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Does that reamer only do where that valve lands ride? I just bought the oversized valve that doesn't need reaming...
Wait, what oversized valve that DOESN'T require reaming? Who makes it?
Do you have a part number?
Because if it's the Sonnax PR valve, you NEED to ream it; it's .010" oversized, and there is no way in hell it's going into the factory bore.
I've been grumbling and bitching about this valve for about two months because it requires a special reamer, and no transmission shops in my area have it, so I had to buy it myself.
Although, to be honest with you guys, I didn't even LOOK at the TransGo products, because I've been hearing for years that their stuff is bad/ a waste of money.
How well does that valve work? I'd sure as hell roll the dice on that one for $20+ instead of the $150 or so that I've spent for the Sonnax valve and tool.
(Anybody want their pump reamed for a Sonnax PR Valve? $10, and you pay shipping. I'm not joking.)
In other news, I finally vacuum tested the TCC apply valve in the pump, and the best reading I could get (from the lower half, near the snap ring) was 16" hg.
I'm going to run it, but I saw a mention of a modification on the Sonnax instructions about guys trying to crutch this issue by increasing the size of the signal orifice; is this a worthwhile modification in my situation, and if so, which orifice is it?
Update: I thought the 3rd accumulator checkball looked a little rusty from wallowing in the South Texas humidity, so I decided to replace the capsule assembly.
ATRA recommended using a 3/8" tap to take it out, and I said "No way in hell is that going to work," BUT IT ACTUALLY WORKED.
No need to maneuver a hammer inside the case... Although, maybe I just got lucky.
Anyway, I mentioned that the TCC Apply valve could use some help (16" hg vacuum test), and I read about drilling the converter clutch signal orifice larger.
Question: What size should I drill this to, in this situation? The orifice in question is #24 in the ATSG manual.
Update: I thought the 3rd accumulator checkball looked a little rusty from wallowing in the South Texas humidity, so I decided to replace the capsule assembly.
ATRA recommended using a 3/8" tap to take it out, and I said "No way in hell is that going to work," BUT IT ACTUALLY WORKED.
No need to maneuver a hammer inside the case... Although, maybe I just got lucky.
Anyway, I mentioned that the TCC Apply valve could use some help (16" hg vacuum test), and I read about drilling the converter clutch signal orifice larger.
Question: What size should I drill this to, in this situation? The orifice in question is #24 in the ATSG manual.
I can't help you on orifice sizes but removed my capsule with a 3/8-16 bolt with 2 nuts & a washer. I'm using the Superior K0156 that looks like a dog whistle, but stick with a new GM capsule, the K0156's are 5x-6x the cost. They were highly recommended by the expert here, just not sure if worth ~$39.
Sheesh, I paid a little over $5 for my GM capsule; I figured if it's that cheap, why not?
I think I used the delivered price of $7 or $8, hence 5x-6x for the other; I think it's fine for an inexpensive stock rebuild. I originally was going to add the Sonnax part that butts up to the stock capsule, but was told to avoid that part and that the Superior brand part was like a gazillion times better... or highly recommended. I still don't fully remember, but I think it doesn't have a timing issue the Sonnax part has with band off/3-4 on (maybe.) Or maybe it's affected by orifice sizing.
To learn more about it, the Sonnax part, and orifice sizes, like the founding fathers say, "...do a search! You'll find all the answers to your questions that way [without wasting others' time."]
(No Ted, I didn't mean you.)
Last edited by matermark; Jun 8, 2022 at 12:34 AM.
I think Matermark is referring to the Sonnax "Servo Release Check Valve". 5+ years ago this was considered a good upgrade according to many posts on this forum, including my own experience with it and promoting it. In theory, at least based on Sonnax's claims, it seems like a good idea in.
However over time, several pro builders reported customer's trans failures which they blamed on this check valve. IIRC they reported the tiny checkball had gotten stuck and thereby restricted the 3/4 clutch apply fluid. In other words, if/when it wears out, it causes total failure.
The pro builders said it was completely unnecessary when performance upgrades were made. (I.e. with proper shift kit, separator plate drilling and servo springs.)
Also, the Sonnax valve's instruction had you drill the feed hole orifices bigger for the Corvette or similar servos. Plus drilling the 3/4 feed hole in the separator plate larger to compensate for the restriction of this valve. Skipping these steps or doing so incorrectly made things worse than not having it at all.
