With all of the problems people been having lately with trannys, at least some I'm sure, I decided to not wait any longer and ordered some coolers and filter kit for my transmission. Currently I run 7 qts of Amsoil synchromesh (http://www.amsoil.com/shop/by-product/transmission-fluid/manual/manual-synchromesh-transmission-fluid-5w-30/?code=MTFQT-EA) for about 4 years and 20k ml now. Heard different opinions on how much to overfill, some say at least a qt some say 8-9 qts. This has probably been beaten to deaf by now, but also some time has gone by, so hoping for some input from guys that use Fast coolers (http://www.genosgarage.com/product/fc-6-spd-dg/transmission-coolers) on one side and filter kit (http://www.quad4x4.com/cgi-bin/commerce.cgi) on the other, or just fast coolers on NV5600, but feel free to post results on NV4500 or anything you put coolers on. But my questions will be directed at NV5600.

Questions are:

How many extra qts of fluid do you run,

What brand of oil, pros cons

Do you have coolers or a filter or both,

How often do you change your fluid, why,

If you have a filter kit on one side which side do you think would be best for it. Meaning will it work on both sides or does oil fly one way better then the other, I've also heard guys running filter kit mounted on top of fast cooler not sure if there is much room that way. I have 5" exhaust, 

If there are other good ideas I'd like to hear them please. What I'm planning on doing is putting filter kit on the exhaust side and cooler on the driver side and thinking about running 8qts. People say that fill hole on NV5600 is too low so 1qt overfill is needed, I can see a way to have it overfilled by 1 qt with fast cooler and filter kit wold be fill it till oil comes out of fill hole, then put another qt in, but it still might not be as high because filter and cooler will have to be filed together with tranny. What do you guys think. 

@Mopar1973Man , are you over-filling the NV4600?  Do you recommend over-filling the NV5600? I'm over filling my NV5600 until it drips out of the top PTO cover bolt. 

1 hour ago, Ironforger said:

Forgot to ask, are you over-filling the NV4600?  I'm over filling my NV5600 until it drips out of the top PTO cover bolt. 

I use amsoil synchromesh for 12.30 a quart as preferred customer. I overfill to top of the pto side bolts. My local transmission guy told me when I first got my truck to overfill by a quart, I'm running 7.5 with a fast cooler on one side and filter kit on the other. Ends up just above bolt holes. No complaints, some day I may try mobil50 or even 15w49 motor oil. My 3rd synchro is weak from po, I thought about getting a g56 for a spear.You can see bolt holes through oil.

53 minutes ago, Ironforger said:

@Mopar1973Man , are you over-filling the NV4600?  Do you recommend over-filling the NV5600? I'm over filling my NV5600 until it drips out of the top PTO cover bolt. 

 

I tried the overfill for one run on Mobile 50 (5 quarts). Nothing gained for me. I went back to standard 1 gallon fills (4 quarts). No coolers still but Trans Temps are always low. The only time I seen high temps ever was that long grade pull on White Bird grade in 115*F weather. Then the long grade pull to Ely, NV heading up to 7,000 feet. again both run topped out at 200 to 220*F My ISSPro is set for 220 warning light. I've only seen it ONCE! Period. Never seen it again after dropping from 235/85 R16 to 245/75 R16 tires. Final ratio makes a HUGE difference on transmission temps. 

 

Even my last pull. 160*F max transmission temp climbing around in the back country. No faster than 20 to 30 MPH. No wind for cooling and no coolers. No heat problems. 7 x 12 trailer and 2 cords plus on the trailer. 

Edited October 6, 20204 yr by Mopar1973Man

1 hour ago, Ironforger said:

@Mopar1973Man , are you over-filling the NV4600?  Do you recommend over-filling the NV5600? I'm over filling my NV5600 until it drips out of the top PTO cover bolt. 

