Tractorman

So the vacuum line pops off when you install RV275 injectors. Does this happen when you install other injectors? I need to know because I have a set of RV275 injectors to install. The vacuum pump is gear driven and is attached to the front gear cover just below the fuel injection pump. The power steering pump is piggy-backed onto the vacuum pump. Follow the power steering hose from the brake booster to the power steering pump which is attached to the back of the vacuum pump. - John

It is likely a vacuum line, which would explain why you can't change your mode settings. Without a vacuum source, the HVAC system will default to defrost mode. Start at the vacuum pump location and follow the lines up to the firewall (near the top part of your photo). You should be able to find the other disconnected part. - John

When I check tire, brake, or bearing temps by feel on road trips, I am not looking for a specific temperature - I am looking for a different temperature between like objects doing the same duty, for example: one front hub bearing being considerably warmer than the other front hub bearing. - John

This has been an interesting read. I am now at 297,000 miles with original non-greased hub bearings. So, should I go to the trouble of greasing them, or should I just replace them? On road trips I routinely check the hub temps by feel, especially on the interstate - I will pull into a rest area using only the exhaust brake and gears to get down to 10 mph and then feel the hub temperature after I have parked. Now I wonder if I should be more concerned after reading the reports of sudden bearing failures. Did anyone happen to do routine hub checks for heat prior to their sudden bearing failure? - John

Since the very tip of the pilot shaft did not receive any damage, a sleeve would not fit over it. I think that in order for a sleeve to work, some machining would have to be done to reduce the diameter of the whole bearing area on the pilot shaft. - John

I am thinking that it was a very good decision. I was getting ready to buy the 235 tires, but you started experimenting with the 245's with even better performance for our application. It is rather ironic though, how long it takes for us to put on the tire that is recommended on the label in the door jamb on our 2002 trucks. How did those guys know that? Another benefit for the 235 or the 245 tire that hasn't been mentioned - a reduced chance for hydroplaning. - John

No, and of course it would have been the most important picture. The needle bearing chewed away a few thousands of an inch of pilot shaft material all the way around the bearing area precisely the length of a needle bearing. Because of the missing material, the new needle bearing will not support the pilot shaft as well as before when the clutch is disengaged. - John

Thought I would show a couple of photos with the new 245/75R16 tires. - John

I thought I would share my experience with the clutch replacement job on my truck. I just did a clutch replacement on my truck after a good service life of 297,000 miles. However, in hindsight, I know now that I should have replaced the clutch much sooner, perhaps at around 225,000 or 250,000 miles. The primary failure was the pilot bearing which I had noticed recently because at times there was difficulty getting the transmission into gear with the engine running. Eventually, the needle bearings were spit out and the shifting problem went away. However, the failed pilot bearing damaged the bearing surface area on the input shaft to the transmission. I replaced the clutch disc, pressure plate, T/O bearing, pilot bearing, and flywheel. I decided to go with Napa because the clutch and pressure plate were manufactured by Luk, as were original clutch parts. I elected not to replace the damaged transmission input shaft at this time because I think that even with the pilot bearing surface damage, I can still get a reasonable service life before doing another clutch job. At that point the transmission may need other parts as well and all the work could be done at the same time. The photos show some of my observations. The friction surface of the pressure plate is not shown, but it looked the same as the friction surface of the flywheel. Also, the heat marks on the flywheel and pressure plate were caused by one event in which I was slipping the clutch repeatedly under a light load to diagnose a steering problem. I could smell hot friction material during this testing. Not one of my brightest moments. - John

Doing some math (3.55/410 = .865 (about 87%) and comparing your speed vs. rpm and my speed vs. rpm, I am guessing that you have a 4.10 axle ratio. One way to check axle ratio is to mark a relationship spot with chalk on the driveshaft end yoke and the rear pinion housing. Then do the same on each rear tire to the ground. Chock the front wheels of the truck and place the transmission in neutral. Have a helper jack up one rear tire and rotate that tire one revolution while you observe and track the revolution of the drive shaft. Then have the helper lower that tire to the ground and repeat the same procedure with the other rear tire. If you have 4.10 axle ratio, then the driveshaft will have rotated 4.1 times. If you have a limited slip rear axle, then both rear tires can be raised at the same. With limited slip, both tires will rotate together. Hope this helps, - John

