kzimmer

You'll be fine towing that, lock out overdrive and let er rip. The D60 and D70 definitely have different gear sets. I have 3.54 diffs as well, and 35" tires. I'd love to swap in 4.10's, I just can't justify the price. The only way I'll do it is if I can find a couple whole axles ready to swap in for dirt cheap.

I had similar issues when my fuel system relay failed in the fuse/relay box under the hood. I swapped with the fog light relay. Still need to order another one.

This is a complete thread derail but I don't want to start a new thread just for this. Apologies in advance. Reading about things failing while driving made me think of this. Last night I finally got my truck rolling after it being down for almost 14 months. Made it probably 10 miles, blew a boot off the turbo somehow (I think it snapped, I probably over tightened it... Close to 2 years ago!). Pulled over and took me a few minutes to find it... In my back tire. FFS. ... Brakes work good though. Hah.

Sweet! Where were you when I bought my last pile of parts lol.

Yep, that and others in the link I posted.

There's 3 different possibilities for the front available here. Surely one of those must be the right one? https://www.rockauto.com/en/catalog/dodge,1998,ram+3500+pickup,5.9l+l6+diesel+turbocharged,1400218,brake+&+wheel+hub,abs+wheel+speed+sensor,1912

I'm not debating the fact that being higher up adds wind drag. Just strictly gear ratio and RPM, I've always understood the 5.9 to be in it's most efficient "sweet spot" between 1800 and 2000 RPM.

Check Rock Auto, I see them in stock.

Can't go by engine load, the load measurement is based on fuel injected "per stroke". As RPM's increase for the same amount of load, naturally, less fuel per stroke is required, so load will appear to drop. Not sure, I never drive that fast. Truck will be back on the road Saturday, I'll try to get you some data on that in the near future. With the 2" level and 35" tires I'm probably seeing a lot of wind resistance. That and where I live it's always so damn windy. Yeah that's what I was getting at, I missed this response at first. This is a very good question for the OP. I was thinking about this myself. Does a failing pyrometer read High?

At those speeds, I'm wondering if a truck with a lower final drive ratio would get better mileage, as it would move the RPM's closer to 2000?

Mike are your EGT's just that low because your RPM's are screaming high?

That's likely not a computer issue, but a trans issue.

I don't want to offend, so take this with a grain of salt, but if you need that much out of it, it might be best to keep it. I don't think you'll get in the ballpark of your asking price. Edit: If you do, let me know, because I'm selling my truck, haha.

I know, I was kind of being sarcastic. I don't believe in paying a company money for the right to purchase their product, when there are plenty of other good quality products out there that I can buy normally.

Injector issues, injection timing retarded, pre turbo exhaust leak, wastegate exhaust leak. Too many possibilities. More real data needed.

There's still something else missing. The gearing may not be great but that's not the only problem. My truck has the same diff ratio on 35" tires and it isn't that bad.

What if the waste gate was leaking?

Never run two tuners than advance timing. Bad news bears.

On the bus he's using to communicate, what's the master? The ECM or PCM?

I think this is the most important clue. I'd like to know this as well. Does a plain old cheapo OBD2 scanner lose connection, or is it the j1939 bus, etc.

My VW could yank a tree stump just fine, haha.

Just yanking your chain.

Except your truck will look like a fat guy with really skinny legs, lol.

Unless you are towing in the city full time and not on the highway, you are comparing apples and oranges. Sounds great to me. Vary the weight a little bit, maybe a slightly heavier foot, more or less stop and go traffic, varying temperatures, varying quality of fuel, 12 mpg is not out of the realm of possibility.

12 mpg in the city with a 7000 LB hunk of steel sounds pretty reasonable to me.