Trans slipping. Easy fix or toasted?

mntb

Original poster
Member
Mar 18, 2016
123
minnesota
This morning the Trans seemed to start slipping in the 2-3 gear change. The rpm's will climb 300-500rpms then shift. The Trans fluid is kind of a brownish color.

The TB EXT has a 5.3l with 310,xxx miles on it right now.
A Trans filter change and fluid top off (not flush) is on my to-do list. Would a filter change help this issue (or at least buy me some time) or is the Trans toast?

Any insight or advice is greatly appreciated as always.

Thanks
 

mntb

Original poster
Member
Mar 18, 2016
123
minnesota
Could it be a shift solenoid?
If it was a solenoid, would it throw a check engine or warning code/light? My check engine light is on but for an o2 sensor/cat issue and I haven't scanned it lately. I will today or tomorrow though.
 

RedRocketZ28

Member
May 16, 2014
114
It's on the way out. If that's the original transmission then I am surprised it lasted that long.

I used to have a 97 Blazer that did the same thing and I tried the fluid and filter change with no luck.
 

AtlWrk

Member
Dec 6, 2011
674
If it’s just a 2-3 flare then you’re a long way from being toasted. You should address it sooner rather than later though. It’s a fairly common problem on the 4L60E and could be caused by a couple of things. Basically the 2-4 band is releasing too early or the 3-4 clutches are engaging too slowly allowing the engine to “flare” up a few hundred RPM while neither is fully engaged.

Start with a fluid and filter change (not likely going to fix it, but it sounds like it’s due anyway) and while you’re in there replace the shift solenoids too. The solenoid isn’t likely the problem either but they’re cheap and you might as well swap em while you have the pan off. You never know…

From there, there are a couple of other things that are more likely causing the flare:
1. Leaking 2-4 servo seals (can be replaced and accessible from the outside--no pan drop). You might consider upgrading to the "vette servo" while you're at it which will firm up your 1-2 shift a lot (some people think too much). Or you can just replace the seals. Either way, Youtube for "vette servo install" to see what you're up against here.
2. Cracked accumulator piston(s). They're plastic and can crack causing leaks leading to slow clutch apply/release. They can be replaced or upgraded to aluminum versions. 2 of the 3 pistons can be replaced without dropping the valve body IIRC.
3. Worn valve body letting the fluid leak around valves. You can try a shift kit like Transgo's "SK 4L60E" Depending on your skill level this can be knocked out in a Saturday afternoon or have a transmission shop install it. It is supposed to fix/prevent a whole host of issues including a sloppy 2-3 shift. I installed one a few years ago and many people swear by them.
4. A damaged separator plate. Steel balls are used as check valves against the separator plate and after years of slamming against it they can wear the plate to the point that it not longer seals (or in extreme cases they just punch all the way through the plate).

5. Worn 2-4 band or 3-4 clutches, input drum, etc. In other words, serious internal damage/wear that can only be corrected with an overhaul.

It all depends on your skill level (i.e. what you consider easy). Frankly, if you plan on keeping the truck for a while I'd look at doing items 2 through 4 all at once. All but #5 are reasonable for a weekend mechanic to tackle or relatively cheap to have a trans shop take care of for you. Point being, you still have plenty of options
 

Sparky

Member
Dec 4, 2011
12,927
To add to AtlWrk's post, there is a seller on ebay called ctpowertrain that sells the Transgo kit along with new separator plate, seals, and accumulator pistons.

That said, I don't know how much I'd put into that transmission, might put the kit in a lower miles unit and swap it in.
 
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mntb

Original poster
Member
Mar 18, 2016
123
minnesota
Sparky, that was going to be my next point. Wouldnt it be kind of pointless to put all of that in a Trans with 300,xxx+ miles on it?
I don't want to get rid of it even at this mileage. The body is in decent condition for being Minnesota, age, even mileage. There are paint bubbles just above the Dr. Side rear wheel wells and bottom of the lift gate. It's not show quality by any means. But decent.
How many solenoids are there?
Change them all or just one?

I called a few shops just to get an idea of worst case scenario. One shop said about $850 for a rebuild and torque converter. But they don't install it.

Another shop quoted $1500 out the door. Install, fluids, labor, core, New parts.

