450 in pieces

[supertramp]

So I had the track loader apart and noticed that the transmission oil temperature sender line had been shredded where it passed through the firewall. I spliced in a new bit of wire and will hopefully find that the gauge on the dash works again. Measured impedance at 50KΩ. Checked coolant temperature gauge at 8KΩ; and hooked it up as well. Oil pressure via mechanical gauge was steady at 40PSI, replaced gauge with a new electronic sender unit showing 50KΩ; wired it up as well. Do these values seem good? I really don't want to replace the transmission temperature sender... Are the gauges or the senders usually suspect?
Other things:

• Replaced worn fan belt, noted crusty dirt/oil buildup on the radiators.
• The transmission oil cooler line running from the transmission to the top of the radiator has two pinhole leaks that are weeping, and the main pressure line coming from the hydraulic pump has some abrasion which has opened up a flap of the outer rubber hose, exposing the wire below. I will re-glue the flap with rubber cement and put some tape around it, and use a coupling and a few feet of hose to fix the leaking radiator hose; since it connects up to the area between the main frame and the transmission, which looks like a real PITA to get at to replace.
• I did notice that all three bolts for the front crossbar to the RH frame are loose, and the nuts behind them are spinning freely, along with the two bolts/nuts coming up vertically to join these two pieces. In addition, the main frame bushing is just...gone! U17212. I have the retainer plates and the bolts, but will need to fabricate or find a replacement. How does one get a wrench on the inside of the frame to tighten them up? Really don't want to leave them loose.
• One of the grease fittings for the front idler, which I hit with some penetrating oil to be able to extract. Any advice there?
• The unconnected cable there is for a missing floor-mounted tach; unsure what may have happened to it....
• The parking brake lock was found in the belly pan, having been cleaned it will be re-mounted soon.
• The coolant itself has likely been in the radiator for two years at this point; should I flush it and clean it? Without a working thermometer I have no idea what temperatures we've been seeing. Should I monitor this and the transmission oil filter temperature with a wireless thermometer?
• Will need to check oil levels in FD's and winch. The winch will retract but not pay out automatically, and it's very tight to turn the drum. Is it supposed to rotate in both directions? Do I need to adjust the linkage?

Looking forward to re-filling hydraulic reservoir, replacing the nose and getting engine coolant, pressure and transmission temperature gauges working, but don't want to rush the process.

[Jim B]

It sounds like you are replacing a section of the low-pressure hose from the transmission to the oil cooler. If that is the case, it needs to be hose rated for oil service, not plain "heater" hose use for coolant. Plain heater hose won't stand up to oil service long term.

As for the ohm ranges. If you bought senders from JD by part number for your machine, they should match the original gauges. If you bought off the shelf senders, they may or may not be the right ohm ranges for the gauges. Many service manuals give the ohms you should see at given temperature or pressure. Have you checked your Service Manual (SM2064) to see if that on has the specs?

[supertramp]

It sounds like you are replacing a section of the low-pressure hose from the transmission to the oil cooler. If that is the case, it needs to be hose rated for oil service, not plain "heater" hose use for coolant. Plain heater hose won't stand up to oil service long term.

I got a shorter section of oil hose, good for 300PSI, and a barb coupler. Plan to cut down near frame members and replace the section going up to the cooler, as it had been rubbing against something in the nose.

As for the ohm ranges. If you bought senders from JD by part number for your machine, they should match the original gauges. If you bought off the shelf senders, they may or may not be the right ohm ranges for the gauges. Many service manuals give the ohms you should see at given temperature or pressure. Have you checked your Service Manual (SM2064) to see if that on has the specs?

Section 100 of SM2064 is helpful as regards the wiring diagrams but provides no data for the impedance of the gauges or sensors. The only sender that is new to me is the oil pressure gauge, so I assume a non-zero and non-infinite value is 'close enough'. If I don't see anything from the gauge cluster I suppose another way to test the gauges might be to see what their response is to a given voltage/current; I have a benchtop power supply so can see if they're dead. The wiring behind the panel is a total rat's nest, so can check to see if the sender unit is getting any voltage from the harness.. I assume I ought to see 12V or less coming from the gauge, through the harness, to the sender unit. Is this how it works?