The reason for overfilling nv5600 is there is a bearing up higher someplace that doesn't get much lube, I've heard of multiple rebuilders say they should have put fill plug a little higher. This doesn't effect nv4500 only nv5600. I'm going to overfill because I trust the guy that rebuilds them. If I had 4500 I'd probably just run it at normal level. 

at 180,000 miles when i did the clutch i drained and refilled my 5600 with what was required +1qt.  no issues.

22 hours ago, Ironforger said:

@Mopar1973Man , are you over-filling the NV4600?  Do you recommend over-filling the NV5600? I'm over filling my NV5600 until it drips out of the top PTO cover bolt. 

 

Eaton/Clark transmission service manual says this:

 

"REFILL - First, removal all dirt around the filler plug, Then refill with new oil of a grade recommended for the existing season and prevailing service. Fill to the bottom of the level testing plug positioned on the side of the transmission. DO NOT OVERFILL, as the excess quantity will serve no useful purpose. If the oil level is too high, it will cause excessive oil churning and high oil temperature and possible leakage."

 

I suspect your high transmission temps may have something to do with this. I would also suspect your temp gauge. Get a I/R temp gun and check it.

 

I do not overfill any gearbox in my fleet, ever.

Exactly... Shouldn't overfill...

Shouldn't but if designed wrong and you have multiple rebuilders day same thing, it only makes sense to overfill, strictly talking about nv5600.

Funny part is the biggest problem is thin fluids. PenzOil is so thin its like 5W or even 0W engine oil hence why the failures. There is no way to make that oil cling to gears or bearings if the oil is slung off with centrifugal forces. One of the few reason I stepped up to thicker lube. Stock NV4500 was 75w-80 when I swapped to Mobil 50 SAE that turns out like 90 weight gear. But being single grade it nearly the same as 80 weight side of the factory fluid you can look up the centistokes at temperature viscosity of both and see it nearly the same. 

 

 

1 hour ago, Dieselfuture said:

Shouldn't but if designed wrong and you have multiple rebuilders day same thing, it only makes sense to overfill, strictly talking about nv5600.

 

I have followed the 1 quart overfill for more than half of the transmission life.  Also, I have only used Pennzoil Synchromesh fluid since the truck was new - no particular reason other than that it was called for.  The NV5600 has never had any repairs (other than a replacement rear seal) and is still running strong with no synchro issues at approximately 345,000 miles.

 

- John

28 minutes ago, Tractorman said:

 

I have followed the 1 quart overfill for more than half of the transmission life.  Also, I have only used Pennzoil Synchromesh fluid since the truck was new - no particular reason other than that it was called for.  The NV5600 has never had any repairs (other than a replacement rear seal) and is still running strong with no synchro issues at approximately 345,000 miles.

 

- John

 

Impressive... 

 

I wished many times PO of my truck wasn't a monkey and took better care it, oh well. 

45 minutes ago, Tractorman said:

 

I have followed the 1 quart overfill for more than half of the transmission life.  Also, I have only used Pennzoil Synchromesh fluid since the truck was new - no particular reason other than that it was called for.  The NV5600 has never had any repairs (other than a replacement rear seal) and is still running strong with no synchro issues at approximately 345,000 miles.

 

- John

Good to hear.  I tried the Pennzoil Synchromesh first but shifting into third was a bit funky.  I took that out and tried Amsoil Synchromesh + 1 quart, now it's all good, so I'll stick with the Amsoil for the rest of the life of the truck. 

 

Got it at just under 100k miles so hopefully it'll last a good long time.

7 hours ago, Mopar1973Man said:

Funny part is the biggest problem is thin fluids. PenzOil is so thin its like 5W or even 0W engine oil hence why the failures. There is no way to make that oil cling to gears or bearings if the oil is slung off with centrifugal forces. 

 

 

I agree. I bought my truck ('01) in '03 with 34k on it and changed the oil with Penzoil Synchromesh, I didn't like it, so when I changed it again I used 15w/40 engine oil, the same thing I was/am running in my '91 w/Getrag. I now have 350k on the '01, 330k on the '91. I change all gear boxes every 36k miles except the front axle, it goes 100k per change.