Aamco offered to look at it for free then go from there. However I have a feeling the "free" had strings attached though.

I think a Trans swap is out of my skill range though. But I've wondered how hard it would really be.
 

mntb

Original poster
Member
Mar 18, 2016
123
minnesota
I came across a short step-by-step for the transmission replacement.
Um, im probably going to try and have a shop do it if it comes to that. I don't think that is something I dare take on at the moment.
I'll probably wait on any shop touching the TB for now. Even the "free" offer. They want to test drive it, run some diagnostics, drop the pan, etc. I don't think that is all "free". I'll probably try replacing the filter, topping off the fluid, and replacing solenoids. And go from there.
Im just unsure if I should replace just one or more of the solenoids. I think there is at least two in there. But I'm unsure at the moment how many there are.

Any other suggestions on what to do?
I don't have a lot of money to work with right now. If I can keep this Trans going for a little while longer or ideally another then I would go ahead and replace it. Money is pretty tight right now though.
 

Reprise

Lifetime VIP Donor
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Jul 22, 2015
2,724
I'd definitely do fluid & filter change. There are 2 shift solenoids, both on same side. They're interchangeable as well, so you could try swapping them and see if problem follows. I wouldn't go farther than that w/o doing a compression test to see how much life is left in the engine. No sense giving her a fresh tranny if the engine follows suit a year later.

I have the ctpowertrain kit. Awesome stuff; you get everything you need. I dont think it will fix your issue, but that's a guess on my part.

Use a good quality synthetic Dexron VI, it may help the slippage from getting worse. Start saving for the rebuild / swap.

When you go to remove the pan bolts, be careful - the oem zinc-coated bolts catalyze with the aluminum case. If you feel one giving a lot of resistance on removal, STOP and reverse direction, along with using some penetrating lube of choice (PB, etc) If you happen to break a bolt, get your extractor kit out. They're all accessible except the one in back passenger side corner (exhaust crossover is right underneath); this is the one I broke off. You may need the extractor for the pan drain bolt; I did.

There's a trick to manuvering the pan past that exhaust crossover, but you can do it.
 

linneje

Member
Apr 26, 2012
404
For what it is worth, I have had this problem for several years now, and the vehicle is still chugging along, and I use it to tow as well in the summers. I am a little gentle on that shift when I accelerate (as I know it will rev a little sometimes), and it hasn't caused a major problem. I had serviced the fluid, but the problem did not go away.

So, no, I do not think your tranny is on its last legs yet.
 

Mooseman

Moderator
Dec 4, 2011
25,347
Ottawa, ON
When you do change the fluid, it may make it worse. Reason being that if it is slipping, the suspended clutch material in the fluid actually helps it to grab more. If that's the case, your tranny is on its way out.

 

littleblazer

Member
Jul 6, 2014
9,265
That's when you put in stopslip. :crackup:
 

Reprise

Lifetime VIP Donor
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Jul 22, 2015
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For what it is worth, I have had this problem for several years now, and the vehicle is still chugging along, and I use it to tow as well in the summers.
::snip::

If I'm ever in a dark alley in a bad neighborhood, I want you by my side. You are fearless. :Boxin:
 

mntb

Original poster
Member
Mar 18, 2016
123
minnesota
The fluid in my TBs transmission looks a little darker (but not by much, just a little) than the middle one he showed in the video. Between good, needs changing, and damaged /bad fluid.

Speaking of stop slip, would it help at all? The guy at the parts store claims to have been a mechanic in the past (if I had a nickel for every time I was told that by a parts store guy I could afford a brand new transmission lol) he said to use Lucas stop slip. I've never really used anything in the transmissions or engine. I always believed only engine oil in the engine and transmission fluid in the transmission.

On a side not, I should say I used my tb for work/delivering newspapers. There is a lot of shifting going on but mostly shifting to reverse, 1st and 2nd gears. Sometimes 3rd while delivering. Of course when I go onto another route, it's just like normal driving.
Maybe the shifting to reverse, 1st/2nd gears hurt something?

I was trying to pay close attention while driving the past two days, I noticed that the slipping happens MOST times it shifts to 3rd. However not ALL of the time.
Sometimes it shifts normal, other times it will slightly slip like I've described in the beginning
Any chance that maybe the filter or something else is clogged?

