I have an Allison MT 647 Mechanical behind a 3208 Cat. It has been shifting fine. I drove it about an hour and a half this morning to a campground. It did not want to shift into 1st when I stopped to check in. I revved it up a little and got to the campsite. Now it won't shift in to 1st at all. It shifts into reverse fine. I did notice the trans temp ran about 245 which was higher (I think it has been running about 220 but it is hot here today) than it has been. The fluid is on the full mark. It SEEMS to smell a little burnt but not much and that may be my imagination. I'm getting paranoid!
Any suggestions? Ideas?
Thanks!
TOM
Hi;
Can you tell us what part of the country you are in? Maybe help is close by.
Merle.
Eastern Shore of Virginia. Little town called Temparenceville. There are aurthorised Allison shops in Salisbury, MD which is not that far away but I am hoping I can drive and not have to be towed.
Also, cell service is awful. I can get texts but that seems to be all.
four four three 52 won seven seven 6 ate
TOM
You have low main pressure Tom ? do you know how to check the pressure by removing the plug and installing a gauge
Clifford, no I don't and I only have minimal tools with me. I haven't had any mechanical troubles with this coach and was only going a couple hundred miles so I thought I could get away without a bunch of tools. That's what I get for thinking! I don't have a gauge either. However, would I still have good reverse with low pressure?
TOM
Yep it only affects the foward low gear
Thanks for the info!
Any thing I can do about it to limp home? If I rev engine is it possible to get it to shift to 2nd without major problems. If I have to go into the trans, it will have to either drive to my shop about 50 miles or be towed. If I have to get it towed I just as well call them tomorrow morning.
TOM
FYI, flat ground all the way. Need to at least get out of the campground. It will be a nightmare getting a wrecker in here.
TOM
http://allisonparts.net/Allison-Transmission-Parts-Tips.html
That might help
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Quote from: Zephod on August 17, 2017, 06:44:57 PM
http://allisonparts.net/Allison-Transmission-Parts-Tips.html (http://allisonparts.net/Allison-Transmission-Parts-Tips.html)
That might help
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Thanks for the link! I guess I will just see If I can get it to move tomorrow morning. Hopefully I can get it somewhere to rebuild the valve body if that is the problem. I'm still hoping for a temporary magic fix! LOL!
I hope it is a easy fix too Tom but the smell of burnt oil is not a good sign,245 is a little warm they run between 180 and 220.They can tell in few minutes with a pressure test where the problem is.If I was closer I would help you and it would only cost you crab-cakes :o
when was the last time the filters and oil were changed?
Quote from: luvrbus on August 17, 2017, 09:08:42 PM
I hope it is a easy fix too Tom but the smell of burnt oil is not a good sign,245 is a little warm they run between 180 and 220.They can tell in few minutes with a pressure test where the problem is.If I was closer I would help you and it would only cost you crab-cakes :o
I know you would help if you were closer and I not only appreciate that but all the help you (and the rest of the guys on here) have been. If you were closer I would buy the crabs cakes anyway....help or no. LOL! Once I get to the shop I will get the manual and pressure test it. I just didn't think I was gonna need hard core tools for a short run. :(
Last question (maybe): It never did stop moving completely, meaning I can rev it up and move in 1st. Any chance I can get it going fast enough to shift into 2nd? Maybe get back to my shop (50 miles)?
Lin: Supposedly all fluids and filters were changed when I bought it. I have put less than 5000 miles on it. I was gonna change it anyway this fall when I do seasonal maintenance. Would filters cause this?
Thanks!!!!
TOM
I'm curious about the burnt smell of fluid. Does that normally only mean burnt fluid b/c it got too hot or does it typically mean a catastrophic break down of the transmission.
Quote from: Branderson on August 18, 2017, 06:17:44 AM
I'm curious about the burnt smell of fluid. Does that normally only mean burnt fluid b/c it got too hot or does it typically mean a catastrophic break down of the transmission.
It has been my experience that once you see/smell burnt fluid it is usually too late. Damage done.
Was it just a faint hint of a burnt smell? Or was it a strong obvious odor and color? With only 5k on the oil and filter and being burnt would not give me a positive feeling, especially with the high temps.
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Sorry to say, Tom, but that is exactly what happened when our tranny went out. I distinctly remember hearing the rev, right before it wouldn't shift. It was a B500 and the Allison guys said that is when the final little bit of clutch went out. We needed a new tranny.
I hope it works out better for you.
John
First, Thanks for all the input and helpful comments!
Now for the rest of the story.
Since the campground would be a nightmare to get a wrecker/motor home out of, I figured I'd try to at least get out to the main road. Fortunately, the old girl made it about 10 miles. There is an old used car sales/junk yard lot with big, paved pull through entrance and exit en-route so I stopped there. I had noticed it was getting harder to start rolling every time I had to stop for a light or traffic. Also, the last time I had to stop, it didn't want to shift to the higher gears either. I checked the fluid again and it still has a good color. Also, it DOES have a slight burnt smell. Secondly, after squinting at the temp gauge and counting the little marks, I realize the actual high temperature was 230. I wish they would make gauges readable again like the ones we had in the 50's! Tranny still shifted into reverse fine.
I thought about calling for a wrecker again. My problem there was going to be how to get it backed into the spot by my house. Once we pulled the axles for the tow, we would have to install the axles setting in the roadway so I could back it into the drive. I can take it to the shop but that's an inconvenient 30 miles away. I then remembered having read on this board about people using the tow vehicle for power in a pinch. So I thought, why not try it?! The worst that can happen is I burn up another vehicle! ;D :o ;D
I called my son & got him to go to my house and pick up the '98 Yukon and towing paraphernalia. He showed up a couple of hours later and we hooked up every thing just like we were towing the Yukon. We plugged in our ear phones to our cell phone for constant communication and I, (using my best Captain's voice) commanded, "All ahead, dead slow!"
EUREKA! IT WORKS!
All worked like a charm! Acceleration was REAL slow but we got up to the 55 speed limit and made it home. the Yukon temp never got over 210, which is what the '07 Tahoe runs all the time with the same engine so I think all is well there. Got home, stopped in the road and unhooked the Yukon, and backed into the drive with no problems!
Now we can finish our eclipse mini-vacation with the grand kids. I'll start digging into the tranny next week. I'll probably need more help and suggestions on parts. We have three Allison shops locally. one doesn't do motor homes/buses, Freightliner has a terrible rep, and I would have to have Trump's money to go the the last one.
Clifford, how many crab cakes would it take to get you to Delaware? ;D ;D ;D
Thanks again to all for the help!
TOM
Sounds like it's time to learn how to pull an engine out of an MCI... Although my tranny shop told me they did an MCI and left the engine in, so I guess it can be done that way. Very sorry to hear of your troubles, and looking forward to finding out what happened, me with a brand new MT-647 and all!
Tom it sounds like you where at Tall Pines?
Quote from: longjohn on August 22, 2017, 07:28:41 AM
Tom it sounds like you where at Tall Pines?
Yes I was. Very nice place, grand kids had a blast.
TOM