Thread: old/new trans cooler - in series or discard the old one?

Originally Posted by davros

What do you reckon guys? In a disco II TD5, I'm installing a RR cooler. Should I leave the old one in and run them in series or discard it?

Dave

Dave

Any heat you can get out of the tanks on the radiator is a good thing for the engine temp, so I prefer manual engine engine radiators and remote transmission coolers on auto cars. Where to remote the cooler is the problem.

In my experience, there are 2 types of standard RRc oil transmission oil coolers, both made out of tubing with little loops of heat exchange wire spiralling along the length of the tube.

• The early type used on the LT230/TF727 which was a lazy "U" which crossed over the radiator aperture near the top then did a 180 degree turn and went back along the bottom of the aperture with the fittings on the LHS.
• The later type was a single tube that only runs once across over the aperture.

I originally had a standard early type lazy U type on my Torqueflyte 727 and I didn't notice high transmission temps even on hot days. (Although I was experiencing high engine temps with the 5 litre alloy V8.)

When the 727 was replaced with the ZF transmission they also replaced the transmission cooler to the later type "because it was more efficient" even though they look to be the same construction to me. What I now notice is that on hot days, particularly on hills like the Mount Ousley
road to Sydney the transmission temps gets up to the mid ranges and on a recent trip back from Dubbo with a 4 ton load in tow I had very significant temperature concerns.

I am planning to fit an additional transmission cooler.

Diana