keithb7

My '98 24V Cummins sees about 6,000 - 7,000 miles per year. I tow my RV in the summer. I run Caterpillar DEO 5W40 full synthetic oil. I change my oil annually. Every October just before winter. I take an oil sample in about April, and another in Oct at the time I drain the old oil. I send it in to a lab for analysis. The lab tells me what's going on with my oil and engine internals. Oxidation is a good one to watch, aside from wear metals. I have no concerns and am not guessing when to change my oil.

Just following up to say that I added a second small bottle of friction modifier and the symptoms are gone. I had added one at the time I changed the diff oil. Apparently its not enough. I also took an oil sample in December and sent it in for analysis. I last changed the diff oil in June, I think. The oil sample came back good. I am in good shape again it seems.

I am attempting to track down a driveline vibration. Seems to be happening when accelerating from a stop while turning left. Unknown history of diff and drive line maintenance. I Changed the diff oil in July. Not many miles use since June. Will take a diff oil sample soon for analysis. This weekend I drove at hiway speeds for about an hour. No issues. Got home and immediately used a laser thermometer to check u-joint and diff housing temps. Ujoints all seemed fine and no hot bearings. Rear Diff housing pumpkin measured about 100F. Housing near pinion recorded about 120F. Is there something maybe going on with a pinion bearing? Any idea on normal housing temps after a good drive? Looking for any clues as to where to look from here. Thx.

Hi folks, I am looking to tap into the tranny oil on my 98.5 47RE transmission. I am unsure where to thread in the gauge temperature probe. I would rather not be reading oil temps after it has been though the cooler and is re-entering the tranny. I was thinking it would be better to read the hot oil as it exits the tranny. No? I was under the truck today looking around for a test port plug. On the RH side I see these two plugs as shown in the photo. Am I even on the right track here? If so, which one is preferred? Thanks, Keith.

Ya, you guys are right. Thanks for the reminder. I was pulling a long steep hill towing the trailer. 2x I pulled over, part way up, to let the fuel pressure build up to 17. Sat for a while at idle to cool down the VP. It helps probably, but it ain’t right, nor the solution. Enough screwing around. I’ll order up the mechanical pump, off the crank pulley.

Just a follow up report. Two week vacation towing a 23 ft travel trailer all around. Trailer is probably 6,000 lbs loaded up. Lots of driving. Lots of hills. Hiway speeds too. ISS Pro fuel gauge that I installed and trust, gives me readings. 60-65 mph on flat nets me about 12 psi. Lots of hills (up and down) and winding roads. Backing off the throttle for corners and down-hills, fuel pressure quickly goes back to 14-16 psi. At idle maintains about 17 psi. Pulling hard up steep hills, watching all my gauges, I back off throttle and gear down. I maintain 10-11 psi. 10-12 lbs boost. 1,000F EGT. Stock engine and newer stock turbo. So far the Herko is hanging in there. VP-44 temps? I have no idea. I do go over 14 psi fairly often. Guessing it’s doing an adequate job cooling.

So far no problem here. Been running the Herko since March. Lots of towing. Depending on the load I’m towing it maintains 10-12-14 or so psi at 65 mph. Not awesome but certainly better than the stock Carter pump. I’m saving pop-cans to get the mechanical pump off the crank. Hopefully my VP holds out. Lol.

I had heated up my old rotors and had a caliper of unknown age seizing. So I had some vibration but it felt different. I installed new rotors, calipers and pads. If the couple of studs were not quite seated properly I was thinking they were the culprit. As mentioned I am going back in to install new wheel bearings with new studs. Thinking I should press in the new studs. Ensuring they are fully seated.

I recently performed my first rotor swap on my 98.5 2500. I pounded out the wheel studs with a single hit of a 5lb sledge. Easily came out. I swapped the wheel bearing assy over to the new rotors. Used same sledge to set the studs back in the same wheel bearing housing. A few studs did not want to set back in place flush. I whacked ‘em a few times and carried on. Thinking I’d pull ‘em right thru when I torqued the lug nuts up at wheel installation. Well I’m still cranking a few nuts tight. I’ve been test driving and get a slight vibration when braking. I have driven, braked and got hubs warm, then retorqued 3X. Seems I am almost there as the vibration is improving with each retorque. What is the correct procedure? A hydraulic press I assume? To seat the wheel studs in the bearing hub properly, the first time? I’m goin back in as I decided to order up new front wheel bearings. Mine appeared original. I ordered new NGK USA built bearings. Came with new studs too. I’d like to seat them right this time. Also I read 175 ft lbs on the centre nut for bearing pre-load. Plus a little more to align the cotter pin. Seems high but I have limited experience with the truck. I’m used to 3-4 ft lbs on other light vehicles I’ve owned. This Torque is right? Just double checking. I appreciate your experience Thx.

