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Title: Is my transmission toast?
Post by: H3Jim on January 02, 2011, 05:04:40 PM
1995 Prevost, B500 World transmission

When I push the R button, the left display changes to R, then the right one changes to R.  The engine will rev to redline with no connection to the rear wheels.

When I do the same with D, it does in fact move the bus forward.

I am hoping that there is some simple control, or wire that might be bad rather than a tranny rebuild.  I understand that a tranny rebuild might easily be in the neighborhood of $25k.  Just don't have that much right now.

Transmission fluid level is at the "full level when cold" and engine was on high idle for about 15 minutes.  Fluid does not smell bad, and looks clear on the dipstick.

Any ideas on things to check, or even better to get it to work again.  I may have to have it towed out of my driveway in order to drive it to the Prevost shop.  Certainly not usable like it is.


Title: Re: Is my transmission toast?
Post by: Busted Knuckle on January 02, 2011, 05:27:04 PM
Jim,
I certainly feel your pain as I had to replace one about this time last yr for different reasons though!

I wish I knew some answers for you but i don't.
I bet some of our more experienced guys here will have some ideas for you.
I wouldn't take it to the Prevost Shop though. I'd have it taken to the Allison Dealer. All Prevost will do is pull it out and take it to Allison for repair and put it back in or put in a rebuilt/remaned unit.
Might as well go straight to the source and cut out the middle man!
Good luck!
;D  BK  ;D


Title: Re: Is my transmission toast?
Post by: luvrbus on January 02, 2011, 05:28:34 PM
Jim, how far are you from Cerritos that is the best Allison shop in Ca was S&J Chevorlet now Penske Chevorlet call and talk to Bob Ware he is retried now but is in the shop on some days sound to me like electrial problem if you can get access to a ProLink check the codes btw the last I heard it was around 10 grand for a rebuild at S&J for the B500    


good luck  


Title: Re: Is my transmission toast?
Post by: stevet903 on January 02, 2011, 06:04:18 PM
Do you have any codes?  The procedure to get them is in the operators manual here:

http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=OM2157EN.pdf (http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=OM2157EN.pdf)

It also says that it will inhibit shifting if the engine is above idle or high idle is on, which it doesn't sound is happening since you can shift into drive.

Steve


Title: Re: Is my transmission toast?
Post by: Zeroclearance on January 02, 2011, 07:45:55 PM
Jim have you replaced the two filters lately?   Are you running synthetic oil?

I'd pull the filters to see what you have in the pleats..  How many miles are on the tranny?


Title: Re: Is my transmission toast?
Post by: niles500 on January 02, 2011, 08:23:09 PM
Unplug the ATEC from the power source for 10 minutes then reconnect and retry - HTH


Title: Re: Is my transmission toast?
Post by: H3Jim on January 02, 2011, 08:40:10 PM
Thx,

Almost all the miles on the bus are with synthetic oil in the tranny.  430,000 or so.  Filters changed two years ago.


Title: Re: Is my transmission toast?
Post by: H3Jim on January 02, 2011, 08:55:54 PM
about 2 1/2 hours from Cerritos, good to know about the Allison shop there.

I will check for codes tomorrow.

Removing power also sounds like a good idea.

The longer term history is when I came back from a trip, I got the bus stuck in my driveway - its a  new house and has not been paved.  there is a moderately steep hill, and the bus was stuck there for several weeks.  At first it was only because of the mud, but after the air leaked out, I could not release the parking brake, no air.  also the tag axle would not pump back up with air, and the kneeling system would not work.  having all the weight on the drives, with no tag support, lowered the back of the bus several inches, further putting it in the mud.  I was able to get it to go in reverse by putting it in drive first - even though the parking brake was on.  Still would not move an inch.  After I got the bus out and on level ground, the air system works fine now, but will not go into reverse.

