Engine/Transmission (1998.5 - 2002) NV5600 & Synchro's

[getblown5.9]

I have Fast Coolers as well and with cooler temps, the needle might never move. If it is in the 40s, it will run about 140. If it is 80, it runs about 180. The coolers seem to have made a difference, however, in cold temps the transmission never gets hot enough to allow good shifting (always cold shifts).

I overfilled by the recommended quart and my NV5600 did not like it. It ran hot until I drained that quart out (simply popped the filler plug and left it drain)... so I'm not sure that is a good idea. Most guys don't have a temp guage top see any difference.

I am currently running straight Amsoil MTF, and it is by far the most consistant oil across the board. It isn't the best at any one thing. The two best oils to date are Amsoil and Redline... they are pretty close in performance. I too had a bad experience with RP. It seems that these trannies are not one-fluid-fits-all, as what works in one might not work in another.

I posted this up over at BITOG and they are telling me to run 6 quarts of MTF, one quart of MTL (the thicker stuff), and up to 4 ounces of friction modifier.

I also posted my ruined RP Synchromax report over there and they said it appeared it had sheared quite a bit... actually a lot because the UOA only had 500 miles or so on the oil itself. But they also found a bunch of other stuff in the sample that wasn't found in virgin synchromax.

steved

MTL and MTF both amsoil products, or redline MTL and amsoil MTF???

i need to get it today, and i can pick up amsoil locally at a small parts store. the redline id have to order. and im gonna try a small amount of the FM and see if i like that.

 

[steved]

MTL and MTF both amsoil products, or redline MTL and amsoil MTF???



i need to get it today, and i can pick up amsoil locally at a small parts store. the redline id have to order. and im gonna try a small amount of the FM and see if i like that.

Both Amsoil... Amsoil MTF (what the NV5600 calls for) and Amsoil MTL (to help protect against shearing). They are saying this has been a good mix in a lot of trans. I am going to be changing here pretty soon and I will have a UOA done on the Amsoil fluid to see what is really going on...



And this isn't Amsoil specific... you could use redline MTL (the NV5600 stuff) and a quart of MT-90 (the thicker stuff), or Royal Purple Synchromax and a quart of there MaxGear. The mani thing is to stay with the same brand when mixing viscosities. They are also saying the Ford LSD additive seems to be the better stuff for whatever reason...



And again, this is what I have been told. I have not yet ran this cocktail in my NV5600 (I just posted this question earlier this week)... as I was actually thinking about THIS exact thread that you dug up!



My only concern is that thickening the fluid even a little bit might make shifting in cold weather worse, but no one has said anything about that...



steved

 

[Texas Diesel]

i just had my notchy and noisy 5600 torn down and re-assembled this week. i am going to fill it with amsoil MTF and the mopar LS additive to see how it does... it has to be better than the RP i had before.



you guys are noting transmission temps in the 190-225* range... my transmission has never been that high. it hardly ever moves the needle. i have the fast coolers and always overfill the transmission by 1 quart and the only time i see the needle move is when im running 75mph for 40-50 miles or more it will go to 120ish... and ive seen 150* when pulling a trailer about 75mph for over 100 miles. its a new temp sensor... do you think it may be a grounding issue or something not giving me a proper reading?

I suspect you have a temp sender problem. Both of my trucks with the 5600 (fastcoolers, overfilled and Royal Purple and before that, the OEM stuff) all ran 190+ in the summer, I have seen them hit 240F towing in 90F summers. Didnt have the gauge before the fastcoolers but I feel the FC lowered the temps. The two different oils didnt make any difference in temps, just better shifting.

 

[MChessick]

FYI, I run Redline MTL in my NV5600. The last time I changed it was 60k ago. Still shifts fine after 140k. You are dreaming if you think you are going to get a 500lb truck transmission to shift like a car. Mine doesn't shift any different in the cold weather either. I live in the Northeast and it has been less than warm. I expect I will change the fluid again in the spring when it warms up. I believe according to the literature, the Redline MTL has the friction modifier in it already.



Mark

 

[steved]

You are dreaming if you think you are going to get a 500lb truck transmission to shift like a car.



Mark

While I understand this, I should still be able to shift without feeling tooth-to-tooth contact under normal shifting.



I don't mind that it "clicks" into each gear, but I get a "bump-bump-bump" when pulling into the next gear... and that is the synchronizers. Just changing the fluid will make a night and day difference in my truck.



steved

 

[MChessick]

I don't mind that it "clicks" into each gear, but I get a "bump-bump-bump" when pulling into the next gear... and that is the synchronizers. Just changing the fluid will make a night and day difference in my truck.



steved[/QUOTE]



While I agree , the bump- bump- bump shouldn't be there, I think you or anyone else has bigger issues with the transmission if you have this type of problem. If the fluid change helps, that is great but is only a band-aid solution to something worse ( more expensive) that needs to be addressed.

I am sticking by Redline as I like the way my transmission has always shifted and I hope it continues for another 150k. Good luck



Mark

 

[Texas Diesel]

While I understand this, I should still be able to shift without feeling tooth-to-tooth contact under normal shifting.



