6 Speed manual transmission ~ NV5600 ~ General Questions

[leety]

Hi I have this most wonderful transmission in my truck.  I'm trying to learn more about it and this is the best place for that!!!

 

For starters, the truck has just under 100k miles on it. 

 

 

1) FLUID TYPE:  What fluid is best to use (The tag is saying Texaco STF 1874 Chrysler P/N 04874464)

2) FLUID TYPE: How much Fluid does it hold?

3) FLUID : Is there an additive that is advisable?

4) TRANSMISSION COOLER: Is there some sort of manual transmission cooler add-on for the trans that would assist in extending the life of the unit?  I understand there were few of these made and the company that made them is out of business.  Therefor my goal is to make it last as long as humanly possible.

5) How many miles can one expect a clutch to last on the NV5600?  I know the answer is somewhat about how it was driven, but let's say worst and best case scenario so I have some idea.

6) The shifting feels a bit vague to me (not nearly as vague as a Porsche 914, which is fun) but still. I'm wondering if it would be a good idea to replace some high wear parts in the shifter or linkage assembly or if that's just how this system is.  Don't get me wrong, I'm loving it!!!!!  Call me silly I actually like a vehicle that requires more skills to drive that your average driver typically possesses!!!  I have a reputation for driving a manual transmission in a way that makes it last beyond it's expected shelf life.  As some of you know, it's all in the feel.

 

Thanks in advance for spilling a small slice of your vast experience and wisdom on me as this awesome group always does.

 

 

 

 

[trreed]

1) Pennzoil or Amsoil Syncromesh is the only aftermarket fluid spec'd for use in the NV5600.  Otherwise the dealer may have some fluid laying around, but it's expensive as hell.

2) Spec sheet says 4.75 quarts.  That is too little.  Most people run 6 quarts without a cooler, 7 quarts if you have one cooler (me) and 8 quarts of you have two coolers (@Dieselfuture)

3) I've never heard of an additive for these transmissions.

4) https://www.fastcoolers.com/product-page/copy-of-fast-coolers-part-2fc300.  Can be bought as a single too.  Adds one quart more capacity each.

5) As you stated, clutch depends on driving and modifications.  My stock clutch held a smarty until I got stupid between shifts, and then it was game over very quickly.  Some members on here are closing in on 300k on the stock clutch.

6) That's cause it's a truck transmission, and not in a Porsche!  These transmissions have very long throws and definitive engagement.  There aren't many replaceable parts without removing the main case from the transmission.  There is a plastic cup on the bottom of the shifter that acts as a bushing for the shifter and the shift forks.  That's about the easiest part to get to. 

Edited June 18, 2018 by trreed

[dripley]

I would have to agree Mr. @trreed kn all of the above. I have run the Penzoil in mine since new. At the quantities listed above. 

 I have heard of a few adding limited slip fluid in theirs but not heard it made any difference. I think these folks are wanting a speed shifting 5600.

 I have the fast coolers on mine but don't know what difference it made since I did not have a temp on it prior to installing them. But they cant hurt any thing.

 I changed my stock clutch out at 240k. It still had some life left in it, 30k to 40k maybe. That on "75hp" Banks Ottomind tuner, pump tapped. Never slipped even pulling a 14k pound 5th wheel over the Blue Ridge mountains. Only towed it 3 or 4 times in those conditions. I think the stock clutch is a little stronger than advertised, but maybe not for @trreed. Hope his new rear end gears are made out of hardened titanium.

 As mentioned above some folks just want to speed shift speed. While I can when jumping out into traffic, I would rather let it shift like it wants to. Much nicer to the tyranny. I also would not allow just anyone to take mine apart. There are a lot crappy parts for them out there that will not last and it is a different animal than the well used NV4500. They only made the 5600 for 6 or 7 years then closed up shop and Dodge was the only one to use it I believe.

Edited June 18, 2018 by dripley

[notlimah]

[dripley]

17 minutes ago, notlimah said:

Don't eat it all, save some for me.