My 98.5 does have the rear load sensing valve. I will consider unhooking it and strapping the lever in the uppermost position. My trailer brakes are in great shape. I took them apart. Inspected cleaned and adjusted. They are nice and tight. I can lock the trailer brakes up using my electronic brake controller. I chose a hitch with anti-sway bars It too doubles as a weight distribution type hitch. Upon installation I did not tweak it to max transfer more weight to the front axle. The tongue weight is still nicely loading up the rear suspension. I chose the anti-sway type hitch to minimize the sail-like effect of trailer walls at hi-way speeds. I was driving a 2017 F-250 today. It has a digital inclinometer. I can’t vouch how accurate it is. It reads in degrees. I drove up my problem-hill today. Average reading was around 6 -7 degrees. However some spots registered 8 degrees. Converting degrees to % slope, that converts to 11% - 12% average. Up to 13% slope at a couple points. No wonder my rotors warped pretty much immediately after a trial run down. Second run down I manually worked the trailer brakes to have them do more of the work, sooner. I can’t take it any slower going down. Gravity wants to pull you at a fixed rate. As mentioned: in first, auto tranny...not gonna do it. I just ordered a set of heavy duty commerial tow grade rotors and pads. New up-rated calipers too. I’ll replace all and also the wheel bearings. All are cooked anyway. Barring this, the next step I am prepared to take is obtaining a lighter trailer. There’s no accounting for the decision to alllow this goat trail to be built, and passed as a drivable road.

I agree guys my 24V eats up normal driving conditions. Hwy or city roads. However, try a 10% grade down hill for 3 miles towing a heavy load. Auto tranny dropped into first gear. Keeping your speed at under 30 mph...I have found the limits of a stock truck. Everytime I hit the brakes this week I am reminded.

Yes my truck is 4x4. Posi-lock?How does that look? I’m unsure. How could I get 2 wheel low? Thx.

I towed my 1938 Plymouth car over 450 or so miles of hiway at various grades over the weekend. I towed an 1800 lb trailer loaded up with a 2800 lb car as well as as additional 400 pound engine block. I was very impressed. The auto tranny was just fine on normal roads and hi-ways. I switched off the OD when climbing hills. Braked and geared down on descents. No issues with brake heat due to excessive breaking. The only issue seems to be the darn steep winding hill near my house. It’s cooking my breaks. It is too winding and steep to lay off the brakes, and descend safely. Otherwise the auto tranny and the 24V 5.9 are certainly adequate for my needs. Dang.

If I have 3.55:1 rear end, and first gear is 2.45:1 is my final ratio 6:1 when in first gear? If I had 4.10 gears, and retained the same tranny, in first at 2.45:1, is my new final drive ratio 6.55:1? Hmm. I wonder how much effect that may have on the hill, both up and down?

John you make some real valid points. The tranny gearing is likely suspect. I have the 47RE. First ratio is 2.45:1 Like you said, hardly ideal. Rear end diff ratio I am not 100% sure. I'll get under there and see diff tag. My tires are stock. Engine is stock.

An update: After the initial tow test with the trailer, I was also not happy with the brake performance. I pulled the rear drums to find them at the end of spec. I had an "oil-misted" wheel cylinder. The front pads and rotors seemed ok. I proceeded to replace rear cylinders, shoes, all springs and hardware. New drums and 2 new rear brake lines. After setting everything up, seemed good. Certainly I feel safer now. This darn aggressive long hill I must deal with, now has me concerned about front brakes. They are getting quite hot. The trailer brakes are working very well. I can lock them up. New tires on the trailer. I go down the hill in first gear, auto tranny. I brake as little as possible however need to maintain a comfortable speed. The powertrain offers little to hold back the speed on the descent. I don't ride the brakes, and additionally I manually hit the brake controller to put a little more to the trailer brakes when braking. Also keep in mind, the trailer is not loaded up yet. The trailer is well within spec of the truck's capacity. The previous owner did the rotors and pads about 2800 miles ago. I have no idea what quality rotors or pads were used. What are my options here? I am not feeling comfortable about this hill every time I leave home with the trailer in tow. Shall I consider premium HD long life brakes? Drilled and slotted rotors? High performance brake pads? Will this help dissipate some heat? Maybe the rotors on there now are economy cheap crap. I don't know. The heat is going to kill them. Does anyone offer an exhaust brake for my 98.5 24V? A feasible solution? Do 1T trucks have larger brakes? I assume so. Wondering, maybe I should have went 1T. What about if I pull over at the top of the hill and engage 4WD low range? Likely this will hold me back, however at what expense to the drive box gears and bearings? Stress them to destruction eventually? Ideas, tips are welcome.