Not sure if the air was a check valve, or even perhaps water in a tank that prevented air from flowing.  I discovered that if I let it completely air down over a week and a half, the first time it aired up, I had one shot to release the parking brake.  Then I took the fenders off and raised the suspension levers to lift the bus as high as the suspension would allow.  That was enough to get it moved.

So I think its likely that some tranny  logic was thwarted, and a reset might do it.


Title: Re: Is my transmission toast?
Post by: stevet903 on January 02, 2011, 09:26:59 PM
Here's a better code reading procedure along with the table to decipher them. 

http://prevostparts.volvo.com/technicalpublications/pdf/pa1107-05.pdf (http://prevostparts.volvo.com/technicalpublications/pdf/pa1107-05.pdf)

Do you get a check transmission light or a do not shift light?

Steve


Title: Re: Is my transmission toast?
Post by: belfert on January 03, 2011, 03:41:50 AM
In case you didn't know, Allison's suggested procedure to check the fluid level is run the vehicle until tranny is fully warmed up and then park on a flat surface and put the tranny in neutral.  Press the upshift and downshift buttons simultaneously.  The transmission shift pad will count down from 10 to 1 over several minutes.  At the end it will display OL and then Ok if the fluid level is good.

Unfortunately this doesn't help with why the B500 won't  go into reverse.


Title: Re: Is my transmission toast?
Post by: luvrbus on January 03, 2011, 06:33:22 AM
Jim if you got 430,000 miles from a B500 you did good most will last around 300,000 miles


good luck


Title: Re: Is my transmission toast?
Post by: H3Jim on January 03, 2011, 08:28:30 AM
There are no erro message such as Do Not Shift or Check Transmission.  It actually reads like its going into reverse.  They have one display that shows the gear selected, and the other shows which gear its in.  That display shows the R.

The rain is finally slowing a bit, I will get out there soon to do the hard reset on the brain.


Title: Re: Is my transmission toast?
Post by: H3Jim on January 03, 2011, 11:11:59 AM
Well rats, it pulled the plugs on the Allison ECU for 15 minutes and it still does not go into reverse.  Parking brake is acting up again too, won't release - although it does shift into 1st.


Title: Re: Is my transmission toast?
Post by: niles500 on January 03, 2011, 12:07:44 PM
I don't have a world tranny and therfore no troubleshooting info - but I might suggest cycling starting it and attempting to shift (back and forth from N to D to R) a number of times - has worked in the past for me - also here's the reset procedure (I believe?) - HTH

Reset Procedures (Fault Mode)
Some of the more minor or temporary transmission faults
that would initiate a CHECK TRANS telltale light may be able
to be cleared. The following reset procedures may be
performed to clear a minor or temporary problem or fault.
Even the more serious faults in the higher gear ranges may
possibly clear for emergency continuation of travel
The most common reset procedure requires that the
coach be brought to a complete stop at a safe location, apply
parking brake, shift transmission to (N), shut off the engine
and wait about 10 seconds before restarting.
However, in a severe fault situation, the transmission
could possibly remain in the neutral position during an
attempted reset procedure. The transmission will remain in
neutral until the telltale is cleared or reset. If the problem
cleared, the telltale should light during its normal selfdiag
nostic check and then go out, and the transmission should
operate in a normal manner.
NOTE: Before turning off the ignition or shifting transmis
sion into (N), again note that the transmission may be
operated for a short period of time while in the fault mode.
If the fault is of a serious or damaging type, the
transmission will not allow shifting into or out of (N). If the
condition is minor or temporary, the telltale will not come
back on and the transmission should operate normally. If
the condition is more serious, the telltale will again light
and the transmission may remain inhibited or operate in a
normal Manner. The type of operation permitted by the
ECM will depend on the type of problem or fault existing.
Clearing WTEC Pushbutton
To attempt a reset and with the selector in (N), simulta
neously press the UP" and DOWN" (symboled) arrow
buttons twice. Press and hold the MODE" button until a
tone is heard. Next, release the button to return to normal
operation.
Clearing WTEC Shift Lever
To attempt a reset and with the selector in (N), push the
DISPLAY MODE" button one time. If equipped with oil level
sensor, push button twice. Press and hold the MODE"
button until a tone is heard. Next, release the button to return
to normal operation.

