Hey Fellas,

 Sorry for the Off Topic but this has me scratching my head and wondering if you guys had come accross anything like this before. I have a Front end loader, It's a Scoopmobile LD5, it's older then i am. Perkins 6.354 coupled with an Allison TT2220 transmission.

The engine starts and runs well for what it is and the hydraulics scoop no problem. But it won't move when it's cold. Winter time (10-25 degreesC) you can have to warm it up for ages before it will even think about moving. Summer time (30+ degreesC outside temp) you jump in it, put it in gear and off you go.

I've checked the screen at the bottom on the oil pickup and that's clear, i've changed the filter (i even tried no filter in case it was the wrong micron rating and restricing it somehow.) It's running Dex3 ATF so it isn't oil too thick. No black in the filters and it works 100% when it's at operating temp so i don't think it's transmission clutches. If it was the pump i imagine it would be worse when hot not better (granted my knowlege of pumps is basic). That leaves my diagnostics with control valves not engaging the clutches or the Tourque conveter.

Going to get some pressures next week when my mate gets back with his guages but any other ideas before i start tearing thing apart? Could it be a collapsed hose or somthing silly? It seems there is a basic type of scavange pump system in the TC but again i imagine it would be worse in the heat, not better.

Only other thing is it has a clutch pressure guage on the dash that jumps around erratically and usually sits at the max. I spoke to the old bloke i got it off and he reckons it's always done that in the 30 years he had it before i got it. But then he also reckons it's always been a bit of a pig when it's cold.

Any input would be appriciated.

Thanks

Hi, Misterskill.
I have operated a couple of LD3s and an LD7 in the past and none of them showed the behavior that you are describing. Good, solid machines, although a little 'unsteady' on their feet due to the oddball center swivel design. The only time I got near an LD5, I had to stand it back on its feet with the Cat 941B that I was operating at the time. NO injuries to the machine but the operator's confidence took a beating.

The only thing that I can think of that you haven't mentioned is if there is a pressure relief valve in there somewhere that either has a weak spring or is sticking - or both. This might help to explain the fluctuations in the pressure gauge too.

Hope yer git it sorted.

Just my 0.02.

Hi Daniel,
by your description of erratic gauge needle when cold--if I understand correctly--can indicate air in the suction line.
This could be from loose hose clamps on suction line--cooked hard hose with loose clamps or crimps at any fittings, a split in the hose etc. and as you allude to the inner sleeve of the hose pulling away and restricting suction with colder/thicker oil--have encountered de-laminating suction hoses before today.
Cheers,
Eddie B.

Deas wrote:

Hi, Misterskill.
I have operated a couple of LD3s and an LD7 in the past and none of them showed the behavior that you are describing. Good, solid machines, although a little 'unsteady' on their feet due to the oddball center swivel design. The only time I got near an LD5, I had to stand it back on its feet with the Cat 941B that I was operating at the time. NO injuries to the machine but the operator's confidence took a beating.

The only thing that I can think of that you haven't mentioned is if there is a pressure relief valve in there somewhere that either has a weak spring or is sticking - or both. This might help to explain the fluctuations in the pressure gauge too.

Hope yer git it sorted.

Just my 0.02.

Yeah, good thinking. Maybe the valve is stuck or somthing and it the machine won't operate until the pressure gets below a certain figure? Found a parts and service book and it looks fairly simple to take off the control bank and check it out. Book mentions a clutch cutout valve sticking.

Books if for some reason anyone is chasing them.

www.numeralkod.com/cross/archivemanuals/...alog%20sa%201133.pdf
www.numeralkod.com/cross/archivemanuals/...%201140/part%201.pdf
www.numeralkod.com/cross/archivemanuals/...%201140/part%202.pdf

Hi Daniel,
by your description of erratic gauge needle when cold--if I understand correctly--can indicate air in the suction line.
This could be from loose hose clamps on suction line--cooked hard hose with loose clamps or crimps at any fittings, a split in the hose etc. and as you allude to the inner sleeve of the hose pulling away and restricting suction with colder/thicker oil--have encountered de-laminating suction hoses before today.
Cheers,

Thanks Eddie. Sorry, Gauge is erratic all the time. Operating temp or cold. I'll check hose clamps though i think it's all hydralic fittings. Maybe when they warm up they get a bit more supple and seal correctly?

Definitely tepreture related as on a hot day you just jump in and drive away, no problems.

Anyway got impatient and pulled the control valve assembly off. One the of the valves had a few marks on it and needed a bit of a tap to come out. I couldn't feel anything inside so i cleaned it up with some fine sandpaper and put it back.

Cleaned the whole thing up, put it back on. Started it up, put in 1 and off we go. Sucess!

Put it back in N, back in 1 and nothing. Took the assembly off again, nothing stuck. Removed the brake/transmission kickout and the same thing.

Remembered i would have dropped a bit of oil when playing with the filter ect. So i put 2 litres in it until it came out the top plug as i was instructed by the previous owner.

Figured i've got the service book now so i may as well read it. Started the thing up, gave it a few rpm and checked it properly by the bottom plug. 6 litres later it still isn't at the bottom plug and i'm out of oil so have to wait until tommorow.

Put it in first and off it goes, N and we stop, 1st and off we go again!

So unless i've accidently knocked somthing else and fixed it, looks like it was a stuck Main pressure regulator valve and it's been low on oil for the past 30 years!

Lesson learnt. Always check the service manual and don't trust the previous owner on preventive maintenance, no matter who it is!

Thanks for the help fellas

that's a good story Mister! the kind of fixes i like and stories with a happy ending. I was thinking maybe a weak or broken spring etc...but great!

Hi Daniel,
WELL DONE, --cold oil gets trapped on the compartment walls/surfaces and so is slow to run back to the reservoir for re-use. Thus the pump is starving for oil and so is pumping air until it can warm up and flow back quick enough for the pump to recycle air free.
Low oil level is the result and as you say incorrect oil level checking advice could and did cause your issues.
Is there an oil volume amount to be added after an oil change given in the book that may work closer than a level plug which seems odd for an Allison trans.
Adding a liter or so of trans. oil until the unit works cold without sucking air could be one way to go--then watch for sign of overheating due to oil drag when hot--could be issues with the trans pump pickup tube being mis-positioned or such if this occurs.
Keep at it and smiling.
Cheers,
Eddie B.

edb wrote:

Hi Daniel,
WELL DONE, --cold oil gets trapped on the compartment walls/surfaces and so is slow to run back to the reservoir for re-use. Thus the pump is starving for oil and so is pumping air until it can warm up and flow back quick enough for the pump to recycle air free.
Low oil level is the result and as you say incorrect oil level checking advice could and did cause your issues.
Is there an oil volume amount to be added after an oil change given in the book that may work closer than a level plug which seems odd for an Allison trans.
Adding a liter or so of trans. oil until the unit works cold without sucking air could be one way to go--then watch for sign of overheating due to oil drag when hot--could be issues with the trans pump pickup tube being mis-positioned or such if this occurs.
Keep at it and smiling.
Cheers,
Eddie B.


 

about 8.5 gallons in total according to the book. So the instruction is to add 6.5 after a service (7.5 after a rebuild) and do the level plug process.


Actaully kind of glad it didn't starve completly and loose drive going up a hill or somthing

Hi Daniel,
you can do the fill by volume test by simply draining your oil into a clean container--measure the volume and refill as for a simple service and then do the level plug thing after a short run and say 3-5 minutes wait time before checking the level. at the plug again.
Other methods may work as well.
Cheers,
Eddie B.