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Chelsea PTO

Yahoo Message Number: 71309
Hi,

I did an inspection of the PTO on my bus (2006 Allure 430 series #31349) and found a hose running from the bottom of the transmission (hooked into the pan) to the casting that appears to interface the PTO gears (or spline) to the driven member in the Allison transmission (3000 MH). I'm assuming this is transmission fluid which circulates over the gears. There is also a very small amount of fluid wicking about the casting indicating the presence of a lubricant. Perhaps this is welcome relief for those concerned about the PTO dry spline failure or maybe just false hopes, Any comments, input and insight welcome.

Best - Scott

2006 Allure 430 #31349
(Bus-Stead Lemon)

Re: Chelsea PTO

Reply #1 –
Yahoo Message Number: 71314
There is a small line that feeds the pump and at that point there should be a tee allowing the line to continue to a second fitting at the top of the casting between the pump and the transmission. Ptos without the wet kit only have the one line going to the pump and i have also found the mid casting to have a small hole in the bottom. Place pics if you want to know for sure.
Rod inspire

Re: Chelsea PTO

Reply #2 –
Yahoo Message Number: 71316
Scott

For what it is worth my 430 Allure #313438 just before yours did not have the wetkit until I paid approximately $800 to the man.

Dan 2006 Allure 31348

Re: Chelsea PTO

Reply #3 –
Yahoo Message Number: 71322
Rod - Thanks for clarifying. I believe my PTO has only a single line meaning the spline connection is dry.

Dan - I'm sure we both have the same setups being only 1 digit off. Thanks for the response.

Weather here is bad with snow, rain, wind, cold, etc. I need to get under the bus and examine a bit closer. I had hoped to separate the pump from the PTO enough for an inspection of the spline. Not sure of the details but it doesn't seem too difficult. If anyone has done this I'd surely appreciate any input.

Of interest is the splines (which are dry) that were used on the early 60s GM cars with 3/4 speed standard transmissions. All the torque required to move the vehicle went through that spline and they never failed. The failed splines on our hydraulic pumps makes me wonder about what steel alloys where used in the shafting. It also begs questions about whether the spline profiles were machined correctly. Could we have gotten a batch of "off spec" parts someone needed to dump in the market somewhere?? In the write ups I've seen I didn't come across anything that explains (beyond lack of lubrication) why this shafting is failing. Just a couple of thoughts that ran through my mind as we deal with a failing part that should never be an issue.

At 12:30 AM 5/29/2011, you wrote:

Quote
>

There is a small line that feeds the pump and at >that point there should be a tee allowing the >line to continue to a second fitting at the top >of the casting between the pump and the >transmission. Ptos without the wet kit only have >the one line going to the pump and i have also >found the mid casting to have a small hole in >the bottom. Place pics if you want to know for sure.
Rod inspire

In

Country-Coach-Owners@yahoogroups.com, >Scott wrote:
>
> Hi,
>

> I did an inspection of the PTO on my bus (2006 Allure 430 > > series #31349) and found a hose running from the bottom of the > > transmission (hooked into the pan) to the casting that appears to > > interface the PTO gears (or spline) to the driven member in the > > Allison transmission (3000 MH). I'm assuming this is transmission > > fluid which circulates over the gears. There is also a very small > > amount of fluid wicking about the casting indicating the presence of > > a lubricant. Perhaps this is welcome relief for those concerned > > about the PTO dry spline failure or maybe just false hopes, Any > > comments, input and insight welcome.
>

