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Discussion Starter #1
My new Raybestos rebuild kit came with new steels and frictions however using all 5 steels and frictions I get a stack up of 1.188. This is below the factory FSM, which states this should be 1.200" to 1.240". Do I need to purchase a thicker steel to replace one of the 0.068" ones that came with the kit? Or is the larger tolerance OK?

I've also seen a lot of posts across the internet showing clearance measuring of everything installed with either feeler gauges or a dial indicator as well. I can do either if that is a better way to measure this. But then what becomes the clearance value?

This is probably the first of many questions...

-Brian
 

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Honestly unless the transmission has extremely low line pressure or you're always rolling 5mph when you shift into reverse, this clutchpack NEVER wears. I literally saw the printing still on every clutch of every drum I ever removed. So as long as the piston seals are staying on the machined surface, you're probably fine.

If you want to make sure it's factory, go to a local transmission shop and ask if you can swap them one of your .078" steels for a 0.090" steel (or two). That will get you within spec. Again, I seriously doubt .012" is gonna make a difference in a clutchpack that never wears. More info here at 9 minutes in:

It's worth making friends with a local trans shop. I found a local guy near me who's super knowledgeable and super nice. Every time I ask him a question I'm super respectful, don't waste his time, bring him a box of protein bars and he's a happy camper. He's sold me a number of parts very cheaply and even re-bushed everything for a killer deal.

BTW just in case somebody's rebuilding their 4L60E and discovers that a shady shop used an old 700R4 drum (as I did when I started with my most recent core), those pistons are steel and have a smaller outer diameter so they won't fit in the 4L60E drums. They also did not use a spring steel, and my local guy didn't have one available, so I just stacked up an extra clutch and 0.0.78" steel to make up the difference and it should be fine.

Last random tidbit while we're talking drums and servos - the Sonnax super hold 2nd gear servo 77911-03k comes with a much longer servo pin that you have to grind and radius to fit. This allows you to use resurfaced drums without a problem, as you'll be custom fitting it anyway.

If you want, I can change this thread to "Brian's 4L60E rebuild questions" so you can just keep adding to it. Advanced Search will still pull up all the topics within. Lemme know.
 

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Discussion Starter #3
One thread to answer them all works for me.

I will press forward with my assembly tomorrow then. Since these so rarely apply and spend most of their life freewheeling having a little extra clearance sounds like no big deal.

-Brian
 
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Yeah. When I stacked mine up it was a bit on the tight side and I'm wondering if maybe I should have left a little more slack in it. But I'll probably take it all apart next year and check for wear anyway so whatever.
 

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Discussion Starter #5
So 2 new questions.

The ASTG Guide mentions a cup plug being drilled out to 1/16" for the reverse apply piston. How critical is this? Is it something I should be doing?

Recommend methods on installing lip seals without damage?

-Brian
 

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I assume this is the low/reverse clutch pack? i had same problem in my 700R4, i just put another steel in to get a tighter clearance. IIRC, those steels come in different 3 different thicknesses. i made friends with a transmission shop and they gave me a bunch of parts and I returned whatever i didn't use. if clearance is too loose there will be a more of a delay going from R to low. hopefully you got the turbulator steels.


I think that cup plug is not necessary, try calling dana @ probuilt automatics.

make a lip seal installer tool. i used a 0.007" feeler gauge and crimped it on the end of an acid brush
 

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Are you talking about the reverse apply piston in the very rear of the case? If so, there was a design flaw in the '93-95 4L60Es that there wasn't a dedicated exhaust in that circuit; any cracks or crossleaks in the valvebody or case passages would leak into that circuit and slowly pressurize it, wearing out the clutches while you were driving. GM fixed it in '96 by redesigning the manual valve and adding a vent in the valvebody next to it (which you can also do, see ATRA 2002-46 for instructions or PM me); TransGo has you chamfer an edge on the '94-95 manual valve, or you can open up that cup plug to allow fluid to exhaust. Any of these options will work. If you are using a '96-up valvebody and manual valve, you don't need to worry about this at all.

For the front piston inside the reverse drum, there is a fairly large bleed hole with no orifice, but it gets sandwiched against that spring when pressure is applied, sealing it off. Just throwing that out there; it caught me by surprise when I first starting doing 4L60Es.

Agreed on using feeler gauges with the lip seals. Sonnax and others do make an installer tool for the reverse drum which is well worth the money, then ReBay it when you're done. They sell a "lip seal installer tool" which has a loop of wire on each end. I've found that tricky to use and it can yank the lip up as you remove it if you're not careful. I'd skip that one.
 

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Discussion Starter #8
I was asking about the one in the reverse drum. The ATSG Manual talks about plugging it with a 1/16" orifice.

After posting the question here I bummed around on YouTube a bit watching install videos. Most use the feeler gauge or some sort of stiff thin plastic sheet to slip the lip seals in place. So I've got a few possible paths to try now.

-Brian
 

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Ok. Yeah you could definitely plug that one. Does it matter? Like I said earlier, the conical spring will block it during apply.
 

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Discussion Starter #10
I left the orifice alone. I figured it seems to work fine as is and being in the reverse drum, I assume it doesn't come into play very often.

-Brian
 

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Discussion Starter #11
So how critical is the pump slide pivot spring... cause I don't know where mine went. Ugh, hopefully the local parts house has one otherwise I'll be paying for speeding shipping from monstertransmisson since they have one listed on their online store.

-Brian
 

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It's the main thing that drives line pressure, so it's critical. There are two springs, a big and a little. I find the best way to reinstall them is to put them in against the slide stop, then insert a screwdriver in the other end of the springs, bear hug the pump and squeeze the springs down into the pump body.

Sonnax does make a stiffer spring that replaces both of them, because the stock ones are designed to lay over above 5500rpm to go easy on the hard parts during shifts, but this isn't desirable for cammed motors making a lot of power above that. I did not put this in my stock rebuild but did put it in another rebuild going behind a motor that makes power to 6300 rpm.
 

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Discussion Starter #13
I have the sonnax HP-4L60E-01 kit so I had a new pump slide spring. I was more so bemoaning the fact that I misplaced the little one that goes underneath the pump slide pin. Deciding I'd buy a replacement on Monday, I started putting the pump back in zip locks before moving on to the valve body. Then I found the little spring hiding under a paper towel.

-Brian
 

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Make sure you check that one in the kit - The Sonnax high-rpm one is wound OPPOSITE of what the stock one is. I only say that because I had a bag of pump slide springs which I THOUGHT were the big high-rpm ones and then I found out that they were just OEM replacements and I still had to use the little spring inside as well.
 

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Discussion Starter #15
It's the high RPM one, not that I expect to see high RPM on a stock 98k mi LT-1.

-Brian
 

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I wouldn't bother with that spring in that transmission then.
 

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Discussion Starter #17
So the transmission is reassembled, and the engine is currently out for a new set of seals. The only major component missing now is the Torque Converter.

Since its a bone stock engine in a 3600lb truck that only ever sees street driving, I'd like to just go with a S10 converter. However, I'm curious as to what the recommended replacement brands are these days? AC Delco reman on Rockauto is almost $300 bucks which is only $100 bucks shy of a Edge Racing Mild Street Converter. Meanwhile TC Reman from Autozone has a 1yr warranty and is $150... For what I'm doing that seems like the best route to me. Opinions?

-Brian
 

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Discussion Starter #19

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That's fine too. I just bought a stock-stall TC Remanufacturing unit for my Impala. The seller above also sells a 2000-stall one; just go to their ebay store.
 
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