Why is water in my tranny?

**Thundare** · 10-31-2009, 04:14 AM

Yea, some how water got into my transmission. Is there some kind of tranny cooling system that is hooked to my engine system?

Model: Tahoe
Year: 1996

**phoebeisis** · 10-31-2009, 10:12 AM

Yes, many Chevys-my 1998 Suburban, probably your Tahoe-have a transmission cooler. It is a little extra -separate radiator on the left or right side of the main radiator(oil cooler one side, transmission cooler the other. You must have a leak in your trans cooler and it lets coolant into the trans fluid.

This is a big deal-you have to fix it-can't have water, or coolant in the trans fluid.

Others will chime in with better info.
Do you have trans fluid in the coolant? Tough to tell because dexcool is red-just like trans fluid.

How do you know you have water in the trans fluid-separates on the trans stick-you can actually see the two layers of fluid??

You can get a new ebay radiator for maybe $170-new local auto zone maybe $300.Genuine GM-delco?? at dealer is expensive-maybe $600

Charlie

**unplugged** · 10-31-2009, 11:03 AM

Yes, phoebesis is correct. Get that fixed asap, and flush the trans. Hopefully serious damage hasn't already occured.
As you can see in the pic I got stuck crossing a river. Luckily, no water intrusion into critical areas.
AAA wouldn't come out, but lucky me someone nearby had a winch.
(Ok jeepsters go ahead and commence with the one liners)

**2COR517** · 10-31-2009, 03:16 PM

I presume you discovered you have water in your transmission because you checked the trans fluid. Why did you check it? Was it shifting funny or something? You need to fix this right away, or you can add rebuilt transmission to your list of recent mods.

**Jimmiee** · 11-01-2009, 08:24 AM

Unfortunatly when water gets into the transmission there is no cure or fix. Flushing the water out ill only prolong the inevitable. You need a new radiator as the cooler <heat exchanger> is inside the radiator and yes, a rebuilt transmission.

Even flushing all the water out will not fix your problem. Once water has touched a clutch plate or band it is absorbed into the friction material. During a shift as the clutch applies the temperature of the friction material flashes above 212 degrees for a milisecond ot two until the heat is absorbed by yhr steel plate. During this time the water boils and steam is produced. The steam is what seperates the friction element from the clutch. :(

**unplugged** · 11-01-2009, 08:29 AM

As my mechanic likes to say:
"It's a grenade and the pin has been pulled"

**Thundare** · 11-01-2009, 03:09 PM

sorry for not responding sooner.. kinda forgot i posted

Anyway to answer 2COR517's question. I checked the tranny fluid cuz the tranny has a whine (pretty sure its the pump) but i have not been driving it.

Thx guys for your help.

**daddytech** · 11-01-2009, 05:31 PM

what you'll probably find is not that there is an extra cooling radiator but instead that your transmission lines in fact plug directly into your radiator and somehow there is a leak in the radiator causing the fluid in the transmission to get water in it. you just need to either replace or have your radiator rebuilt to resolve the problem. IF there is a lot of water in the transmission flushing it may help but more than likely if it's been that way a while now there may be some permanent damage done to the gears and such in the transmission because there is nothing more than wax coated paper between some of the gear plates inside your transmission. if water got in there it could easily degrade that paper or rust the gear plates then you are looking at a rebuild. you might get lucky enough to be able to just flush the trans with new fluid and replace the radiator if it wasn't run long and hadn't been left sitting too long with the water in the transmission and if there wasn't much water in there to begin with. but if it's been sitting a while with a lot of water in there then you may be looking at a rebuild for sure.

i'd start with the radiator and draining the fluid into a clean container to see what amount of water is in the fluid and if it's been sitting there for more than a week or so then I would be looking at a trans rebuild just so the thing doesn't leave you sitting somewhere later.

**Thundare** · 11-01-2009, 07:09 PM

pretty sure its not the radiator cuz it sat for about 9 months and its still topped off

**daddytech** · 11-02-2009, 02:15 AM

FYI it doesn't take a whole lot of water to get in the transmission to ruin it so even if it's a really slow leak and it's pulling in new coolant from your over flow tank you may not realize that much has gotten in that way. I may be wrong but again start with the fluid first