> Best - Scott

> 2006 Allure 430 #31349
> (Bus-Stead Lemon)
>

Best - Scott

2006 Allure 430 #31349
(Bus-Stead Lemon)

Re: Chelsea PTO

Reply #4 –
Yahoo Message Number: 71336
I put a wet kit on mine a few weeks ago.
For the initial inspection, it's just 2 bolts to pull the pump away from the PTO. I removed some hose hangars, as there was not a lot of slack in the hydraulic hose from the reservoir. I did not have to open the hydraulic system at any time!
My spline was not worn, but it was corroded a bit. The corrosion probably kept it from wearing. I had to pry a bit to separate the pump from the PTO. I was able to clean the corrosion off the pump shaft. The mating spline is one of the new parts that I got in the kit from JDRV.
The messiest part is when you pull the PTO off of the tranny. You will get a couple of cups of tranny fluid. You will need a 12 point 3/8 drive socket and a swivel (universal) joint to remove the PTO. Plus a torque wrench for the re-assembly.
The most difficult part was pressing the shaft out of the PTO, and pressing the new shaft and bearing seal back in. You will need a precision gauge or two to make sure that everything goes back together in the same place it came apart. Dial gauge and maybe a micrometer, or a digital caliper.
I bought a 2 gallon parts washer plus solvent to make sure that I got everything clean. Somehow I find myself adding to my tool collection when I do projects like this.
You could probably find a machine shop, or a hydraulic shop with a press, gauges, and a parts washer to help out, if you don't want to deal with this part yourself.
JD was very helpful over the phone. I would of waited till my next trip to Oregon to have him do the work, but I didn't want to take a chance on damaging the pump spline.

Mike 03 Lexa.

P.S. Where are you that you are getting snow?

Re: Chelsea PTO

Reply #5 –
Yahoo Message Number: 71343
Mike,

Thanks for the details and recapping your experience. I'm just not in a position to perform that repair (don't have my shop anymore) so I'll need to rely on someone else. I hope I can find quality service personnel. We're in Park City, UT at the moment. 36F this morning with some snow. They are having a tough spring needless to say. Looking forward to our exodus this Wednesday.

At 10:49 PM 5/29/2011, you wrote:

Quote
>

I put a wet kit on mine a few weeks ago.

For the initial inspection, it's just 2 bolts to >pull the pump away from the PTO. I removed some >hose hangars, as there was not a lot of slack in >the hydraulic hose from the reservoir. I did not >have to open the hydraulic system at any time! >

My spline was not worn, but it was corroded a >bit. The corrosion probably kept it from >wearing. I had to pry a bit to separate the pump >from the PTO. I was able to clean the corrosion >off the pump shaft. The mating spline is one of >the new parts that I got in the kit from JDRV.

The messiest part is when you pull the PTO off >of the tranny. You will get a couple of cups of >tranny fluid. You will need a 12 point 3/8 drive >socket and a swivel (universal) joint to remove >the PTO. Plus a torque wrench for the re-assembly.

The most difficult part was pressing the shaft >out of the PTO, and pressing the new shaft and >bearing seal back in. You will need a precision >gauge or two to make sure that everything goes >back together in the same place it came apart.
Dial gauge and maybe a micrometer, or a digital caliper.

I bought a 2 gallon parts washer plus solvent to >make sure that I got everything clean. Somehow I >find myself adding to my tool collection when I do projects like this.

You could probably find a machine shop, or a >hydraulic shop with a press, gauges, and a parts >washer to help out, if you don't want to deal with this part yourself.

JD was very helpful over the phone. I would of >waited till my next trip to Oregon to have him >do the work, but I didn't want to take a chance on damaging the pump spline.

Mike 03 Lexa.

P.S. Where are you that you are getting snow? >

In

Country-Coach-Owners@yahoogroups.com, >Scott wrote:
>

> Rod - Thanks for clarifying. I believe my PTO > > has only a single line meaning the spline connection is dry.
>

> Dan - I'm sure we both have the same setups being > > only 1 digit off. Thanks for the response.
>

> Weather here is bad with snow, rain, wind, cold, > > etc. I need to get under the bus and examine a > > bit closer. I had hoped to separate the pump > > from the PTO enough for an inspection of the > > spline. Not sure of the details but it doesn't > > seem too difficult. If anyone has done this > I'd surely appreciate any input.
>