P.S. - sorry I meant WTEC on prior post


Title: Re: Is my transmission toast?
Post by: niles500 on January 03, 2011, 12:11:27 PM
One more suggestion - before shifting or releasing the parking brake apply a hard service brake application and hold it while attempting to shift - HTH


Title: Re: Is my transmission toast?
Post by: robertglines1 on January 03, 2011, 12:29:03 PM
how far was it down? transmission wireplug wet-speed sensors in rear differential-air line tore loose? Good luck.


Title: Re: Is my transmission toast?
Post by: H3Jim on January 03, 2011, 01:07:45 PM
the far rear was down far, trailer hitch about 4" in the dirt.  I don't think the differential was even close to hitting.

Attached, I hope, is a picture


Title: Re: Is my transmission toast?
Post by: H3Jim on January 03, 2011, 01:45:18 PM
Talked to the free emergency tech at Prevost.

He confirmed that its not likely that the reset would work as the computer seems to be working - iot does shift into 1st gear.

I checked for codes and there are no codes.

He said the next thing to try is to carefully clean the battery posts for the 12 volt circuit - even though the bus starts (on 24 volts) if the 12 volt batteries have corrosion or are not fully charged, it can make the tranny computer go crazy.

He said that if that does not work, it needs to get itself to a shop.


Title: Re: Is my transmission toast?
Post by: Busted Knuckle on January 03, 2011, 02:05:59 PM
Talked to the free emergency tech at Prevost.
He said that if that does not work, it needs to get itself to a shop.

Great news! Did he mention a FREE way for it to get itself to a shop? ;)
;D  BK  ;D


Title: Re: Is my transmission toast?
Post by: rv_safetyman on January 03, 2011, 02:24:15 PM
Jim, I have to wonder out loud if the parking brake and transmission are related.  The DDEC has a signal from the parking brake.  It, for example, will not go to high idle unless the parking brake is on.  The engine talks to the transmission and I wonder if there is an interlock that keeps it from going into reverse until the parking brake is released.  That is a long shot.  You would think that there would be an interlock on the forward gears as well, but these computers have strange algorithms.

Jim


Title: Re: Is my transmission toast?
Post by: robertglines1 on January 03, 2011, 02:38:00 PM
Have had A  bad battery screw ddec up. So prevost might have something. Could be a corroded terminal-fuse holder or loose connection. Do you have the 4 group 31 battery-thats what I had and one was bad when load tested.


Title: Re: Is my transmission toast?
Post by: Don Fairchild on January 03, 2011, 03:36:01 PM
Jim;

After you get all the batts checked out build air so you can get under the bus. With the batts disconnected unplug all the conectors from the trans. Clean them good and put some dielectric greese on them and plug them back in. If that does not work take it out for a drive and see if you have a shift flairup in third or fourth gear. (engine rpm will go up but the bus will not pick up speed). Hope thats not it.

It may be a solinoid, but it should give you a code.

Bob ware as clifford suggested is a good source, we used to share ideas when I was building allisons at Delaney & Ahlf way back when. You might give dartco a call. I think their is a out let in orange county.


Hope that helps

Don


Title: Re: Is my transmission toast?
Post by: luvrbus on January 03, 2011, 04:47:16 PM
Jim, I spoke with Bob he said he thought Prevost used the output function relays on that bus he said check wires 112,114,125 and 132 see if you have relays on those wires one controls the reverse function and there should be a 15 amp fuse to supply power to the relays hope this helps


good luck   


Title: Re: Is my transmission toast?
Post by: Ace on January 03, 2011, 05:27:54 PM
It could be a simple tripped breaker. Has that happen on mine.


