First off let me say... I've followed some of the advise here and double checked a bunch of stuff. The transmission is over filled enough that the sensor is submerged in fluid constantly even in 5th gear and transfer case in neutral. As for the shift quality after nearly 1,000 miles already is still really tight feeling and not sloppy. As for transmission fluid temps empty running I see no more that 130*F tops at 68 MPH after 40 miles of driving even climbing grades. If the morning temperatures are down around 45*F it takes nearly a full 20 miles to rise off of the 100*F mark of the gauge. At midday with 75-80*F temps outside its barely reaching 130*F with flat travel might bump 140*F if climbing a 7% grade.Remember this is all empty truck and no towing... Now you might question the number of the fluid temps from the gauge I've used 2 different thermometers to verify the temperature reported by the gauge and alway darn close to the same value. No I did not install fast coolers nor did I change anything since installing the transmission on the temp gauge other than adding enough fluid to keep the sensor submerged.

 

 

As you see the first few days after the transmission install MPG was bit low. After working hard and pulling thee RV down south and back which would say the break in period of the transmission occurred. Now with the job I had in New Meadows, ID and running back and forth to McCall climbing a 7% grade doesn't seem to bother the MPG's like in the past.

 

 

Other that that I will say I'm pleased with Weller Trucks transmission rebuild it very tight and precise feel in the stick now compared to before.  As for the transmission fluid I would have to say at this point of the game which is early yet but its a good solution for future fluid for NV4500.

I seem to see about 20* more than you. Could just be the different trannys or driving habits. One thing that I do have i common with you is how long it takes to put heat into the tranny. Typically I will see anywhere from 20 to 30 miles before the temp comes off of the 100* mark. On some occasion it has taken even longer. 

Like the last few days leaving early for New Meadows and having morning temperature of 45*F it takes for ever for the transmission to warm up. I'm really not wanting even think of installing transmission coolers. The few months of hot weather here isn't going to be enough to even require coolers I really doubt it so far. Even while I was towing I only bumped the 190*F climbing a grade with the RV. With a fluid failure point of 300*F I've got the warning light set for 220*F yet. Some how I think I'm never going to see that light pop on.

Good information and maybe.....just maybe this is a viable replacement fluid for the 4500.  And potentially the reason you're seeing lower overall temperatures relative to the load is based on the lighter viscosity, since a heavier viscosity will always run hotter simply due to the increase in friction having to churn through it.  SyntroqLT is a 75-85 and I believe what you have in there now is a 50 right?

The temperature safety values of the fluid isnt a variable for me simply because ANY fluid over 225* is too freaking hot for my taste and would pose as a problem.  But if you can prove with your monitoring that this Mobil fluid is capable of maintaining well under 200* then thats awesome.....

Keep up the reports and lets see what this stuff does over time and in the summer heat when you have a trailer back there.

Wood hauling season is just around the corner. I'm just waiting for the rain storm to stop here and I'm packing up to head out cut firewood. So lots of steep climbing, trailer pulling and working the truck.

1 hour ago, KATOOM said:

SyntroqLT is a 75-85 and I believe what you have in there now is a 50 right?

 

Yes... I'm running Mobil Delvac 50 SAE Synthetic Transmission Fluid GL-4. Also you right the Mopar Fluid is 75w-85.

 

http://pds.mobil.com/USA-English/Lubes/PDS/NAXXENCVLMOMobil_Delvac_Synthetic_Transmission_Fluid_50.aspx

 

 

Edited May 20, 20168 yr by Mopar1973Man

The hottest I have seen is right at the 220* mark. That was on a hot day towing in 6th. Not pulling steep grades with my foot matted by any means but some inclines. Just curious what you tow think how the 2 tranny would compare. Should there be that much difference in the two at highway speeds? Mid gears maybe since that seems to be the difference between the two.

Dave the only differences will be trailer weight and road speeds. BigTex is a 7,000 pound GVWR typically haul it up hill empty and down hill loaded. As for the RV I'm right close to 8,000 pounds  but typically avoid interstate travels. So in either case max towing speed will not exceed 65 MPH typically.

 

Gear ratio wise my 5th to your 6th are basically the same as my 4th to your 5th are both direct. So from that point on its a matter of driver, weight, speed, and other factors.

Edited May 20, 20168 yr by Mopar1973Man

Mike, I was mainly speaking of being empty other than the reference to the 220* temps. Towing we cannot compare due to the trailers we pull. Night an day difference. But we are not that far apart empty. I am a little warmer but getting up to temp is  very similar.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Good information!

 

How did you verify the fluid is covering the sensor? Just curious. 

 

Just a reminder that the fluid is not a GL-4 fluid and is only rated as an MT-1 fluid. MT-1 and GL-4 are different fluid specs. 

 

Mobil states you can use in in GL-1 thru GL-4 applications but it's not rated GL-4. 

 

The biggest difference between MT-1 and GL-4 is the design application for MT-1 doesn't have syncro's and GL-4 does.

On 5/20/2016 at 5:18 PM, Mopar1973Man said:

Like the last few days leaving early for New Meadows and having morning temperature of 45*F it takes for ever for the transmission to warm up. I'm really not wanting even think of installing transmission coolers. The few months of hot weather here isn't going to be enough to even require coolers I really doubt it so far. Even while I was towing I only bumped the 190*F climbing a grade with the RV. With a fluid failure point of 300*F I've got the warning light set for 220*F yet. Some how I think I'm never going to see that light pop on.

 

Just curious as to where you found this particular information.

1 hour ago, KATOOM said:

 

Just curious as to where you found this particular information.

 

Made a phone call and asked Abe at Weller Truck about the working limitations of the fluid and had him look it up for me.

 

 

Interesting.  Do you think he could supply you with some printable data with that information because I was comparing the differences between the Mobil you're trying out and the SyntorqLT.  Thanks.

Katoom I'll see what I can get from Abe at Weller Truck.

Figure I would update with my fuel logs for the last few days. I've been working a job in New Meadows, ID and leave the house here early in the mornings while the temps are low like this morning it was barely 40*F. The transmission temp never rose off of 100*F. When I got to the job site I did crawl under and hand check the transmission case and it was cool to the touch yet after 22 miles of travel. Even on my trip home it was raining moderate and transmission temp again did not rise off of 100*F.

 

Thats crazy that your trans stays that cool Mike. I just posted another topic, but it involves checking the trans fluid just after shutdown and the trans seemed pretty warm. Now I was on the exhaust side and I do not have any kind of heat shield, but still....I wonder if that lighter fluid makes that much of a difference.

It's nice and cool for sure! 

 

Still curious what method you used to see the trans fluid level in gear. I know you mentioned N on the xcase but that doesn't tell the whole procedure.

59 minutes ago, leathermaneod said:

Thats crazy that your trans stays that cool Mike. I just posted another topic, but it involves checking the trans fluid just after shutdown and the trans seemed pretty warm. Now I was on the exhaust side and I do not have any kind of heat shield, but still....I wonder if that lighter fluid makes that much of a difference.

 

I'm not sure as of yet. I'm wanting to see some warm and dry weather to see changes. This is going to be a long term study of the effects of the 50 SAE transmission fluid, transmission temperatures, MPG changes, etc. So I'm going to continue updated as the days go on.

I was surprised when I first got my gauge how long it took to get heat in the tranny. I saw 30 miles or a touch more before the gauge moved with cool weather.

My differential heats up way before the transmission does.

 

Keep up the updates Mike.  Good info.