Thanks for the feed back. It's appreciated.
 
Last edited:

Sparky

Member
Dec 4, 2011
12,927
Sounds like band-aid gunk, and Lucas has lots of snake oil products. Every time I hear "Lucas" now I cringe.

I'd just go ahead and change the fluid and filter, go from there. My brother's old car was slipping bad, found the trans fluid was mud brown. Flushed it out, fresh filter, and it went back to shifting normally again. He drove it another year, sold it, and it has kept going for at least 2 years since.

A trans fluid change won't kill the transmission. I don't subscribe to the "grit suspended in the old fluid making it work" theory, just because, well, the filter should catch any grit! And if there was enough in the fluid to allow the clutch packs to work, wouldn't that grit just be tearing up the bearings..?

Not trying to start an argument, but, I can't see that theory making any sense after thinking over it heavily a while back, and it hasn't been my experience either.
 
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mntb

Original poster
Member
Mar 18, 2016
123
minnesota
Are all of the transmission filters the same regardless of name/store brand?

Should I use strictly dexron Vl or can the dex/mercon "for gm, etc" stuff be used?

Just top off the fluid after the filter change or should I remove the cooler line and replace all fluid? How many quarts either way?
 

Sparky

Member
Dec 4, 2011
12,927
I have always used the Valvoline "Dex/Merc" 75k mile red jug stuff. Never had any issues with it and have used it for a combined total of over 200k miles on 3 different 4L60E transmissions of various miles (02 TB had 215k, have one in my 99 Camaro with 170-something k on it, and the one in my Silverado with 154k on it). I don't know the fluid that was in them before I got the vehicles so I don't count those miles lol.

Here's how I'd do the trans fluid change. Do it all.

 

Mooseman

Moderator
Dec 4, 2011
25,347
Ottawa, ON
Dex VI is the current GM standard, which is a superior fluid compared to its predecessor. Although the Dex/Merc stuff would be OK for the older tranny's, anything 2006+ must use Dex VI (just wanted to throw that for reference). If price is equal, I'd go with Dex VI. The Dex/Merc stuff is based on Dex III. And as per Wikipedia:
although fluids asserted by their manufacturers to meet Dexron-III standards continue to be sold under names such as Dex/Merc. These fluids are not regulated or endorsed by GM.[
 

Sparky

Member
Dec 4, 2011
12,927
The red jug Valvoline Dex/Merc meets Dexron VI spec (according to the jug label).

Other brands I have no idea.
 

gmcman

Member
Dec 12, 2011
4,656
Sorry for not reading all the posts, I will follow up later but mine did the same thing. One of the check balls pushed through the separator plate so I replaced the plate and added a vette servo.

This happened around 160K, I now have 253K and all is still good.
 

knuckled1

Member
Jul 20, 2017
39
Albany
Can too much fluid cause a problem? I too experienced this slipping from 2-3. Nothing major, easy to manipulate with pedal. I did flush,fluid and filter and it shifted perfectly, ran great too. But, it was a little low when I checked it, so I added entire quart, now it shifts funny again. Smh. Could draining a little fluid correct this?
 

Mooseman

Moderator
Dec 4, 2011
25,347
Ottawa, ON
Maybe. Check the level with the trans hot and level.
 

budwich

Member
Jun 16, 2013
2,050
kanata
too much fluid may cause "frothing" which might do strange things in terms of pressures in the plate.
 

gmcman

Member
Dec 12, 2011
4,656
Can too much fluid cause a problem? I too experienced this slipping from 2-3. Nothing major, easy to manipulate with pedal. I did flush,fluid and filter and it shifted perfectly, ran great too. But, it was a little low when I checked it, so I added entire quart, now it shifts funny again. Smh. Could draining a little fluid correct this?

When mine slipped or flared during the 2-3 shift, the culprit was the seperator plate.

I would strongly urge you to at least check. I also strongly recommend purchasing a new plate from the dealer. They are VIN matched for your specific setup, and come with the two gaskets molded tonthe plate with the small filters already installed in the plate.

If you wait too long you can smoke the band and at that point it's game over.....will need a rebuild.
 
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