[Jim B]

Yes, you should see some voltage at a sender's wire from the gauge. generally grounding a wire at the sender will make the gauge needle sweep full range. No movement should indicate an open in the wire or bad gauge.

The 450B manual gives the following sending unit info. I didn't check the parts books to see if they used the same senders. It may help you.
Engine coolant temperature and Transmission Temperature both show 200 degrees F at 122 +/- 10% ohms. Engine oil pressure shows 40 psi at 102 +/- 10% ohms.

[supertramp]

I was able to look at the gauges on Sunday. Replaced mechanical oil pressure gauge with electrical. Readings went from 40 PSI to 20. Must be a mis-match between the sending unit and the gauge itself. Can I select a resistor to fix this discrepancy?
Wired up coolant temperature gauge and found that it didn't really detect anything, but it came with its own sending unit I will slap in to see if that fixes it.
Wired up Transmission temperature gauge but the needle is totally unresponsive when 12V was applied to the leg. I think I will need a new one.

The five bolts holding the front crossbar to the RH frame are still loose, will need to tighten them up. Is there a good way to do this? Maybe two people - one underneath the machine and the other on the outside of the track? Are the nuts supposed to be tack welded to the frame so they don't spin?

One big issue I noticed is that I was able to start up the engine, but as I disengaged the clutch (in neutral mind you) the engine reacted as though there was a good amount of load on it. I can't tell how much, since the transmission temperature isn't working, but it seemed non-trivial. I tried letting out the clutch, and pulling all the way back on both steering levers to see if this would disengage those two clutches and cause the engine load to decrease, but it didn't. The original concern that we had was that the engine was bogging down and wouldn't run at idle; perhaps there is something causing friction to build up in the transmission?

[supertramp]

Yes, you should see some voltage at a sender's wire from the gauge. generally grounding a wire at the sender will make the gauge needle sweep full range. No movement should indicate an open in the wire or bad gauge.

The 450B manual gives the following sending unit info. I didn't check the parts books to see if they used the same senders. It may help you.
Engine coolant temperature and Transmission Temperature both show 200 degrees F at 122 +/- 10% ohms. Engine oil pressure shows 40 psi at 102 +/- 10% ohms.

This is very helpful, thank you. I'm going to check these values and may have to throw in a few resistors to get those nominal values.. hoping that doesn't screw up the rest of the scale.

[supertramp]

One big issue I noticed is that I was able to start up the engine, but as I disengaged the clutch (in neutral mind you) the engine reacted as though there was a good amount of load on it. I can't tell how much, since the transmission temperature isn't working, but it seemed non-trivial. I tried letting out the clutch, and pulling all the way back on both steering levers to see if this would disengage those two clutches and cause the engine load to decrease, but it didn't. The original concern that we had was that the engine was bogging down and wouldn't run at idle; perhaps there is something causing friction to build up in the transmission?

[supertramp]

One big issue I noticed is that I was able to start up the engine, but as I disengaged the clutch (in neutral mind you) the engine reacted as though there was a good amount of load on it. I can't tell how much, since the transmission temperature isn't working, but it seemed non-trivial. I tried letting out the clutch, and pulling all the way back on both steering levers to see if this would disengage those two clutches and cause the engine load to decrease, but it didn't. The original concern that we had was that the engine was bogging down and wouldn't run at idle; perhaps there is something causing friction to build up in the transmission?

Here's a video of the aforementioned:

https://imgur.com/5sjBuIo

[B Town]

Check the clutch housing. Like mouse nest, debris, corrosion etc. check the drain hole in the bottom of the clutch housing. Is it free or plugged?

[supertramp]

Check the clutch housing. Like mouse nest, debris, corrosion etc. check the drain hole in the bottom of the clutch housing. Is it free or plugged?

Unsure, will look into this.

Also, the button head grease fitting on the LH unit fitting is a few threads loose. RH idler grease fitting either busted off, or it has a sealed unit. Is this a sealed idler?