I have a 69 Impala that has a 350SBC+TH350 with 2.76 rear gears, the vehicle weight afaik is about 4000 lbs. The 350 is an L48 from 69 that was rated at 300hp at the time, it has stock 041 heads, upgraded summit 1102K cam and a TPI intake from an 89 Corvette. Runs and drives nice and has nice torque, future upgrades I plan to replace the ram horn exhaust with mid-length headers, upgrade valve springs and maybe 1.6 rockers. This should probably bring the power to actually 300hp. The rear end will be upgraded with 3.73 gears and a truetrac. And you might have guessed it the plan is to upgrade the transmission to a 4L60E which this thread is about. The ECU I have is an MS2Extra and I will be using a second unit to control the trans. Here is the Manual and Sup manual if you want to check it out. I don't know what other TCM:s allow you to do but when I link the ECU to the TCM I should be able to retard the ignition during shifts to soften the shift with high line pressure etc.

I got a 1-piece case 4L60E -96 model. I bought it as "needs repair" unit from a mechanic who was selling it on behalf of a friend. "It started slipping so we swapped it out" The autopsy tells a different story. It seems to have been rebuilt at least once and failed. My suspicion is that the unit had the 3-4 pack fail and they tried to address it with a rebuild.

Endplay on the input shaft was 0.071" the endplay adjusting washer was actually missing completely!

The pump was swapped I believe, according to the ATSG update handbook it should not have had the raised edges for a bellhousing, but it did. The pump is fubar I think. The stator shaft has super worn splines and the surfaces are very worn and there is single big gouge on one of the surfaces. The filter seal plastic was somehow broken, it had a big gouge in it.

The input drum shaft was leaking from the 3-4 circuit. 3-4 pack had 9 steels (8x 0.0585-0.060 and 1x 0.0475) and 8 clutches (varied 0.035-0.051), it had heated up so much that even the snap ring had gone blue in some areas! Also the 3-4 pack normally has the helper springs (5 retainers with 2 springs in each) This pack had 4 retainers installed and 2 retainers had 2 springs and 2 retainers with 1 spring.

They had upgraded to 3-4 piston to a rubber molded one but left the aluminum forward and overruns in place. The overrun return springs were twisted on their axis(?) like if you look from the side normally the springs are straight like ||||| these were like \\\\\. The overrun sprag inner race looked like it had chatter marks as if the sprag was jumping on the race, is that possible? The 3-4 piston housing The forward piston housing had weird needle like damage.

It had a wide band that was probably red when new but now 97% black, the reverse input drum seems to have been a new generic part but it had bluing. It actually has a blue circle where the band has a hole. The servo was a corvette servo, but it had what looked like wear.

It had a "Superior K4L60-E kit" installed for the most part. It had what I believe to be a remanufactured valve body that has an aftermarket serial number (202090725) on it near the manual valve and it has Sonnax parts for the AFL and TCC circuits. I don't think they installed the VB parts from the superior kit tho. One electrical connector was held on with a ziptie...

It also had a TransGo 46-96 separator plate, but it had weird damage on bolt holes, many of theme had a raised edge as if the plate had crashed to a bolt(?)

I think they reused the sun shell, it was halfway broken in the middle of the splines, it also had witness marks from valve body bolts hitting it. Also the low-reverse piston has a witness mark from crashing into a bolt. The case had some damage on the threads where they had used the long bolts, when I washed the case there was some loose tiny aluminum from the threads but I think there is enough thread to hold.

Most gears and splines had pitting and or wear.

The main parts I have already acquired to use with the rebuild:
(some are still on their way in shipping, crossing my fingers things arrive intact)

Used but tested input drum from ebay.
Used hard parts kit from ebay with the bearing type reaction carrier shaft.

Borg Warner
27363BW 2-4 Band High Energy
34253KIT 4L65E HE frictions
29236AM 29 Element sprag
28571AM Low-Reverse sprag

Raybestos
STMGM14 Steel kit for 4L65E

SONNAX
77749-02K Sonnax Smart Shell
HP4L60E01 Performance pack
777010-4K 2th corvette servo
77767K 4th super hold
77787-05K Servo Pin Kit

GM
24205272 Forward molded piston
24205273 Overrun molded piston
24200290 3-4 molded piston
24245624 Reverse Input drum

I also have other various parts I have but haven't listed like seals, new apply plates.

