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2005 chevy trailblazer
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Discussion Starter #1
I have a couple questions regarding these 4l60E Trans

My 05 has 190K and runs and drives perfect... we have owned it for 2 years. in the summer I can start and go.... in cold weather.. below 30 degrees. If we start and go there is nothing or it moves a few feet and goes to neutral... Let it warm up for 5 mins and its perfect.It did this last winter then was fine all summer and now again. We are in NH. Your thoughts on cause? When this finally goes... What years will interchange? Can I do an 03 or 04 ?

Next... I was just given a 02 4.2 with 225K ... Runs perfect... no 3rd or 4th gear. What are my replacement options? I have found an 03 TB with a fairly new trans and a bad frame. Will the 03 be plug and play? What about a 4l60E from a 99 GMC truck? The GMC is a 1500 with a 5.3?

There are a tons of these arounf NH with rotted frames... so lots of parts rigs available. Spending 1500-2500 to rebuild a trans is not an option. But Swapping in used is.
 

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2003 chevy trailblazer_ltz
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113 Posts
My '03 has done that in Reverse in the winter for ten-plus years. The colder it is, the slower it is going into reverse. Mine will go forward without problem no matter how cold it is.

I was told that the aluminum valve body warps, and the fluid pressure leaks until it "warms up". I don't know how accurate this is. You could talk to a local trans shop, and see if they can fix the valve body without doing a total trans overhaul.

Since the trans works fine otherwise, and the fluid level and color is good (I changed the fluid 'n' filter a few years ago, although it's probably due again this spring) I'm just allowing an extra minute or two for the trans to warm enough to engage reverse. When I park it, I have it facing out so reverse isn't needed; but my wife is incapable of doing that.

No idea about interchange among years and between 4.2L and 5.3L. Knowing GM in these more-modern vehicles, the odds are probably not good.
 

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2005 chevy trailblazer
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Discussion Starter #3
My '03 has done that in Reverse in the winter for ten-plus years. The colder it is, the slower it is going into reverse. Mine will go forward without problem no matter how cold it is.

I was told that the aluminum valve body warps, and the fluid pressure leaks until it "warms up". I don't know how accurate this is. You could talk to a local trans shop, and see if they can fix the valve body without doing a total trans overhaul.

Since the trans works fine otherwise, and the fluid level and color is good (I changed the fluid 'n' filter a few years ago, although it's probably due again this spring) I'm just allowing an extra minute or two for the trans to warm enough to engage reverse. When I park it, I have it facing out so reverse isn't needed; but my wife is incapable of doing that.

No idea about interchange among years and between 4.2L and 5.3L. Knowing GM in these more-modern vehicles, the odds are probably not good.

Im actually ok with the 5 min warm up.... I was just wondering what the cause was. Today I drove it 50 miles with an empty trailer and 50 miles home with a 03 Trailblazer on it.... Picked it up cheap... owner thought the frame was rotted... turned out both upper control arms were broke in back... 140K on the clock.... New Daily driver for my with.... Ill take over the "wait for 5 mins" Rig.

Still searching for a good parts rig LOL
 

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My '03 has done that in Reverse in the winter for ten-plus years. The colder it is, the slower it is going into reverse. Mine will go forward without problem no matter how cold it is.

I was told that the aluminum valve body warps, and the fluid pressure leaks until it "warms up". I don't know how accurate this is. You could talk to a local trans shop, and see if they can fix the valve body without doing a total trans overhaul.

Since the trans works fine otherwise, and the fluid level and color is good (I changed the fluid 'n' filter a few years ago, although it's probably due again this spring) I'm just allowing an extra minute or two for the trans to warm enough to engage reverse. When I park it, I have it facing out so reverse isn't needed; but my wife is incapable of doing that.

No idea about interchange among years and between 4.2L and 5.3L. Knowing GM in these more-modern vehicles, the odds are probably not good.
Your: " ....My '03 has done that in Reverse in the winter for ten-plus years. The colder it is, the slower it is going into reverse. Mine will go forward without problem no matter how cold it is."

..... tells me your problem is in applying your FORWARD CLUTCH.

