Tranny cooler working too well?
 

I have a 24,000 GVW B&M tranny cooler in my car and last night I noticed something strange.

It was about 12 degrees and I was driving along on the freeway at about 80MPH. The RPMs were reading about 3700. I believe that means that the torque converter wasn't locking up.

This is the first winter with the cooler installed.

Doug

Re: Tranny cooler working too well?
 

That's a very good possibility, Doug. That's why greater GVW coolers are not always a good idea. Best idea is to get one closer to the weight of your car.

Wow.. 12.. It gets balmy down south! :)

that sounds like about what I notice when I have to jump on the highway before the car is heated up. Actually, I believe the car won't shift to 4th or engage the torque convertor until the tranny is heated up a bit (somebody correct me on this?), and 3700rpm sounds like maybe it was still in 3rd. Did the revs ever drop (how long were you on the freeway)?

Re: Tranny cooler working too well?
 

I have the B&M 19000 GVW cooler on my 92 and it does the same thing when the temp gets down to about 25F. I take it easy for about 2 miles and then it shifts in to 4th. Basically, I've learned to ignore it. It seemed to be the lesser of 2 evils.

Y'all could throw a few bucks towards an in-line thermostat. Check out B&M, etc.

Beav

Thermostat
 

Doug,
A thermostat will certainly help, it will stop the oil from being cooled too much, and then release oil to the cooler once past a certain temp.

However, in colder weather, this will set up a "cycle". Once the cooler is open, it may have the ability to cool the tranny below lock-up temp again. My suggestion is simpler, use cable ties or wire to blank off a portion of the cooler fins using cardboard or something which will not soften for rain[assuming it is out front] Start with one third blanked, and go to a half if it does not lock up quickly enough. Get it right[one third maybe?] and you can leave it on all year round and forget about it.

Joe

Doug,

Repipe the ATF hose to split the ATF flow so part of the flow goes to the auiliary cooler and part goes to the original SVX radiator cooler/heater. Put a valve in the line to the original radiator cooler/heater. That way you can easily split the flow in cold winter and send it all to the aux. cooler in the summer.
Good Luck.


Larry III

I would not recomend shutting off the flow of ATF to the cooler, at anytime. The transfer clutch will bind from lack of pilot pressure flow and the planetary gearset will lack lubrication.

If slow warmup is a problem, a short stall test will bring the temp up ok.
Harvey.
(ps. Y'"all complain about the cold!. It's 102degs here and the bushfires are rageing.):confused:

Slow flow
 

Hi Harvey!
happy new year.

I was presuming Doug has piped in the cooler in parallel, and original still in place.
Most of my worries in the matter of extra coolers relates to what changes in flow rate and pressure are caused by putting extra pipes in, or indeed, restricting the pipes that are there.

And of course it will be 102 degrees down under if you got people setting fire to the place!

Keep safe, and I hope you and yours escape any damage.

Joe

my case
 

i've two little coolers installed in front of my radiator as the 'v'-shape. i don't know what GVW is. (it came with the car) there's not too much delay in shifting to 4th.(when is abt 35F). recently is about 13F, i noticed that the car took 1,2 mins longer to warm up. usually, i drove after a while, it'll shift to 4th naturally. :)

PS:it's indeed from the same family. weather's getting lower and cold as 12F, my 'brake light' sometimes couldn't go off and came on. :eek: eh, it's not a big deal. didn't pull the brake, back wheels didn't lock up. :D

Let me back up here a little. Is there a negative side to this delayed shift into 4th? I know the engine RPMs will be up while driving highway speeds in 3rd (but not too much).

My question, though, is assuming you keep your speed reasonable during this time.

Uh...transmission cooler t'stats are bypass type, not a block off type. The fluid will bypass the cooler until temperature dictates the need of the cooler. It's no more 'cycling' than the t'stat in your engine, requires no maintenance and will allow for full flow through the cooler when necessary (not restricted cooling by blocking with cardboard.)

Try: http://www.bmracing.com/noflash/prod...moControl.html

Beav

my car does this too.....
 

probably more annoying than damaging. inside five minutes the car begins shifting normally. honestly for me it is a little comforting because it means my cooler is doing its job. :D