1-2 accumulator bore gouged..

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Christian Nelson

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Here's a pic of the 1-2 accumulator bore from that 4l60e I am finally close to putting together..

How critical is the bore surface on these? Can I sand it smooth or anything?

I think the pin was so loose the original piston was fluttering. I am going with pinless accumulators now, and since it has two sets of teflon seals, I am doubtful it will leak, but wanted to run it by you guys here.

Here's a pic, I can feel it with my fingernail.

picture.php
 

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It is really hard to say what is to much for us with out being able to see and feel it personally. Pinless pistons would defintly help but if it is gouged bad enough it will still leak, you may have to either get a new accumulator housing or possably sleeve it.
 

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Well, I went ahead and ordered one, $8.50 + $10 shipping..

Not bad, though I hate paying more for shipping than the part.

I took some scotch brite pad to it, and this didn't take it out all the way, so I went ahead and ordered a replacement.
 

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Well, I went ahead and ordered one, $8.50 + $10 shipping..

Not bad, though I hate paying more for shipping than the part.

I took some scotch brite pad to it, and this didn't take it out all the way, so I went ahead and ordered a replacement.

defintly better safe then sorry
 

HotRodPC

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I wouldn't worry the least about that. Rock with it. Accumulator is pretty much just a cushion to soften a shift so its not erratic. In fact, when I build hipo transmisisons, I usually leave the 1-2 accumulaor spring out, so the piston just stays at the back or the top of the bore and allows a hard firm and fast 1-2 shift. So even if a little fluid gets by the piston, you're still going to have some cushion affect and all will be just fine.
 

oneluckypops

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I wouldn't worry the least about that. Rock with it. Accumulator is pretty much just a cushion to soften a shift so its not erratic. In fact, when I build hipo transmisisons, I usually leave the 1-2 accumulaor spring out, so the piston just stays at the back or the top of the bore and allows a hard firm and fast 1-2 shift. So even if a little fluid gets by the piston, you're still going to have some cushion affect and all will be just fine.

I dis agree hotrod. That is another common concern with these transmissions, and it DOES cause premature failure.
 

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As long as you cant catch your fingernail on the grooves I would think they aren't severe enough for the piston to catch on or cause binding/hanging up, but it is better to go ahead and replace it now than later.
 

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I dis agree hotrod. That is another common concern with these transmissions, and it DOES cause premature failure.

You might be right if this is a 700r4. They can't handle much of manly shift. But, nontheless, that damage is not bad enough to not cushion the shift. I'd still rock with it even in OEM method. For the time of a shift, about a second, 2 seconds if its really really slow shifting, enough fluid can't get by the piston and rings to not cushion the shift and do its job. Looks like some shavings got caught up in that bore, couldn't get past the piston ring, so the shavings rode with the piston until they got their own little groove to ride in.
 

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Well, I COULD catch it with my fingernail.. However, I think if I had used some sand paper, and more scotchbrite, I could have smoothed it out, I don't know how sensitive these are to leakage, as there's two orings in a pinless accumulator. Or how far out of round they can be before the orings don't catch it. This was why I asked. Now, I also didn't know that I could find a replacement housing as cheap as I did either. I just wish the shipping was cheaper.

This is practice for the 700R4 I want to eventually put in my square. I have it sitting on my bench now.

HRPC, I thought you were mad at me for a bit there, you never chimed in on the question I had about the tailshaft not spinning easy in one direction when I assembled it. That one REALLY had me worried, I still don't know why the video shows the guy spinning it back and forth, with little effort (he also just slides the servo in with one hand, like butter, when I had to whack it and drive it in- I also noticed he was missing a spring and the big thick oring when he put it in)

It never occurred to me to try it out on the 700r4 I had sitting next to it DUH!!

I still can't believe I missed the gouges on this acumulator when I disassembled it and went over my parts to see what to order!

I am putting together a list of must have tools, and stuff I improvised.

I have so far not needed any special tools, I made my own clutch spring compressor out of some bent mild steel, a harmonic balancer puller, and some all thread. For installing and compressing the teflon seals, I used a cut up 2 liter pop bottle and some hose clamps to compress the rings. For the clutch spring on the input drum (where the 3-4 clutches are) I used 2 C-clamps, wired them together with some heavy guage wire, and had an assistant help me keep it all lined up, with the bent steel ring..

One trick I wish I had learned earlier so I didn't gouge the band a bit was to slide a couple of transparencies in around the band betweenit and the drum as you lower it.

All the stuff I did would apply as well to a 700r4, so I may post some pics of the tools I used/modified, if you all would find that usefull?

ONly area that stumped me so far was the bushings, how to drive them in and out, when I do the 700r4, I will need to figure that out.

Buddy of mine wants me to do his 904 from his Charger now too.. I hear they are easier than the 700r4/4l60's.. Tranny's have been something I have always wanted to learn how to do. They are such a black box for so many mechanics.

You guys are so much help, pricelss!!

I still think I want to get one of those universal spring compressor thingies, but man, they don't look like $100 worth of stuff there, I almost think I could make one for cheaper than that I just need tthe dimensions, etc..
 

HotRodPC

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Just so long as you have no burrs protruding into the bore to hang up the accumulator piston or snag the seals, I'd expect it will work just fine. As said, the acumulator is only haveing pressure on it for a very short time to cushion the 1-2 shift. If its got a few grooves in it, I doubt it'll hurt much at all.

NO, I wasn't mad at all. Just been friggin busy driving the tow truck all day, being on call and taking tows at 1, 2, 4 and 5am etc and staying pretty tired, and still working the part time job 4 nights a week, 4 hours a night. I've been on call the last 8 days. Starting Saturday after 5pm, I'm the secondary on-call, so next week shouldn't be as rough and I won't miss as much.
 

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