hot tranny
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Elder User
Joined: May 2007
Posts: 943
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From: North East, MD
hot tranny
When pulling my tranny runs about 180-195* if I leave it in D and let it shift on its own but I like to manually pull it down into 1 and 2 b/c the shift points suck but the trans seems to get really hot doing this( 210+). Does it cut off cooling by doing this or is the trans slipping?
Post Fiend
Joined: Oct 2003
Posts: 5,903
Likes: 1
From: MICHIGAN
The temps don't seem all that bad in Auto mode. How heavy are you pulling?
That seems normal after looking at the trans application charts. When you manually use 1st or 2nd gear you are activating more components in the trans than when using it in the automatic mode. ie. intermediate band, coast clutch and believe it or not the reverse clutch when in 1st gear are being applied in manual mode. All that extra pressure has to produce more heat.
I never noticed it before, I'm going to try it this week end during a heavy pull. I'll let you know if mine does the same thing. Hopefully Others will chime in here.
That seems normal after looking at the trans application charts. When you manually use 1st or 2nd gear you are activating more components in the trans than when using it in the automatic mode. ie. intermediate band, coast clutch and believe it or not the reverse clutch when in 1st gear are being applied in manual mode. All that extra pressure has to produce more heat.
I never noticed it before, I'm going to try it this week end during a heavy pull. I'll let you know if mine does the same thing. Hopefully Others will chime in here.
Post Fiend
Joined: Oct 2003
Posts: 5,903
Likes: 1
From: MICHIGAN
I just returned from the trip. Pulling about 12K, I had no noticable differences in the temps from manual shifts to automatic. I really tried to get the tranny hot but it stayed on 180F all day in stop and go traffic, up and down hills, shifting manually. I have an extra cooler out front with a thermostat, maybe that's the difference between yours and mine?
If your shift points are that screwed up you should get it looked at by a tranny shop.
If your shift points are that screwed up you should get it looked at by a tranny shop.
Lead Driver
Joined: May 2007
Posts: 8,608
Likes: 13
From: Belair md
your shift points may be early from having the 18k installed, since it takes less throttle to get going the pcm bases shift points off of that partialy. even full throttle they wont shift at the limiter stock, just the way the power curve is set. i have never been happy with the shift points when towing stock but the pcm doesnt know you have 15k back there
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Elder User
Joined: May 2007
Posts: 943
Likes: 0
From: North East, MD
i didnt notice any diffrence when i installed the 18k. I think it is just bad programming. its not to bad if you go easy but if you get it up to 3000+ rpm the tc locks the same time as 1-2 and then it hunts for gears a couple times. I guess ill just get a bigger cooler and keep manualy shifting it
