Lat week as we were headed into Brunswick Maryland to park for the weekend the Allison shifted real hard when going from second down to fist. I checked the fluid with the engine running and no sign of fluid. Oh crap what now. Parked and let everything settle, added as couple quarts and the level looked a bit low but acceptable, cold. Checked under the rig and couldn't see any leaks. Started out this AM drove 3/4 mile in first gear checked fluid and nada on the dip stick. Back to the campground. Going to be towed tomorrow to an Allison dealer in Hagerstown to check stuff out. I check my oil level in the Cummins and it may be my imagination but it seemed to be "overfull". wasn't before. Can transmission fluid find it's way into the engine? Still can't see any signs of leaking under the coach but the stuff has to be going somewhere.
Roland
Roland, you may want to check transmission fluid level at the keypad. On ours, press ^ and v at the same time. The transmission must be at operating temperature and the engine at idle. The transmission will go into a countdown mode to let fluid settle, then show values for quarts high or quarts low.
Best wishes for a simple solution.
Roland,
My coach had an oil to water transmission oil cooler.
Have you checked your coolent for signs of oil?
On 1993 Allison MD3060, there is no "check fluid level from the shift pad".
That feature was added later.
Your transmission cooler is in the radiator. So, if transmission fluid loss, it would not be in the engine oil, but in the engine coolant.
I think John and Brett may have it right. Another thing that happened to me on this leg,I had a lot of coolant leak out of the reservoir tank all over the side of the car. I assumed that I needed a new reservoir never thought the two may be connected. Will follow up with a post once this gets diagnosed and repaired. My appointment is with Truck Enterprises in Hagerstown Maryland,found them on the Allison website. Anyone have any experience with them.
Roland
If you need a new Radiator, Keystone is an authorized service center and is probably 10 miles from you at exit one on I81
Thanks John will keep that in mind.
Roland
Also there is a allison detroit place in Manassas about 80 miles from you or so.
Finally got the rig to the shop in Hagerstown, however they will not get to it until tomorrow afternoon. We have Sampson with us so the motel accommodations are a bit limited. Such is life. The tow truck drive did not have a 1 1/2 inch socket to remove the axles,and neither did I. you better believe that I will have that size socket in my tool,box after this experience.
Roland
To get to the plate that is removed to access the axle you first have to remove the chrome "hubcap?". It is really removing the nuts for the outside dually. I did not have the proper socket and neither did the driver, although we both swore it would never happen again.
Roland
Dave,
You are quite correct as I was thinking the same thing, however, you can't get to the axle nuts unless you remove the big chrome cover held down by EVERY OTHER 1 1/2" wheel nut. Roland also needs to buy a "flip" socket or he won't be able to remove the inside dual. Since we have the same year, the attached flip socket is the one. In case the specs can't be read, the inside stud takes a 13/16" square drive. That's why they call it a flip socket. Flip it over, put the extension in and off comes the stud (unless it breaks off).
Good to tell the towing service that it is a large RV so they send the right driver.
Attached is what I use. The long pipe is not in the photo and the "Big Bertha" 1" impact can be seen in the background (with the red cap on the quick connect).
Pierce
The inside dually doesn't have to be removes for access to the axle does it?
Roland
No, no tire has to be removed, just the chrome cover to get to the axle fastners.
Good to buy the plastic hub covers ahead of time or pull one axle, use a piece of cardboard as a template and then make a couple of covers from plastic, plywood etc. Be sure to pull both axles to tow not one like the lazy tow truck drivers want to do.
Pierce
I forgot the biggest consideration. One side of the coach has left hand threads. Nuts are marked. Bad to forget!
Pierce
I too have the plastic screw on caps so do not need to remove a "chrome cover and every other nut" so my comment is removed.
JohnH
The problem has been diagnosed as an accumulator tank failure. Engine coolant did make its way into the transmission, so they have to remove the transmission and fix whatever got messed up by the antifreeze. That may be the easy part as the accumulator tank is not available any more, at least there aren't any in Nacogdoches. The saga continues.I am wondering if it would be a good idea to replace the radiator at the same time. Might make it easier to repair?
Roland
Roland,
Clearly, you need to determine the source of the "crossover" between ATF and coolant and fix that. Yes, the radiator is the "first suspect".
FT gets there radiator from Atlas in Texas or did for our model years.
Hopefully the Transmission will be ok as Trans oil and coolant/antifreeze are a definite no-no together. It seems the coolant ruins the plates etc.
Sounds like lots of coach Bucks to me!!!
Good luck.
JohnH
Cannot seem to locate an accumulator, and not sure these folks are interested in modifying to install an inter cooler. Is it possible to bypass the accumulator and drive the coach until I can get to where I can install an inter cooler for the transmission? I know I would have to watch the transmission temperatures, but I do that now in any case. Just wondering if it is possible to run for a distance without the accumulator.
Roland
Roland,
An accumulator and an intercooler are two different things.
