1-2 accumulator

[dirtautoguy]

In my 96 k1500 with a 4l60e Iv been having some abnormal 1-2 shifts.

When I start normally from a stop it it like it’s delayed mushy and late, feels a lot like a stumble

If I get after it from a stop it also feels delayed but it becomes a harsh shift and sometimes feels like it has a slight shudder.

Other than 1-2 the rest of the trans feels good

In my searching I found that alot of these issues point towards a 1-2 accumulator. Or a tps sensor. I used my scangauge to watch tps data and it seems to be smooth and it goes into overdrive fine.

Other than that I couldn’t find a whole lot to match the issues I’m having.

Here’s the most frustrating part. About 6 years ago it got stuck in park. The shop I took it to said the trans had to come out to fix it. So I decided If it was coming out it may as well have a freshen up as it had 220 some thousand miles on it. I ran it for a couple years and started getting hard shifts so I took it back to him and found that the harnness inside the pan had a issue and the valve body wasn’t holding. The shop replaced both at no charge they were great to deal with.

The problem is I don’t know what I did with the invoice and I don’t recall what all parts he used. The total was about $1300 and I know he did clutch packs and the valve body but that’s about all I remember. I called the shop today to see if they had record of what all was done. It would appear the shop has a new owner and the shop has moved. They don’t have any records from the old shop and the guy was not willing to talk to me about it and got ruder when he told me to bring it in so they could look at it and I told him I now lived 4 hours away so that wasn’t a very good option.

So now here I am. I planned on doing a fluid change and pan replacement this spring anyway but now I’m thinkin it might need to be done sooner. Are there any tests or other checks I can do that you guys recomend? It does not feel like it’s pulling itself apart but I don’t think it’s doing it any good driving it around this way?

Regardless of what the issue is what are your thoughts on a sonnax 1-2 accumulator, sonnax boost valve and a corvette servo? I was thinking about doing these when I dropped the pan anyway but I’m not certain if they have been done or not. I was a broke college student so I’m pretty sure everything was stock spec for the most part.

Thanks

The trans has about 50k on it was gone through

 

[east302]

I put that Sonnax kit on my 98 a while back, but it had a different stock piston than earlier years and I don’t think it was the issue. Mine had a broken inner spring. It would shift hard under light acceleration, smoother under moderate. It was so firm that the dash shook.

Original piston and springs on right, new GM ones on left in the photo. It’s a quick check once you drop the pan, so it may not hurt to buy the springs in advance just in case.

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[dirtautoguy]

thats interesting. I still have been driving it to work, I have noticed that when the weather is warmer the 1-2 shift is not as messed up. it also is not as bad if the truck has been driven to or from work.

I think I am going to be nice to it for the time being and maybe avoid driving it some untill my driveway melts off and drys up some ( a month or 2)

I think I am going to do some more research on a sonnax boost valve, spring, and accumulator and at the very least Ill get the acumulator and have it ready for when I drop the pan.

I also plan on replacing the pan. I am not certain yet if I want to buy a aftermarket pan with a drain plug or find a 4l60e "deep" pan with a drain plug. I feel like the OEM would be a better option and possibly cheaper

I also of course plan on putting fresh fluid in it Ill probably use valvoline dexron although I am uncertain if Ill just do a drain and fill or if Ill try to change it out of the converter as well. and of course a new filter with it all too.

if there are any more experiences or thoughts Id be happy to hear them.

 

[stutaeng]

I also plan on replacing the pan. I am not certain yet if I want to buy a aftermarket pan with a drain plug or find a 4l60e "deep" pan with a drain plug. I feel like the OEM would be a better option and possibly cheaper

I also of course plan on putting fresh fluid in it Ill probably use valvoline dexron although I am uncertain if Ill just do a drain and fill or if Ill try to change it out of the converter as well. and of course a new filter with it all too.

if there are any more experiences or thoughts Id be happy to hear them.

I think as long as you get the matching filter for the correct pan, should be fine.

I've been adding a drain plug on my transmission oil pans that don't have one. Just a 1/2-13 bolt with a nut welded on the inside of the pan and use a nylon washer as sealing ring. Works nicely and only costs a few dollars.

You can unplug one of your transmission fluid cooler lines and pump out almost all the fluid out. It's not that difficult.

 

[Caman96]

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This pan is deeper than OEM and provides a bit extra cooling w/plug. https://www.ebay.com/itm/GM-Chevy-7...p2349624.m46890.l6249&mkrid=711-127632-2357-0

 

[Schurkey]

Deep pans are great for hanging down into the undercar air stream...


...and getting whanged by rocks, parking barriers, small animals, etc.

 

[someotherguy]

Deep pans are great for hanging down into the undercar air stream...


...and getting whanged by rocks, parking barriers, small animals, etc.

You have a point, but I think the 4L60E's are tougher than we're giving them credit for.

BTW that's a factory "deep" pan, from a later model (actually I think it may have been on a GMT800 I towed, been a couple years now), IIRC they hit the scene mid-1997. No drain plug or fancy cooling fins, just a bit more capacity.

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Richard

 

[Caman96]

Deep pans are great for hanging down into the undercar air stream...


...and getting whanged by rocks, parking barriers, small animals, etc.

It’s not that much deeper, maybe 5/8”. Like I said it might add a little cooling between that and cooling fins. I mostly got it for the drain plug.

 

[dirtautoguy]

I managed to get a hold of the original invoice for the work done by contacting the shop again. And wouldn’t you know it it was the guy that did my trans in the first place!

Im not certain what all the other guy was talking about maybe we were both confused.

Anyway he sent me a photo of the invoice (I was hoping for a pdf) but I was happy to recover any info I could. Here are the things listed.

Banner kit

Filter

Band

Shell

Pump bushing

Torque converter

Sprag

Overrun steel

3-4 steel

Shift kit

Fluid

Each item has a part number But the picture is blurry and I cannot make out what they are. He didn’t have much to say about my parts idea other than he’d like to drive it then he could tell me exactly what’s going on.

There isn’t a transmission shop around here, there are some a couple of hours away in Idaho but if I did that I may as well go a little further and take it to him.

I plan on doing a fluid change and going with a deeper pan regardless I’m just a little hesitant to change parts that may not play well with other parts that have been installed.

In driving and paying more attention I have found that the warmer it is the less it does it. When it’s cold it’s worse. Sometimes it is a hard shift like it isn’t cushioned, other times it kinda does a double bump almost like it shifts twice, and sometimes it is just really soft like it’s cushioned way to much. Once when getting on it it shifted really hard and it felt like it even shuddered a little. But it’s alway 1-2 shift everything else feels normal

 

[stutaeng]

Um, that really doesn't seem to me like a complete overhaul if that's really the only thing that was changed. What about all the o-rings, teflon seals, pistons? Rubber seals get brittle with age and heat cycles. When they leak fluid or fail, the drums can't apply because the hydraulic force is not there and frictions burn up.

Unless that was also replaced and not mentioned? Perhaps "Banner Kit" actually means "Master kit?" The master overhaul kits typically do have all rubber and gasket sets, just no hard parts.