Transmission Dilemma...

[davidbeaver1]

I have a dilemma that I hope some can help me with. I have a 2005 Tahoe 4x4 LT with 159K on the clock. A couple of weeks ago, I ran into the dreaded transfer case "pump rub" and had the back half of the case replaced with the stronger case. I got the truck back and everything seemed to be fine. I then took a trip where speeds got up to around 80 mph, standard interstate speeds. When I stopped, smoke surrounded the truck. When I looked underneath, the transmission was leaking on the cross pipe and it was leaking out of shifter seal.

So I took it to my trusted mechanic and he replaced the shifter seal and the vent hose on the transmission but when testing any speed above 75 mph, the transmission now builds enough pressure that it is blowing the seal back out and starts leaking again. I think it is odd that all of this started after having the transfer case repaired and I had no issues with it before the transfer case repair. I drive many highway miles at 75-80 mph.

Anyone know what would have changed that would be causing the transmission to build up enough pressure to blow out seals? It is the original transmission. Thanks for any insight you can provide.
Very Frustrating....

 

[B-train]

Has the level of the trans fluid risen since the repair? Check the level in the transfer case too while you're at it. If they damaged the seal between the transfer case and transmission, it can pump fluid into it. Also, check the vent line, even though it was fixed or replaced. Just make sure it flows easily.

 

[davidbeaver1]

My mechanic stated that the levels were in spec and that neither were high or low. He ran a scanner and said the temps stayed in range after he ran the truck up and down the road. He had no issues with leaks as long as he stayed under 60mph. As soon as he got above 60, it started pushing trans fluid out of the seals and onto the crossover exhaust pipe causing smoke. He replaced the vent tube on the transmission and made sure it was free as well. Baffling....

 

[rockola1971]

Bad pressure control solenoid or sticking associated valve which is usually caused by bore wear or dirty fluid.

 

[davidbeaver1]

Thank you Rockola1971. Is that an easy fix or something that is indication of a rebuild?

 

[rockola1971]

Thank you Rockola1971. Is that an easy fix or something that is indication of a rebuild?

If valve body needs sleeved or honed then it will need to be dropped. Not a job for someone to learn on unless with a competent builder.

 

[davidbeaver1]

I have it scheduled to be rebuilt the week after Christmas. The truck has 160K on the original fluid. I spoke to my mechanic when I first got it and he said that if I changed transmission fluid that old, I would be rebuilding it sooner than later. He said just ride it out until it wouldn't go anymore so thats what I did. I don't really want to keep messing around with it since its my daily driver so a rebuild is what is going to happen. That way I can just move on. Thanks for helping make that decision.

 

[OR VietVet]

I have it scheduled to be rebuilt the week after Christmas. The truck has 160K on the original fluid. I spoke to my mechanic when I first got it and he said that if I changed transmission fluid that old, I would be rebuilding it sooner than later. He said just ride it out until it wouldn't go anymore so thats what I did. I don't really want to keep messing around with it since its my daily driver so a rebuild is what is going to happen. That way I can just move on. Thanks for helping make that decision.

IMO, I would make sure to share what @rockola1971 has said here, to that mechanic, if he is rebuilding the existing unit. If swapping in a rebuilt, is a moot point but fun to talk about with him, anyway.

 

[davidbeaver1]

Will do. Thanks!

 

[YukonRog]

One thing I learned when replacing the transmission in my 05 Yukon, make sure you don't get a "stock" rebuild. The OE parts in the stock 4L60E are really inferior. Just like the TC Pump Rub issue. The upgraded Sun Shell as well as the Regulator Valve, Aluminum Accumulator Pistons and a better extra plate clutch pack to mention a few. Lastly, look into maybe a better/bigger cooler too.

 

[davidbeaver1]

The gentleman that is going to rebuild it was telling me all of the same information. He plans to rebuild it with all upgraded parts like you mentioned. He has done many of these over the years so I'm glad he is able to do it. The name of his place is Guardian Transmission in Graham, NC. Small one man shop, but specializes in the 4L60E.

