What should the stock transmission fluid temp be when cruising?

I just got my gauge back from Westach that has had the pointer stuck since I installed it. I have the sensor on the transmission line, not in the pan so I know it will be a bit cooler there. Haven’t gotten around to installing the port in the pan yet.

Yesterday it was 45 degrees out and the temps indicated from 100 to 110-not towing anything.

She rolled over 114,000 miles and y’all have me thinking my transmission might be getting short in the tooth.

Not bad. Now I know it not exactly the same my little 1996 Dodge Ram 1500 with a 46RE is tipping 130-140*F on a 50-60*F weather day. That is travel distance of 150 miles of mostly highway miles. 

 

My sensor is just clamped to the line for now. Soon I want to weld in a bung for the pan for the sensor. 

Edited April 8, 20186 yr by Mopar1973Man

I recently bought a 28.5’ fifth wheel and have been getting the truck checked out to do some towing this summer. I changed the fluid and filter about 10k miles back and it was really clean. I might just be getting paranoid about the tranny. No indications of problems yet. The biggest load I have pulled is a 18’ trailer loaded with hedge firewood over a couple of passes in Co.

Also, any correlation between tranny failure and gearing ratios? I have the 4.10’s so I am in overdrive at a slow highway speed.

2 minutes ago, comanche79p said:

Also, any correlation between tranny failure and gearing ratios? I have the 4.10’s so I am in overdrive at a slow highway speed.

 

More so in tires than gears. Transmission issues tend to rise more when people put 35 to 37 inch tires on a truck with 3.55 gear ratio. This puts way too much stress on the transmission. I'm going to assume you have stock tires with 4.10 gears then you going to have no issues at all and the transmission will live a nice long life because of the reduced stress of 4.10 gearing. 

Yes, it had 35’s on it and I got rid of them and put stock tires on. That really helped to keep the EGT’s in check with the HY turbo.

I am at 2000 rpm at 65 mph.

Perfect. That is exactly what you want for towing your at the top of your torque curve and the stress is lower for the transmission. Still have good road speed. There is another thread going right now where a member is running 37" tire and having EGT issues and will be heading for gear swapping for both axles so he can keep the 37" tires. The bad part is the final ratio after tthe 37" tire and 3.55 gears is 3.00:1 which is WAY TOO TALL. He's heading for 4.88 gear most likely. 

Those temps sound fine. 

 

I have my trans temp in the pan and if I’m not towing or hitting around (multiple WOT runs with the quad turned up) my gauge won’t even register. It’s an ISSPRO gauge that starts at 100. If I’ve been driving and start idling in a parking lot or stop and go traffic I can see temps come up to 130-160 But as soon as I start moving again temps are down to 130-140 empty.

Another thing to consider in the transmission temperatures is the radiator condition and how clean the face of the radiator is. There is the cooler in the radiator and the cooler on the side of the block but it won't be able to exchange the heat if the coolant is running upwards on you. So I would consider pulling the radiator out and power washing both faces with a degreaser to remove any oil that might vent from the stock crankcase vent. Even if you relocate like I have I still got to pull it now and then to wash the mud out of the face of the radiator. Once that done you might as well flush the block and reload with fresh coolant and install a fresh thermostat too.

My trans temp from my edge in my Magtec deep pan would show 10-15 degrees above engine temp.  If engine was 190 trans temp was 200-205

3 minutes ago, Tom Robarts said:

My trans temp from my edge in my Magtec deep pan would show 10-15 degrees above engine temp.  If engine was 190 trans temp was 200-205

 

That doesn't sound right. You might talk to @Dynamic about why the transmission temperature is so high. The only time I see temps like that is when I'm stuck in stop and go traffic on 100*F day. 

Yea those do seem high, is that from the pan? 

2 hours ago, Mopar1973Man said:

Another thing to consider in the transmission temperatures is the radiator condition and how clean the face of the radiator is. There is the cooler in the radiator and the cooler on the side of the block but it won't be able to exchange the heat if the coolant is running upwards on you. So I would consider pulling the radiator out and power washing both faces with a degreaser to remove any oil that might vent from the stock crankcase vent. Even if you relocate like I have I still got to pull it now and then to wash the mud out of the face of the radiator. Once that done you might as well flush the block and reload with fresh coolant and install a fresh thermostat too.

I cleaned the radiators and coolers last fall and just put new belt, hoses, water pump, new coolant and new power steering fluid in last week. Going to do the same with the brake fluid soon. Got rid of the puke bottle. That made a mess of my radiator.

You are ahead of the game! Your on the right track I wouldn't worry then. You've covered all the important bases. 

18 minutes ago, Mopar1973Man said:

 

That doesn't sound right. You might talk to @Dynamic about why the transmission temperature is so high. The only time I see temps like that is when I'm stuck in stop and go traffic on 100*F day. 

Its not right from the pan, I realized after I typed it.  Its from the port on the rear pass. side of the trans.  It will be getting rebuilt again as soon as the truck gets put back together.  It was rebuilt twice in 2016 and was slipping at stock power levels last spring when we started the tear down on the truck.  

You in the accumulator. Not good. There are issues where some sensor actual extend inward to much and can interfere with the piston. The fluid isn't moving much back there so the temperature reading is way off. 

1 minute ago, Mopar1973Man said:

You in the accumulator. Not good. There are issues where some sensor actual extend inward to much and can interfere with the piston. The fluid isn't moving much back there so the temperature reading is way off. 

After my experience getting ripped of by a transmission shop who said they knew what they were doing, I asked around to see what shop actually knew what they are doing.  There is a shop up here that builds transmissions for the guys here in the pulling circuit.  I'm going to take the truck to them and have them build me a trans with billet internals and a triple disc.  The price they quoted wasn't far off what I'd spent on the stock rebuild that didn't hold up, first time they rebuilt it I got 3 weeks before is started slipping and shifting bad.

Ouch. 

 

That was my worry when I started losing my 46RE in the 1996 Dodge. Jon @Dynamic settled my worries and showed me a bunch of stuff on how to rebuild the transmission and how to even test the functions using air pressure. Sad to hear of shops still doing this to people building underrate and charging a premium for the work.

13 minutes ago, Mopar1973Man said:

Ouch. 

 

That was my worry when I started losing my 46RE in the 1996 Dodge. Jon @Dynamic settled my worries and showed me a bunch of stuff on how to rebuild the transmission and how to even test the functions using air pressure. Sad to hear of shops still doing this to people building underrate and charging a premium for the work.

I provided the valve body and pan and governor.  He had bought the shop from my exe's uncle.  I was thinking they still did decent work.  My $7500 slipping transmission tells me otherwise

1 hour ago, Tom Robarts said:

I provided the valve body and pan and governor.  He had bought the shop from my exe's uncle.  I was thinking they still did decent work.  My $7500 slipping transmission tells me otherwise

Sounds like your ex had something to do with the pricing.

19 minutes ago, dripley said:

Sounds like your ex had something to do with the pricing.

We were still together then

Yea that’s rough man. 

 

Either way, sounds like you’re currently tapped into one of the hot lines or areas that get little flow so show hot. This also comes into debate onto where to actually monitor temps. Most people on the forum say to monitor to hot return line. Everyone who actually works on these trans says to monitor the pan temp.