Another Rebuild of the same Allison Gearbox

[Jasper]

Another failure on Allison Gearbox.
The Port side gearbox (MH20) failed last year (forward gear) and was rebuilt.
At the time a new Hydreco oil pump was also installed.
The boat has been run around 20 hours since then.
In Queensland the fishing season has kicked off and I had the boat hauled, polished, propspeed etc.
Then, together with a mechanic friend, I serviced both engines, new filters, oil etc. But did not service the GB as it had only a few hours on it.

Last week, the boat was running perfectly. Engines have never run better, all gears fine. Until the next morning when the anchor was lifted. The Forward gear would NOT fully engage, except in idle.
I immediately checked the GB oil pressure. It read 40 psi in FWD.
Checked oil & it was dry.
Filled with 40w oil and pressure momentarily went to 155psi in gear, but still would not go past idle.
Then pressure was back to 40 psi. I shut down the engine & returned home on the Stbd motor.

The guys who rebuilt the gearbox came next day. They are very experienced with Allison’s and Detroit’s.
We checked the Hydreco, it was running perfect.
Cannot find any leaks.
Oil in the engine “seems” slightly higher than when I last checked.
Checked the filter in the 3 bolt flange fitting & found a small amount of clutch material but a lot of lint type material.
Gear selector was removed & tested, it is good.
All cables are working properly.

Lifted the gearbox off the engine & disassembled.
Clutch plate is still good, with very little wear.
Pressure plate has some burnt spots.
All bearings, gaskets & seals were good.
We shaved a thousandth off the back flywheel to the back of crank, just in case, even though it showed no damage.
The mechanics have spent the last week looking for a cause/problem.


In short, we cannot find anything wrong with the gearbox.

The ONLY major item damaged is the oil filter for the gearbox. When the filter casing was opened, the mechanic had to work very hard to remove the filter from the casing. The filter had been sucked deeply into the hose opening that leads to the control block. See the images. Unfortunately, this seems to be a symptom, not a cause for the loss of oil pressure. Seems the filter was starved of oil & was sucked into the hose. This was a new filter 20 hours ago!

Now the Gearbox will be re-installed, we will bypass the oil cooler momentarily to see whether there is a blockage there & check whether the gearbox works.
However, I believe that the it will work, which will then point to a blockage or problem in the oil cooler. So the oil cooler will then be removed & tested.
Is there a way of testing the oil cooler for blockages without removing it? I suggested compressed air, but apparently air will bypass an obstruction that oil will not.
Is there any cause for this problem that anyone can point to or advise on?

Everyone tells me that an Allison gearbox, once re-built, should be good for many years & thousands of hours!
This will be the 3rd rebuild I have had to do in 3 years! The 1st rebuild was apparently done incorrectly & the mechanics refunded the cost & recommended the present mechanics who have a good reputation.
They are doing the work under warranty, so you can imagine they are just as concerned as I am, to find the cause and make sure it does not happen again.

 

[rsmith]

That is NoT the correct element!!!

 

[Jasper]

That is NoT the correct element!!!

The filter in the photo had a metal insert.
Which filter should it be?
Thanks!

 

[rsmith]

It should look like a metal can like the secondary fuel

 

[rsmith]

That one is the old sock filter for the primary fuel

 

[rsmith]

Hold on I'll get my manual

 

[rsmith]

I don't have my books here but this is what it should look like. I do NOT know if this is the correct filter# but you get the idea it is not a sock filter

 

[Jasper]

Sounds logical to me, considering all the pressure.When I changed filters in 2011 when I took delivery of the boat, I used the filter type you are showing me here!
When the mechanic first found this filter he questioned whether I had installed it, saying it was the wrong filter. I showed him the invoice for the filters I replaced during the service, explained I did NOT change the gearbox filter because it was new (from him) and also showed him that this filter was installed by him and now he says either type is acceptable!
I will phone him tomorrow.

 

[davidwigler]

May be a good time to install a remote spin-on filter. I have them on both engines and trannies.