> Of interest is the splines (which are dry) that > > were used on the early 60s GM cars with 3/4 speed > > standard transmissions. All the torque required > > to move the vehicle went through that spline and > > they never failed. The failed splines on our > > hydraulic pumps makes me wonder about what steel > > alloys where used in the shafting. It also begs > > questions about whether the spline profiles were > > machined correctly. Could we have gotten a batch > > of "off spec" parts someone needed to dump in the > > market somewhere?? In the write ups I've seen I > > didn't come across anything that explains (beyond > > lack of lubrication) why this shafting is > > failing. Just a couple of thoughts that ran > > through my mind as we deal with a failing > part that should never be an issue.
>
>

> At 12:30 AM 5/29/2011, you wrote: > > >
> >

> >There is a small line that feeds the pump and at > > >that point there should be a tee allowing the > > >line to continue to a second fitting at the top > > >of the casting between the pump and the > > >transmission. Ptos without the wet kit only have > > >the one line going to the pump and i have also > > >found the mid casting to have a small hole in > > >the bottom. Place pics if you want to know for sure.
> >Rod inspire
> >

> >--- In

> > > m>Country-Coach-Owners@yahoogroups.com, >

> >Scott wrote:
> > >
> > > Hi,
> > >

> > > I did an inspection of the PTO on my bus (2006 Allure 430 > > > > series #31349) and found a hose running from the bottom of the > > > > transmission (hooked into the pan) to the casting that appears to > > > > interface the PTO gears (or spline) to the driven member in the > > > > Allison transmission (3000 MH). I'm assuming this is transmission > > > > fluid which circulates over the gears. There is also a very small > > > > amount of fluid wicking about the casting indicating the presence of > > > > a lubricant. Perhaps this is welcome relief for those concerned > > > > about the PTO dry spline failure or maybe just false hopes, Any > > > > comments, input and insight welcome.
> > >

> > > Best - Scott

> > > 2006 Allure 430 #31349
> > > (Bus-Stead Lemon)
> > >
> >
> >
>

> Best - Scott

> 2006 Allure 430 #31349
> (Bus-Stead Lemon)
>

Best - Scott

2006 Allure 430 #31349
(Bus-Stead Lemon)

Re: Chelsea PTO

Reply #6 –
Yahoo Message Number: 71359
Scott:

Are you heading South?

If the pump shaft needs to be replaced, it could take a few weeks to get that handled. Just FYI.

Gil Bourdon
'05 Inspire
51322

Re: Chelsea PTO

Reply #8 –
Yahoo Message Number: 71372
Gil,

We are heading to Montrose, CO. I think there may be a place there that can take a look. Got plenty of time for parts. Thanks.

At 12:05 PM 5/30/2011, you wrote:

Quote
>

Scott:

Are you heading South?

If the pump shaft needs to be replaced, it could >take a few weeks to get that handled. Just FYI.

Gil Bourdon
05 Inspire
51322

In

Country-Coach-Owners@yahoogroups.com, >Scott wrote:
>

> Mike,
>

> Thanks for the details and recapping > > your experience. I'm just not in a position to > > perform that repair (don't have my shop anymore) > > so I'll need to rely on someone else. I hope I > > can find quality service personnel. We're in > > Park City, UT at the moment. 36F this morning > > with some snow. They are having a tough spring > > needless to say. Looking forward to our exodus this Wednesday.
>

> At 10:49 PM 5/29/2011, you wrote: > > >
> >

> >I put a wet kit on mine a few weeks ago.
> >

> >For the initial inspection, it's just 2 bolts to > > >pull the pump away from the PTO. I removed some > > >hose hangars, as there was not a lot of slack in > > >the hydraulic hose from the reservoir. I did not > > >have to open the hydraulic system at any time! > > >

> >My spline was not worn, but it was corroded a > > >bit. The corrosion probably kept it from > > >wearing. I had to pry a bit to separate the pump > > >from the PTO. I was able to clean the corrosion > > >off the pump shaft. The mating spline is one of > > >the new parts that I got in the kit from JDRV.
> >

