New to diesels - Questions

[iniviate]

Hey, i bought my first diesel a couple months ago. it's a 92 W350, cummins, 5spd. i've been slowly getting it back into mechanical shape. anyway, i've got a couple of questions maybe you guys can help me with.

1.) My truck has 320,000 miles on the odometer and it's broken, so i'm sure it's higher than that. What are the chances that my truck has already had the killer down pin problem fixed? Is there a way i can check on it without pulling the timing cover off? With this many miles, do i really need to worry about it coming out on me? i mean, if it was going to come loose, wouldnt it have done it by now?

2.) 3200rpm spring. Do i need to change valve springs or anything else to run this? or is it just as simple as changing the spring? (i've already had my spring out fixing a leaky throttle shaft, i just didnt know about it at the time)

3.) Where should i be trying to run this thing while towing? i've got 315/75/16 tires and i believe 3.54 gears. I was towing my jeep and was around 1800rpm and 1100EGT's.... but on here i've read that 1800rpm is lugging the engine. would i be better off in 4th with more RPMs? Am i best to try and get the lowest boost and EGT, without really worrying about RPM?

thanks fellas. i'm already pulling right along with my buddys new diesels and getting better mileage doing it.

[iniviate]

another question i just thought about....

i read on here that the grid heaters don't even kick on if it's under something like 59 degrees. so, if it's above 59 degrees, do i need to "wait to start" ?

[dodgetkboy78]

I don't wait to start unless it's below freezing. And as far as RPM's, if it feels smooth, your fine, if it feels like your lugging, your lugging. 1800 is a bit low for pulling hard, but for cruising around, not workinghard, I think your fine. Mine is, at least. And my truck is equipped with a anti-lug system in the getrag, it scares the piss outta' me if I lug it by sounding like a trash compactor.

[SChandler]

1) The kdp can fall out at any time is my understanding. Mileage is not a guarantee it won't come out. It may never fall out or it might fall out within the first 100,000 miles of truck life. Having said that, I'm living dangerously as I have not checked either of my trucks (combined mileage of 800,000 miles). Pulling the timing cover is the only way to check.

2) You don't need to changed valve springs when you do the 3200rpm spring, unless you are running it at redline constantly. Just change the spring.

3) 1800rpm is probably ok for the Getrag, 2000rpm would probably be better. When towing, I downshift when I climb hills. Less stress on the trans in 4th than in 5th and it helps to keep the EGT's down. Plus, with the gov. spring in, I could still do 70 in 4th if I was so inclined.

[iniviate]

cool. thanks....

[PToombs]

It's better to keep it above 1800. Around town cruising easy or downhill I leave it there. When I come to a hill or if I'm pulling the trailer I shift down and don't let it pull below 2k.
Make sure you over fill the trans by 1 qt of oil, it helps the trans live longer.

[SChandler]

Good call Pete, I forgot about overfilling the trans. I fill mine through the top bolt hole on the PTO cover on the driver side until oil starts running out (about 5 qts total, 1.5 qts more than factory fill). The extra oil helps keep the front case bearings lubed when climbing hills.

[iniviate]

maybe i need to swtich back to a smaller tire then, as 2000rpm is about 70mph. (GPS) That's about as fast as i want to be towing, and that's the primary use for this truck. unless i would just be better off in 4th gear, then i could run faster when unloaded. i guess i'll just have to try things and figure it out.

i've read about overfilling the transmission. mine is grinding 2nd, so i'm going to end up rebuilding it. i figured i would just leave it alone till it gets rebuilt, then overfill it when it gets reinstalled. although, i guess it can't hurt anything to overfill it now. i'll probably do that if i get some free time on my hands.

i just installed a boost gauge the other day. i was surprised to see it would maintain boost the whole time on the interstate, and even during a shift. i guess i'm just used to a gas turbo engine. btw - my truck hits 14psi just before what i assume is "defueling" .... is that about stock?

[SChandler]

14psi sounds right for stock. I think mine was about there when it was stock. Overfilling it might help some with the grinding. When you rebuild it, don't run the good stuff in it right away. You'll want to change the oil in it after 500 miles or so. I changed the oil in my 92 after driving the rebuilt trans for a week. The oil looked like a metallic paint job in the sun . I overfilled it with Amsoil after that and its been good so far (it's been in for a year).

[PToombs]

If it's making noise now, STOP DRIVING IT! It will cost you way more to fix. The Getrags are known to get worse and worse if they are making noise. If you catch it soon enough, the repair bill won't be too bad. A few of the parts are getting hard to get, some of the other guys know which ones.
I put a 90*pipe elbow on mine to fill the extra quart.

[krazykarl454]

don't get smaller tires. just re-gear, i run 38.5s and 4.56s gears n tow around stuff alot more heavy then a jeep. with no problems. at 70 mph im at 2200, and it runns like a top, n no egt issuses on the hills. if your goin to keep ur 35's get sum 4.10s, and u'll love it

[cummins king]

don't get smaller tires. just re-gear, i run 38.5s and 4.56s gears n tow around stuff alot more heavy then a jeep. with no problems. at 70 mph im at 2200, and it runns like a top, n no egt issuses on the hills. if your goin to keep ur 35's get sum 4.10s, and u'll love it

35's and 4:10s are great, i can turn my pinto down and run 55miles at 1600rpms or better

[iniviate]

If it's making noise now, STOP DRIVING IT! It will cost you way more to fix. The Getrags are known to get worse and worse if they are making noise. If you catch it soon enough, the repair bill won't be too bad. A few of the parts are getting hard to get, some of the other guys know which ones.
I put a 90*pipe elbow on mine to fill the extra quart.

it's not making any abnormal noises, it's just grinding 2nd. thanks though, if i start to hear any noises, i'll stop driving it.

don't get smaller tires. just re-gear, i run 38.5s and 4.56s gears n tow around stuff alot more heavy then a jeep. with no problems. at 70 mph im at 2200, and it runns like a top, n no egt issuses on the hills. if your goin to keep ur 35's get sum 4.10s, and u'll love it

yeah, not gonna re-gear both diffs when i could change tire size for way cheaper. not to mention, it's going to need tires before too long anyway. plus, my speedometer would get right. besides....it's a tow rig, function over form.

i wasn't having any problems towing the jeep. it was keeping up with my buddys d-max just fine and we were both leaving our other friend's ford 6.0 in the dust. i was asking if i was lugging the motor at 1800rpms, and if i'd be better off getting the RPMs higher.

[dodgetkboy78]

If it's making noise now, STOP DRIVING IT! It will cost you way more to fix. The Getrags are known to get worse and worse if they are making noise. If you catch it soon enough, the repair bill won't be too bad. A few of the parts are getting hard to get, some of the other guys know which ones.
I put a 90*pipe elbow on mine to fill the extra quart.

Would you quit saying that? Mine grinds in every gear, AND makes all kinds of noises.........I guess I'll run it till theres nothing inside but oily metal shavings..............

If it is grinding in a gear, try adjusting your RPM's to the gear, to help your synchro's out, or you will end up like me.
Well, I didn't do it, it was that way when I bought it, I swear.

[Ace]

Aren't these engines at or approaching the torque peak around 18-1900 rpm? Wouldn't that be the most efficient place to run steady state towing, assuming EGT allows with a given setup?