 

[MikeP]

Clearly the filter collapsed. Either it is the wrong filter or it got so clogged up with material that it could no longer pass oil. The former seems to be the answer based on the above posts. My engines have remote spin-ons so I have never purchased an oem filter and don't know what they are supposed to look like. But the shop manual should clearly identify them.

 

[rsmith]

See figure 57

 

[saltshaker]

That one is the old sock filter for the primary fuel

That's what I was thinking. I had spin ons for the gears but still had the old style cartridges like you posted. That would explain the drop in pressure but where did the oil go? Seems to be a reoccurring issue here this week.

 

[Jasper]

Thanks to all!!!
Let’s see what the mechanic say now!
BTW, they initially claimed that the WRONG FILTER HAD BEEN INSTALLED BY THE GUY SERVICING THE ENGINES.
Until I proved that the gearbox filter had NOT been done due to the recent overhaul.
Let’s see what is next.
I will update.
MANY THANKS TO ALL CONTREBITUORS!
GEORGE

 

[Genesis]

The OEM is the cartridge as posted. Paper element encapsulated in a metal can.

It's definitely not a "sock type".

If the oil was properly filled and then measured low it went somewhere. The only two realistic places for it to go are in the boat (e.g. bilge) due to an external leak or into the cooling system (either engine or raw water, depending on where your cooler is.) A leaking rear main seal on the engine typically deposits small amounts of engine oil into the gear rather than the other way around; it usually doesn't raise the level materially but does make the oil black. Some Detroit-powered boats used the auxiliary cooler core in the primary H/E tank, some had a raw-water cooler. Series II 45cs with the twin dry turbos had the latter on the suction side of the raw water system and I was told the reason was that the secondary core in the H/E tank was not capable of dissipating enough heat and there were some early failures due to excessive gear oil temperatures.

 

[Jasper]

Lets ask the question that, to me at least, seems obvious:
WAS THE WRONG TYPE OF FILTER INSTALLED???

 

[Jasper]

The OEM is the cartridge as posted. Paper element encapsulated in a metal can.

It's definitely not a "sock type".

If the oil was properly filled and then measured low it went somewhere. The only two realistic places for it to go are in the boat (e.g. bilge) due to an external leak or into the cooling system (either engine or raw water, depending on where your cooler is.) A leaking rear main seal on the engine typically deposits small amounts of engine oil into the gear rather than the other way around; it usually doesn't raise the level materially but does make the oil black. Some Detroit-powered boats used the auxiliary cooler core in the primary H/E tank, some had a raw-water cooler. Series II 45cs with the twin dry turbos had the latter on the suction side of the raw water system and I was told the reason was that the secondary core in the H/E tank was not capable of dissipating enough heat and there were some early failures due to excessive gear oil temperatures.

We found no oil in the bilge, heat exchanger (coolant was fine).
The screen was full of lint with a little clutch material. i assume the lint was from the "sock filter".
The fact that the clutch plate can be re-used is because the motor was shut down as soon as the problem was realised.
I will know more today.
Many thanks to you all.

 

[Jasper]

Now this is AMAZING Greed or a mechanic living in denial!
A few weeks ago the mechanic who owns the shop that did the second re-build sent me AN ACCOUNT OF OVER $10,000 for the work to re-build the Port side gearbox.

He refutes that this was a warranty claim because, he says, the problem was an "INHERENT PROBLEM" meaning to him, that the hoses from the gearbox filter canister to the oil cooler were ALREADY INSTALLED INCORRECTLY before he did the first re-build. He also claims that the "sock filter" is correct, because Allison gives the code number of this filter, then it must be ok!
He is claiming the hoses were incorrectly installed in the US and not in his "Scope of Works" to check. Meantime my regular mechanic had already noticed the hoses were in the wrong order and changed them over before he ever stepped foot on my boat.
What he seems to not realise, or simply ignores, is the fact that when his mechanics rebuilt the gearbox in the first place, they disconnected these hoses, they had to during the rebuild and they probably reconnected them the way they had seen the Starboard hoses done (which was the wrong way at the time) Then he found them in the second rebuild to be wrong, not realising it's his own people!.
Here's what he denies:
That the first things a mechanic should do BEFORE TEARING OUT A GEARBOX is check the oil, oil filter, screens for clutch material etc.

