JD450c tranny trouble

[skitsmith]

I just bought the machine like it sat, the engine runs good, hydraulics are good. I can put it in gear and nothing happens when clutch is released. The guy I bought it from said the torque converter needed priming, I don't know if this is the case or how to go about doing it. I unscrewd the dipstick under the seat and shows full. Please help

[jdemaris]

I just bought the machine like it sat, the engine runs good, hydraulics are good. I can put it in gear and nothing happens when clutch is released. The guy I bought it from said the torque converter needed priming, I don't know if this is the case or how to go about doing it. I unscrewd the dipstick under the seat and shows full. Please help

There is no torque converter in a 450C. It has a dry mechanical clutch on the flywheel - coupled to a power shift transmission that uses wet clutch packs and is powered by its own hydraulic pump to power those clutch packs along with the steering clutches. They are either full engaged, or not engaged at all - i.e. "on" or "off."

There is no priming procedure, someone is telling you stories.

The HL-R powershift trans is very expensive to work on if it has serious problems. Many 450s get cut up for parts once it goes.

One possible easy fix is the trans-pressure-valve linkage. It tends to come loose in all the 450 crawlers. The adjuster nut is under an access plug in the floor-board. You need a pressure gauge to know what you're doing - along with some knowledge.

In brief, the clutch pedal is two-stage. Half-way down cuts off the hydraulic pressure in the HL-R powershift trans. All the way down disengages the mechanical clutch on the flywheel so the four-speed gear transmission can be shifted. There is a piece of linkage that connects them all together with a 5/16" or 3/8" jam nut (or an added lock nut). When it comes loose, trans pressure can drop so low the machine won't move.

[digitup2]

Kind of hard to prime something that isn't there !!.But I would say you have clutch pack pressure problems .450Cs were not known for an accurate transmission pressure guage on the dash but if you have one look for adiquate pressure on the guage . If you don't have one and know where to test for trans/pressure .Check on external transmission plumbing and shift through all gears watching for pressure change the clutch packs may need rebuilding .This would be a good first step .Digitup.

[pdmech08]

Jdemaris is right. They can be quite expensive to repair. Best bet is to first get the books. The tech manual and parts book can be very helpful when it comes to repairs. Follow the adjustment procedures to the letter and see what happens. If it does not cure your problem then you'll probably have to tear it apart. If you need assistance feel free to contact me directly. We have repaired many of these over the years. Steve.

[skitsmith]

Thanks a bunch guys I am going to find a book anyone know the best place?

[shinnery]

Here is one place at least.

http://www.johndeeretechinfo.com/

Bryce

[skitsmith]

I have a book, the local jd dealership let me borrow. Let me start before I got the book I pulled the top off the tranny when I release the clutch in gear all the gears move very-- very slowley . The book was not very clear to me on trouble shooting. I feel either the manual clutch or the h l r oil pump is not working. How do the two tye together? All the gears look good to me, I changed the screen filter and the filter in front or the radiator. Thanks in advance

[pdmech08]

Skitsmith: If I understand you correctly, you have the large top cover off and can see the HLR clutches. With the engine running the forward most gear in the HLR case should turn at engine speed providing the master clutch is not released, slipping or damaged. When the HLR transmission is placed into gear the HLR clutch drums should begin to turn. If they do not, then a pressure test is in order to determine if the system is developing pressure or to pinpoint any areas of internal leakage. Creeping of the drums and shafts is probably due to drag. Test procedures should be in the tech manual under "system testing", "powertrain". Good luck. Steve.