I don 't think I have ever seen an accumulator in a transmission oil cooling circuit.
Do you see two transmission oil lines going to the bottom of the radiator?
If you do that's where the intercooler is located in the radiator.
If so then the radiator needs to come out and be repaired or replaced.
Decisions $ decisions $!!!
John guess I am not using the proper terminology. The accumulator is attached to the engine radiator and that is used to cool the transmission fluid. This part is not available. My thought was to reroute the transmission coolant lines to a separately mounted "radiator" with a separate fan to cool the transmission fluid. The folks here are not keen on modifying hence my question on wether it is feasible to run a bit bypassing the accumulator so I can do it myself.
Roland
I don't think you could go very far without over heating the transmission.
A call to Allison might help.
Roland,
Nothing wrong with your idea. Race cars cool conventional transaxles with external oil coolers all the time. Would have to be a rugged unit with well engineered mounts, etc. Heat is the biggest enemy of automatic transmissions with their lifespan dropping dramatically once the temp gets too warm. In other words, the little transmission coolers you see at Autozone won't do the trick.
Here is something to look at but would want to contact B&M to see how one of their products matches up to the liter per minute flow rate required by the Allison. New B M Hi Tek Automatic Transmission Oil Cooling System Cooler Free Shipping HN (http://www.ebay.com/itm/NEW-B-M-Hi-Tek-Automatic-Transmission-Oil-Cooling-System-Cooler-Free-Shipping-hn-/301195682582?pt=Motors_Car_Truck_Parts_Accessories&hash=item4620a96316&vxp=mtr)
B&M has been a leader in racing and HD automatic transmissions modifications for as long as I can remember. Here is their website: B&M HOME ยป B&M (http://www.bmracing.com/)
Pierce
Roland,
Sounds like what you're wanting to know is if it would be possible to disconnect the lines from the transmission to the cooling coil inside the radiator, tie them together, and drive the coach without a trans cooler. Since your radiator is also full of tranny oil, it would need to be dealt with and a line installed across the abandoned couplings for trans oil. Maybe others more knowledgeable will know the answer to that, but you for sure won't want to drive it any further with contaminated ATF in the tranny. One can always hope that a flush and new fluid will show the trans is ok. Hopefully all you need is some cleanup and a new radiator.
How about it....is it feasible to drive the coach without a transmission cooler? Anyone know?
I hope I'm not violating a forum policy here, but there has been, in the past, an Allison fluid engineer on the IRV2 forum. I believe he has shown up on this forum also, a very knowledgeable guy. Might give a shout out to him....Tom I believe.
Chuck, the dealer here said that they had to remove the tranny, they are certain the the solinoids will need attentions as well sat the plates. The engine coolant will also have to be flushed etc. However they won't start the process unless they have all the parts. Kinda don't blame them as the coach will then be occupying a bay and they are a busy outfit. That is the reason for my driving sans accumulator until I can install a transmission cooler. Would not let the temps go over two hundred, but I wonder if it feasible.
Roland
Chuck,
Again, heat is the enemy here and torque converter slippage at idle and first gear will create a lot of heat. Roland has lockup half of second and all of third and fourth so the heat generated will be much less but still there. I watch my trans temp like a hawk.
No, you can't drive without a tranny cooler and expect the Allison to live.
Pierce
Roland,
Trying to read between the lines here. Are you thinking of putting the lines together and perhaps driving to another shop? Or, do you want to get it fixed leaving the radiator alone with the AT lines directly connected to get somewhere to then install a separate cooler? With ATF in the coolant and probably vice versa, both issues should be addressed before any drive. Then you could drive the vehicle to another shop for cooler installation but not to another city in summer heat.
Pierce
Was thinking of getting it fixed, bypassing the accumulator, and driving it to where I or someone can install a transmission cooler. Not sure there is a shop in the immediate area that would install a cooler.
Roland
OK, then contact someone like B&M to see how feasible a separate cooler would be. They have the experience to tell you how far and under what conditions you can drive the coach without a cooler installed.
Pierce
Just got back from the shop. They could not find the original part or a substitute part for the accumulator. They did however search for a separate transmission cooler and have come up with a cooler that will work with the Allison. Got a quote for parts :o :o 5 coach bucks, waiting for the labor quote. Guess when I went to the shop yesterday they were extremely busy and kinda short with me so I got the impression that they did not want to modify. They will not get the parts until the end of next week sometime, don't think I can stay in a Motel 6 that long and maintain my sanity. Going to continue our journey in the toad and come back when the coach is ready.
Roland
Have you priced a genuine Allison reman transmission?
Brett, haven't priced the reman transmission, but a big part of the parts cost was for the transmission cooler and associated hydraulic hoses. Will ask though when they call as that might make a difference in total cost.
Roland
Has the fluid been drained from the transmission and checked for contamination? I'd sure do this before tearing into it. It could be that it is not contaminated, or that it's an insignificant amount, could be the filters caught it. After all, sounds like your ATF has been blowing into the radiator, and level dropping in the trans. Other than a hard shift, wasn't the trans working? I'd sure do some checking before committing to a trans tear down or replacement.