 

[rockola1971]

One thing I learned when replacing the transmission in my 05 Yukon, make sure you don't get a "stock" rebuild. The OE parts in the stock 4L60E are really inferior. Just like the TC Pump Rub issue. The upgraded Sun Shell as well as the Regulator Valve, Aluminum Accumulator Pistons and a better extra plate clutch pack to mention a few. Lastly, look into maybe a better/bigger cooler too.

also .....Corvette servo, kevlar 2-4 band, always aluminum pistons with molded seals and just like you leaded up to....NEVER EVER stick an OEM sunshell back in a 4L60E!

Build it with all the updates Yukon mentioned and the ones I listed with all valve body updates performed the tranny will last way longer than the stock one. And you dont even have to baby it.

 

[davidbeaver1]

So the guy I had scheduled to rebuild my transmission can't do it for almost 4 weeks due to his parts washer going down and him ordering another one. Anyone know of a reliable transmission builder around the Raleigh NC area? I have to get this thing back on the road for work and I can't wait 4 weeks....

 

[MassHoe04]

So the guy I had scheduled to rebuild my transmission can't do it for almost 4 weeks due to his parts washer going down and him ordering another one. Anyone know of a reliable transmission builder around the Raleigh NC area? I have to get this thing back on the road for work and I can't wait 4 weeks....

Does the job require a fancy parts washer? A wash tub full of degreaser and a brush would work to stay in business. I would think... Maybe a little wash-down pump and a hose, if you want to go all fancy-like...

 

[davidbeaver1]

I agree. I'm not sure he really wants to do it. I'm doing some searches right now and found Cottman Transmission in Raleigh. They have a really good rating and he was the first one that actually talked to me about my issue. He is saying around $2400 to rebuild it.

 

[OR VietVet]

I agree. I'm not sure he really wants to do it. I'm doing some searches right now and found Cottman Transmission in Raleigh. They have a really good rating and he was the first one that actually talked to me about my issue. He is saying around $2400 to rebuild it.

$2400 to rebuild transmission? That includes remove and replace and fluid and flush cooler and lines? What kind of warranty?

The other guy is saying the his parts washer is down? Business shut down till gets the parts washer and closing the doors till then or what is he doing?

 

[MassHoe04]

A reman. unit from JEGS is under $2k delivered with a warranty and doesn't mention any added core charge, sou you could sell the old one for someone else to rebuild.
Not sure I would have that kind of money myself, but it is an option.

You were looking to get back on the road quick... Find a reputable installer and have them find one from lower milage salvage parts.
Short warranty, but definitely a cheaper option.

Probably what I would do.

 

[davidbeaver1]

Yeah, he's a small business and has a new parts washer on the way. I spoke to him again today and he is going to end up doing it in two weeks. I had thought about the JEGS but I think I would feel better with a rebuild and knowing that is done correctly which I know this guy will do. Plus he has a 2 year 24K warranty on his work. All in it will be right under $2K which is fair. He is going to do all of the mods and upgrades you guys mentioned as well so that makes me feel much better about it.

 

[davidbeaver1]

Well, after all this time, I finally got my Tahoe back from the transmission guy. He rebuilt the transmission and upgraded many of the components you guys listed out for me. Here comes the crazy part, I was driving for work today and got up to 80 mph on the interstate, looked behind me and there was a trail of smoke. Same issue is still happening! UGH!!! So back in it goes this Friday. As I'm thinking through it, none of the problems started until he replaced the rear half of the transfer case with a new one. Once he did that, it has been pushing transmission fluid out of the seals once I get over 70 mph. I'm at a loss...

 

[S33k3r]

There's a seal between the transfer case and the transmission that requires a special tool to install. We went through something similar on my daughter's '03 Sierra Denali. Do you have any fluid leaks on the pavement, or just the smoke?