Safe HP for the G360

[ihredneck]

I have two ways I may go with the mods on my 92 W350
- P7100 180HP pump & mods with 215 sticks, or 5x12's (have a spare fuel system in my shop)
- VE pump with simple mods (pump and injectors rebuilt not too long ago)
I'm wanting this to be reliable and was wondering what would be a safe HP to have without worrying about taking out the input or any of the other bearings in the tranny.

Just rebuilt it too, so it is "fresh" currently

[dieselcountry85]

Not sure of the specs on the 360 but if its anything like the 4500 or 56 about 75-100 over stock and things start to get sloppy.

[CumminsPower59]

Not sure of the specs on the 360 but if its anything like the 4500 or 56 about 75-100 over stock and things start to get sloppy.

I dunno about that, bgilbert ran 550+hp through a Getrag, plus plenty other guys using thiers to tow a good chunk of weight too...

A good clutch goes a long ways in anything...

One big thing about Getrags is that it is plenty full, over full. I ran 5 quarts in mine. Change the lube often too. Don't shift them hard, or lug them, they get angry at that

[Tacoclaw]

If you don't abuse the poor thing I don't forsee a problem with either of those two paths. They seems to hold together even up to the 4-500 horse range pretty well, but all it takes is one clutch dump or one sled pull for it to all go wrong.

[ihredneck]

Thanks for the input!

My main concern was to use it as a truck, because it is.

I probably wont even go over 375 at the wheels, but I know that enough stress with a load and things can go down hill quick with the rear axle, tranny and any other weaker links

Got any suggestions for fluid? As I mentioned, got a fresh rebuild and so might as well do it good. I've heard of synthetic gear lube, not sure about that though...

[CumminsPower59]

Lube in the Getrag is kind of personal preference, I ran 5w30 Royal Purple. Some guys run 15w40, or even 50w. It really depends. I run synthetics as much as I can, except the engine oil, as I run old school CI-4 rated oil.

[BobS]

Back in 2004 when I bought my truck the Getrag transmission in it was shot. I remember a spiral piece of metal sticking out of the bearing retainer. it had 102,000 miles on it. I did some research back then and there was a transmission site that stated the G360 was rated for 400 ft/lbs of torque. This met Chryslers Cummins engine specifications and appears to be why they went with it. No, I can't remember what the website name was. The previous owner of my truck turned up the pump slightly and pulled a gooseneck trailer to local farm shows. We both figured that the transmission failed because of the increased torque in combination with the weight of the trailer. The transmission was overfilled with synthetic oil just as everybody else has been doing. There seems to be no consistent pattern of when this transmission will fail. Some are much luckier than others. I replaced mine with an NV4500 45,000 miles ago and everything so far has been just fine.

[oldestof11]

Stomp put 800+ through his.

The only reason you need a bigger input is if you are going to dual-disk IMO. The greater clamp load, less slippage, more torque is what kills inputs on autos.

Put a good synthetic in it, overfill by 1 quart, don't lug in low RPMs (going from 45-60 in 5th with stock power can kills these things too.).

The NV's don't like HP and 5th gear so keep that in mind too.

[ihredneck]

Ok, I guess they Synthetic Castrol 85W-90 that was suggested isn't so bad, I'll be sure to overfill then.

Bobs, that's what I'm concerned about, because I'm gonna be pulling, but at least not very often more than 10k, but maybe the newer bearings have some mods that will improve wear on it

Old, I'll remember not to lug it and keep the RPM's up. I also have a 95 NV4500 and haven't had the 5th gear come off, then again it had 400k on it when I rebuilt it and then did the 5th gear fix when it was rebuilt.

[CumminsPower59]

Ok, I guess they Synthetic Castrol 85W-90 that was suggested isn't so bad, I'll be sure to overfill then.

BOOM!

Use something lighter

[ihredneck]

BOOM!

Use something lighter

Yeah, I just did some research and found that out! lol, I'll probably use synthetic 5W30 in it as I realized also needed to get oil into that input bearing ASAP

[CumminsPower59]

BOOM!

Use something lighter

Yeah, I just did some research and found that out! lol, I'll probably use synthetic 5W30 in it as I realized also needed to get oil into that input bearing ASAP

Good deal! I used to buy 5 quart containers and use that. Easiest/cleanest way I found to overfill the Getrag is I would remove the shifter and pour it in that way. Otherwise you can fill it through the top PTO cover bolt or something. I have a pair of large 90deg. snap ring pliers just for the snap ring on the shifter. I can be a pain in the arse to do the first time, but it gets easier each time after that

[ihredneck]

You know, I've never tried pulling the shifter with the tranny in the truck, but it sounds like it's just like the 2nd gens spring loaded locking collar, you either got it in, or you stabbed yourself with a screw driver!
I'll remember that, and changing intervals every...40k miles?

[CumminsPower59]

It is spring loaded, I usually put my chest against the shifter to take the pressure off the snap ring, it would come right out

As for change intervals, not sure on that. Just like the weight of oil people use in these things, its personal preference. Speaking only for myself, I canged the lube every 10k. Some guys go alot longer. The Getrag I had in my old 92 was still original, with almost 160k on it, so I didn't beat on it too much and kept it plenty full with fresh lube.

[oldestof11]

Old, I'll remember not to lug it and keep the RPM's up. I also have a 95 NV4500 and haven't had the 5th gear come off, then again it had 400k on it when I rebuilt it and then did the 5th gear fix when it was rebuilt.

No, it is not just the nut. Towing + 400hp + 5th gear = boom.