I don't mind that it "clicks" into each gear, but I get a "bump-bump-bump" when pulling into the next gear... and that is the synchronizers. Just changing the fluid will make a night and day difference in my truck.



steved

A "bump-bump-bump" feel is just a grind slowed way down. Either way, the synchros arent doing their job. Try a fluid change first, there have been several suggested. What gear is the "bump-bump-bump" worst in?

 

[getblown5.9]

well i couldnt find amsoil in stock but a local place had redline MTL. im gonna add the 4oz. of mopar FM to the oil and see how it drives.

gotta get a new sensor to see if my trans temp gauge will finally work right.

 

[steved]

A "bump-bump-bump" feel is just a grind slowed way down. Either way, the synchros arent doing their job. Try a fluid change first, there have been several suggested. What gear is the "bump-bump-bump" worst in?

Typically only 3rd and 5th... and it is only if I try to get a little faster shift... if is go nice and slow I have no issues... it is worst when cold. Everything is fine once I get over 140*F and best at 180*F.



As far as this being some more than fluid... yeah, poor design. This trans has done this sort of thing since new and I had it to several dodge dealers and all told me it was "normal".



Fluid changes will bring it right back to that "like-new" feeling... the one report of RP I had, it had sheared quite badly in only a short time... I am going to try that "cocktail" first, then see what else I can do...



steved

 

[JasonCzerak]

Trying putting the T-Case in N, and putting the transmission in 3rd while you idle up in the morning.



Since it's gotten to a high of 10 or below here I have started doing this.



Running though the gears while the T-case is in N a few times, getting the oil moving and everything spinning helps.



Also a great idea is to double clutch your shifts until the transmission warms up.



This morning it was -7. I took a hot lap around the block taking my time shifting to warm things up under a load, so that I don't hold up traffic trying to shift with out destroying things

 

[Texas Diesel]

Mine grinds in 4th but only when cold. And then sometimes it doesnt grind when cold. I'm afraid something mechanical is jamming the synchro/blocker rings.



No fluid, regardless how good can correct a mechanical issue And 5600's are difficult to teardown.



I had a Mitsubishi truck that would grind all gears till it got warm, the dealer said it was normal and a note was in the owners manual about that being ok. It ran fine (and worked hard) for 150k miles.



A guy that rebuilds 5600's lives about an hour from here, I'll have to take him to lunch and run by him your problem and mine.



Let me know on the additive, I have about 6 bottles in the toll box (along with 5 $65 lift pumps and two rebuilt vacuum pumps). Is there a trend here?



My Royal Purple has been in there for 44,000 miles and due for a change. Perhaps the FM will let me finish the winter before changing the fluid.

 

[Texas Diesel]

Trying putting the T-Case in N, and putting the transmission in 3rd while you idle up in the morning.



Since it's gotten to a high of 10 or below here I have started doing this.



Running though the gears while the T-case is in N a few times, getting the oil moving and everything spinning helps.



Also a great idea is to double clutch your shifts until the transmission warms up.



This morning it was -7. I took a hot lap around the block taking my time shifting to warm things up under a load, so that I don't hold up traffic trying to shift with out destroying things

I'll try that.



I've been doing the double clutch thing and it really works well.

 

[Silver_Ram]

If you're gonna use Amsoil, pay the $20. 00 and become a preferred customer (just like Costco or Sam's Club). You can order what you want at good prices & have it delivered to your door. The pricing for the preferred customer is better than I can buy the product locally.

 

[steved]

Bringing this back to life...



Here is a UOA of Amsoil MTF from my nv5600.



I was told it looks like it sheared and THAT might be the reason for poor shifting.



To counteract the shearing, it was recommended to me to possibly mix one quart of Amsoil MTG and the rest (about 6 quarts) of MTL to slightly thicken it up.



So, I guess I'll be doing this in a month or so...



steved

 

[Silver_Ram]

My mix is still working great & I haven't had any shifting problems.



I will be using the 75W90 at the advice of a local drivetrain rebuilder. It will be interesting to see how the thicker oil works.

 

[Texas Diesel]

My mix is still working great & I haven't had any shifting problems.



I will be using the 75W90 at the advice of a local drivetrain rebuilder. It will be interesting to see how the thicker oil works.

Please let us know how that works.

 

[steved]

I have heard from several that straight 75w90 doesn't work too well... tht's the reason for mixing the MTF and MTG.

steved

 

[Duluth Diesel]

I run the AMSOIL 5W30 MTF that is spec for the NV5600, and it shifts fine.



-Chuck

 

[steved]

OK, I am changing from Amsoil MTF to Redline... Amsoil's website caused me too much grief so I ordered Redline MTL and a couple quarts of MT-90 from Summit racing... I will place one last order to Amsoil for EaBPs and then never deal with them again... I will change the bypass when I need filters next.



I had an interesting conversation with an oil guy (who knows more than I do)... he thinks that overfilling the NV5600 is causing "hot parts" (bearing and gears) to recieve more lubrication and cooling from the oil. And that is what caused my guage to read hotter! It makes sense to me, so I'm going to overfill again on this attempt.



How is the fill with 75w90 going???



steved

 

[steved]

I should also add I added 7 ounces of LSD modifier on top of the already used Amsoil with no change in shift characteristics.



steved