Title: Re: Is my transmission toast?
Post by: rv_safetyman on January 07, 2011, 08:32:24 PM
Jim, any resolution yet?

I was thinking about this yesterday and wonder if being stuck in the mud might have dislodged one of the connections.

Jim


Title: Re: Is my transmission toast?
Post by: Busted Knuckle on January 27, 2011, 09:21:45 PM
Just curious if we ever found out the problem here?
;D  BK  ;D


Title: Re: Is my transmission toast?
Post by: dougyes on January 29, 2011, 10:53:05 AM
Regarding the parking brake issue. Ours was sticking. Replaced a diaphragm and it's good to go.
Was the tranny issue solved?


Title: Re: Is my transmission toast?
Post by: rv_safetyman on January 29, 2011, 06:03:10 PM
I wrote to Jim off-line and he said that he is bogged down by a bunch of other projects and it could be a month or two before he gets back to the bus.

Jim


Title: Re: Is my transmission toast?
Post by: Busted Knuckle on January 29, 2011, 09:00:24 PM
I wrote to Jim off-line and he said that he is bogged down by a bunch of other projects and it could be a month or two before he gets back to the bus.

Jim

Thanx Jim. I was just curious.
;D  BK  ;D


Title: Re: Is my transmission toast?
Post by: blank on January 30, 2011, 07:42:38 AM
  Man, thats like reading a really interesting story in a magazine, and half way through it says "continued in next months issue".

  In all seriousness though, is this transmission really $25K? Why so expensive??


Title: Re: Is my transmission toast?
Post by: luvrbus on January 30, 2011, 08:30:55 AM
A new off the self B500 is close to 30 grand best for him to exchange instead of a shop rebuild exchanges run from 10 grand up plus labor to install he could be looking at 20+ grand for a shop rebuild.
I know people with the V730 and 740's has cost over 10 grand for a shop rebuild always cheaper to exchange than rebuild your own fwiw 



good luck


Title: Re: Is my transmission toast?
Post by: Tom Y on January 30, 2011, 09:36:13 AM
I talked to a shop in Ca. that had new 4560s I think. New takeouts for 5500.00. Some prices out there are amazing. These are from test trucks that must be dismantled. This would be the same as the 500 unless he has a retarder. I think I saw one on Ebay for 5 or 6K  Tom Y


Title: Re: Is my transmission toast?
Post by: blank on January 30, 2011, 10:15:47 AM
I know people with the V730 and 740's has cost over 10 grand for a shop rebuild always cheaper to exchange than rebuild your own fwiw 

good luck

  Wow. I think I would really be wondering just how heavy a clutch is if they threw those figures at me.


Title: Re: Is my transmission toast?
Post by: Melbo on January 30, 2011, 12:32:18 PM
My 4 speed ZF was 10 grand -- give or take a bit for a rebuild --- I took it in and got it back in about a three weeks.

I thought that was plenty but a rebuild on them can run 15 to 20 I was told.

A rebuild and good maintenance and you should be good for at least two or three years ;-)

Melbo


Title: Re: Is my transmission toast?
Post by: Boomer on January 30, 2011, 07:18:59 PM
In my experience the Prevost regional service managers are more savy than the 800 tech number.  Try Tom Munds, Rocky Mountain regional tech rep in Denver.  You can get his number off the Prevost web site.  If it comes down to a trans replacement or rebuild look for the surplus fire truck sites.  After you part out the truck you get the trans for free.  Would have to have Allison reconfigure the ECU for coach application though.


Title: Re: Is my transmission toast?
Post by: mikke60 on February 01, 2011, 03:56:40 PM
does your bus have linkage or does it shift with a solenoid as I have seen on Some beaver motorhomes


Title: Re: Is my transmission toast?
Post by: belfert on February 01, 2011, 05:11:34 PM
does your bus have linkage or does it shift with a solenoid as I have seen on Some beaver motorhomes

B500 transmissions are completely electronic.  If you're talking a shift linkage from front to back like a mechanical HT740 they do not have that.  They have a push button electronic pad for shifting.


