727 Auto

[Kiohio]

Should I put on an aftermarket cooler?

I need to tow with it.

I know that the Cummins has enough torque to kill it if pushed but,

using common sense I think it should last ok.

It was rebuilt approx 30k ago.



Truck is the 89 in Sig.



Thanks, KO

 

[jimnance]

Heat is what generally kills these transmissions. The first, and most important thing you need is a transmision oil temp guage.



Assuming that you are hauling something 5,000 lbs or less the transmission should last indefinately if you keep the temps under 200 df. Cooler is better in this case. Transmission life is dependent on the lubricant temp and repaidly decreases as the temperatures rise.



For heavier loads a seperate cooler may need to be installed to keep temperatures in check. The 727 transmission is a very fine one, though a dated design. Yes, you are correct that the Cummins can stretch it to it's limits especially if you are pulling big loads.

 

[sdstriper]

Should I put on an aftermarket cooler?

I need to tow with it.

I know that the Cummins has enough torque to kill it if pushed but,

using common sense I think it should last ok.

It was rebuilt approx 30k ago.



Truck is the 89 in Sig.



Thanks, KO

Get a transmission oil temp gauge now and put it on the cooler out (pressure out) line, I recommend a B&M deep pan too, Summit has them for 136. 00 bucks, damn cheap for a deep pan. I would get another transmission oil cooler and add it as another, not as a replacement. Tru Cool HB7, DTT uses these and I don't think you could go wrong if they are using them, they are reasonable in price. I would also visit DTT's site and read thru their forum, Bill has some interesting reading on parallel or series plumbing of an additional cooler depending on what towing your specifically going to be doing. You will find that the transmission oil temps will heat up the radiator coolant if/when towing with your early 1st gen, the early small downflow radiator could be replaced with a later crossflow if it is a real problem. Mine was nearly new when I got the truck so I have a hard time dropping the money in this area. I would much rather spend it on a better torque converter. I have been slowing down when/if I encounter the problem (high wind, heavy towing). There is a ton of good info here and great people willing to share and help. Good luck.