This part: ".... I was told that the aluminum valve body warps, and the fluid pressure leaks until it "warms up". I don't know how accurate this is. You could talk to a local trans shop, and see if they can fix the valve body without doing a total trans overhaul."

Valve bodies don't behave that way. They either ARE or ARE NOT warped, but not selectively so. Add in that fluid loses viscosity as it warns and any leak when cold would be much worse when things got warmed up.

There is one other possibility to consider.... converter drainback.

When you shut off the engine, the convertor could conceivably drop to half full .... and next startup it may take a few moments to refill/recharge. THIS IS NOT TYPICALLY A THM PROBLEM... but I have seen it a time or tr wo from worn out hub bushings or missing checkballs, etc.

I mention that for the other post, not yours with decent Forward but no Reverse. A drainback will hobble both forward or reverse with equal aplomb.

Before you start your vehicle next time, check the fluid level to see how high it is up the stick. GMs don't typically drain back much ... if at all... and there should be very little change once running.
 

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2003 chevy trailblazer_ltz
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Your: " ....My '03 has done that in Reverse in the winter for ten-plus years. The colder it is, the slower it is going into reverse. Mine will go forward without problem no matter how cold it is."

..... tells me your problem is in applying your FORWARD CLUTCH.
The Forward clutch isn't engaged in REVERSE. All the FORWARD gears work fine. Therefore, not the Forward clutch.

IF (big IF) the problem is in the friction (clutches or bands) it would have to be something that's engaged in REVERSE, but not in first gear, since first gear works fine even when cold. The old 3-speed auto trans--TH 400 for example, and Ford C6, had a Forward, High-reverse, low-reverse, and intermediate friction (clutch or band); plus some one-way clutches. (GM didn't use that terminology, but that's their function. "High-Reverse" was called the Direct clutch, for example.) Forward clutch plus low-reverse = low gear going forward. High-Reverse plus Low-Reverse = reverse.

A problem in the Reverse Input Clutch (or it's hydraulic control circuitry) on a 4L60 could be a viable diagnosis. It's not used in any other range but reverse. The shift solenoids and the Low-Reverse clutch are also used in low gear, and that works fine.

IF (big IF) this were a failing seal on the clutch piston for the Reverse input clutch, I wouldn't expect it to have survived for ten+ years. The seal would have crapped-out fairly quickly and then there'd be no reverse ever. Same deal for a failed hard-part (Sun shell, or some shaft, one-way clutch, drum splines, etc. The thing would have totally died by now. I don't think it can be a clutch/clutch piston problem since it magically "heals" every spring, and then fails again in late-fall.

This part: ".... I was told that the aluminum valve body warps, and the fluid pressure leaks until it "warms up". I don't know how accurate this is. You could talk to a local trans shop, and see if they can fix the valve body without doing a total trans overhaul."

Valve bodies don't behave that way. They either ARE or ARE NOT warped, but not selectively so. Add in that fluid loses viscosity as it warns and any leak when cold would be much worse when things got warmed up.
Depends on what distorts with temperature. As said, I'm not convinced the valve body warpage theory is credible; but I'll say that it's possible.

I just have the "feeling" that this is a hydraulic control problem, possibly in the valve body, maybe a loose bolt or sticking valve or something, and when the aluminum valve body expands a little from heat, it works again. I'm also thinking that there's a pressure-boosting valve that is supposed to engage in Reverse, and if that's partially-failed so that it leaks until it warms a little, that could cause my symptoms.

There is one other possibility to consider.... converter drainback.
As you said, it doesn't fit the symptoms for my vehicle. Forward gears work fine. If the converter were draining back, it'd be slow into forward or reverse. I can drive forward, slap it into reverse...and have no "gear" until it warms up some. Might be a possibility for the original poster; but I'd really think the trans pump should fill the converter in much less than several minutes--unless the filter is plugged or the fluid level is very incorrect.

For the original poster, "I" would (and DID) change fluid and filter as the first point of potential repairs for a slow-to-engage condition.
 

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The Forward clutch isn't engaged in REVERSE. All the FORWARD gears work fine. Therefore, not the Forward clutch.

