1977 JD 450c Loader has no power in reverse

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Sabaro
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1977 JD 450c Loader has no power in reverse

Post by Sabaro » Tue Mar 20, 2018 11:17 pm

Back in 2013 I used this forum to diagnose a steering problem with the left final drive. As it was pointed out by one of the members We had a hole in the left side final drive clutch pressure line. We replaced it and the tractor was fixed, steering left and right in H/L/R. However last year the tractor has been developing a different problem. It doesn't have much power in reverse. The tractor will roll backwards (slow) on flat ground but when on any sort of incline it doesn't have the power to move the tractor up the incline. I was worried that my dad or I might of accidently changed the H/L/R lever linkage adjustment length when we reassembled the tractor after replacing the hose in the left final. My thought was that if the linkage length was changed (longer or shorter) it might not be putting the transmission fully into reverse. I removed the pin from the H/L/R lever and operated the linkage by hand to make sure the transmission was getting into reverse. It was and the problem is still there. I've been doing some reading on the forum and it sounds like I need to do a pressure test on the transmission to verify the transmission is at 160psi with a 5psi pressure drop when clutch is depressed 1/2" to 3/4". Is there anything else to check that I'm missing? I have Technical Manual TM1102 on hand. Any Ideas or help will be greatly appreciated.

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Re: 1977 JD 450c Loader has no power in reverse

Post by Sabaro » Wed Mar 21, 2018 6:30 am

I've been reading Tech Manual TM1102, and in the back there is a section called system testing. Within this section there are groups and power group happens to be 70, and subsection or page 20-5 talks about troubles and possible solutions for the H/L/R and steering clutches. I see there is a heading titled "loss of power transmitted". The cause is brake out of adjustment, and the fix is to adjust the brakes. I would think brake out of adjustment would effect both forward gears and reverse. My trouble is just in reverse at the moment. I only bring this up because I was in both final drives 5 years ago to replace the pressure hoses that supply oil to the clutches. Also at that time I installed new brake bands.

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amos
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Re: 1977 JD 450c Loader has no power in reverse

Post by amos » Wed Mar 21, 2018 6:36 am

I would do the testing to check pressures and go from there. Could be another seal blown or bad clutch pack(don't think the clutch pack is shot though).
Good you have the manual so testing should be somewhat simple. Keep posting what you find please.
Amos
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Re: 1977 JD 450c Loader has no power in reverse

Post by DrLoch » Wed Mar 21, 2018 6:40 am

Look at the clutch control valve, 20-7. Also here is a write up from Roy Suomi about getting the pressures and adjustments correct fo the HLR.
I know it's long but it may be helpful, I know it was when I was having issues.

Roy Suomi
Re: JD 450 Clutch Adjustment in reply to Tweeter, 11-19-2006 16:50:42
The steel line is steering..The HLR adjustment nut should be somewhere midway from top to bottom of threads.. OK 1 last time..; first , adjust the clutch bolt to 3 and 3/4" "freeplay" from top of pedal to where you feel the fingers of the clutch contact the throw-out bearing..Back off the adjustment inside the clutch housing rubber plug so the pressure drops off to about lets say 50 lbs. Turn the nut in and watch the pressure guage . It should go to it's maximum pressure then drop off slightly , without pulling the clutch pedal off its stop. If it pulls the pedal off it's stop before it gets to it's maximum pressure , there's a problem in the HLR clutch operating shaft or roll pins..Once you have your max. pressure ,push in the clutch pedal about 1/2" the oil pressure should raise about 5-10 lbs..Now you're gonna have to fine tune that adjustment from there. The speed of shift shouldn't be so fast that you can't shift from reverse to forward at wide open throttle without using the clutch pedal..Optimum pressure for HLR is about 180 lbs operating pressure..

