Radiator/transmission question

[Rmcoy0017]

2007 Tahoe 200k plus miles.

The wife came home and couldn't make it up our snowy driveway. I noticed the back wheels spinning to get traction but front wheels weren't. I hollered to put it in 4wd and she said it was. I got in to try and noticed the data center say service 4wd. We then noticed orange coolant in the snow. I salted the drive and got it in the parking spot.The next day I'm at work and she calls to say it's shifting hard from 1st to 2nd and she's doing 30 mph and it's at 3k rpm. I told her go back home, it's in limp mode.

I get home and take it to our mechanic (just around the corner from our house) While pulling out I notice when she turns right that her front tires lock. I give all same info to my mechanic and after a few hours im told that the upper and lower lines from radiator are leaking and need replaced. I'm assuming the lines from radiator to transmission.

He doesn't know if transmission is damaged yet. Could a small leak and less than 2 miles driving damage it? Is the radiator leak why the 4wd wouldn't engage? Seems odd it all happened at once and not be related, but I'm not a car guy myself and just know basics.

Can anyone clarify for me please?
Thank you.

 

[lspann3525]

I doubt the transmission sustained any damage just driving a few miles limping it home. I would scan the truck for codes and start from there.

Misfires will also cause the service 4wd to display

 

[petethepug]

Mechanic needs to pull trans dipstick and verify fluid level on cold indicator and it’s not a chocolate milkshake inside.

Next repair the lines, check trans fluid on warm indicator. Top off coolant level and potentially replace coolant reservoir if it’s sensor did not light up it was low.

 

[Rmcoy0017]

Thank you for replies.

I think the lines were broken pulling in the driveway. There was 6-7 inches of snow and ice and my drive has deep ruts in it. When I eyeballed the reservoir it was about 2 inches below the line.

 

[Fless]

What reservoir hangs down that low?

 

[Rmcoy0017]

I worded it poorly.

The antifreeze in the reservoir was about 2 inches below the fill line.

 

[petethepug]

Prolly meant coolant resi. On the bright side, who ever has their trans lines break in the driveway at the end of the day, at home, with snow?

Best case scenario huh?

 

[Rmcoy0017]

My mechanic just called. It's still running with rpm too high for its speed and shifting out of first hard. They recommended a transmission shop

 

[swathdiver]

My mechanic just called. It's still running with rpm too high for its speed and shifting out of first hard. They recommended a transmission shop

@NickTransmissions

 

[rdezs]

2007 with 200k miles....if that's the original trans, probably best to just get it rebuilt.

 

[NickTransmissions]

Could a small leak and less than 2 miles driving damage it?

How do you know it has only been leaking for the two miles or so that you're referring to? How do you know it hasn't been leaking for quite some time and possibly leaking coolant into the transmission? Did your mechanic drop the pan to confirm/deny the presence of coolant in the transmission?

Just looking at the dip stick won't tell you anything as the lighter transmission fluid will sit on top of the heavier coolant/radiator fluid, all other things equal.

I agree w/ those who suggested a rebuild, or at least start preparing for one...And if your radiator is found to have been leaking coolant into the transmission, it's likely completely shot in that if I were the one working on your vehicle, I'd send your existing transmission to the scrap yard (assuming it's fully contaminated w/coolant) and build you another, entirely different one out of my inventory of cores.

 

[Rmcoy0017]

Picked it up.

It wasn't a radiator leak. The transmission was leaking.

Going to have to take it to a transmission shop.

 

[NickTransmissions]

Picked it up.

It wasn't a radiator leak. The transmission was leaking.

Going to have to take it to a transmission shop.

I must have misunderstood, my apologies...I thought your mechanic stated the cooler lines were leaking into the radiator, not externally. If they're leaking externally, you can just replace the lines and/or even put RTV on the fittings that thread into the radiator to prevent further leaks. This doesn't require the vehicle to be taken to a transmission shop for that (I'm surprised your mechanic can't fix the leak)...Unless I'm still not getting an accurate understanding of the problem.

 

[rdezs]

I think he's talking about the transmission itself leaking, like the front seal.

 

[Rmcoy0017]

Yes. The fluid I thought was radiator fluid was actually transmission fluid.

 

[NickTransmissions]

Yes. The fluid I thought was radiator fluid was actually transmission fluid.

So where exactly is it leaking from? If it's anywhere other than the front pump-tc hub seal then you should be able to fix that yourself...You can even do the front seal but you'd have to pull the trans which can be tricky if you're limited on space and/or ceiling height if doing it in your garage.

 

[houstontaylor]

At one time my transfer case was shifting into four-wheel drive low randomly which it sounds like yours could be doing since the wheels were locking up in a turn and it had high RPM to get anywhere. I also had the service four wheel drive message. On mine it ended up being the transfer case module underneath the dash and that fixed it. I don't know how bad the transmission cooling line leaks were but that may be a separate issue if it is not bad.

 

[Doubeleive]

ya this sounds more like a transfer case issue, which was why the service 4wd was lit up.
if your lucky all it needs is a encoder motor and fix the leak and be on your way.

 

[waveryd]

ya this sounds more like a transfer case issue, which was why the service 4wd was lit up.
if your lucky all it needs is a encoder motor and fix the leak and be on your way.

I agree. Sounds more like a transfer case encoder ring or motor. Many times this condition won't trigger a code.

 

[man n black]

Its pretty common knowledge that these transmissions last about 100K miles to the mile with regular service.....Our 2008 went out with zero warning right at 99.7K with religious service and the shop said it was a known regular fail. Replaced with a rebuilt in less than 48 hours in Reno at the time (2012) and no probs afterwards.

I agree its prolly time for a rebuild....

Ch