[Tractorman]

I am currently approaching 294,000 miles on the original clutch and transmission with lots of towing over its life.  The last 45,000 miles have been with a Smarty programmer set on Software 5.  I don't have coolers on the transmission (someday I will), but I overfill by one quart.

 

If you make an effort to match road speed to engine rpm during shifts (up and down), you can make a transmission and a clutch last for a very long time.

 

Enjoy the truck!

 

- John

Edited June 18, 2018 by Tractorman

[leety]

2 hours ago, trreed said:

1) Pennzoil or Amsoil Syncromesh is the only aftermarket fluid spec'd for use in the NV5600.  Otherwise the dealer may have some fluid laying around, but it's expensive as hell.

2) Spec sheet says 4.75 quarts.  That is too little.  Most people run 6 quarts without a cooler, 7 quarts if you have one cooler (me) and 8 quarts of you have two coolers (@Dieselfuture)

3) I've never heard of an additive for these transmissions.

4) https://www.fastcoolers.com/product-page/copy-of-fast-coolers-part-2fc300.  Can be bought as a single too.  Adds one quart more capacity each.

5) As you stated, clutch depends on driving and modifications.  My stock clutch held a smarty until I got stupid between shifts, and then it was game over very quickly.  Some members on here are closing in on 300k on the stock clutch.

6) That's cause it's a truck transmission, and not in a Porsche!  These transmissions have very long throws and definitive engagement.  There aren't many replaceable parts without removing the main case from the transmission.  There is a plastic cup on the bottom of the shifter that acts as a bushing for the shifter and the shift forks.  That's about the easiest part to get to. 

"...it's a truck transmission, and not in a Porsche!" And that's all part of the fun of it!!!!!

 

Thanks for the cogent responses!!!

 

Each vehicle is a purpose built machine.  I actually enjoy the long leisurely slightly vague rowing through the gears on this tranny.  To set this up as a short shifter would take all that fun out of it.  The only mods I seek are to support best gas mileage and longevity.All of your comments are supper helpful!

2 hours ago, dripley said:

I would have to agree Mr. @trreed kn all of the above. I have run the Penzoil in mine since new. At the quantities listed above. 

 I have heard of a few adding limited slip fluid in theirs but not heard it made any difference. I think these folks are wanting a speed shifting 5600.

 I have the fast coolers on mine but don't know what difference it made since I did not have a temp on it prior to installing them. But they cant hurt any thing.

 I changed my stock clutch out at 240k. It still had some life left in it, 30k to 40k maybe. That on "75hp" Banks Ottomind tuner, pump tapped. Never slipped even pulling a 14k pound 5th wheel over the Blue Ridge mountains. Only towed it 3 or 4 times in those conditions. I think the stock clutch is a little stronger than advertised, but maybe not for @trreed. Hope his new rear end gears are made out of hardened titanium.

 As mentioned above some folks just want to speed shift speed. While I can when jumping out into traffic, I would rather let it shift like it wants to. Much nicer to the tyranny. I also would not allow just anyone to take mine apart. There are a lot crappy parts for them out there that will not last and it is a different animal than the well used NV4500. They only made the 5600 for 6 or 7 years then closed up shop and Dodge was the only one to use it I believe.

I agree I enjoy the leisure rowing through gears on this tranny, I find it relaxing really :-)

1 hour ago, Tractorman said:

I am currently approaching 294,000 miles on the original clutch and transmission with lots of towing over its life.  The last 45,000 miles have been with a Smarty programmer set on Software 5.  I don't have coolers on the transmission (someday I will), but I overfill by one quart.

 

If you make an effort to match road speed to engine rpm during shifts (up and down), you can make a transmission and a clutch last for a very long time.

 

Enjoy the truck!

 

- John

Wow 294,000 that's impressive!!!!

 

Gear matching is one of my specialities, that and driving fast, backwards LOL.  Dad taught me how to match gears when I first started driving.  Not only is it fun, but having the feel for that makes trannies last exponentially longer.

