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Topic: My Allison transmission is acting up  (Read 3810 times) previous topic - next topic

Re: My Allison transmission is acting up

Reply #40 –
Quote from: sfbmw –
Roland..

So what option are you taking..??? pull the transmission for an inspection or flush.??

Hans
I am taking the remove transmission and fix whatever needs to be done. They told me they would only replace and charge me for what needed to be replace. I inquired what a reman mission would cost, they found one for 8coach bucks but no core credit. Reman mission more than total labor cost. So I Opted to repair mine. I am happy that they will be installing a separate transmission cooler, no more issues with cross contamination. I contemplated driving with the transmission cooler bypassed and installing a xmission coole myself but decided I am better off letting them take care of it.

Roland

Re: My Allison transmission is acting up

Reply #41 –
As an aside to this thread, I called Joe Triana today he returned my call. Agrees that I stand a good chance of overheating the xmission driving without a cooler. Re-enforces my belief that we have good support in NAC for a 20+ year old coach. How many SOB can make that claim? With all the issues I have had I would still would not have anything but a Foretravel.

Roland

Re: My Allison transmission is acting up

Reply #42 –
Roland, Thanks for sharing the details with us and Brett makes it clear that coolant is in the transmission and it sounds like internal exam is the best long term route. Good luck.

Re: My Allison transmission is acting up

Reply #43 –
Perhaps I will state what I will do differently: I absolutely would check with the closest Allison dealer for the price on an Allison factory reman.  Then have the dealer where the coach is located install and THROUGHLY flush the lines.

I still don't know what accumulator you are talking about, but either James Triana or Allison could certainly address that.

And, I would have the radiator repaired or replaced.  External transmission oil coolers  can easily OVER-cool in cold temperatures.  You don't want ATF really hot OR really cold.

And, for those who want to add an external oil cooler, Hayden and many others make them in enough different sizes to accommodate your transmission.  I would install it BEFORE the in-radiator cooler,  That way, if in very cold temperatures, at least it would have a chance to warm slightly.  A better solution IMO would be to have ball valves that would allow you to send ATF through the extra cooler in the summer and straight to the radiator cooler in winter.

Brett

Re: My Allison transmission is acting up

Reply #44 –
Quote from: wolfe10 –
Perhaps I will state what I will do differently: I absolutely would check with the closest Allison dealer for the price on an Allison factory reman.

Brett
I am at an Allison dealer. They searched for a replacement cooler (what I was calling the accumulator, my error) without any success. They did price out a reman Allison at $8'000 with no core credit. Decided to fix mine instead, my choice. The separate cooler will be mounted in the engine compartment and that may mitigate the excess cooling. In any case this was the Allison dealer's recommendation and I went with it.

Roland

Re: My Allison transmission is acting up

Reply #45 –
Roland,

Replacing my lift pump yesterday, I looked down and thought "hmmmm, what is that thing."  About 8" in diameter, hydraulic lines running in, coolant line connecting it to radiator, and realized it's an external closed loop transmission cooler, installed in radiator circuit.  So, it appears to me this is most likely the accumulator referred to in your posts.  Just a thought, if you can't find an exact replacement for that piece, it's a pretty standard item in the marine industry, commonly called a "gear cooler", gear being the transmission.  Items like this are spec'd by horspower, line size, corrosion resistance, and connection configuration. Hydraulic fluid flows through a loop inside, cooling water flows around loop, heat is transferred.  Most are cupro nickel as the cooling is by seawater. 

While I realize you've already got the solution figured out for your situation, I owe you an apology for questioning the existence of the accumulator.  If possible, don't junk this part.  It may well be repairable, I've got a guy who does these sort of things. 

Re: My Allison transmission is acting up

Reply #46 –
Chuck, if I understood correctly the shop is not going to remove the cooler, accumulator, or whatever that thing is called, they are just going to cap it off. Now in the event that they do remove it I will make sure that I keep the thing and see if it can be repaired.

Roland

Re: My Allison transmission is acting up

Reply #47 –
I believe FT replaced one when I was in Nac this jan on a friends coach it was 3,000 bucks. 

Re: My Allison transmission is acting up

Reply #48 –
John, when I called NAC they did not have any for my coach. Told me they had been discontinued by Allison. The Allison dealer in Hagerstown could not find any replacement parts either. Don't believe they searched any marine industry applications though, but didn't know about that back then. I did find a couple on e-Bay but the bidding was closed and the parts were no longer available. Unfortunately, my contribution to the Hagerstown economy is going to be a bit more than three coach bucks. :(

Roland

Re: My Allison transmission is acting up

Reply #49 –
I will check and see but I think it was a transmission cooler. They thought they would have to retrofit it but it fit in.

