Engine/Transmission (1998.5 - 2002) high transmission temp

[lwiseman]

On several long (6-9 mile), 6-7% grade pulls, my auto transmission temperature reached 250 degrees pulling a 10k lb. 5th wheel trailer. Not in overdrive. To keep egt's in check (1200) I backed off speed and to keep rpm's over 2000 as recommeded I shifted down to 2nd. Thats when the transmission temp went over the top. What to do?... to keep in the safe zone. Stock '02 Dodge Ram2500 sb, auto transmission, 3. 54 rear end. Hy-Tech dbl deep pan. Standard ATF.

 

[GWHaley]

First thing to do is get rid of the std. transmission fluid and go to a high quality synthetic-quick! Synthetics always take the heat much better, Gordon

 

[KenHokie]

I believe that the problem is that the stock valve body will not allow the TC to lock up in second gear. Without being locked up, the TC will generate a lot of heat quickly. So the question is do you toast your transmission or your tubo? Synthetic ATF is a good suggestion. I've got Redline C+ in mine. You might think about a 4" or 5" exhaust and a new air intake box to help lower EGT's. I assume you have gauges, I wonder how many people are towing with these trucks without gauges and have no idea how hot both their transmission's and EGT's are??

 

[wlowe]

Ditto on the synthetic trans fluid. Also, is your temp guage reading in-line or pan temps? 250 degrees in the line isn't near as bad as 250 degrees in the pan.

 

[pwr2tow]

On a stock truck you shouldn't have to worry about EGT's. I would leave it in third locked and as long as you do not go under 1700 RPM's you will be fine, on a stock truck you could probably even go lower than 1700 RPM's just watch your gauges. If none of this helps your probably looking at an after market valve body or kit if you can do it yourself.



Synthetic oil will be better and last longer but the heat will still kill the seals no matter what fluid your useing.



Ron

 

[lwiseman]

Thanks for the replies, guys

 

[GaryKrahmer]

Wlowe... His sender is in the line headed to the cooler. He says that the gauge was pegged when he looked at it and since it's an Autometer that only reaqds up to 250* God only knows how hot it really got.

How do I know this??? I helped him installed his gauges.



He told me he was watching the EGTs and keeping them under 1250* when he glanced over to a have a look see at the transmission temp gauge and almost freaked out. He said it was buried.



I'm trying to talk him into either a ATS or DTT transmission and also get a Edge Comp, and some stage II injectors so he wouldn't have an issue with getting up the hill.

Of course he'll have to let me drive it so I can see wether or not my truck needs those goodies!



Are trucks ar identical except for the gear ratios.

 

[rblomquist]

Get a mag-hytec double deep pan, I couldn't believe how well it works keeping the running temp down as well as seriously slowing down temp rises on those long climbs when the TC can't or doesn't stay locked up. I tow a 11-12k TT about once or twice a month.

 

[MCummings]

Originally posted by lwiseman

To keep egt's in check (1200) I backed off speed and to keep rpm's over 2000 as recommeded I shifted down to 2nd.



Stock '02 Dodge Ram2500 sb, auto transmission, 3. 54 rear end. Hy-Tech dbl deep pan. Standard ATF.

How are you getting 1250*F EGT on a STOCK Truck??





Trany temp is high in 2nd gear 'cause all you are doing is whipping the transmission fluid around in the TC, and not putting it to the ground, that makes alot of heat, and soaks up plenty of ponies from the motor.



I want to know why the EGT??



If it really is ALL Stock, then get a AFE Mega-Cannon, and get rid of the muffler, or get a different, bigger exhaust. If you are still haveing EGT problems, do a bigger turbo,, for that much weight I would run a HX-40/16W from Piers.



My $. 02

Merrick Cummings Jr

 

[barryg41]

Merrick



I got the EGT's up to 1275 when we were crossing Raton Pass a couple of summers ago. As soon as It got there tho' the engine was defueled by the ECM.



Back then I was all stock except for gauges.

 

[amsoilman]

I would definately go to a high quality Synthetic ATF. Just make sure it is +3 or +4 rated. When I first installed syntehtic in my 94' CTD, fluid temp decreased some 30 degree F.



Wayne

amsoilman

 

[rweis]

Maybe take the transmission check valve out if you have one. Clears the hose restriction, better fluid flow. Make sure you know the consequences of no check valve though.



Bob Weis

 

[JTBMC]

What does removing the check valve do, in refereance to the consequences. Also is the Amsoil ATF, Plus 3 & 4 rated.

Thanks TJ

 

[MCummings]

Originally posted by tjlaffite

What does removing the check valve do, in refereance to the consequences. Also is the Amsoil ATF, Plus 3 & 4 rated.

Thanks TJ

Removing the check valve will allow Torque Converter drain back. The only side effects of this are that it could take up to 2 minutes for the truck to go into gear after it has been sitting a day or two.



Usually, it takes only 15-30 seconds to go in gear after sitting 12 hours.



Am I correct in thinking that this is the valve you are talking about?



Merrick Cummings Jr

 

[illflem]

If the transmission truely got to 250+ the trans idiot light should have come on and it wouldn't be able to go into OD.

 

[CUMINNTSTRKN]

bill



i have been told that the idiot light doesn't come on until 300 in the pan. i was told that if that light ever comes on get to a service station quick becuase the transmission is garbage. last year when we went to muncie we did some testing while towing my truck. are gcvw was over 23k we ran it up to 325+ in the output line and the idiot light never came on. i'm not sure how hot it was in the pan though.



jim

 

[fox]

These high trans temps are from the loose converter. The stall speed is too low. Tight fluid coupling is a good option.



Of course this requires a converter change and then Dodge is no longer the warrantee station.

The good side is the truck won't need a trans rebuild for a long time if done right.

 

[Big White Beast]

As far as line & pan temps go.........

After I tried putting some fans on for the transmission cooler I put a sender on the pan as well. Have a switch in the cab to monitor the two. The resistance of the senders is off a little so there may be a few degrees of difference there.



Anyway, I haven't got the temps up super high since I've done this but I can say that the pan temps do not follow the line temps that close. Sitting at a long light and the temps quickly rising in the line is barely noticeable in the pan. And this is with minimal air moving across the cooler (aux fans off).



I think the duration here would be the killer. The longer it's run super hot the more chance the pan temps will rise to an unacceptable level. The good news is if your moving, more air will flow through the cooler and help keep the pan temps down. With the double deep pan that lwiseman has it will take even longer for the pan to heat up.



While I would keep a close eye on the temps I wouldn't worry about a short spike in temps. Unfortunately there aren't any major grades nearby to climb to try and get some better data as to length of time that it would take to get pan temps up really high.



Garrett

 

[GaryKrahmer]

High EGTs with a Stock Engine

MCummings... . I also have a stock engine like LWiseman's and when I hit a steep grade towing my 27' Komfort 5th wheel (10K) I can get my EGTs up to 1300* before I have to let up. All EGT readings are pre-turbo



LWiseman does have a Afe Mega Cannon filter on his rig but I do not, but that's the only thing he's added. Exhaust is stock... . The rest of the engine is bone stock, all mainly for warranty reasons.

(He only has around 25K miles on the truck)



GWB. . I'm going to talk LWiseman into putting a sender in his Mag-Hytec Double deep pan so he can monitor both his Line temps and his pan temps. Since he retired two weeks ago he'll be towing his trailer a lot more now. We're also going to get him a fuel pressure gauge.



Great site guys. . thanks for all the info!