Title: Re: Is my transmission toast?
Post by: mikke60 on February 02, 2011, 02:50:42 AM
oh ,ok, I am not that familiar with that transmission. I have seen trannys that do shift with electric solenoids however. had the same issue with one,only to find a wire had broken loose and would no allow the trans to shift into reverse, just the forward gears.


Title: Re: Is my transmission toast?
Post by: luvrbus on February 02, 2011, 06:36:35 AM
They are electronic control but have 3 different shifters 2 different pads and 1 shifter lever type not all keypads Brian 


good luck


Title: Re: Is my transmission toast?
Post by: H3Jim on November 05, 2012, 03:28:11 PM
Well after two years, I finally have some resolution to the issue.  I moved to a new house, had both my knees repalced and had a major heart attack.  Finally got back to trying to do something with the bus. Its just been a very expensive mouse house in my yard.  I thought I'd post this rather than start a new topic for some continuity to those that had been following my plight.

I had towing insurance, so had it towed to Valley Power Systems in La Jolla, in the San Diego Area for a diagnosis.  They said that a drive hub was broken along with one of the clutches was burnt.  The best thing to do is to have them R&R with a factory rebuilt.  $9406.  comes with a warrantee, and all wear parts are brought back to spec.  ouch, but with out a trans, the bus won't ever move again.

For those of you that want to know the guts of a B500, here is a good overview from a very knoweldgeable source.  I lifted this from YUKU, TOW411 site. 

I'll give you a quickie overview on what the Allison World transmission is made of and how it works. To achieve any range, two clutches must be applied. When you start the engine and have proper pressure, C-5 clutch, located at the very rear of the trans, is applied, and is used in reverse, neutral, and 1st range only. There are 5 clutches in a standard on- highway application (military and some off-highway/severe duty applications have 6 to achieve 7 forward ranges) and they are labeled C-1 thru C-5. There are 3 planetaries, labeled P-1 thru P-3. The numeral designation is from front to back of trans. C-1 and C-2 are located behind the front pump in what's called a rotating clutch hub, C-3 thru C-5 are called stationary clutches, they are secured to the inside of the main housing by a series of tabs located on their reaction plates. The clutches are applied and/or dropped to change what component of the planetary gear needs to be held or released. Rule on planetary components is: one input, one held = one output. The sun gear is in the center, surrounded by four planetary gears, with the ring gear on the outside. A sun gear is located on any of the the shafts that run thru the center of the trans: turbine shaft, which connects torque converter to C-1, C-2 rotating clutch hub, the main shaft, which runs thru C-3-C-5 and P-1 and P-2 carriers, and the output shaft, which is in P-3 carrier. C-1 clutch is used in 1-4 ranges as a constant, C-2 in 5-6. If your customer states that he has reverse but no forward range, chances are likely that there is a problem with C-1. Allison had a problem with the C-1 clutch hub in 2000-20003 production models where the center was breaking out of them. The torque converter can be both a fluid and mechanical connection to the engine. In a World trans, you start off in converter mode(fluid) and change to lock-up mode(mechanical) thru each shift. By the time you are in 3rd or 4th, when you shift, the converter does not have to drop lock-up to achieve the shift. Note: if you have a truck that has an active ABS light on, and the trans feels sluggish or like it's slipping, or if you let off the throttle at highway speed and your engine rpm's drop out but your speed doesn't, it is because when you have an active ABS fault, the lock-up clutch in the converter is dropped to prevent internal trans damage. If you came to a stop with the lock-up clutch on, it would stall your engine just like a manual clutch, so the trans, thinking that you might be spinning your wheels, protects itself. The bottom line is that all these clutches are electronically controlled thru solenoids, that change the hydraulic fluid path to apply and/or drop clutches. I see more wiring harness (OEM supplied) issues that cause transmission complaints than anything. That being said, if the harness has shorted out, you can never know what is going on inside the trans, and the pricing for replacement w/out labor is as follows: 1000/2000 series - $2500.00, 3000 series - $4200.00-$5200.00 depending on model, 4000 series - $8200.00-$9200.00 depending on model. Use some of this info to dazzle your customers with, or apply to your own vehicles. You can always contact me if you are having specific problems and I will do my best to assist. And always CYA and pull an axle or the drive line!

