of course the RPMs climb with the speed, and I have to apply the brakes.

To get all geeky on you. Think of it this way. It is easier to think in terms of acceleration. The lower the gear ratio the more the torque is multiplied to the rear wheels. So lower gear means the torque the engine is producing is greater at the wheel. Assume the engine also has a maximum negative torque when the jakes are on maximum. So the lower the gear, the more negative torque is transferred to the drive wheels for braking.

Thanks I have always had a mental block on this. You made it easy to understand.

[Randy Dupree]

ssome of us have the jake set to 6th gear,not 5th or 4th.
i can always downshift by pushing the buttons on the shift pad.
Andy is here at my place,drive down and he can reset the shift for you.