I have this setup. Just last week I changed over to four 245/75R16 Yokohama tires. For the previous 297,000 miles I ran 265/75R16 Michelins. The 245's are performing just like Mopar1973Man states and I like the benefits - less steering effort, better braking (with and without exhaust brake), and more time spent in sixth gear. One more benefit - the truck is 1/2 inch closer to the ground. Also, I do tow in sixth gear if my road speed is higher than 45 mph, which is most of the time. And, if the grade is 5% or less I will stay in sixth gear just as long as my road speed is 50 mph or higher and the speed can easily be maintained. I agree with Mopar1973Man here. Your engine rpm numbers don't match the road speed numbers for 3.55 gears. Your 235/85R16 tire and my previous 265/75R16 tire are virtually the same diameter. With my 265 tire the tach would read 2000 rpm @ 50 mph in fifth gear and right near 2000 rpm @ 70 mph in sixth gear. Thanks, Mopar1973Man, for introducing the 245 tire idea. - John

The MPG's sound good along with the overall performance benefits. Tomorrow, my wife and I will be leaving with the travel trailer to Baker City - we purchased a 5 acre parcel of land there right at the base of the Elkhorn Mountains, about 14 miles northwest of Baker City. We will spend about three or four days there figuring out where to put the well and septic system and to find out what is required from the county to build a house there. This will be the last trip with the 265 tires and the next set of tires will be the 245's. Thanks for your prompt response about the fuel mileage. - John It sounds like you are happy with the 245 tires, as well. Thank you for your input. Having the 6 spd manual transmission, my overdrive is not quite as tall as yours, so I think that I will be able to climb most grades in overdrive - my combined truck and travel trailer weight is 12,500 lbs. - John

I have noted that for a number of years you have used 235/85R16 tires on your truck and you have liked their performance – less stress on the steering components, less rotating mass, better snow traction, etc. I have run 265/75R16’s for the life of the truck and was going to make the change to 235/R8516’s because I agree with your observations. I am ready to buy the tires now, but I just read about your testing of the 245/75R16 tires on your truck and your positive performance observations. So, I am holding off purchasing tires until I read about your fuel economy with the different final drive ratio using the 245 tires. I rarely drive over 65 mph (especially when I’m towing), so the benefits of 245 tires would seem to be excellent. I am looking forward to hearing the results of your fuel economy test. - John

When I lived in Leadville, Colorado, I bought a new Honda Foreman four wheeler in 1987 - I think it was the first year for them. Back then it came with a 350 cc engine and a 5 speed manual transmission with first and reverse gear being extra low ratio. I modified a used electric over hydraulic power unit and mounted it and a large battery on the rear rack. I then modified my 5 ft snow plow blade with a hydraulic angle cylinder and plowed snow for eight winters there - didn't even need chains. It was an awesome machine. My daughter just sold the four wheeler last year (30 years old and still running, of course). - John

I am currently approaching 294,000 miles on the original clutch and transmission with lots of towing over its life. The last 45,000 miles have been with a Smarty programmer set on Software 5. I don't have coolers on the transmission (someday I will), but I overfill by one quart. If you make an effort to match road speed to engine rpm during shifts (up and down), you can make a transmission and a clutch last for a very long time. Enjoy the truck! - John

For awhile I thought you were going to have to change your slogan to "Truckless for the first time FOR a decade". - John

When I quit calling my truck a dog, it started behaving much better. First, can you confirm that it is the brake light (not the taillight) that is staying on? The two circuits share the same bulb (but different filaments) in the rear of the truck. Also, is the problem light illuminated at full brightness when this occurs? The turn signal switch (mulit-function switch) and the emergency flashers are also a source of power to the brake lights and the both circuits share the same filament in the dual filament bulb. You might try removing the emergency flasher fuse to see if that changes the symptoms. The brake fuse and emergency flasher fuse are supplied with unswitched power, and the turn signal circuit fuse is supplied with switched power. - John