> >The messiest part is when you pull the PTO off > > >of the tranny. You will get a couple of cups of > > >tranny fluid. You will need a 12 point 3/8 drive > > >socket and a swivel (universal) joint to remove > > >the PTO. Plus a torque wrench for the re-assembly.
> >

> >The most difficult part was pressing the shaft > > >out of the PTO, and pressing the new shaft and > > >bearing seal back in. You will need a precision > > >gauge or two to make sure that everything goes > > >back together in the same place it came apart.
> >Dial gauge and maybe a micrometer, or a digital caliper.
> >

> >I bought a 2 gallon parts washer plus solvent to > > >make sure that I got everything clean. Somehow I > > >find myself adding to my tool collection when I do projects like this.
> >

> >You could probably find a machine shop, or a > > >hydraulic shop with a press, gauges, and a parts > > >washer to help out, if you don't want to deal with this part yourself.
> >

> >JD was very helpful over the phone. I would of > > >waited till my next trip to Oregon to have him > > >do the work, but I didn't want to take a > chance on damaging the pump spline.
> >

> >Mike 03 Lexa.
> >

> >P.S. Where are you that you are getting snow? > > >

> >--- In

> > > m>Country-Coach-Owners@yahoogroups.com, >

> >Scott wrote:
> > >

> > > Rod - Thanks for clarifying. I believe my PTO > > > > has only a single line meaning the spline connection is dry.
> > >

> > > Dan - I'm sure we both have the same setups being > > > > only 1 digit off. Thanks for the response.
> > >

> > > Weather here is bad with snow, rain, wind, cold, > > > > etc. I need to get under the bus and examine a > > > > bit closer. I had hoped to separate the pump > > > > from the PTO enough for an inspection of the > > > > spline. Not sure of the details but it doesn't > > > > seem too difficult. If anyone has done this > > > I'd surely appreciate any input.
> > >

> > > Of interest is the splines (which are dry) that > > > > were used on the early 60s GM cars with 3/4 speed > > > > standard transmissions. All the torque required > > > > to move the vehicle went through that spline and > > > > they never failed. The failed splines on our > > > > hydraulic pumps makes me wonder about what steel > > > > alloys where used in the shafting. It also begs > > > > questions about whether the spline profiles were > > > > machined correctly. Could we have gotten a batch > > > > of "off spec" parts someone needed to dump in the > > > > market somewhere?? In the write ups I've seen I > > > > didn't come across anything that explains (beyond > > > > lack of lubrication) why this shafting is > > > > failing. Just a couple of thoughts that ran > > > > through my mind as we deal with a failing > > > part that should never be an issue.
> > >
> > >

> > > At 12:30 AM 5/29/2011, you wrote: > > > > >
> > > >

> > > >There is a small line that feeds the pump and at > > > > >that point there should be a tee allowing the > > > > >line to continue to a second fitting at the top > > > > >of the casting between the pump and the > > > > >transmission. Ptos without the wet kit only have > > > > >the one line going to the pump and i have also > > > > >found the mid casting to have a small hole in > > > > >the bottom. Place pics if you want to know for sure.
> > > >Rod inspire
> > > >

> > > >--- In
> > > > > > >

m>Country-Coach-Owners@yahoogroups.com, >
> >

> > > >Scott wrote:
> > > > >
> > > > > Hi,
> > > > >

> > > > > I did an inspection of the PTO on my bus (2006 Allure 430 > > > > > > series #31349) and found a hose running from the bottom of the > > > > > > transmission (hooked into the pan) to the casting that appears to > > > > > > interface the PTO gears (or spline) to the driven member in the > > > > > > Allison transmission (3000 MH). I'm assuming this is transmission > > > > > > fluid which circulates over the gears. There is also a very small > > > > > > amount of fluid wicking about the > casting indicating the presence of > > > > > > a lubricant. Perhaps this is welcome relief for those concerned > > > > > > about the PTO dry spline failure or maybe just false hopes, Any > > > > > > comments, input and insight welcome.
> > > > >