Interesting! So I went back out and tweaked the rear manual adjusters even more. Moving the shoes yet closer to the drum. I read that the proportion valve limits hydraulic braking power to the front, until there is enough pressure built up on the rear brakes. Some sort of system relief in the proportion valve determines this. The rear wheel pistons only travel so far. Really not much at all. With the rear drums out of adjustment, the rear hydraulic pressure does not built up quite enough to offer full equal braking front and rear, it seems. Braking is better now. Like it was before I started this brake work. However, I'd still like the pedal higher with more positive feel. I suppose one should consider the 21 year old master cylinder at this point. Likely well past it's prime. The previous owners did not do a good job with brake maintenance. Wheel cylinder brake fluid came out looking like the ganges river.

1998.5 24V. Rear wheel ABS. Recent work included: 2 new rear wheel cylinders. New rear shoes. New shoe springs & related hardware and new rear drums. Two rear brake lines were so corroded they snapped off at the nut on wheel cylinders. I made new lines. Mounted everything up. Unfortunately had to go to work, and could not get the new lines on for a day or two so master self drained. All rear shoes and hardware seemed to go on fine, and appears to be functioning properly. Recently I read several posts about bleeding brakes. I filled up master and started with my mity-vac vacuum system at each corner. Attempted to bleed by myself. Little results felt on the pedal. Tried again this morning with a helper and manually bled the system. Helper pumped and held down while cracked lines. I started at the master cylinder lines and bled, then on to the proportion valve line connections. Then the ABS connections. Then left rear, then right rear cylinders. Then front right and finally front left. All the while constantly topping up the master cylinder reservoir. Not allowing any air in the system. Master cylinder is still too low. I have rear end jacked up, re-installed wheels and fired up the truck. Rotated wheels and applied the brakes. I am barely getting enough to stop the rear wheels. There are no leaks. I just can't seem to get enough power through the master to each wheel. Maybe there is more air in there? I've gone through a fair bit of brake fluid and pumping. Brakes worked fine before I touched them. I went in for a leaking rear seal and went further based on other findings. Front pads are decent. Going back out now to manually adjust the rears. Make sure they are right and try again. Any tips? Thanks. Keith

Thanks for your feedback so far folks. The truck has 156,000 miles. Stock injectors. The trailer as mentioned is 4,950 dry. Loaded up to the max, (which we hope I'm not doing) it's rated at 7,7670 lbs GVWR. Meaning I have room for 2,720 lbs of cargo, water etc. I will do some research on injectors. Thanks for the tip. My pyro is installed at the exhaust manifold collector right before the turbo mount flange. Slightly off center, toward the rear of the engine. I assume a tuner is required to advance the stock timing? I will pursue to the tranny temp gauge hook up next.

