automatic transmissions question
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Joined: May 2006
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automatic transmissions question
I'm considering trading to a 99 RAM 1500 4X4 with auto trans.
Seems to shift ok on test drive, but I've heard a lot of horror stories about them.
What's the scoop? What causes so many failures?
Does an additional tranny cooler seem to lengthen the life on these?
I work as an engineer for a trans cooler company so I can build whatever I need, but not sure what the root cause of the failures is.
Any thoughts? Any suggestions on what to look for or how to "stress test it" before I decide on trading?
Thanks in advance.
Seems to shift ok on test drive, but I've heard a lot of horror stories about them.
What's the scoop? What causes so many failures?
Does an additional tranny cooler seem to lengthen the life on these?
I work as an engineer for a trans cooler company so I can build whatever I need, but not sure what the root cause of the failures is.
Any thoughts? Any suggestions on what to look for or how to "stress test it" before I decide on trading?
Thanks in advance.
Administrator
Joined: Apr 2010
Posts: 87,370
Likes: 4,209
From: Clayton MI
For a 'stress test', just drive it hard. see what happens.
Torque converters on these were weak from the factory. Also, there is a check valve in the cooler lines that likes to clog up, and toast transmissions. Additional cooling wouldn't hurt, but, first, make sure the stock system works right. (dump the check valve, and clean out the cooler circuit.)
Torque converters on these were weak from the factory. Also, there is a check valve in the cooler lines that likes to clog up, and toast transmissions. Additional cooling wouldn't hurt, but, first, make sure the stock system works right. (dump the check valve, and clean out the cooler circuit.)
Administrator
Joined: Apr 2010
Posts: 87,370
Likes: 4,209
From: Clayton MI
Seems to be a popular piece to donate to the scrap yard. I took mine out, and noticed NO difference at all. Aside from my transmission being able to circulate fluid through the cooler again.
Hall Of Fame
Joined: Jul 2006
Posts: 12,204
Likes: 10
From: Gainesville, Ga.
no problem w/o it. its supposed to prevent cooler fluid from draining back into the trans or draining the TC or some such nonsense. all it really accomplishes is getting clogged up and causing trans failure.
test drive the truck pretty hard for 10-15 miles and get everything nice and hot. get on it up and down and see if it shifts correctly. sometimes a bad trans will work ok when cold, and then act up when hot. if it does, then you've found the reason they're selling it. if it shifts ok, then its as good as it gets.
the parts in the trans are weak to start with, and then heat is the enemy. put a big cooler on it and change the fluid and filter about every 24k, if it hasn't failed yet, then it'll probably last a long time.
test drive the truck pretty hard for 10-15 miles and get everything nice and hot. get on it up and down and see if it shifts correctly. sometimes a bad trans will work ok when cold, and then act up when hot. if it does, then you've found the reason they're selling it. if it shifts ok, then its as good as it gets.
the parts in the trans are weak to start with, and then heat is the enemy. put a big cooler on it and change the fluid and filter about every 24k, if it hasn't failed yet, then it'll probably last a long time.