 

My dad had an old Toyota dually and I almost NEVER used the clutch on that when shifting LOL.

 

I had a 1962 Volvo P130 that had a bad clutch slave for several months (no $ to fix it) I drove through Topanga Canyon from Pacific Palisades to Pierce College every day to get to school.  No clutch at all.  I started her up off the line in 2nd gear and matched all the way too and from.  A girl's gota do, what a girl's gota do, to get where she's gota go. 

 

Those were great experiences!!!

3 hours ago, trreed said:

1) Pennzoil or Amsoil Syncromesh is the only aftermarket fluid spec'd for use in the NV5600.  Otherwise the dealer may have some fluid laying around, but it's expensive as hell.

2) Spec sheet says 4.75 quarts.  That is too little.  Most people run 6 quarts without a cooler, 7 quarts if you have one cooler (me) and 8 quarts of you have two coolers (@Dieselfuture)

3) I've never heard of an additive for these transmissions.

4) https://www.fastcoolers.com/product-page/copy-of-fast-coolers-part-2fc300.  Can be bought as a single too.  Adds one quart more capacity each.

5) As you stated, clutch depends on driving and modifications.  My stock clutch held a smarty until I got stupid between shifts, and then it was game over very quickly.  Some members on here are closing in on 300k on the stock clutch.

6) That's cause it's a truck transmission, and not in a Porsche!  These transmissions have very long throws and definitive engagement.  There aren't many replaceable parts without removing the main case from the transmission.  There is a plastic cup on the bottom of the shifter that acts as a bushing for the shifter and the shift forks.  That's about the easiest part to get to. 

Is this the correct stuff?

 

https://www.amsoil.com/shop/by-product/transmission-fluid/manual/manual-synchromesh-transmission-fluid-5w-30/

[AH64ID]

1 hour ago, leety said:

 

Is this the correct stuff?

 

https://www.amsoil.com/shop/by-product/transmission-fluid/manual/manual-synchromesh-transmission-fluid-5w-30/

 

That's what I run in mine. 

[Dieselfuture]

I've been running right at 8 qt of amsoil 5-30 synchromesh stuff with one fass cooler on driver side and a filter on the other. Reason you put filter on passenger side is oil naturally flings that way, and gravity drains back though filter media to tranny. I fill it through shifter tower to top side bolts of pto cover looking down through shifter tower. Comes out to about 8qt, depending on if you get it all out when you remove pto covers. I scooped as much as I could out with my hand and lifting rear end up/down. That's where all sediment was too, part of the reason I put filter on passenger side. Fass now offers a filter that fits inside of their cooler, my problem was it's too long and my 5" exhaust would be in the way, so I went with  http://www.quad4x4.com/catalog/category/filterkits

It's not as tall and clears my exhaust. 

Also if you don't want to run amsoil, penzoil synchromesh has been recommended to me by a local reputable tranny shop. Biggest thing is over filling it, I think a sweet spot is right around top side pto bolts, otherwise you're guessing how much to put in. 

On the other hand I've put 400ml in last 2 days in 95f weather and empty on hwy going 70-75 my tranny temp was 170-175. Which seems high to me, but my mpg on this tank were right at 18 hand calculating. Maybe I'm running to much oil and there for the heat  @AH64ID

But I do know you want at least 1 extra qt because of a bearing location, (too high) and gets minimum amount of oil, so it fails, that's what my local shop told me. And reason for filter is to get all fine brass particles from synchros out of oil along with other junk. I've had mine on for few years now, soon I'll be changing the filter. Can't wait to see what it trapped if anything. There is a huge debate about it. I wanted to know for my self if they work. 

[leety]

How often should the fluid be changed?

[trreed]

I try to stick to 50k mile fluid changes. Also, floating gears in these 6 speeds is inadvisable. The synchronizer cones are made out of brass, which is a self lubricating (read: sacrificial) bearing material. So floating the gears and relying on the brass syncros to match the speed is more harmful to the transmission than using the clutch. 