If the clutch engagement is reliably at about half pedal during all driving conditions, this would indicate that the clutch is operating as it should. If the pilot bearing is dragging and forcing the transmission input shaft to rotate when the clutch pedal is depressed, it will be hard to select a gear from neutral with the engine running and the vehicle stopped. Here is a way to test for a dragging pilot bearing. After driving the truck for a few minutes and when your hard-shifting symptoms are showing, drive the tuck to a safe parking place. Set the park brake, shift the transmission to neutral and leave the engine running. Do the following sequence several times: 1. Depress the clutch pedal and wait for about 3 seconds (this will give time for the mass of the transmission input shaft and countershaft to come to a stop). 2. Leaving the transmission in neutral, release the clutch pedal fairly quickly ( you should hear the engine slightly load when the clutch engages the transmission input shaft) Note approximate pedal position when you hear the engine slightly load. If you do detect the engine loading during this process, then the pilot bearing is doing its job by allowing the transmission input shaft to stop rotating. If you do NOT detect the engine loading during this process, then friction from pilot bearing is latching onto the transmission input shaft and not allowing the input shaft to stop rotating. Some other things that can contribute to hard shifting while driving. * wrong type of oil in transmission * not matching road speed to engine rpm during shifting * low oil level in transmission - John

I agree. It was partly for this reason, and also to gain the option of having two wheel drive in low range, that I disconnected the vacuum controls at the transfer case and installed a manual vacuum control valve in the cab to engage the CAD. When roads are expected to be snowpacked, I will engage the CAD before I move the truck so that I can go in and out of 4wd on the fly as needed without harming the syncrho in the transfer case or harming the CAD unit. The vacuum control valve is a heater control valve from a Pontiac in a salvage yard. The cost was $2.00 and with a slight modification it has been in use for over 200,000 miles. The truck has 292,000 miles currently with no CAD problems yet. - John

Just wanted to share a dead pedal experience. One March 19, 2018, during a return trip from Crescent City pulling my travel trailer, I exerienced the dead pedal syndrome about fifteen times in the last 35 miles to home. Each event lasted about 20 seconds (sometimes longer). It was a slow 35 miles, but the truck made it home. At this time the truck had logged a total of 289,000 miles with 202,000 miles on the VP44. The check engine light came on and stayed on and code P0121 ( Accelerator Position Sensor Signal Voltage Too Low) was set. I was hoping that I could replace the APPS and the problem would be resolved. I went on-line to Blue Chip Diesel for help. I was immediately disillusioned when I read the following: “The symptom of Dead Pedal is rarely caused by the APPS (Accelerator Pedal Position aka Throttle Position Sensor) and 90% of the time it is caused by a faulty computer on the top of VP44 Injection Pump. These numbers are NOT an exaggeration.” My old analog voltmeter doesn’t work anymore, so no testing of the APPS. I decided to replace the APPS with a Timbo since the original had logged 289,000 miiles. The good news is that I have driven over 3,000 miles (mostly towing) and the dead pedal condition has never returned and no codes have been set. The engine runs strong. Only time will tell if replacing the APPS was the correct solution. I will post again if I the dead pedal condition returns. - John

Check tightness of fuel injector line clamps for knocking sound at idle or just off idle. A friend of mine has an 07 truck that the engine knocked at low rpms and I was looking into re-clocking the CP3 pump when he noticed #4 injector line clamp vibrating. I tightened the very loose clamp and the knocking sound immediately disappeared.. Check for broken or loose boost clamps between the turbo outlet and intercooler, and between intercooler and engine. Also, check exhaust manifold for cracks or leaks. Either situation could lead to significant loss of boost or drive pressure, and a squealing sound could occur as air or exhaust gases escape under pressure. - John

I should have stayed with my OEM pump. - John

Interesting. At 215,000 miles on my truck I replaced the original power steering pump even though it was still working. I replaced it with the Boregeson pump. The Borgeson pump had started making a very minor noise under certain conditions a few months ago and it failed suddenly and completely at just under 75,000 miles later. I now have a Napa remanufactured pump on the truck. It will be interesting to see how long it will last. I was disappointed in the short life of the Borgeson pump. How many miles did you get out of your Napa pump? - John

I understand - good luck with your search. - John

One year ago I purchased a Denso compressor (same as OEM ) from Amazon for $203.00 with free shipping. The original compressor was still working fine at 270,000 miles, but the shaft seal was leaking refrigerant, so I was having to recharge frequently. Since the first compressor, a Denso, was so reliable, I went with another new one. - John