I own a 1998.5 24V 2500 long bed extra cab, with canopy. Pretty well stock powertrain. I installed a new HX35W turbo a couple of months ago. Currently running a Herko fuel lift pump that gives me18 psi at idle. Maintains 10 psi pulling a decent load up a hill. Today I installed an A-pillar gauge package. So far boost, lift pump pressure, and exhaust temp gauges are functioning. The transmission temp gauge, I'll hook up later. This January we purchased a 23 ft RV trailer. We've been getting it ready for camping season. Empty weight of the trailer is 4,950 lbs. Dual 3500 lb axles under it. I just installed new tires on the trailer and upsized them to a higher weight rating. I installed a new heavy duty, square bar type equalizer hitch. It feels good, I feel safe on the hi-way. It tows nice. What has me a little weary are a couple of things. The added gauges on the truck keep me well informed. So much so, maybe I was better off ignorant and clueless. LOL. It's a stock truck as mentioned. The truck never had exhaust pyros when new. How much concern should I have about exhaust temps with this truck? Under hard acceleration, unloaded I can get exhaust temp to about 1050-1100F. I live up a mountain. The road home is pretty steep. It's a slower 2 lane winding road. Speed limit 30 mph. It's about 3.5 miles from the start, to my driveway. I gain about 1100 feet elevation over the 3.5 mile climb home. Average road grade over the 3.5 miles is 10%. You cannot get a run at the hill. My 24V 5.9, to me feels like its working hard to tow my trailer up this hill. Watching the exhaust temps, I backed off the throttle and maintained 950F to 1000F while climbing the hill home. I was at about 8-10 psi boost. My speed was about 15-18 MPH. As mentioned this is all new to me as I prepare the trailer for camping season. The cooling system in the truck handled the climb well. Fuel lift pump pressure steady at 10 psi. Engine steady at about 1900 to 2100 RPM up the hill. I did not actually time the the climb up the hill, but doing the math its about 12-13 minutes up. I feel like I am working the truck damn hard. There are no other hills around here that I know of like this. I suspect I can comfortably tow the trailer most anywhere except back up the hill home. Towing with my Cummins today is new to me. Is this normal? The engines are pretty hearty it seems. Maybe I am just not used to hearing the engine grunt so hard. Should I be concerned or am I being too cautious. Just work the SOB, that's what it's deigned to do? Your experience and comments are appreciated. Here is the rig as driven today.

My 98.5 24V has a hose that comes down and ends up near the front pinion yoke. I did not like the slight drip from my diff pinion area. I thought it was the pinion seal. I changed the seal and cleaned everything up. Then I extended the hose slightly longer so now the drip comes off lower down past everything. Straight to the ground. About a small spot about the size of a quarter drips out after each drive. It does not ammount to much. Just an annoyance on my driveway. I get out there with some heavy duty degreaser, a scrub brush and a hose every few months and clean up the spots. My diff and pinion are staying clean too now!

The wear on the valve train components, to me is concerning. The top end is the last to get oil. It takes a few seconds to get oil pressure up there every time you start the engine. Residual oil sits there from the last time the engine was shut off. So you get some protection. Cold starts, cold thick oil, add more time to get oil up there. Let these engines get oil up there before any throttle is applied, at initial start up. This is where good quality oil really shines, in valve train components. They have the highest stresses in the engine, is my understanding. Once the rocker shafts and bores are scored like this, you're into the shxt, and it keeps getting worse and worse from what I have seen. Oil samples sent to a lab will turn up metal, coming from these scored surfaces. I'd get those parts out of any engine that I intend to keep and run. The metal will get picked up by your filter, however what will it go through before it gets to the filter? What about a filter that goes into by-pass mode? Bad stuff. On another note, speaking of Turbos. Just this week I wrapped up the install of a new stock replacement Holset HX35W in my 98.5. Wow. What a difference. There was some end shaft play present on the original turbo. I noticed the original turbo was starting to let oil through to the air intake side. If you have a high mile turbo, I'd waste no time thinking about replacing it. I'd just do it, based on what benefits I experienced.

Swap is complete. Flashed up and test drove. Nice results! It pulls hills better and seems to have more grunt. I can feel it. I wish had a gauge installed to measure boost with the old turbo to compare to the new one. I am proceding with a boost, pyro, and transmission temp gauge package now. This job was rewarding and well worth my time and investment. Just wondering: Had I taken my truck in to a shop for a boost test, followed by a new replacement stock Holset turbo, what would that likely have cost? Parts and labor of course. Around here I’d guess $3K USD out the door?

I just about ready to flash up with the new turbo. I have read that engine oil should be changed when installing a new turbo. I assume due to the tight tolerances that are present and lubricated by the oil. I have about 1500 miles on a full synthetic oil and new filter when I serviced the truck last October. 5W40. Seems kinda wasteful to dump that pricey oil. I get clean oil and its benefits. Just wondering if the general statement to change oil is pretty generic and they are assuming you have old dirty oil? I chose 5W40 based on our cold Canadian winters and getting good cranking speed. It was effective and I never plugged in all winter and it flashed up just using the air intake pre-heater. I’m thinking if I’m going to dump this oil, I’ll go with conventional oil this time. Then dump it again in the fall to put synthetic back in for the winter.

This is the first time for me replacing a turbo on a diesel engine. I would like to crank the engine to get a good supply of engine oil up to the turbo, before actually stating the engine. What is the proper procedure to do this? Is there a fuse that can be pulled so the VP 44 won't push fuel? Thanks.