Roy Suomi
I've found that a penny is good for about 15 lbs when adjusting pressure valve..I've used them many times when out in the field adjusting transmissions..Take out all the shims and grease them together..Makes it easier to install nut without loosing shims..Get a 200 lb gauge..Install a flex hose from a grease gun..You might also have to install an extension [ 1/8 th pipe ] to clear any obstacles inside the pressure tap casting...Gear transmission in neutral [ between 3rd and 4th gear ] lock brakes down, start machine and check to make sure you're in neutral there. carefully release the clutch to make sure it's in neutral..Then you can shift the HLR from gear to gear without the machine taking off on you..Adjust the clutch pedal "free-play" [ top of the pedal to where you can feel the clutch throw-out bearing contact the clutch fingers].. 3-3/4"..Adjustable with the 3/4" headed bolt next to the clutch pedal..If when you turn this adjustment and nothing happens except the bolt raises and lowers. That tells me it's a pretty good indication that the linkage on the side of the clutch housing is frozen and needs to be freed up. If that adjustment works OK then pull the rubber plug on the clutch pedal side of the clutch housing [ top of housing ] There you will find a stud with a 5/16" nut [ 1/2" socket]..With the engine running at about 1/2 throttle, check the pressure..Should be about 180 lbs. . Turn the nut clockwise and watch the pressure .. It should go to it's maximum pressure then fall off..When it falls off back it back out about 1/2 turn..Push in the pedal about a half inch and watch the gauge..It should go up slightly [ 5-10 lbs ]..If it does this , you're real close..shift the HLR from gear to gear to check pressures [ remember , 4 speed in neutral ] if the transmission shifts harshly , turn it in one flat at a time while trying the speed of shift..Now put the 4 speed into 2nd gear , brake off , and try it at near idle speed..When it's adjusted properly , you should be able to shift it at wide open throttle without touching the clutch..Don't make it too mushy shifting , trans will heat up from slipping..You should be able to shift it lets say from forward to reverse an it just sucks you out of the seatback..Not a " Neck snapper "..There are several adjustments for this transmission...Try these first and let us know how it turns out..

Roy Suomi

You need to get it up to where it should be[ 185 lbs]..Are all ranges identical pressure or is one lower than the others??? When you adjust the pedal [ 3-3/4 to 4" ] does the bolt go up and down off its detent plate?? or does it stay down against the detent plate on the pedal assembly?? This makes a difference..If it's ok and free to work properly we go to next step..With a gauge in the hlr port [ on the trans top cover between steering levers ] Look for a drum bung looking plug , remove it and insert a 3/16" allen with a dab of grease on it to remove the 1/8th pipe plug..Install a clean grease gun hose with a 200 lb. gauge on it . Lock down the brake , Feel around for the neutral position on the 4 speed shifter [between 3rd and 4th gear] . Carefully release the clutch pedal to be sure you're in neutral . Start the machine and read the pressures in all 3 ranges..They should all be even and consistent..At 185 lbs.. If you need to raise the pressure , on the top of the clutch housing ,there will be 2 rubber plugs , of course you know the left one is the adjustment and the right one is the pressure control valve..Pull the pressure control valve nut , again use a greased socket so it stays with the socket, carefully remove the plug and watch for shims in the plug and on top of the spring..I use copper pennies to adjust the pressure up..One penny is good for about 10 to 12 lbs....If the pressures aren't consistant you have an internal leak..Manifold , rings , clutch pistons..All speeds should be about the same lag time between shifts..If one isn't as fast as the others, either the linkage needs to be adjusted so the internal detents jive with the shifter quadrant..If shift quadrant and detents jive , you might have that leak....


Re: JD 450c speed of shift in reply to jdemaris, 12-03-2005 14:59:09
Speed of shift is a relativley easy adjustment. Pull the left floorboard out. There is a rubber plug there. pop the plug out and you will find a 5/16" nut on a threaded rod sticking straight upright. I use a 3/8 ratchet with a 1/2" deep socket on a short extension. To do it right you will need to put a guage into the pressure tap hole. This is located between the steering levers on the cast top cover. There will be a " drum bung " there . remove the bung plug. Inside you will find a 1/8" pipe plug with a 3/16 allen head.I use a dab of grease on the allen when removing the plug. This plug is on an angle, pointing forward. Install a guage with a 1/8 nipple . A 250 lb guage will work fine.Adjust the pedal free-play to about 4 1/4" from top of pedal to where the throw out bearing just touches the clutch fingers. Put the 4 speed into the neutral position between 3rd and 4th gears.Lock the brakes down.Start the machine, ease out the clutch pedal to make sure the 4 speed is in neutral. You can now start adjusting the HLR speed of shift. I usually back off the adjustment till the pressure drops off a bit. Then I turn the adjustment in till the pressure goes to maximum psi. Turn it a bit more till the pressure just starts to drop off [ 5 to 10 lbs ]. You will be real close now. Try the speed of shift with the 4 speed still in neutral at about 1/2 throttle. The guage will show a lag between high and reverse . when you have it close, put the 4speed into 2nd gear and try it out. If it's still fast, turn the adjustment in 1/4 turn at a time till it's comfortable. It should just suck you out of the seat slightly going high to reverse . don't make it too " lazy " or too slow. This could cause overheating because of slippage. If it's too slow back off the adjustment 1/4 turn at a time. Usually when it's adjusted right, you can push the clutch pedal down 1/2" and the pressure guage will show a slight increase in pressure . The book can be a little intimidating . Go with the above and you should be OK. If you don't feel confident doing it yourself , print this page and take it to your mechanic. Oh , the pressure should read 175 to 185 lbs. . If after doing adjustments the pressure isn't up to snuff, under the right floorboard is a rubber plug. Under the plug you will find a cap of the pressure control valve.[ A penny is good for about 12 to 15 lbs.]

