OldRedMack

Did they put different gear sets in this transmission for dumps and semis? Mine started life as a semi, but with a double frame, 44s, and 4.42 we bought it and converted it to a dump. In GA we are at 64k gross on tandems. Even after the engine upgrades with way more power, this transmission just doesn't seem to transfer power right too me. I know what Mr. Wild will have to say about it, and with our other trucks being fuller's I tend to agree, but I dont want to give up on this transmission yet.

That is the way mine is.

If I remember right, I think mack tech posted a few years back that mike at K&S figures the optimal life span of those injectors at 5k hours. Or was that just for the AI engines.

Did you change the eup that was throwing a code? I had no codes for a weak eup and never would have known if I didn't install new injectors and developed a skip.

Have you changed the drums or pads?

Looking for the wide person and a half passenger seat so I can take my son's with me when I go get sand.

Opening all the way at only 8psi seems like the problem in my mind at least. Seems like it shouldn't go full on till 20-25psi.

It's a bostrom seat, you can get a replacement for cheaper but it wont match. If you want it too match, probably have to go thru mack. I just bought a new seat for 1 of mine, the bostrom replacement was like $480.00 for the entire seat including base with the airbag from mack. The factory matched seat was $1,400.00.

You will also get this noise if you have a hitch on the back. The d-rings for the safety chains slapping on the hitch plate.

Have you pressure checked the CAC and intake manifold?

Maybe stuck in the manifold?

Check the yoke bolt for the driveshaft, mine has lossened twice with loctite.

I wouldn't think the manifold swap would accomplish much because if remember right the s300 has the smaller restricted ports leading to the turbine. Anyway you can talk him into installing a pyrometer? How much is the modified stock turbo costing him, I think you can pickup a generic s400 for under a thousand.

So it's a 370 with a 460ac cam. Is that all the mods? Do you know what the egt's are? Is it an electronic boost gauge or manual? If it's a manual gauge is there a lot of needle deflection? Sorry for all the questions, just wanted to know all the variables. In the end though, that s300 and ai manifold are only useful as a paper weight.

Check the belt tensioner pulley.

I do like the KISS method being applied here, and would love to try out that setup, but dont know if I could get over that price tag. Having never had to buy a vgt though, that price might be on point.

We have always gone off the flywheel and done it 1 at a time working our way around. Pain if your doing it by yourself, but I would rather only do it once.

I would recommend pressure checking the intake and also unplug ecm and check for corrosion. Plastic coolant tanks are prone to cracking and leaking on ecm.

Yes, but it is a dump truck so I dont calculate fuel mileage. On average I'm probably saving an 1/8 of a tank or better a day.

The one other thing I think about is air flow. The turbo and injectors could be matched perfectly, but the filter is too restrictive or the 3" inlet on the compressor housing is not enough. Maybe re-working the piping and putting on a 5" "race" housing could create enough volume to satisfy it?

He did, im kinda stumped on it. Only thing I can figure is the turbo isn't exactly right for that setup, but that's hard to say not knowing exactly what they did to come up with their injector stages. Need to know what's been done so the turbo can be mapped right and everything works in harmony. That's not saying the turbo is the wrong size, but the minute changes in the pitch and length of the compressor wheel blades can make big changes in power and temps. I say that from experience, we tried a couple different wheels trying to see if there was anymore to gain out of it and ended right back where the math told us to be. The "higher performing" blades we tried resulted in higher temps and less power.

Get a high temp manifold.

Well, sorta. That is for the AI series engines. The AC series engines have an external egr and I'm not sure if anyone has tried to convert an AC into an AI.

Please dont retire the pic, it is fantastic.

Thank you.