 

My thoughts on some builders that say overfill, is, they get a tranny that shows lack of oil, damage. What they don't know, is, how many owners has the tranny had that may have let it get low or poor maintenance. If you keep it clean and full at all times, it will be fine. This is especially important on 4x4 models. If the tranny develops an internal leak to the t-case and you don't check it very often it will be toast in short order. 

 

The dip stick or fill plug is where it is, for a reason. Don't overfill and for sure don't underfill or let them get low. Is it just the Dodge forums that recommend tranny overfill, (Getrag, NV4500, NV5600, G56) or do Ford and GM forums say it too? I really don't think Dodge tranny manufacturers goofed with their fill plugs. 

 

Now, with all that said, if you want to overfill, have at it, I don't mind

 

 

 

 

1 hour ago, NIsaacs said:

I bought my truck ('01) in '03 with 34k on it and changed the oil with Penzoil Synchromesh, I didn't like it, so when I changed it again I used 15w/40 engine oil, the same thing I was/am running in my '91 w/Getrag. I now have 350k on the '01

Well you're a living proof that 15w40 engine oil works, or you're on of the lucky ones that can do these things. I know my luck and the second i decided to try it if be screwed. Guess what I've done seems to work too and as little as I use it 10k a year or so, I don't mind spending few bucks on amsoil, although it's cheaper than 50 that Mike gets in bulk. Idk maybe next time I change it I'll try 15w40 for few weeks and see what difference I notice in shifting, temp, etc. Perhaps some day I'll switch. 

Yes, and you can use it for flush if you don't like it. Mine takes one gallon @ $9.69 per gallon, so you aren't out much. I do have Valvoline 50w synthetic manual transmission fluid in my Ford w/Clark 5spd. I tried it in my NV5600 but I didn't like it. It seemed like it was too slippery and the synchro's were not liking it. I really wanted to switch over to it for everything but since the '01 didn't like it I quit using it. The '91 liked it too but my Dodge Neon did not. I used the whole 5 gallons switching everything over.

 

Spicer even tells you to not use synthetic on some of their light duty 5-6spds. Yet most everything is going that direction so I tried it too, but no go. 

 

  

I run quart of the penzoil synchromesh and have for a very long time. 300k+ on this one but it would be nicr to have someone go thru it. The only time temps got up was towing in 6th. As far as overfilling the 5600 it would only be dodge forums since dodge was the only one use them as far as I know.

I would love to hear from people that designed the nv5600 and their reasoning for synchromesh fluid. What is so special about it, I'm sure it's base is oil something like 5w30 at least it felt like it when I was dumping it in. So there are additives to protect synchros, but from what? Because the rest of metal parts could care less as long as they get lubrication. Guessing 15w40 motor oil does great on gears and bearings and apparently have no I'll effect on synchros. It seems that 3rd gear is the weakest as too many have issues with it. So if PO of my truck used synchromesh fluid and 3rd is getting tight, this would mean 2 things, one he had no idea how to shift, two the synchromesh fluid is not doing its job. It seems it would come down more to a driver and not the fluid according to what I'm seeing. 

But then there is @dripley... On his second trans... Maybe his transmission was built on Monday 

1 hour ago, Dieselfuture said:

But then there is @dripley... On his second trans... Maybe his transmission was built on Monday 

I would like to know what happened to the first one. 4th had started whining some and next thing I knew it got stuck in 4th one day. Had to pull off the road and hulk it out of gear, didn't know you could jerk on a shifter as hard as I did to get it out. Never went back in after that. Never saw anything out of the ordinary when I drained the fluid. Figured a bearing must of let but did not grenade. I did run that tranny low on fluid once, how long I was never sure. Best I recall It was around 150k to 160k and it let go about around 240k. Bought one from a junkyard with 52k on it and that is the current one I have put an additional 270k on it that was all using the Penzoil.