Re: JD 450c speed of shift in reply to Roy Suomi, 12-03-2005 21:41:58

OK , there is an adjustment on the side of the transmission case, that you don't usually have to touch.It's on the brake pedal side. You will notice a square head plug about 2 inches from the top cover joint , just under the hourmeter plate. If you take out the plug there is a needle valve and a jam nut in there, I use an 11/16 deep socket and a short screw driver to adjust it. I have a special socket with a roll pin driven into the hole in the socket so I can turn the jam nut without disturbing the needle valve adjustment. Turn the needle valve in 1/4 turn at a time . It's kind of a bugger to get to, but it's the only other thing to do about aggressive shifts..Sorry about not getting back sooner, but I work full time for a road dept in the snow belt.I usually put about 64 miles on my Mack truck just plowing my route one time .

Re: JD 450c speed of shift in reply to Roy Suomi, 12-10-2005 21:00:48

Roy. I tried that before I took the clutch accumulator out and went through it. The book says that if you can screw the needle valve in all the way and there is no difference in the speed of shift that you should check the screen, ball valve, and the orfice at the screen. I removed the needle valve and there were signs that it had been screwed in to tight at one time. I cleaned the burrs of the needle valve and put every thing back together. It still shifts to hard. I noticed that the book says that the pressure should go up about 5 pounds when you depress the clutch about half an inch. The pressure of mine goes down as soon as you depress the clutch. We don't get much snow down here in Texas thank goodness. Thanks for your help.


Roy Suomi
12-11-2005 19:51:45
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Re: JD 450c speed of shift in reply to drk, 12-11-2005 16:33:55

When adjusting the HLR thru clutch housing , as I stated turn it down till the pressure drops off slightly. Did you do that? When it is adjusted this way it should increase pressure when clutch pedal is slightly depressed. I've seen some actually lower the clutch pedal when adjusting the speed of shift. Usually what is wrong there is the clutch linkage on the side of clutch housing is rusted stuck. If you study the linkage there is an adjuster to adjust clutch pedal free-play. When you back it off it should change the free-play on the pedal. If it doesn't , chances are the linkage is stuck. This adjustment is a 1/2" bolt next to the pedal[ 3/4" wrench]. If you back it off it should not make the bolt raise from it's seat. If it raises , the linkage is frozen on the shaft it pivots on..





MY 1980 J.D.450 C IS SLIPPING MORE IN FORWARD AND REVERSE AS IT IS GETTING USED A LOT. DOESN'T SLIP ALL THE TIME BUT IT'S BAD WHEN BACKING UP. SLIPS SOME WHEN PUSHING, SEEMS IF I'M WORKING THE SIX WAY BLADE WHEN PUSHING A LOAD, HAS SOMETHING TO DO WITH IT. AT ONE TIME I WAS TOLD HERE, WHAT THE PRESSURE SHOULD BE ON THE CLUTCH PACKS BUT I'VE MISS PLACED THE INFO. ALSO, I'VE FORGOTTEN IF THE TRANS. AND CLUTCH PACKS HAVE THEIR OWN PUMP OR IF THE FRONT PUMP SUPPLIES THEIR PRESSURE. THANK ALL OF YOU IN ADVANCE FOR YOU HELP. vwnjr