I still need to acquire a pump and and a bushing kit but I think I am mostly there as far as parts are concerned. I am also trying to decide between doing the Overrun mod in D or Overrun in OD

I will do a separate post about my valve body vacuum test results next. I can also post some autopsy pictures if there is interest.

Edit: corrected my error

 

That is an incredible 'chamber of horrors' you’ve uncovered. Given the 4,000 lb curb weight of a '69 Impala and the torque of a 408 (even with the current TPI 350), that transmission was a ticking time bomb. The missing endplay washer and .071" endplay likely caused the 'chatter' and pitting you see on the gears, as the entire rotating assembly was hammering back and forth.

 

I have a 69 Impala that has a 350SBC+TH350 with 2.76 rear gears, the vehicle weight afaik is about 4000 lbs. The 350 is an L48 from 69 that was rated at 300hp at the time, it has stock 041 heads, upgraded summit 1102K cam and a TPI intake from an 89 Corvette. Runs and drives nice and has nice torque, future upgrades I plan to replace the ram horn exhaust with mid-length headers, upgrade valve springs and maybe 1.6 rockers. This should probably bring the power to actually 300hp. The rear end will be upgraded with 3.73 gears and a truetrac. And you might have guessed it the plan is to upgrade the transmission to a 4L60E which this thread is about. The ECU I have is an MS2Extra and I will be using a second unit to control the trans. Here is the Manual and Sup manual if you want to check it out. I don't know what other TCM:s allow you to do but when I link the ECU to the TCM I should be able to retard the ignition during shifts to soften the shift with high line pressure etc.

The timing retard is to reduce applied torque during a shift , Not to reduce presure or soften shift , Thow there are tables to reduce presure during the shifts at various throtttle postions.

I got a 1-piece case 4L60E -96 model. I bought it as "needs repair" unit from a mechanic who was selling it on behalf of a friend. "It started slipping so we swapped it out" The autopsy tells a different story. It seems to have been rebuilt at least once and failed. My suspicion is that the unit had the 3-4 pack fail and they tried to address it with a rebuild.

The most common reason for repeated 3-4 failure is failure to address leaks in the 3-4 hydraulics in VALVEBODY-DRUM-CASE-PR VALVE. Simply replacing the clutches and seals or piston is generally not enough.

Endplay on the input shaft was 0.071" the endplay adjusting washer was actually missing completely!

This is an issue endplay would be very high but probably more a longer term than short term issue and didnt cause the 3-4 failure.

The pump was swapped I believe, according to the ATSG update handbook it should not have had the raised edges for a bellhousing, but it did. The pump is fubar I think. The stator shaft has super worn splines and the surfaces are very worn and there is single big gouge on one of the surfaces. The filter seal plastic was somehow broken, it had a big gouge in it.

Yes sounds like the pump is done, But the style pump with or without raised would not matter as long as correct stator. Some of the 97 came with that style pump even before the bolt on bell.

The input drum shaft was leaking from the 3-4 circuit. 3-4 pack had 9 steels (8x 0.0585-0.060 and 1x 0.0475) and 8 clutches (varied 0.035-0.051), it had heated up so much that even the snap ring had gone blue in some areas! Also the 3-4 pack normally has the helper springs (5 retainers with 2 springs in each) This pack had 3 retainers installed and 1 retainer had 2 springs and 2 retainers with 1 spring.

^NOT good and leaks as I mentioned. No idea why they would put in a partcial set , Wierd I would either use them all or none at all . preferable use all ^

They had upgraded to 3-4 piston to a rubber molded one but left the aluminum forward and overruns in place. The overrun return springs were twisted on their axis(?) like if you look from the side normally the springs are straight like ||||| these were like \\\\\. The overrun sprag inner race looked like it had chatter marks as if the sprag was jumping on the race, is that possible? The 3-4 piston housing had weird needle like damage.

The markings probably related to the missing end play washer. and may have allow grab of the spring cage.
96 AND 97 units it is not uncommon to fine the rubber 3-4 cultch piston but still have the aluminun others and that is fine, See it in many cores when I tear down .

It had a wide band that was probably red when new but now 97% black, the reverse input drum seems to have been a new generic part but it had bluing. It actually has a blue circle where the band has a hole. The servo was a corvette servo, but it had what looked like wear.

Obvioulsy slipping again leaks - Also note on perceive generic I get GM drums in the GM package that say "Made in tiawain " so not likley issue I would replace now ,
I prefer also the raybestos pro series wide band but each there own, Some think it to agressive.

