Extreme Transmission Leak

[bcaddel]

I am pretty sure it had Dextron III in it from the rebuild since it was/is bright red in color. I did read on one of the Allison web site that Allison recommends Dextron III,TranSynd (synthetic fluid I think), SAE 10W. SAE 15W-40, SAE 30, SAE 40 so I stuck with the Dextron III. I dont know what the Tranynd fluid looks or smells like so it could have had that in it. Do you think not having the filter changed could  have cause these problems?

[luvrbus]

Baddel, the transmission oil should have been changed before driving after setting that long the ATF with all the additives will become acidified after a long period of time that is why a rebuilt transmission will never have oil. I know Kim at Az Transmission some don't like him but he does turn out a good product give him a call before you take it to dealer and he may can answer your question.  

good luck

[bcaddel]

I never even thought of changing the fluid in the transmission, we did change the fuel filters and engine oil. Live and learn I guess. I am assuming after going through 10 gallons of fluid over the last few days that could that as a transmission fluid change??? I am reading that I need to get the filter changed also. I don't see a externial filter so I assume it is internal.

[makemineatwostroke]

bcaddel; install you a remote filter they don't cost that much and not hard to install you will save time and money you can buy the base and filter at NAPA.I wish the best for you but do not try and replace the gasket yourself that is not a diy  project you have the clutch pack to worry about falling out.      have a great evening

[JohnEd]

Bcad,

2stroke has me hands down on first hand info.  I guess the gasket is a bridge too far for us.

No, you have not changed the fluid.  It is a class problem in chemistry to find out how many times you have to replace 1 gallon in a ten gallon tank to get to 50% changed.  It is way more than you might think using common sense.  If all is well an automobile trans gets the pan oil changed but not the torque converter so it gets maybe a 20 percent change.  That "change" is expected to "rejuvenate" the rest of the fluid.  Some torque converters have a plug in them and you can drain the torque converter there.  I would expect the Allison to have a Torq drain plug but I don't know.  I do know that if you are advised to change the fluid a couple gallons in and out won't do that.  If you changed your as often as you indicate and with as much volume as you did you might be there.  Have the fluid analyzed.  You should do that on an annual basis anyway but with your problems I don't know if you should analyze it now or wait for the flush or?

[RickB]

Sorry about your misfortunes.... Just an idea. Why don't you try having a friend or your wife put the transmission in gear with either the parking brakes or the pedal brake engaged? Because the system will be pressurized maybe it might give you a clearer view of where it is leaking. Chock the wheels so you don't end up running over yourself of course.

Let us know what you find out

[buswarrior]

And, I'll add, stop driving it until this gets better identified.

Or you'll be buying a new one!

happy coaching!
buswarrior

[belfert]

If you do crawl under I would be sure not only to chock the wheels, but also block up the bus just in case an air bag or valve or something causes the suspension to drop.

[busshawg]

I don't believe it's your trans, not sure what it is but my guess is something simple. As mentioned by others , I'd try lots of other things before changing the trans. Could be as simple as the gasket.

Good Luck

[JohnEd]

MMa2S,

In another post here it was mentioned that the 4speed manual takes 40wt oil, same as the engine. Not the 4 speed Alison Auto.  I guess I got my 4 speeds confused. Sorry!   Almost the same though, right?  Nitpicker!

Thanks,

John

[NJT5047]

Allison approved 40 wt motor oil for HT740s.  Same as engine oil.  I don't use it, but it worked without issues.
Same for MCI power steering systems.  If it's brown, its motor oil.  If red, its Dexron. 
FWIW, I wouldn't go to the trouble of changing the transmission oil and filters if you have identified a housing gasket leaking. That's a waste of time and money. 
If you have not precisely visualized the leak, noting exactly where it's coming from would be the next step.
Identifying the leak's  exact location will allow you to call Allison dealers and get a quote without wasting time on diagnostics at the dealer.
You may wish to locate a service manual for your trans.  You might find that it's more 'doable' than you think...may not too.   A safe place to work beneath the bus will make the job much more doable. 
Good luck, JR

[makemineatwostroke]

JR, never said 40w wasn't approved but I have never seen it used here in the US maybe where it's a 140 in the shade but every manual I own states 30W no mention of 40W and the 30W has to be preheated at 32 degrees , and this guy does not want to pull the end plate off if he doesn't know what is involved.    have a great evening

[NJT5047]

JR, never said 40w wasn't approved but I have never seen it used here in the US maybe where it's a 140 in the shade but every manual I own states 30W no mention of 40W and the 30W has to be preheated at 32 degrees , and this guy does not want to pull the end plate off if he doesn't know what is involved.    have a great evening

Nope.  You didn't.   
I was actually responding to John's post...should'a made it clearer.  John was correct about the 40wt motor oil.   
I wasn't recommending 40 wt either.  Just offering up a useless factoid that it was an option under cetain circumstances. 
I tend to agree with you on DIY auto transmission projects, but, with a place to work, some assistance from any auto trans guy, and a manual that describes what special tools will be required..who knows.  Most DIY folk wouldn't get past the DS yoke/flange retaining nut.  Some will.
Unless one is pretty wealthy, dealing with an authorized Allison dealer could be a show stopper.     
Bcad will definitely want an estimate before allowing anyone to dink with his transmission.   He may well find that buying a good takeout and installing it is cheaper than allowing an authorized dealer to replace a gasket....I don't know.  But I would want to know the options (pitfalls?) and potential cost of repairs prior to the bus being rendered undrivable.
I think like a poor man...obviously not everyone approaches repairs as I do.   But losing control of the situation is what I wish to avoid.  The Allison tech sees a $24,000 commercial transmission in which all systems must be returned to proper working order irrespective of cost.       

Cheers, JR


 

[bcaddel]

Thanks for all the input and suggestions. I took Luvrbus's advice and called the place where our transmission was purchased AZ Transmissions & Engine Exchange. I talked to Kim there and he said ship the transmission back to him (if I can get it out from under the bus) or drive it back and he felt he would be able to fix it for under $1,000. After we talked and I described the severity of the leaks (a gallon an hour) he said it could very well be the gasket on the rear of the transmission.

I am thinking about purchasing a couple of 5 gallon containers of Dextron III and heading to Tucson (850 mi from Reno). I am still a working dude so it may take some doing to get off work for the wife and I but that may be what we do. I have also thought about going down to the Allison shop and talking with them about changing the gasket but no matter what they say I am quite confident once the transmission is apart there will be many additional charges that will be much more than the $1,000 it will cost in fuel and ATF fluid to drive to Tucson

Plus I have a new Jake Brake, Tow Bar and Tach that I am really anxious to get some miles on them all. I will keep you posted as to how we fix the problem and the trip if we make it.

[Don4107]

I would not count on the leak rate staying the same.  It could suddenly get much worse leaving you stranded or with a totaled tranny and a big tow bill. 

If the leak is just seepage from a non pressurized gasket, a careful cleaning of the exterior of the case and some good sealer might reduce or stop the loss of fluid until proper repair. 

I would be present when whoever pulls the leaking gasket to see if it was installed properly.  If not, the tranny shop that did the repair should stand behind it.

Good luck
Don 4107