He even admits that all the gearbox needed to be repaired was for the sock filter to be pulled out the hose and a paper cartridge filter to be installed.
He never needed to re-build the gearbox, just change a filter!!!

The other amusing thing is that the Starboard engine has run for the last 3 and a half years without ANY problems, and the hoses were back to front on that too. They are changed around now, but as long as there was a paper cartridge filter installed it made no difference.
So we are going to court........
If it wasn't so embarrassing for his trade I would laugh.

 

[Jasper]

Update:
The people that rebuilt my Port gearbox last year, then, in January this year, could not diagnose the problem of a filter blocking the hydraulic hose and instead dis-assembled, then re-assembled the gearbox, before finally checking the oil cooler hoses and the filter to find that the problem could have been rectified in an hour at most, are now demanding a large payment for their work. See the above posts for the history of this.
BTW I was told by them at the time, NOT to do anything as it may negate my warranty.

They are charging $10,300 in labour for the work done in January, consisting of diagnosing the fault, removing the gearbox, dissambley, then re-assembly and reinstalling the gearbox. Double the cost they charged for the Labour to rebuild the gearbox in 2013.

So we are going to Court on the 3rd of July.

Question for the members:
Is there an amount of time given be Allison to do a dis-assambley and re-assembly of an Allison gearbox?

 

[Tim Powell]

Update:
The people that rebuilt my Port gearbox last year, then, in January this year, could not diagnose the problem of a filter blocking the hydraulic hose and instead dis-assembled, then re-assembled the gearbox, before finally checking the oil cooler hoses and the filter to find that the problem could have been rectified in an hour at most, are now demanding a large payment for their work. See the above posts for the history of this.
BTW I was told by them at the time, NOT to do anything as it may negate my warranty.

They are charging $10,300 in labour for the work done in January, consisting of diagnosing the fault, removing the gearbox, dissambley, then re-assembly and reinstalling the gearbox. Double the cost they charged for the Labour to rebuild the gearbox in 2013.

So we are going to Court on the 3rd of July.

Question for the members:
Is there an amount of time given be Allison to do a dis-assambley and re-assembly of an Allison gearbox?

Hi Jasper
So So sorry for the problems let me see maybee this will help.

Mr Rick Zurick is operations manager at Western Branch Diesel in Portsmouth Virginia. They represent Detroit and MUT HE IS ABOUT OUR AGE AND A GRATE GUY. Please send him a e mail about your cituation he will give you the numbers you are looking for as far as hours for repair direct from allison manuals. Maybee eaven fax the manual or parts of it.


Mr Rick Zurick
operations manager
e mail rzuraw@wbdiesel.com
direct # 757-673-7210
cell# 757-373-8600
office # 757-673-7000

You can use my name if you like probley will not help but will not hurt.
Tell him the story he will do his best tell me if you decide to send him a email or call i will call him and infor him you will be calling

Your friend as you say Mate
Tim

 

[Jasper]

Hi Jasper
So So sorry for the problems let me see maybee this will help.

Mr Rick Zurick is operations manager at Western Branch Diesel in Portsmouth Virginia. They represent Detroit and MUT HE IS ABOUT OUR AGE AND A GRATE GUY. Please send him a e mail about your cituation he will give you the numbers you are looking for as far as hours for repair direct from allison manuals. Maybee eaven fax the manual or parts of it.


Mr Rick Zurick
operations manager
e mail rzuraw@wbdiesel.com
direct # 757-673-7210
cell# 757-373-8600
office # 757-673-7000

You can use my name if you like probley will not help but will not hurt.
Tell him the story he will do his best tell me if you decide to send him a email or call i will call him and infor him you will be calling

Your friend as you say Mate
Tim

Many thanks Tim!
Really appreciate the effort.
I will email him today.
Cheers,
George