When you put it into drive does it take a few seconds and then kind of 'thump' into gear?? If the selector isn't flashing 'R' then the ECU (trans puter) thinks everything is OK and thinks the proper solenoids are being activated, so you may have either an internal pressure problem or a stuck solenoid. Revving the engine up some while in reverse should throw a code at some point, because the puter will see reverse selected and engine input speed, but no turbine speed (internal trans speed) or output speed. Reverse requires the highest fluid pressure of any range in the trans.Today at 6:49 am
You: Yes it thumps into drive. I've tried keeping rpm at 1500 for a bit, no code. Yes the R is steady, not blinking. Could it be a wire somewhere that got knocked off, chewed off?


Thanks.


Jim


svcmgrnow: Unfortunately I'm thinking you may have a low pressure problem. If it was strictly electrical you should have gotten a 'range verification' code when going to reverse: the ECU looks for the output signal and a return voltage signal to verify the solenoids have been commanded on properly. I'm thinking this is more mechanical. Reverse uses C3 and C5 clutches, 1st uses C1 and C5 clutches so either C3 is not being applied properly or there is a pressure issue like a bad clutch piston seal. Unit been sitting awhile or used regularly??Today at 7:09 am
You: Been sitting.

So, kind of a drain on the bank account, but have to do it, can't let it sit on their lot.  Not many other alternatives.


Title: Re: Is my transmission toast?
Post by: belfert on November 05, 2012, 03:59:30 PM
That price doesn't seem too bad for a rebuild from an Allison dealer.  Glad to see you got the bus running again.


Title: Re: Is my transmission toast?
Post by: luvrbus on November 05, 2012, 04:05:03 PM
Always cheaper to exchange a B500


Title: Re: Is my transmission toast?
Post by: TomC on November 05, 2012, 10:43:41 PM
Ahh-one of the nice things about having a dirt reliable HT740-albeit only 4spds with no overdrive.  But-our relatively light weight buses really don't need the overdrive if you have the right rear end ratio.  Good Luck, TomC


Title: Re: Is my transmission toast?
Post by: Zeroclearance on November 05, 2012, 11:56:16 PM
Jim;

You might want to call Prevost and ask if they are still running there summer exchange special.  Last year they ran a great deal on brake parts, this year I swear I seen transmission pricing.   Clifford might have also seen it.   I find that Prevost has some pretty good deals.   


Title: Re: Is my transmission toast?
Post by: luvrbus on November 06, 2012, 04:52:39 AM
Best deal I found on the B500 was from Penske in Cerritos Ca I paid 9000 xchange (no install labor) out the door with the fluid, filters , ECU and new harness with nation wide warranty we all do it different but no way would I buy a takeout or used transmission for a H-41 those suckers are heavy

Buy rebuilt from dealer you get all the upgrades made to transmission over the years and a warranty and there has been plenty of upgrades made over the years Jim will be into it for over 12,000 before it is finished 

Not for sure but I was told Penske does the rebuild xchange program for Prevost


good luck


Title: Re: Is my transmission toast?
Post by: H3Jim on November 06, 2012, 12:21:00 PM
Valley Power seems to have the best deal.  $9406 includes parts, labor, fluids, reprogramming, hazmat and tax.   and the bus is in their yard.

Allison distributor, all Allison parts, all done by Allison trained mechanics.  Will use my tranny as a model, so all the variations and options are correct for my bus.