Normal Operating Temperature for an NV5600, 6 Speed

[Grizzly]

What is a normal operating temperature for an NV5600, 6 speed with stock oil? While towing a 12K 5er? Same questions with synthetic transmission oil. Which transmission runs cooler while towing a 12K 5er, NV5600 or a G56? Thanks.

 

[Grizzly]

Is 200* normal while towing a 5th wheel?

 

[Gary - K7GLD]

Regarding transmission temps in towing or otherwise heavily loaded, 200+ degrees seems quite normal - based upon figures quoted by others who have done actual testing. Personally, I'd prefer to keep temps at or below 200 in those circumstances, and that's why I have added a FastCooler and filter to mine - but still need to do more RV towing runs and temp measurements to see if I've reached my goal.



Regards



Gary

 

[JHardwick]

What is a normal operating temperature for an NV5600, 6 speed with stock oil? While towing a 12K 5er? Same questions with synthetic transmission oil. Which transmission runs cooler while towing a 12K 5er, NV5600 or a G56? Thanks.

I guess I should pay more attention, but isn't the syncromesh a synthetic oil already?

 

[steved]

I have seen 235*F (non-towing) running 100+*F ambient temps... that's with Redline MTL... never tried Amsoil or RP before I added the coolers.



With the fast coolers, I have not seen above 180*F... IMO, these should be a factory addition.



I never tried straight synchromesh (tried as in with a gauge), but of the three main replacement synthetics, not one runs cooler than another.



And, IMO, the G56 (not unlike the ALL ALUMINUM transfercase) should run very cool.



steved

 

[Briman]

I have seen 225* F on a 90* day going up a steep grade with Penzoil Syncromesh while pulling a 30' TT. I expect that on a long haul on a hot day 225*-250* would be likely. That's too hot for my taste. I'll be taking a couple thousand mile trip the first week of August. After the trip I will likey change fluid. I've spent my wad on the truck lately and can't afford fast coolers right now. Anybody want to split a set? I don't think I'd put one on the exhaust side of the transmission.

 

[Gary - K7GLD]

I have seen 225* F on a 90* day going up a steep grade with Penzoil Syncromesh while pulling a 30' TT. I expect that on a long haul on a hot day 225*-250* would be likely. That's too hot for my taste. I'll be taking a couple thousand mile trip the first week of August. After the trip I will likey change fluid. I've spent my wad on the truck lately and can't afford fast coolers right now. Anybody want to split a set? I don't think I'd put one on the exhaust side of the transmission.

Here's how I did my "Half FastCooler" install:



#ad




FastCooler plus PC processor cooler on one side, filter and another PC cooler on the other side:



#ad




Should have run temp test on last week's RV trip, but didn't - oh well, next trip... :-laf

 

[DWeiler]

Running the same as Gary,but without the PC coolers,cruising i see 160-170 at 75MPH,pulling the 11K fiver i hit around 200---that with RED LINE+an extra quart added.

 

[dsherman]

Running the same as Gary,but without the PC coolers,cruising i see 160-170 at 75MPH,pulling the 11K fiver i hit around 200---that with RED LINE+an extra quart added.

I have the fast coolers on trans and one on transfer case and run OEM oil and I tow about 14k @ 60 to 65MPH I see 150-160 F trans and transfer case 180 F front diff 150 F rear diff 180



When not towing @ 65-75MPH I see trans 140-150 F, transfer case 160-170 F, front diff 130-140 F, rear diff 160 F.

I have Mag Hytec diff covers on rear. Had them on the front but had clearance problems so went back to OEM stock and ran the temp probes in both OEM diff covers and the Mag hytec covers with no difference in temp readings in either application.

The rear diff with the Mag Hytec cover did take a red hair longer to get to temp but did not see any difference in temp readings after that.

 

[steved]

--that with RED LINE+an extra quart added.

And the added quart of fluid will make you see higher temps... for whatever reason, I don't know. I have seen this EVERY time I have overfilled by a quart.



steved

 

[JCasper]

It kind of sounds like I should be some Fast coolers and put in a little extra oil.

