Where's the fluid going

[88 two tone]

I have a 88 k1500 I keep going through transmission fluid. I have added 4 qts in the past week. I have not noticed any leaks. What could be the cause of the consumption

 

[454cid]

Check the transfercase.

 

[88 two tone]

Check the transfercase.

Ok thanks

 

[HotWheelsBurban]

Check your antifreeze in the radiator. If it looks like chocolate milk, your leak is in the integral transmission cooler inside the radiator. Had this happen on a non GM vehicle, but GMs can do it too.
I went through 3 quarts in less than 10 days; the truck would shift strangely and the stick was dry, so I figured it was leaking. Couldn't find any leaks underneath (it's a 4x4 and lifted a little so I could get underneath it, unlike my Burb). Changed a leaking hose clamp and found the milky fluid.

 

[thegawd]

I also had an internal tranny fluid leak inside the rad or more like coolant was getting into the tranny fluid. just not enough to notice with the naked eye however, your leaks must be huge. I blew a tranny, replaced it myself and then blew that one 20 000kms later. damn pissed off I searched for a reputable rebuilder to have them install a 4l80e, he insisted it is not necessary and that the weak 4l60e can be built as strong as I wanted it. I found a race shop that been building trannys since the 60's. followed the entire transmission evolution and is a mom n pop family run race shop.

anyways they do a fluid analysis on every single tranny they touch and found coolant in the fluid. needless to say the rads tranny cooler has been bypassed ever since and ran to the factory's aux cool that was never hooked up. just because you have an rpo code for hd towing equipment only means it is provisioned for it. like the 7way trailer plug wires hidden under the brake booster, the aux tranny cooler is not plummed at all.

my truck has been like this for 5 or 6 years and I have not had any problems whatsoever. people say its supposed to help the tranny get up to temp faster but i dont buy it. the tranny shop said it wouldnt harm anything but obviously recommended replacing the rad. they plugged the cooler ports on the rad and it passed a pressure test. it's been this way ever since.

Al

 

[HotWheelsBurban]

I also had an internal tranny fluid leak inside the rad or more like coolant was getting into the tranny fluid. just not enough to notice with the naked eye however, your leaks must be huge. I blew a tranny, replaced it myself and then blew that one 20 000kms later. damn pissed off I searched for a reputable rebuilder to have them install a 4l80e, he insisted it is not necessary and that the weak 4l60e can be built as strong as I wanted it. I found a race shop that been building trannys since the 60's. followed the entire transmission evolution and was a mom n pop family run race shop.

anyways they do a fluid analysis on every single tranny they touch and found coolant in the fluid. needless to say the rads tranny cooler has been bypassed ever since and ran to the factory's aux cool that was never hooked up. just because you have an rpo code for hd towing equipment only means it is provisioned for it. like the 7way trailer plug wires hidden under the brake booster, the aux tranny cooler is not plummed at all.

my truck has been like this for 5 or 6 years and I have not had any problems whatsoever. people say its supposed to help the tranny get up to temp faster but i dont buy it. the tranny shop said it wouldnt harm anything but obviously recommended replacing the rad. they plugged the cooler ports on the rad and it passed a pressure test. it's been this way ever since.

Al

Yes that was on that F150 we got earlier this year. One of the reasons it's been parked since Labor Day. I was off and had time to work on it LOL. Didn't look to see if it had an auxiliary cooler; not sure how to get the grille off and just thoroughly disgusted with it by then. The truck has been mostly sitting for the last few years, so I'm not surprised the radiator is ate up......

 

[thegawd]

another thing.... if you have a plugged cooler line all the fluid will puke out the vent tube.

but you say theres no sign of leak... I'd have a close look on top with mirror....

Al