please, not the tranny!

[charlell8]

hello all, new to this site, referred from trailvoy. so this is my problem: towing the hybrid out to camp on fri., hilly areas on i84 west of Hartford, no prob. kept it in "d", 60-65 mph. coming home sun., started up the first long, not so steep hill, it had like 2 sounds. the normal acceleration, then a throatier sound, kind of winding out, kind of sounded like a turbine. my first instinct was "the tranny - oh cr@p" I let off the pedal, it stopped right away. got into it again, same thing. backed off the pedal, eased it up the hill at about 50, got going on a flat space, took it up to 60-65 slowly, no problem. next hill, same thing as the first. eased it the rest of the way home at 55-60, mostly pretty flat. checked the tranny fluid, it's filled to where it should be and is the right pink color, my s.i.l. changed it and the filter a couple of months ago. what else can I check, or can someplace like auto zone run a code check? edit: the "SES" light came on today, auto zone said code P0410. could that have any impact/correlation? any and all insight greatly appreciated as I really cant by a truck right now. thanks, chuck.

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#2 ​

08-01-2014, 05:40 PM​

 

[The_Roadie]

Welcome! Glad you got a clue where we all took off to.

P0410 is totally uninvolved, but it may be affected by a flaky or sluggish O2 sensor.

Gotta ask my usual questions......how many miles, are you current on all fluids and spark plugs, and any other maintenance history on the truck?

Are you running with an aux external tranny cooler? Highly, highly recommended for a trailer like yours with large frontal area.

And towing up hills in 3, not D, is also highly recommended.

I'm thinking you had a momentary transmission overheat and the fan clutch went on and that was the turbine sound.

Do you have an Android phone? Can you read up a bit on tranny coolers and consider installing one? Many or us use Hayden brand, and that would be a fruitful search phrase.

 

[KNBlazer]

Word for word what Roadie said :lol:

 

[charlell8]

thanks for the reply's. it's got 133,000 miles, plugs are new 2 months go, all fluids are checked regularly. I will start towing in 3rd. going out again in a couple of weeks with the camper, fingers crossed.

 

[Mounce]

Have you changed the transmission fluid though? All fluids are supposed to be changed at 100,000 miles.

 

[The_Roadie]

And the transfer case every 50K, religiously.

And by every fluid, we mean not only coolant and tranny, but brakes and differentials.

 

[gmcman]

At your current mileage if you want to buy yourself some tranny life, I would very strongly recommend changing the separator plate, which gets worn from the check balls, and add the vette servo along with the Sonnax Super Hold servo.

While you're in there, you can change out the factory PWM controlled torque converter lock over to an off/on style of lock by replacing a few parts in the valve body, known as a PWM eliminator valve.

You can do all this for about $150-$200 and you will thank yourself later.

 

[charlell8]

tranny and diff changed a couple months ago also. gmcman, can the changes you suggest be done by your average joe who can turn a wrench with a well stocked tool box? would I have to drop the tranny? any walk throughs or videos out there?

 

[IllogicTC]

tranny and diff changed a couple months ago also. gmcman, can the changes you suggest be done by your average joe who can turn a wrench with a well stocked tool box? would I have to drop the tranny? any walk throughs or videos out there?

How well stocked are we talking, because I would say possibly-to-yes.

I believe all the upgrades are within or near the valve body area. Someone who's done this stuff would know, but I would figure you can just drop the pan to gain access to everything you will be doing.

 

[Mounce]

Is it the 4L60E? If you're wanting to rebuild it, I found some decent videos on YouTube of a guy that does it for a living and he tore the whole transmission into single parts in around 30 minutes including him talking about different things. It was hard to follow but he explained what to check for wear and what to replace or not. That's only if you have the nerve to dive into the task, just let me know and I'll find his video. I'm sure he has one on the 4L80E also if that's what you have.


Edit: he didn't show pulling it outta the car though, just started with it on the table.

 

[charlell8]

I don't know which one it is. how do I find out?

 

[gmcman]

In your Envoy it would be the 4L60E. I would put the level of difficulty around that of a power steering rack, with twice as many bolts. Not too bad but takes a few hours if you have never done it since you will be noting where everything goes.

You can lower the trans cross member and access the 2nd and 4th apply pistons. The 2nd would be the new vette servo and the 4th would be the new Sonnax Super Hold.

Here's a video on what's under the cover: http://www.youtube.com/watch?v=4WpjGQnEixo

The transmission won't fall out, just remove all the cross member bolts except for the far drivers side since it will pivot down. I had to use a pry bar to pull it down then the cover is easily accessible.

 

[gmcman]

The valve body is different and takes a little time. There are alot of bolts and some don't come out, some are longer than others. Leave the center bolt in and remove when you are ready to remove valve body, I will try to find a vid or something but it's not hard at all.

I would not keep driving it until you fix it or you WILL need a rebuild.

 

[DocBrown]

Ditto what gmcman says. I wrote up my experience on the shift and servo kit upgrades. Take your time, it took me about 5 hours. Well worth it.

http://gmtnation.com/forums/topic/8182-4l60e-upgrades-shift-kit-and-new-separator-plate/

Unfortunatly it seems the links I provided that had part lists are no longer valid.