After researching the whole TCC orifice size thing, I've decided to not enlarge the stock size; I've been studying the hydraulic schematic, and since I'm using the Fitzall valve ("plug" is actually more like it), the TCC will be getting full line pressure.
Between that, and the newly reamed pressure regulator valve, I don't think 16" hg on the apply valve will really be that consequential... Unless someone wants to talk me out of it.
In other news, I've assembled the pump, and did the MaroonMonster-approved mod of shimming the slide spring with a 5/16" bolt. It went in a lot easier than I thought it would; I used vise-grips and a small hammer. One tap was all it took.
I'll check back with y'all after I check the endplay.
I may have missed it but what's this going into? If it's something heavy or 4wd see weiner's thread, (sorry, don't know how to spell the rest but just look in the trans section), he did a whole rebuild and added the Corvette servo and other parts and wishes it was milder than it ended up being; I thought you intended this to be a cheap close-to-stock rebuild...
I may have missed it but what's this going into? If it's something heavy or 4wd see weiner's thread, (sorry, don't know how to spell the rest but just look in the trans section), he did a whole rebuild and added the Corvette servo and other parts and wishes it was milder than it ended up being; I thought you intended this to be a cheap close-to-stock rebuild...
It's a cheap, close to stock rebuild for my wife's 4.8 swapped '89 Firebird.
A rebuild that I ABSOLUTELY do not want to touch again once it's done, hence the sweating over leaks and vacuum numbers.
After researching the whole TCC orifice size thing, I've decided to not enlarge the stock size; I've been studying the hydraulic schematic, and since I'm using the Fitzall valve ("plug" is actually more like it), the TCC will be getting full line pressure.
Between that, and the newly reamed pressure regulator valve, I don't think 16" hg on the apply valve will really be that consequential... Unless someone wants to talk me out of it.
In other news, I've assembled the pump, and did the MaroonMonster-approved mod of shimming the slide spring with a 5/16" bolt. It went in a lot easier than I thought it would; I used vise-grips and a small hammer. One tap was all it took.
I'll check back with y'all after I check the endplay.
How long is the bolt, if you don't mind sharing? That looks like it blocks the slide at full open.
How long is the bolt, if you don't mind sharing? That looks like it blocks the slide at full open.
I don't know, but I'll check tomorrow; I didn't even think about the slide travel.
Originally Posted by tayto
i think it's just a poor man's version of the sonnax 77917-RV...
Well, yeah, that's pretty much the same way that MaroonMonster described it. He thought (I'm paraphrasing here, he can correct me) the Sonnax spring was overpriced for what it was, and you could accomplish the same goal for cheaper with this ghetto solution.
While this thread is at the top, I've got a question for all of you smart people:
Since I've blocked the feed to the 4th accumulator, and removed the internals, 2BFAST mentioned leaving out the checkball as well.
That is the #1 checkball, correct? (Circled in red)
How long is the bolt, if you don't mind sharing? That looks like it blocks the slide at full open.
Okay, the bolt is a 5/16" X 1" shank.
It DOES block the slide slightly at full stroke, maybe about 1/16", maybe less. I'll cut about a 1/4" off of it tomorrow.
Good call, bbond, although I doubt it would have amounted to much in this case. However, if I'd chosen a 1 1/4" bolt, I'd probably be in big trouble at higher rpms.
Yes, that is the checkball to leave out. You will feel 4th apply firm, but its not overly firm at all. And you will def feel lockup with that Fitzall solid valve.
Hi guys! I'm not dead, but I'm bringing this thread back from the dead.
My new job has had me busy as hell, and I haven't touched the transmission since the last update.
I'm ready to assemble it, but I have one concern:
I was air-checking the input drum clutches with the reverse drum and front pump installed, and I really didn't like the results.
For the record, the input drum passed ALL of the air checks, but once it is assembled with the reverse drum and pump, I was getting A LOT of leakage on the 3-4 clutch circuit.
Specifically, there was a lot of air blowing out through the forward clutch hole.
If I block the forward clutch hole, I get good engagement with minimal leakage. I'm using solid teflon rings, and they are not torn/ nicked. I can provide photos.
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