[trreed]

16 hours ago, dripley said:

Hope his new rear end gears are made out of hardened titanium

Stock Spicer replacement units. I'll allot one more brain cell to 'monitoring driving habits' duty to keep it alive this time.

[Mopar1973Man]

10 hours ago, leety said:

How often should the fluid be changed?

 

When the fluid color starts to darken. Like I'm at about 80k miles on my Mobil 50 SAE GL-4 fluid and the amber color is still visible and there is just light tint of black starting. By the time I reach 100k it should be a bit darker and pronounced. This interval changes with the amount of heat in the fluid. Like my average transmission oil temp is about 120-140*F so the lifespan of the fluid is much longer. All winter the gauge never rises off of 100*F at all. So the fluid gets little abuse. Even towing I only see 140-160*F like my last load of firewood from the high country. 

 

 

 

[leety]

1 hour ago, Mopar1973Man said:

 

When the fluid color starts to darken. Like I'm at about 80k miles on my Mobil 50 SAE GL-4 fluid and the amber color is still visible and there is just light tint of black starting. By the time I reach 100k it should be a bit darker and pronounced. This interval changes with the amount of heat in the fluid. Like my average transmission oil temp is about 120-140*F so the lifespan of the fluid is much longer. All winter the gauge never rises off of 100*F at all. So the fluid gets little abuse. Even towing I only see 140-160*F like my last load of firewood from the high country. 

 

 

 

Now that is load!!!!

1 hour ago, Mopar1973Man said:

 

When the fluid color starts to darken. Like I'm at about 80k miles on my Mobil 50 SAE GL-4 fluid and the amber color is still visible and there is just light tint of black starting. By the time I reach 100k it should be a bit darker and pronounced. This interval changes with the amount of heat in the fluid. Like my average transmission oil temp is about 120-140*F so the lifespan of the fluid is much longer. All winter the gauge never rises off of 100*F at all. So the fluid gets little abuse. Even towing I only see 140-160*F like my last load of firewood from the high country. 

 

 

 

Tell me more about your fluid please "Mobil 50 SAE GL-4"?

[Mopar1973Man]

I wanted to break the bonds of only this or that fluids so I'm stepping out and running 50 weight fluid. Basically it 90 weight gear lube rated GL-4. It a synthetic as well but fraction the price of the factory guild I used to buy for the NV4500 from the dealer.

[dripley]

It is not suitable for the 5600 either. 

[Mopar1973Man]

Technical not designed for the NV4500 either but working great. Ill have get home post up what I know in regards to this.

[AH64ID]

13 hours ago, leety said:

How often should the fluid be changed?

 

With my added power and how much I tow I change it at 50K mile intervals. 

 

13 hours ago, Dieselfuture said:

On the other hand I've put 400ml in last 2 days in 95f weather and empty on hwy going 70-75 my tranny temp was 170-175. Which seems high to me, but my mpg on this tank were right at 18 hand calculating. Maybe I'm running to much oil and there for the heat  @AH64ID

 

That doesn't sound too hot to me, based on what little I have seen. 

 

The trans with added fluid seem to run hotter, but the concencus is that it's drawing extra heat from the bearings with more of a oil bath and that's a good thing. 

 

 

3 minutes ago, Mopar1973Man said:

Technical not designed for the NV4500 either but working great. Ill have get home post up what I know in regards to this.

 

At least it's a GL-4, which is what the NV4500 wants. A GL-4 is not advisable for a NV-5600.

[Mopar1973Man]

Strange just looking for specs on the PennzOil lube there is little to no information about ratings. Just quotes vehicle specifications. As for oil specifications the two documents I did find are limited as well.

