The Mad Norsky wrote:

One last thought from me.

As I mentioned before, I have the 385/Aisin Cummins in my 14 Ram. 3:73 rear axle ratio. I have NOT towed my fifth wheel with this rig yet, as I have just been way too busy hauling my truck camper around the country.

Now there are posters here who claim their Ram never shifts out of sixth gear.

Mine does, and in fact, at certain speeds, it goes gear hunting.

It does this mostly in the low 60 to say about 64 MPH speed range. I've used the plus/minus button on the gear shift to display gears, and I can see it going from sixth to fifth then back and forth. Mostly with a good head wind, and on hills. But it gets to the point where I just lock out sixth gear.

Now I can get it to go away from this by increasing speed to say 67 MPH, which seems to be the sweet spot with this gear ratio (the 3:73).

Tow haul mode does not allow the shift to sixth gear until just about at 60 MPH, so I do see the gear hunting as a result of just not being enough RPM'S or speed into sixth gear to allow it to stay there.

So perhaps the 4:10 may have been a better choice for speeds in the upper 50's to low 60's speed ranges.

Sport45 wrote:

Whoever set those gears up did a good job. Nice contact pattern in both directions.

I wouldn't use it a poster pic for Amsoil though. I've seen plenty of clean diffs with just as many hard miles running store-brand oil. The cleanest are the ones with no limited slip clutches, but the 3.73 LS in my F-250 was pretty nice looking running the O'Reilly's synthetic lube with their friction modifier.

The worst looking diffs are the ones that get water in them because the vent tube gets pulled off for some reason or another...

Cummins12V98 wrote:



I know that is not enough miles to prove anything but I was showing the people that said I would ruin my running gear towing that heavy with the 3:42's. I wish I had a pic of my 98 with 300K using AMZ/OIL the gears looked very nice!

Closer pic. I still think it looks pretty darn good Fish!

Cummins12V98 wrote:



I assume you are joking about the transmission pan being small. If you did not know that is a MagHytec aftermarket Aircraft Aluminum "deep" pan. But I am sure you heard of one of your neighbor having a negative experience with one of those also.

Also I am sure you have heard of negative experiences with AMZ/OIL also.

65K on the rear diff towing a combined 29K. AMZ/OIL Severe Gear.

I'm Rick James wrote:


Yes, I've had both the 68RFE and Aisin in a '12 and '14 respectively. Unloaded I cannot tell a difference between the two and when towing my toy hauler the Aisin simply seems to shift faster and firmer than the 68RFE but nothing dramatic. The 5R100 I had in my '08 Ford beats both of the Ram offerings IMO.

FishOnOne wrote:



Just calling a spade... a spade! The above statement I made is undeniable facts but spin it however you like rick.

Perhaps Rick James can chime in as well since he's one of the few straight shooters here that I've read.

Ron3rd wrote:



I think the reason a lot of folks go with the 68 is it's cheaper and if you like the truck and the overall package, the 68 is fine. I'm gonna be in the market for a new CTD (probably Tradsman trim) and all the local ones I've seen have the 68 so that's what I'll go with. Maybe if I was fulltiming with a 5er I would consider the Aisin.

IdaD wrote:



I'm the poster child for this. I could have eeked by with a heavy half ton but a 3/4 ton is just a lot better solution for me, and it really doesn't cost much more than the heavy half once you add HD Payload and Max Tow. I paid $39k and literally couldn't find an F150 on any lot for less than that equipped with those two packages. So, why not opt for the heavier duty truck with all the heavy duty components? I really didn't see any downsides to stepping up a level.

I've been real pleased with the 68 so far and in my case I didn't think it was worth the extra money for the Aisin. This truck is my daily driver and weekend tow vehicle and I figured the 68 would be fine for that workload.