It had a "Superior K4L60-E kit" installed for the most part. It had what I believe to be a remanufactured valve body that has an aftermarket serial number (202090725) on it near the manual valve and it has Sonnax parts for the AFL and TCC circuits. I don't think they installed the VB parts from the superior kit tho. One electrical connector was held on with a ziptie...

I am not big on mixing sonnax and superior or transgo but probably not an issue, But then I dont use any of thems shift kits, Those do use some parts.
Harnesses are cheap enoug just replace .

It also had a TransGo 46-96 separator plate, but it had weird damage on bolt holes, many of theme had a raised edge as if the plate had crashed to a bolt(?)

I think they reused the sun shell, it was halfway broken in the middle of the splines, it also had witness marks from valve body bolts hitting it. Also the low-reverse piston has a witness mark from crashing into a bolt. The case had some damage on the threads where they had used the long bolts, when I washed the case there was some loose tiny aluminum from the threads but I think there is enough thread to hold.

----------

Most gears and splines had pitting and or wear.

The main parts I have already acquired to use with the rebuild:
(some are still on their way in shipping, crossing my fingers things arrive intact)

Used but tested input drum from ebay.
Used hard parts kit from ebay with the bearing type reaction carrier shaft.

Borg Warner
27363BW 2-4 Band High Energy -fine
34253KIT 4L65E HE frictions -fine
29236AM 29 Element sprag-fine
28571AM Low-Reverse sprag-fine

Raybestos
STMGM14 Steel kit for 4L65E

SONNAX
77749-02K Sonnax Smart Shell -good
HP4L60E01 Performance pack - fine
777010-4K 2th corvette servo -fine
77767K 4th super hold-fine
77787-05K Servo Pin Kit - make sure had teflon of I use orings myself on them ,

GM
24205272 Forward molded piston -fine
24205273 Overrun molded piston- fine
24200290 3-4 molded piston fine
24245624 Reverse Input drum -great

I also have other various parts I have but haven't listed like seals, new apply plates.

I still need to acquire a pump and and a bushing kit but I think I am mostly there as far as parts are concerned. I am also trying to decide between doing the Overrun mod in D or Overrun in OD overun in OD position is my go to on all builds

I will do a separate post about my valve body vacuum test results next. I can also post some autopsy pictures if there is interest.

 

 

I am also trying to have this same thread running on Impalassforum.com I want all the info that can help me 😇

Quote:

Originally Posted by SoulH

That is an incredible 'chamber of horrors' you’ve uncovered. Given the 4,000 lb curb weight of a '69 Impala and the torque of a 408 (even with the current TPI 350), that transmission was a ticking time bomb. The missing endplay washer and .071" endplay likely caused the 'chatter' and pitting you see on the gears, as the entire rotating assembly was hammering back and forth.

I think there is a misunderstanding, the car has a TH350. I bought this 4L60E unit separately to rebuild for it. Also the engine is just a 350, the designation is L48. Probably pretty close to a stock L98 TPI 350.

Quote:

Originally Posted by FranksCustomTrans

The timing retard is to reduce applied torque during a shift , Not to reduce presure or soften shift , Thow there are tables to reduce presure during the shifts at various throtttle postions.

I thought this would soften the shifts but thinking about it now it could make it feel more aggressive when full timing comes back on.

Quote:

Originally Posted by FranksCustomTrans

I am not big on mixing sonnax and superior or transgo but probably not an issue, But then I dont use any of thems shift kits, Those do use some parts.
Harnesses are cheap enoug just replace .

I am not planning on mixing them just reporting what I found inside the trans. Only thing I can't remove (don't want the hassle of drilling out) from the superior kit is a restrictor for the 3-4 accumulator feed that is punched into the case. What I have read here this will probably be a good thing. I am planning to run the Sonnax pinless pistons that come in the performance pack I have.

I have the HD 2-3 shift valve but I didn't want to drill the valve body and I came across the thread about modifying the overruns on OD and figured out that you can just modify the spacer plate to do that. But know I think I figured out a way to do the shift valve mod for overruns in 1st & 2nd in D with just modifying the spacer plate. I 3D-printed some models to look at to make figuring these things out easier.

There is an easy place to drill a hole in the spacer plate to combine the 34 & 35

It will be an easy reversible way to test how the downshifts feel and if I ever do go for the heavy towing the D position will meet the needs for that.