 

http://www.stealth316.com/misc/synchromeshfluid.pdf

 

https://prodepc.blob.core.windows.net/epcblobstorage/GPCDOC_GTDS_Pzl_Synchromesh_Fluid_(en)_TDS.pdf

 

There is something about the fluid that it contains or doesn't contain that doesn't allow it to be rated as a GL-4 lube. So close... because the GL-4 rating is for yellow metals. Again like I said either its missing something or has something added that doesn't allow GL-4 rating. Not enough info.

 

This document sheds some light on the syncromech lube. Basically too thin to make the GL-4 ratng...

http://www.widman.biz/uploads/Transaxle_oil.pdf

 

Quote

Synchromesh transmission oils General Motors, Honda and others have developed oils that combine the best shift characteristics with their transmission components for reduced wear. These products in general could classify as GL-4 oils if they wanted to, but actually when we analyze their components they are very similar to 5W-30 diesel motor oils, with a few friction modifiers added. The viscosity is closer to an ATF. They are way too thin for a Corvair transmission or any other where a SAE 80W-90 or 75W-90 is recommended.

 

 

So like in my case the 50 weight Mobil is equal to 90 weight Gear lube. NV4500 came with 75w-80 Mopar Lube. So the NV5600 is more like 5w-30 diesel oil or ATF. Hmmm... Funny how the 3rd Gens are using ATF in the manual transmissions. Hmmm... Then funny how the old GetRag's of the past ran 5w-30 engine oil as well.

Edited June 20, 2018 by Mopar1973Man

[leety]

Brilliant!  Thanks to everyone for their comments and info.  You guys are the best!!!

 

I have a long trip to go collect a BigFoot camper around the corner so I'm going to put some Pennzoil in there for now.  It's not too expensive and I could get my hands on it locally, barely.  I'll make a plan to put some coolers and what not on it after my trip and I can further research my set up and oil selection then.  I'm reasonably certain there is neither enough oil or the right type of oil in there.  The dealer I got the truck from, a lil mom and pop joint in the middle of nowhere, fixed a leak in the tranny and I don't trust them on the fluid selection.  The leek is fixed though so that's good.  Once I put in the Pennzoil, at least I will feel like there's enough of something acceptableish in there for my trip.

 

Getting the truck up to snuff is fun but a bit of work.  With this group in the mix, it's way more fun!!!!  I consider myself a steward of history with my older cars, so it's totally worth it. 

 

 

41 minutes ago, Mopar1973Man said:

Strange just looking for specs on the PennzOil lube there is little to no information about ratings. Just quotes vehicle specifications. As for oil specifications the two documents I did find are limited as well.

 

http://www.stealth316.com/misc/synchromeshfluid.pdf

 

https://prodepc.blob.core.windows.net/epcblobstorage/GPCDOC_GTDS_Pzl_Synchromesh_Fluid_(en)_TDS.pdf

 

There is something about the fluid that it contains or doesn't contain that doesn't allow it to be rated as a GL-4 lube. So close... because the GL-4 rating is for yellow metals. Again like I said either its missing something or has something added that doesn't allow GL-4 rating. Not enough info.

 

This document sheds some light on the syncromech lube. Basically too thin to make the GL-4 ratng...

http://www.widman.biz/uploads/Transaxle_oil.pdf

 

 

 

So like in my case the 50 weight Mobil is equal to 90 weight Gear lube. NV4500 came with 75w-80 Mopar Lube. So the NV5600 is more like 5w-30 diesel oil or ATF. Hmmm... Funny how the 3rd Gens are using ATF in the manual transmissions. Hmmm... Then funny how the old GetRag's of the past ran 5w-30 engine oil as well.

I ran across this article you posted in a cummins forum:  

https://highgeartransmission.wordpress.com/tag/nv5600-6-speed-transmission/

This is where I found your post.

http://www.cumminsforum.com/forum/98-5-02-powertrain/2172521-diy-nv5600-fluid-change-refill-through-shifttower.html

 

Was this more or less what influenced you to go with the 50 weight and are you using the Mobil Delvac 50 weight as recommended in the article?