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Loud Bang

Yahoo Message Number: 79722
Hello Everyone,

I had just got back from Premier RV in Juncion City Oregon, where Gary and Brian had done a great job of taking care of a bunch of little repairs and some maintenance issues for me. Everything worked great. Parked for a couple of days and last week I headed to Mammoth Lakes CA to do some Fly Fishing.
On the way there I was only in 5th gear about 50 MPH because the people in our little RV train couldn't go any faster in the 25 MPH with 45 gust winds. As we came to a small town. I started slowing down and everything worked fine until the transmission shifted into 3rd gear. There was a very loud bang and the whole coach shook. It scared me.
I thought the driveline had blown or something. I didn't give it any gas but coasted to a stop and looked underneath and everything looked fine. I gingerly tried to accelerate and headed down the road and everything worked fine. The next small town heading up 395 I slowed down but the engine brake never came on and didn't have any problem.
The third small town I started slowing down, the engine brake was working and "Bam" another loud bang and shook the whole coach. I pulled over outside of town and tried to look at the motor mounts but it was 95 degrees outside and it was hot and hard to see.
It was mostly up hill from there and I just decided to keep going after Bishop up that big grade without the engine brake on.
I called a friend and he called an Allison Rep. The Allison rep said as best as he could tell, the transmission was getting a signal to disengage the torgue converter and loud bang was when it reengaged.
The next day when it was cooled down I crawled under and checked the motor mounts. They looked good. I had a friend get inside and power brake while I looked on and the mounts were fine.
I was afraid to drive it home since it was mostly down hill with two steep down grades one into Bishop CA from Mammoth and the other from Techapi down to Bakersfield. The rep said to manually put the transmission in 3rd and go down the grade. I did and everything worked fine.
From that point on I drove it like normal, 6 Cyl Enging Brake engaged, and everything worked fine all the way home. There wasn't anything for the Allison rep to see since the drive home had cleared the memory.

Anybody else ever have something like that happen to them?
Also, between Bishop and Mammoth Lakes, the little red plug in the Axle Oil resevoir popped out and leaked oil all over my front left Wheel. I put the plug back in and it worked fine all the way home. First time that has happened to me in 14,000 miles. only lost about 1/16" from the full line. Anybody ever have that happen to them?

Mark and Helen Surber
07 Intrigue 530 12162
C13 Cat Allison
06 Rubicon LJ

Re: Loud Bang

Reply #1 –
Yahoo Message Number: 79723
Apparently you haven't called the CAT Hot Line (877-777-3126). Why not call them and see if they have anything to contribute.

Lee (leozbrowski@...) 2007 Country Coach Intrigue 12153
CAT C-13

Re: Loud Bang

Reply #2 –
Yahoo Message Number: 79736
Lee,

I called a friend who put me in contact with the Allison rep after he called Quinn Cat. They said it was a transmission problem. I will call the CAT Hot Line and see what they say for myself. Thanks.

Re: Loud Bang

Reply #4 –
Yahoo Message Number: 79741
Hi Lee,

Fortunately for me I have not had the transmission situation you described, so sorry, I cannot offer any advice there.
Regarding the oil cap........... I believe what you experienced is a difference is air pressure that caused the cap to pop out. The cap should have a tiny hole in its' center, so that the air pressure can be automatically equalized as you climb or descend great elevations. I have had the cap pop out and I simply replaced it. Check the hole to make sure that it is not totally blocked. On one cap, I made sure that the hole was "open" using the point of a fine nail. Also, do NOT over fill the axle oil. Make sure that you stay between the two circular lines. If you over fill, as I once did, it will take a long, long time before the excess oil stops leaking out and making a mess of your aluminum wheel.

Good luck,

Denny Zarnt CC 2001 42' Affinity, Bed & Breakfast # 5972

Re: Loud Bang

Reply #5 –
Yahoo Message Number: 79742
Mark, I know this is a long shot, but I had an intermittent "loud bang" develop and it took me a while to figure it out. A lock nut on one of the two links that go from the frame to the ends of the front torsion bar came off. Occasionally the end of the link was coming u[ out of its hole when the coach leaned, then it would snap back into place causing a very disturbing bang. You likely have some other problem, but it's an easy check under the front end to see if the links to your torsion bar are properly fastened. Good luck, whatever the problem.

Stuart Thornton, 2005 Allure, #31217.

Re: Loud Bang

Reply #6 –
Yahoo Message Number: 79744
Denny, it is Mark and Helen Surber with these problems. Thanks anyway as I'm sure they will see your post.

Lee

Re: Loud Bang

Reply #7 –
Yahoo Message Number: 79746
Thanks guys I got it. That really makes sense. I will replace the cap. I only lost about 1/16 of an inch below the full line and still way above the add line.

What kind of oil does it take?
Mark

Re: Loud Bang

Reply #8 –
Yahoo Message Number: 79756
We also had a loud bang, especially when we hit a bump or slowed down and or stopped. Turns out that it was a broken bracket under the front attached to the sway bar. We found it by turning the wheel sharply to the side and you could see the u-bracket cracked and hanging by the bolts on either side. We took it to Tampa Spring (Tampa FL). They called for a part but no response and they decided to make a new one. We told them to replace both. The new ones look more sturdy. Very reasonable cost and labor. We also replaced the front shocks and will now replace the rear shocks and bushings.

Lonny & Diane Livingston
'04 Allure #31065
 

Re: Loud Bang

Reply #9 –
Yahoo Message Number: 79822
Lee,

Thanks for the info. I call the "CAT" hotline. Spoke to Doug. Very patient and nice guy, seemed very knowledgeable. Explained everything to him and he suggested that it was the torgue converter and to speak to Allison.

Mark & Helen Surber
07 Intrigue 12162
C13 Cat Allison
06 Rubicon LJ.