Re: My Allison transmission is acting up

Reply #50 –
A bit late in posting this. Called Truck Ent. in Hagerstown Maryland on Monday and they told me the transmission had been removed and was being rebuilt. Hope to pick up the rig at the nd of this week. Being "homeless" is the pits, DW doesn't like pushing a grocery cart around. :P

Roland

Re: My Allison transmission is acting up

Reply #51 –
Quote from: Roland Begin –
I am taking the remove transmission and fix whatever needs to be done. They told me they would only replace and charge me for what needed to be replace. I inquired what a reman mission would cost, they found one for 8coach bucks but no core credit. Reman mission more than total labor cost. So I Opted to repair mine. I am happy that they will be installing a separate transmission cooler, no more issues with cross contamination. I contemplated driving with the transmission cooler bypassed and installing a xmission coole myself but decided I am better off letting them take care of it.

Roland
When all said and done...ask for the old parts they replaced.!!

Re: My Allison transmission is acting up

Reply #52 –
When asking for the old parts, you best be careful how you ask, you might get more than you wanted :o :o

Re: My Allison transmission is acting up

Reply #53 –
Quote from: sfbmw –
When all said and done...ask for the old parts they replaced.!!
If they have removed the transmission cooler I will certainly be asking for that as I may be able to get it "rebuilt". Or use it to find a replacement. As for the transmission solenoids, not so sure. Latest word is that the transmission has been rebuilt and they are installing the transmission cooler. Coach should be ready to pick up on Tuesday. Being "homeless" is for the birds. DW is getting tired of pushing the shopping cart. :P

Roland

Re: My Allison transmission is acting up

Reply #54 –
My transmission cooler is an intergral part of the engine radiator. It is built into the side of the radiator. When the tranny radiator failed, the tranny fluid was pushed into the engine coolant then out the overflow of the coolant reservoir and all over the side of our Jeep. When the engine was shut down the engine coolant was pushed into the tranny. Not a good thing.

OK here is the wrap up. I picked the coach up on Wednesday and got a chance to spend some time with the mechanic that did the fix. He removed the transmission and completely rebuilt it. He told me that just flushing the tranny after getting antifreeze in it was setting up a time bomb. That's why they highly recommended rebuilding versus only flushing.

The mechanic remotely mounted a new transmission cooler. The transmission cooler that he installed is one that is recommended by Allison and used in "big" trucks. His major "issues" were marrying the new transmission cooler to the existing engine cooling system. He had to make up couplings to bring the engine coolant through the tranny cooler. He also had to make up new hydraulic hoses for the tranny fluid. The system that he set up is the same as the systems in all our coaches except my tranny cooler is not mounted next to the radiator.

The next step was to flush the engine cooling system. Because the transmission cooler is still attached to the engine radiator, the mechanic made certain that the old transmission cooler was also flushed out. He the "capped" off the input and output ports of the original tranny cooler.

He then filled the tranny with transsyn and the engine cooling system with antifreeze. And Voila, we are no longer homeless.

I drove the coach from Hagerstown Maryland to Farmington Maine watching the engine and tranny temps. Everything was normal. Engine temp right around 180, tranny temp right around the same, just like it had always been.

I would have included "piccys" but it be raining here in Maine. Will try to post photos later to close out this thread.

Roland

Re: My Allison transmission is acting up

Reply #55 –
Glad to hear that you're back on the road and everything works as it should. 

Re: My Allison transmission is acting up

Reply #56 –
Great news Roland! Glad you're rolling again. :)

see ya
ken

Re: My Allison transmission is acting up

Reply #57 –
Yes, glad to hear you are on the road again. Probably not a cheap fix but food for thought for the rest of us. While our 6V-92TA does not have a trans cooler in the radiator, it does have a different style of transmission cooler where engine coolant could mix with AFT in case of a failure. Wondering now if our type has any history of failures. Will have to look that one up.

Think you did the wise option by going to an external cooler. Otherwise, it would have been constantly in the back of your mind.

Pierce

Re: My Allison transmission is acting up

Reply #58 –
I am glad that I got a chance to spend some time with the mechanic that also gave me "peace of mind". Although these folks do not work on a lot of RVs, he has thirty years of experience with transmissions. Would not hesitate to go to. Truck Enterprises of Hagerstown for transmission work. They are also a Cummins dealer though not in the Power Club group.

Roland

Re: My Allison transmission is acting up

Reply #59 –
Just a note about transmission coolers, on the 8V-DDC engine there is space to mount the DDC TRANS COOLER it fits beside the oil cooler, mounts on block and works great.  On the shorter 6V series, there is no room for the cooler, so the heat exchanger in the bottom hose is required and they work fine.