Hydraulics and transmission are separate systems.. If the transmission is slipping, adjust it.. first.. The speed of shift and pressures can be tested as follows; pull floorboards , find the "drum bung" on the top of transmission case cover, between steering levers. Remove drum bung , there you will find a 1/8th pipe plug in there on an angle. I use a dab of grease so the plug sticks onto the allen wrench [ 3/16" ] an doesn't fall off when removing..I use a grease gun hose with a 200 or 300 psi gauge attached to it. Screw the hose into the hole you took the pipe plug out of. Place 4 speed shifter between 3rd and 4th gears. [ there is a neutral position there.] Start machine with brake lock engaged. run engine at 1200 t0 1500 rpm. Slowly release the clutch pedal to make sure you have the gear transmission in neutral [ with hlr transmission in gear]. read the pressure on the gauge. It should read approx. 185 lbs. If speed of shift was real aggressive between forward and reverse thats a good indication it's out of adjustment. you should be able to shift the HLR transmission at wide open throttle without using clutch pedal. If pressure reading is low you can adjust the speed of shift and pressure reading at the same place.First adjust the pedal freeplay, this is where you shut off oil in the clutchpack transmission. If you take a tape measure from the top of pedal stroke to where the throw-out bearing contacts the clutch pressure plate. There is a upright bolt next to the clutch pedal that adjusts the freeplay. Should be 4 and 1/4". . If you look at the clutch housing below your left foot , you will find a rubber plug about 2 1/2" in diameter. pry out the plug. Inside you will find a stud with a 5/16" nut [ 1/2" deep socket size] while running at the above rpm turn the adjustment nut down[ clockwise]. As you turn the nut you will eventually see the pressure rise. keep turning the nut till the guage stops rising At that point turn it a little more clockwise , the pressure will begin to drop. The adjustment is close if you can push the pedal 1/2 to 3/4" and pressure rises slightly, back to where the maximum reading was.You can then do the speed of shift fine tuning now. With the gear transmission in 2 nd gear , engine running just above idle speed , sit in seat put the HLR lever in gear, Lets say high range, pull the lever into reverse. It should shift smoothly without whiplash. If it's still aggressive turn the 5/16" nut clockwise 1/4 turn at a time till the trans shifts smoothly. All shifts forward to reverse should be tight but not painfull. you should just be " sucked out of the seat" lightly when doing this shift. You can fine tune it to your preference. If you want it more smooth turn it clockwise. If it's too slow turn it counter-clockwise. The pressure should read 175 to 185 psi. If it shifts ok but pressure is down slightly you can use a penny or two to shim up the pressure control valve. Each penny is good for about 15 lbs.
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Re: 1977 JD 450c Loader has no power in reverse

Post by Sabaro » Fri Mar 23, 2018 6:21 am

Thanks for the write up DrLock. I will check Transmission psi tomorrow and post results. It looks like the psi test port is 1/8npt?

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Re: 1977 JD 450c Loader has no power in reverse

Post by DrLoch » Sat Mar 24, 2018 6:57 am

Yes, 1/8" NPT. Mine was a bear to get out. Stripped the hex out, had to remove valve and drill it out and re-tap.

Not my write-up. I got it from a number of posts from Roy and I've hung onto the information. Mine needed to be adjusted because I was having the same issues you are having now.

Good luck.
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Re: 1977 JD 450c Loader has no power in reverse

Post by Sabaro » Sun Mar 25, 2018 9:24 pm

So I can’t find my 200psi test gauge so I need to get a new one to complete the transmission psi test. My dad was exercising the tractor yesterday and the dang trans started working kind of like it’s suppose to. He was getting full power while in reverse most of the time. On the few occasions that it didn’t have power while in reverse he would shift it into forward gear and then right back to reverse and full power would be back. How do you have power then not?!?!

In case I didn’t say it before here is what I know about the tractor:
It was retired from family business in the late 80’s early 90’s. It sat more than it ran. In 2012-2013 we were going to build a barn and needed to use the tractor to level a pad when we noticed that it wasn’t tractor wouldn’t steer to the right. We dug into the final drives and found a hole in the hose supply psi hose to the final drive clutch pack. We replace both hoses in the final drive and we put new brake bands onto each steering clutch brake.

Thanks Jerry
My dad told me he noticed that the frictions are not set the same. One side grabs the brake sooner than the other does, might be out of adjustment. Back in 2013 when I replaced the finals psi hose I also put new oil in because the oil was white and milky, plus there was debris. Would the Left friction being out of adjustment cause the reverser to be out of power too

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