My trans siezed again last week in 6th gear. It was rebuilt 2 yrs ago and I found the shop that did it, didn't know WTH they were doing(my bad) After may calls and searching the net, I ordered one from Smart Auto in OKC. They had a good price, $2595 discounted $100 and were knowledgeable on the updates/mods to oiling system. The shop put in OEM amount/type of fluid. It drove great, shifted like it's supposed to. When I got it home I pulled the top off trans to add extra fluid, after 1qt of Lucas and extra mopar fluid, it ended up with 8qts total to the top PTO cover bolt( I could see it via the top shifter opening) Truck has 331k, and if this trans holds up like they claim, I should be well over 500k B4 any issues. Not a cheap fix, but have learned more of these trans because of it and hope it may help others in future. ASK when having a rebuild or buying re-man trans if it has updates and what they do to them. Good luck!

 

I agree. High Gear Trans in Memphis, TN knows them well also. They built one for me when my 2000's nv5600 died at 74k miles (10k miles after I bought it!) previous owner put wrong oil in it. They updated everything to 2004 specs and redrill case as well as drilling/tapping a fill hole high up on the case for proper oil level without pulling shifter. It shifts better than my 05! Smooth as silk after about 30k miles.

 

So what makes then actually I'm out ? The wrong fluid or what I ran royal purple is that good fluid for these trannys

 

Can't we just add the extra oil without the retrofit I mean I can't think of what has to be done to make it hold a little more oil I would think a quart or two more should work

 

Mine shifts the best with RP synchromax - 6 qts. Craig

 

http://www.high-impact.net/transmiss...iesel10cyl.htm

 

I did talk to the people at HighGear as well. As for over filling it, you can use the top bolt of the PTO cover if you don't want to pull the shifter top assy. I did find by filling it to the top bolt, I came up with 8 qts. total fluid, 3.25 over OEM specs. Shifts a touch harder in cold weather until fluid gets warmed up, but if it helps rear brg. to live, then so be it. Once fluid is warmed up, it shifts nicely. or as nice as a NV5600 can that is.

 

You put Lucas oil additive in it? Got to Bobistheoilguy.com and see how well that stuff makes oil foam.

Also I would be leary of overfilling it too much. Overfilling can make to oil temp skyrocket. Seen it lots on gearboxes we have at work.

 

I've ran Lucas in my trucks from day 1. The origional trans had 237k on it B4 letting go. The 3rd memeber is still factory, engine carries 50lbs at temp. My 02 has right at 300k on it. I run it in engine,trans and 3rd member. So far it has worked for me. Think I'll stick with what seems to work for me. I will give Pennzoil a try at next trans change vs. OEM fluid. Will see what that link has to say, always willing to look at anothers opinion. Am curious as to how over filling can cause an over heating issue. IMO more fluid takes longer to over heat. If that were the case, maybe we shouldn't run near 3 gal of oil in crankcase? BTW, I do oil sampling at every change via Blackstone labs and they're reports have always come back positive.

 

If you overfill, the oil get frothy from air entrainment. Once the oil has air entrainment, it not only loses its ability to lubricate, but builds temperature in a hurry.

If more was better why not just fill it to the top?

On our gear boxes (speed increasers on pump drives) we found the manufacturer specified level works best. Same thing on oil bath bearings on the electric drive motors.

Makes sense, it is thier product, and I'm sure they put R&D into proper oil level.

I would not play with the level at all unless you have a reliable method of checking the oil temp as your driving. My bet is your tranny is running quite a bit hotter than it would with with the oil at manufacture recommended level.

It all comes down to what you are comfortable with, but I've seen proof more is not better, so take it for what it's worth.

 

Any reputable rebuilder will tell you that ya need to run these trannys over filled to get sufficent oil to the rear bearing (a fact. snafu) along with updates to the case. If anything in this case, it takes longer for fluid to warm up to smooth the shifting, after up to operating temp, this thing is nice n smooth. Ran the org. trans 2 qts over with Lucas and got 237k out of it. think I'll stick to whats worked for myself and others with same trans.

 

Never overfilled mine, ran a pto cover filter and Pennzoil Synchromesh. Also got 237k before it dropped its guts. VERY disappointing, inconvenient, and EXPENSIVE! I know of 5 speeds with 600k+ heavy miles. 237k lifespan is just plain unacceptable.