4.3 V6 Transmission Cooler Install and power

gunked

around

Two things, you have too much cooler for your needs and "Mr Trannsmision" told you wrong and how to hook it up. You run fluid through tank cooler first then aux cooler and you will have a lot more stable fluid temps. Also 110 to 120 is to cold if you are reading temp of fluid leaving tranny and it is not good for long tranny life. 180 is about perfect and 160 to 200 is a good operating range to be in. Try a smaller cooler, about 12,000 GVW, and hook it up as a said above and you will see more stable tranny temps. Also, on a side note on a hot day you are decreasing AC performance some because you are currently dumping all of the heat from tranny into the consendor which is limiting the cooling of the freon before it is expanded to cool your car.

On this issue the best and simplest solution is to regear the truck. The 4.3 is not a weak motor but is usually coupled to tall gears and makes if feel weaker than it really is. Install a set of 4.10 or ao and you will think you installed a V8 but without the extra gas and cooling problems from it towing and also it will lower tanny temps and extend its service life from reduced torque load. I am curuious aboth the tranyy though because it should be either a THM350 or a 700R4 behind that engine and not a THM400.

lines to the cooler

came with the

probably all gunked up

runs around 110 -

will go up to 160

it was around 80,

the temp hit 190

temp is too cold?

that V6? I guess a

Hello Slap,

If you are concerned about your tranny running "too cold" which might be a real concern for you come the winter months, you could install an oil cooler thermostat between the radiator and the auxilliary oil cooler (if not hot enough, will bypass the aux oil cooler). Do a google search and you should get numerous hits (Jegs, Moroso, etc.). Good luck. Franko

lines to the cooler

came with the

probably all gunked up

runs around 110 -

will go up to 160

it was around 80,

the temp hit 190

temp is too cold?

that V6? I guess a

For sure she is a TH400. Just had it serviced. I have a friend that was also surprised saying "that's one big honkin transmission to be behind a V6".

Re-gearing the truck sounds like a job for a pro and thus might be quite expensive but I'll check into it to see what a job like that would cost.

I'm not too sure but I think the '87 4.3L had around 150 HP and later years they were up to 200 HP.

You have an opinion on these 'Throttle Body Spacers'? Might be snake oil I don't know. I'll start another thread on them to get some opinions.

Thanks for your suggestions.

I'll look into that. Thanks.

-- Dave