> > > > > Best - Scott

> > > > > 2006 Allure 430 #31349 > > > > > > (Bus-Stead Lemon)
> > > > >
> > > >
> > > >
> > >

> > > Best - Scott

> > > 2006 Allure 430 #31349
> > > (Bus-Stead Lemon)
> > >
> >
> >
>

> Best - Scott

> 2006 Allure 430 #31349
> (Bus-Stead Lemon)
>

Best - Scott

2006 Allure 430 #31349
(Bus-Stead Lemon)

Re: Chelsea PTO

Reply #9 –
Yahoo Message Number: 71379
Scott

There is a phenomenon called "harmonic vibration" characteristic of diesels that eats away on a dry spline.

George Harper
04 Allure
31093

Re: Chelsea PTO

Reply #10 –
Yahoo Message Number: 71380
George,

I'm familiar with that as it relates to cylinder walls and pitting of the metal in contact with coolant. My PTO is mounted on the transmission, however. Some busses don't have the "soft start" on the radiator fan. This causes a surge of pressure when the fan starts from a dead standstill. I'd imagine this also places an impulse load on the hydraulic pump's spline. Other fan controls keep the fan spinning at low RPM to reduce starting torque. This places less of a load on the hydraulic components. I'm wondering what the effects of constant "hard starts" are on the pump's spline. Thanks for your input.

At 07:03 AM 5/31/2011, you wrote:

Quote
>

Scott

There is a phenomenon called "harmonic >vibration" characteristic of diesels that eats away on a dry spline.

George Harper
04 Allure
31093

In

Country-Coach-Owners@yahoogroups.com, >Scott wrote:
>

> Of interest is the splines (which are dry) that > > were used on the early 60s GM cars with 3/4 speed > > standard transmissions. All the torque required > > to move the vehicle went through that spline and > > they never failed. The failed splines on our > > hydraulic pumps makes me wonder about what steel > > alloys where used in the shafting.

Best - Scott

2006 Allure 430 #31349
(Bus-Stead Lemon)

Re: Chelsea PTO

Reply #11 –
Yahoo Message Number: 71381
There are several differences, even though the 2 splines are the same size. First on the car clutch, the load is different, usually heavier. The pto does not have a great load against it so it is more prone to the chatter that causes the wear. The rpm is lower on the pto pump. The clutch application has a pilot bearing at the "other" end to maintain alignment, further reducing its ability to chatter.
Another thing to consider is dump trucks, etc use the same set up, however they are part time ptos. Being only engaged when they are needed. The coach pto runs 100% do the time.

Mikee

Re: Chelsea PTO

Reply #12 –
Yahoo Message Number: 71398
To those who have not followed this site since the PTO issues really surfaced:
The single hose going from the Allison to the PTO provides lubricant to the PTO gear drive that meshes with the Allison gear. Return of the excess fluid is through the opening where the PTO fastens to the Allison body.
The PTO shaft cavity does NOT receive fluid from the gear-drive side of the PTO. These two cavities are sealed from each other. So, the shaft that is connected to the hydraulic pump is receiving no lubricant.
So, the purpose of the wet kit is to take a portion of this fluid from the Allison-to-the-PTO-gear-side and put it into the shaft cavity.
A new end cap for the PTO, which comes in the wet kit, has a horizontal hole drilled in it to allow drainage of the shaft cavity into the gear cavity.
So, bottom line........just because you see a hydraulic hose going from the Allison to the PTO does NOT mean you have lubrication to the shaft coupling.

Roger Uhlich

'07 Intrigue 12170
 

Re: Chelsea PTO

Reply #13 –
Yahoo Message Number: 71449
Scott

I would think that a heavy load on the PTO at start-up would make a wet PTO setup even more desirable, but I think the major cause of the excessive wear on the shafts is the harmonic vibration characteristic of diesels.
Regarding diesel cooling system cavitation, I think the problem is that there is no contact between the cylinder wall and the coolant where a bubble exists.

George Harper
04 Allure
31093