IF (big IF) the problem is in the friction (clutches or bands) it would have to be something that's engaged in REVERSE, but not in first gear, since first gear works fine even when cold. The old 3-speed auto trans--TH 400 for example, and Ford C6, had a Forward, High-reverse, low-reverse, and intermediate friction (clutch or band); plus some one-way clutches. (GM didn't use that terminology, but that's their function. "High-Reverse" was called the Direct clutch, for example.) Forward clutch plus low-reverse = low gear going forward. High-Reverse plus Low-Reverse = reverse.

A problem in the Reverse Input Clutch (or it's hydraulic control circuitry) on a 4L60 could be a viable diagnosis. It's not used in any other range but reverse. The shift solenoids and the Low-Reverse clutch are also used in low gear, and that works fine.

IF (big IF) this were a failing seal on the clutch piston for the Reverse input clutch, I wouldn't expect it to have survived for ten+ years. The seal would have crapped-out fairly quickly and then there'd be no reverse ever. Same deal for a failed hard-part (Sun shell, or some shaft, one-way clutch, drum splines, etc. The thing would have totally died by now. I don't think it can be a clutch/clutch piston problem since it magically "heals" every spring, and then fails again in late-fall.


Depends on what distorts with temperature. As said, I'm not convinced the valve body warpage theory is credible; but I'll say that it's possible.

I just have the "feeling" that this is a hydraulic control problem, possibly in the valve body, maybe a loose bolt or sticking valve or something, and when the aluminum valve body expands a little from heat, it works again. I'm also thinking that there's a pressure-boosting valve that is supposed to engage in Reverse, and if that's partially-failed so that it leaks until it warms a little, that could cause my symptoms.


As you said, it doesn't fit the symptoms for my vehicle. Forward gears work fine. If the converter were draining back, it'd be slow into forward or reverse. I can drive forward, slap it into reverse...and have no "gear" until it warms up some. Might be a possibility for the original poster; but I'd really think the trans pump should fill the converter in much less than several minutes--unless the filter is plugged or the fluid level is very incorrect.

For the original poster, "I" would (and DID) change fluid and filter as the first point of potential repairs for a slow-to-engage condition.
You're right ... I was spitballing for ideas... and frankly I was looking for a common denominator... not a final analysis. This is only internet rocket surgery at best....

I'm still tossing out the idea of warpage since fluid loses viscosity as it warms and can leak much easier. Besides, there's gaskets that blow out if things aren't at least moderately tight and don't move around from thermal changes. There COULD be gasket failure... or wrong intermediate gasket installation...

For the Reverse apply situation... there might be a boost valve not actuating... I'd also try a cold start in manual Low... which calls for full boost like Reverse does ... and run a pressure test.

Still in the exploratory process...... but at this point a pressure test is next.
 

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2002 gmc envoy_slt_xl
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A lot of good comments / technical discussion so far. To the OP, try one more simple test. If neither forward or reverse function happens when cold, double double check the fluid level. The OEM dipstick is a bit tricky. Make sure that the outer tube is properly located/retained. Automatic Transmission Fluid (ATF) expands much more than typical lubricants when warm. Just for grins, put in an extra pint or two and see if the symptoms change. You can drive a few miles at low speeds without too much foaming, if overfilled, but you'll have to suck the excess out after the test. I can not say for sure on the 4L60e, but the usual HOT fluid level is at the aluminum case-to-steel oil pan split line. You can drop the pan and eyeball where the dipstick marks show up. OK, this is just a left-field possibility, but certainly a cheap fix if it helps. Remember that trans fluid levels are checked HOT, parked level, idling, and after shifting into every gear selector position for several seconds, then back to park.
 

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2004 chevy trailblazer_ls_ext 4.2 4wd
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I have an 04 Trailblazer EXT 4.2l, an 03 Envoy 5.7l, a 99 Yukon SLE, and an 02 Blazer. All 4 have the 4l60E. I’ve spent a lot of quality time underneath all 4, including replacing 2 and swapping one more of these transmissions. They’re all the same. The only difference I saw between my 4 SUV’s was how much room I had under, over, and around the transmission. Based on my experience, I’d say the 4l60E was GM’s standard for most of their trucks and SUV’s for several years.
 
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