 

[Johnstra]

So should we overfill the nv5600? I know Quad4x4 says you should. If it causes temps to run higher seems it might not be so good to do.

-john

 

[ENafziger]

front diff 130-140 F, rear diff 160 F.

This is interesting. I've not towed anything heavy since installing my MagHytec's and gauges, but my front differential always seems to run 20 - 25° hotter than the rear...

Is anyone making fast coolers for the G56 yet? --Eric

 

[steved]

If it causes temps to run higher seems it might not be so good to do.

-john

Two possible reasons:



Reason 1: You overfill the trans and that causes parts of the trans to be flooded and other parts to be starved due to lack of "sling" lubrication (because of the flooding)... resulting in a hotter trans oil temp and shorter component life.



Reason 2: You overfill the trans and that causes parts that were only receiving marginal fluid and running hot (at normal oil levels) to become lubricated AND cooled by the oil, resulting in an increased trans oil temp and longer component life.



Being we don't see a lot of failures running with MORE fluid, I kinda think Reason 2 is what is actually happening.



As I noted, I have experimented with normal and overfill scenarios, and regardless of oil used, the temps climb faster and level off sooner at overfill than at a normal fill level. They run about 20*F hotter, but still well within the "normal" range.



steved

 

[steved]

I guess I should pay more attention, but isn't the syncromesh a synthetic oil already?

I think I remember someone stating it was a low grade synthetic... not a true high-grade synthetic like redline, amsoil, or RP. Sorta like the comparison of Rotella 5w40 sythetic to Amsoil... a Group III vs a Group IV base.



steved

 

[Grizzly]

Thank you Gary and to all who supplied much appreciated information on transmission temperatures. My next step is to install a temperature gauge, maybe a set of three. What other two gauges are worth having?

 

[MMiller]

I wish I could get this much info on my question about the getrag in my first gen.



With the coolers, and 50wt synthetic transmission oil, in 4th gear loaded(direct drive), on an 80*F day, the trans temp will run 180-190*. Flip it into OD and run 70 mph(loaded at 28,000#) the trans will heat up and after about 2 hours will bury the 250* gauge! Drop to 4th, and run 60 mph and temp steadly goes back to 180-190.



I've been thinking about sourcing a 12 volt pump, and a trans cooler, and maybe even a tube in the trans that will flush cool oil onto the input gears, and 5th gears/output bearing. The only reason I can think of this is a bad idea, is if I have a problem, and am just masking it with an extra large cooler. The problem is I don't know if this is "normal" operation for my getrag, or maybe its a little "tight" after the rebuild I did this winter. It has probably at least 1000 miles of heavy towing on it this summer so far, and I leaving as we speak to tow about 22,000#.



Michael

 

[steved]

Thank you Gary and to all who supplied much appreciated information on transmission temperatures. My next step is to install a temperature gauge, maybe a set of three. What other two gauges are worth having?

I have a trans temp, oil pressure, and outside air temp (mines an ST)... I'm going to add a fuel pressure and rail pressure eventually.



steved

 

[steved]

I wish I could get this much info on my question about the getrag in my first gen.



With the coolers, and 50wt synthetic transmission oil, in 4th gear loaded(direct drive), on an 80*F day, the trans temp will run 180-190*. Flip it into OD and run 70 mph(loaded at 28,000#) the trans will heat up and after about 2 hours will bury the 250* gauge! Drop to 4th, and run 60 mph and temp steadly goes back to 180-190.



I've been thinking about sourcing a 12 volt pump, and a trans cooler, and maybe even a tube in the trans that will flush cool oil onto the input gears, and 5th gears/output bearing. The only reason I can think of this is a bad idea, is if I have a problem, and am just masking it with an extra large cooler. The problem is I don't know if this is "normal" operation for my getrag, or maybe its a little "tight" after the rebuild I did this winter. It has probably at least 1000 miles of heavy towing on it this summer so far, and I leaving as we speak to tow about 22,000#.



Michael

There are a few guys who have added oil pumps to their trans... just do a search on it.



steved

 

[STEVEBROOKS]

Gary-K7GLD,

How did you mount the PC coolers to the Fast Cooler cover and filter cover?



Thanks,

Steve