a few oliver questions

Here we go, hoping someone may have an answer or two:
1. Why is there a difference in the long pto shaft between an Oliver 2255 2wd with a 3150 cat engine versus an Oliver 2255 4wd with a 3208 cat engine. The latter uses a 67 inch shaft while the former uses a 68 & 3/8's inch long shaft. Discovered this when the short plug went too far and dropped a bit. It was loose in the pto tube. We put the old shaft back in.
2. I suspect my Oliver 1950 with a Detroit diesel needs new fuel filters. It misfires under a load but runs fine with no load. Had a GM expert come out and tune it up but it never misfired before. I will try the filters first.
3. Same tractor (1950), hydraulics seemed to overflow and were running hot. This tractor sat for 2 years and wasn't really used much after a Dupont overhaul. Hydraulic oil seemed to bubble up. Looks like it is Hy-tran. Maybe a filter again or is some valve stuck.
4. My Oliver 1855 temp gauge indicates it is almost in the hot area but the tractor is not overheating or spewing radiator fluid. Would I start with the sender or the gauge to see if one is faulty?

Does the temp. gage go to the cold reading when you shut off the tractor? On #4, we had a 1650 that would read cold for maybe a minute after start up, then swing to hot. Changed the sender and still the same. Took the dash apart and tested at the gage and it would work normal. Finally, by accident, I was replacing a dash light when I wiggled some wires and the gage swings to hot again. We had a bare spot on the temp. sender wire and when moving the tilt steering, the wire would rub.

For troubleshooting, start with disconnecting the wire from the gage and sender. Run a separate jumper wire to the sender and see if it still does that. Even a crack in the wire covering will sometimes change resistance enough to get false readings. If that fails, sending units are only a few dollars at an auto parts place vs. the price of a gage.

Good idea to get a mechanical water temp gauge as a double check anyway. Bought new 50 series gauges/sending units last year, and the water temp on my 1650 went wacky -- goes right to hot after startup. Sending unit and/or gauge may not be grounded enough.

Question # 2 probable cause -

Your GM expert is not an expert.

What I do when setting the individual injector racks and rocker clearances is run the tractor at all rpms. I use a dyno but he should have at least simulated a load by dragging the brakes at full throttle.

What's probably going on is 1 cylinder fuel load is high or low, this will cause a 'miss' effect.

Could be filters or something else your expert did. Like maybe leaving a fuel line nut loose under the rocker cover?

The 4-53 fuel system is easy to tune, just read your manual slowly line by line and then you're an expert.

Good luck.

The expert came out and tuned the tractor two years ago and since we had it partially tore apart, we decided to repaid and install new vinyl. Looks real nice but it didn't get put under load till this past weekend. I will change the filters first. The problem he was supposed to fix was an over run at or near the open throttle position. If you didn't bring it down, it would want to rev up to almost 3K. No overrun anymore, just the miss fire.

I also see I have a head gasket that is leaking oil. So much for the paint job. I assume this is simply a take apart and replace job to get it fixed.

Removing the head is not too bad a job, just the hassle of hinging up the fuel tank for access. If there's not too much fuel in the tank, I just get it out of the way. I use a special O-Ring Lube for the o-rings which really helps them seal nice and tight.

Oliver used 2 different GM engines in the 1950, one was id'd as the 'N series' and the other was the '4 valve' series. There are subtle differences but easy to identify. One of these series had a near 3000 rpm high idle, I believe it was 2850 or 2950 rpms. Don't quote me on these values as my data is on another computer.

There is a possible chance that your GM expert just tried adjusting the governor and he has created a super bad hunting effect that sounds like a miss.

Hopefully you're using DELO 100 40wt oil or similar brand. This is a must do TSB by Detroit Diesel. If you're using 15-40wt, might be why you're seeing some seepage.

Good luck.

the shaft is different because it is. Probably a mid year change. I fix things often with used parts, even though they supposedly came from the same machine I have to use something from the old to make the new work.

Obviously the Mechanic did something wrong, probably broke a wire tugging on it. Had that a few times in different things, one specifically by a GM mechanic and why I do all my own work unless I can't and I couldn't that time, had to be done on a computer.Changing filters is a good place to start, seldom is the fix.

My 1850 gas had a problem after I'd tuned it, for some reason the coil wire would pop of the cap, never saw that before. I attribute it to after market parts poorly made to spec.

If your sure the temp isn't high start at the easiest and work from there. Personally I'd look into redoing it from end to end, what could it cost and it's old school easy. Fault ground could definitely cause problems. Spewing fluid isn't a good way to determine if there's a problem.

Got a friend who used to run Olivers on his farm, his biggest beef with his was vapor lock caused by heat, they tried everything to keep the fuel cool enough, never could.