HLR transmission

John bates · Sep 3, 2020

took top cover off of my JD 450 tranny to see why I only have 80 pounds of pressure. Figured sheer pin was broke but it wasn't. The the rod that has the arm on it that opens the valve for the fluid. Could that valve be junk? Clutches look great. Was working good for a few days then lost my 150 psi of pressure. Can anyone help me please

Jim.ME · Sep 4, 2020

Yes a valve could be bad and hanging open a bit. There could be a pressure leak somewhere. The pump may be weak. Beyond going through all the adjustments and pressure checks again to try to pinpoint the problem, I don't know what to tell you.

From your posts on the John Deere Forum you had a good bit of wear in the HLR pump that you reinstalled when you changed the input shaft. It may not be able to make full pressure or volume any more. If you have a leak in the HLR oil system the pump may not be moving volume enough to hide the leak and build the required pressure any more.

You say the clutches look good. I don't remember if you completely disassembled and resealed the HLR or not. It is unlikely both clutch packs lost their seals at the same time. Since you lost both directions I would look first at things common to both directions. Starting at the pump suction through the direction control valve.

John bates · Sep 4, 2020

how do you test for leaks with air? My
manual doesn't say. When I put air to
clutch housing as I have in the picture
when I shift through foward and reverse the
fluid bubble in case. Is this normal

Jim.ME · Sep 5, 2020

Are you seeing bubbles directly from the clutch packs or from a return line into the case? Does it bubble all the time you have air on? Your manual should describe there are paths for excess oil to return to the case after the filter and cooling needs are met. The valving and circuits is likely passing your air through them as well as the clutches.

John bates · Sep 5, 2020

no it bubbles directly under that valve
body where I took the line off to put air.
The bottom side.if I recall when in neutral
it doesnt bubble. Jim like you said before
it probably is a bad pump housing. Almost
impossible to find though

Roy Suomi · Sep 5, 2020

If you take off the upper valve from the lower valve block [2 5/16" bolts ] Watch you don't loose the itty bitty clip that secures the shift rod to the valve lever. There are 5 o-rings in there .. each seals a function.. You can air up the clutches by putting air into the sealed holes with a rubber tipped blow gun.. Should show leakage that way. Man, that's an early one you got there.. I haven't seen threaded line attachment fittings in a long time.

John bates · Sep 5, 2020

ua its a 69 450 JD

Dugger · Sep 10, 2020

(reply to post at 22:40:40 09/03/20)

In your second pic there is a hole in the line
Better check it out
Dugger

John bates · Sep 11, 2020

it looks like a hole but its not. Its a
black spot on line

HLR transmission

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