What or where is this accumulator? Maybe I'm wrong but the only one I'm aware of is on the retarder, a hydraulic unit.
Sounds like this is getting out of hand for a transmission cooler leak. I'm thinking more like Chuck. Have you seen any coolant in the transmission fluid?
Pierce
Roland, I have been reading your dilemma. Your coach is different than ours, so the terminology is not clear to me.
We have a transmission retarder which has an Allison accumulator that activates the retarder and it is not related to cooling. We also have a transmission cooler that flows transmission fluid from and to transmission, and to remove heat from transmission fluid, the cooler also has engine coolant flowing in and out, but the two fluids are not in contact with each other. I can see that if the cooler insides deteriorate they could allow engine coolant to flow to transmission and vice versa.
Do you have a retarder and if not, is the 'accumulator' your transmission cooler? And is the Cummins shop installing an air cooled transmission cooler.or another type of engine coolant - transmission fluid cooler?
I have heard that our type of accumulator and our transmission cooler may no longer be available, so we all could face similar issues.
Good luck.
Chuck makes sense on not having coolant in the transmission, because the transmission fluid pressures are probably much higher than the coolant, which tops out about 15 PSI, limited by radiator cap setting.
1. The transmission fluid is contaminated. The shop took fluid out of the tranny and it was colored like my antifreeze. So although a lot of tranny fluid wound up in the antifreeze for the engine there was some "cross contamination". Shop says only way to assess what needs to be done is to look inside. They will only replace what needs to be replaced. They do not feel that merely flushing the tranny is the appropriate approach although they did give me that option.
1a. The tranny was shifting OK but was a real slam shifting down to first gear. I had to add three quarts of fluid before it was visible on the stick without the engine running. With the engine running it "disappeared".
2. I called the parts department In NAC and described my issue. They said it sounded like a bad transmission cooler. The part number they gave me 29506669 is described as an accumulator. The shop here says that us an incorrect part number as it mounts on the side of the radiator whereas my defunct piece is on the bottom. The Allison shop cannot find a new cooler for my tranny, it is no longer manufactured and there is no replacement therefore they will install a separate tranny cooler.
3. I do not have a retarder so perhaps "accumulator" is not an appropriate description of the bad module. The bad module is my tranny cooler.
I hope this clears things up a bit.
Roland
Roland..
So what option are you taking..??? pull the transmission for an inspection or flush.??
Hans
Actually, a leak between transmission and coolant OFTEN does the following:
When driving, ATF is generally under more pressure so ATF gets into the coolant.
With engine off, ATF pressure drops to zero and the pressure cap on the coolant system gives the cooling system higher pressure, so coolant flows into the transmission.
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
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
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.
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
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
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.
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
I believe FT replaced one when I was in Nac this jan on a friends coach it was 3,000 bucks.
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
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.
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
When all said and done...ask for the old parts they replaced.!!
When asking for the old parts, you best be careful how you ask, you might get more than you wanted :o :o
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
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
Glad to hear that you're back on the road and everything works as it should.
Great news Roland! Glad you're rolling again. :)
see ya
ken
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
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
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.
On the side radiator U300s, the trans cooler is just forward of the muffler on the driver's side (opposite side from radiator) with the big bottom flex coolant hose going into it.
Pierce
Here is a photo of the transmission cooler that was installed by Truck enterprises of Maryland. The cooler is mounted to the back rail of the coach. I have also included a photo of the old cooler, you can see the plugs that the mechanic installed in the transmission fluid input and output ports. Photos don't show the amount of labor that went into resolving this transmission cooler failure.
Roland
Here is a photo and link for the transmission cooler used by a U300/350HP side radiator. Looks just about like the one Roland had installed. They also make a straight through model. Before anyone gets too excited, it lists at $2624 and is "discounted" to $2152. The silicone coolant hoses are each about three feet long and must add several hundred to the total before the ATF fittings and hoses are included. Not a cheap installation.
Aside from the super HD construction, it does put the hoses on the opposite side from the radiator and there is enough room to fit another radiator to meet any additional HP addition.
Manufacture part number and photo at: 29541643-DF - COOLER PARTS & ASSEMBLIES - ALLISON MD/B400/3000RDS/T200 (http://www.defeomfg.com/allison-md-b400-3000rds-t200-series/cooler-parts-assemblies-63/29541643-df.html)
Price from supplier: Prom Contract - Excel (http://www.docstoc.com/docs/87234360/Prom-Contract---Excel)
Pierce
The cooler that was installed in my rig was $1600, plus shipping and handling of course.
Roland
Roland,
Seems like a more affordable price. You don't have the make/model do you?
Pierce
No, I looked at my invoice and the part number did not make sense. I was told however that it is the cooler that is recommended by Allison for my year and model.
Roalnd