This turned out be total junk, all the parts worn or damaged to the point of being unusable. If anyone knows any reputable sellers I could source hard parts that would be fantastic. I don't know if the damage to both planetary pinion gears make them unusable, tbh I don't even know what I am looking at. I am also a bit worried about that low reverse piston that crashed into a bolt.

I do have a 700R4 from early 86 I was planning on rebuilding first, it was also sold to me as a "needs rebuilding" I was told it had the symptoms of losing all gears when hot and when cold it worked normally. I have not disassembled it yet but I could source some hard parts from there too. This unit I believe has been rebuilt, according to the codes it started life in an F body but it was in an old C10 with a lazy big block.

I have made up my mind that I want that new bearing type reaction carrier shaft though 😂 I know SONNAX sells one but it is expensive, I see some aftermarket ones on ebay, anyone know if they're any good?

 

Here is a link to the layout:
Sonnax 4L60-E, 4L65-E, 4L70-E

The valve body had the:
Sonnax Isolator Sleeve Kit - 77754-ISO
Sonnax TCC Regulator & Isolator Valve Kit - 77754-03K
and
Sonnax Actuator Feed Limit Valve Kit - 77754-09K

I later installed:
Sonnax 3-4 Relay O-Ringed End Plug Kit - 77964-08K
Sonnax Forward & Reverse Abuse Bore Plug - 77754-21 Installed in both circuits

I am using a and I don't have a big test plate that could cover the whole VB but I looked at the SONNAX test plate instructions and tried to simulate the covered circuits and the ones that need an air vent as best I could.
The vac test results are as follows:
202A - 24.5 inHg (no spring)
202B - 21.5 inHg (no spring)
202C - 17 inHg (no spring) 8 inHg in rest position with the spring
203A - 20.5 inHg
203B - 19.5 inHg
204A - 18.5 inHg
204B - 21.25 inHg
205A - 18 inHg if I simulate the big test plate and cover the cavities connected (36&37 overrun) by the valve and leave the one open. 14 inHg if I test the port on its own.
205B - 10 inHg
205C - 13 inHg
205D - 18 inHg
206A - 25 inHg Probably not valid because of the SONNAX parts
206B - 24 inHg Probably not valid because of the SONNAX parts
207A - 21 inHg Probably not valid because of the SONNAX parts, can't open the valve as in the instructions.
208A - 21 inHg
209A - 22 inHg
209B - 21.5 inHg
209C - 16 inHg this is difficult to measure because the valve moves outboard and the value settle only after, also wiggling the solenoid affects the result.
210A - 17 inHg
210B - 23 inHg
211A - 14 inHg
211B - 13 inHg
I also managed to get a reading on one of the forward abuse valve ports by opening the accumulator cover and blocking the passage with my finger, it had 19.5 inHg

So the 3-4 relay valve - 4-3 sequence valve seems to be the fail point. Could this be the cause of the absolutely smoked band & drum? Studying the schematics it seems the 205B leaks some servo feed pressure in 2nd gear. I tested the 205B more and if I cover the exhaust 43 it gets to 15 inHg. If I cover the 205C&D it goes to 12 inHg. So I guess most of the leak is to the exhaust.

205C I can get to 17.5 inHg if 205D is covered.

This is weird, if you take a look at SONNAX Vac Test Guide it has additional instructions compared to the SONNAX test plate instructions regarding the 3-2 Control valve aka the 202 bore. It says you need to remove the spring to position the valve in the bottom of the bore for testing and that is what I did. That is why I mention (no spring).

 

I would absolutly love a 3d print like that for the 4l60e-700r4 and 4L80E wow I like that. Do you offer them for sale ?
Best parts place WITS, "WHATEVER IT TAKES TRANSMISSION PARTS" imo for hard parts. I think I am safe in giving this as as far as I know no sponsor here just sells hard parts, Call 5706554200 ask for TOM he ussually answers anyway they can set you up on hard parts and prices are very resonable or go to thier EBAY or AMAZON stores.
If I am wrong about anyone offering just hard parts here who is a sponsor please let me know or ADMIN feel free to delete or remove names from post.

 

I think it's okay to post companies' names. You just can't post a link to their website. Don't hold me to this.

 

When I was reading your first post, I was thinking "this guy should just start over with a new core."

I don't know where you live, but I'd check with the local junkyards, or even Facebook marketplace. Don't bother with anyone trying to sell you a "rebuilt" transmission - you've already seen what you might be in for.

I wouldn't pay more than $250 for a core, but that's how it is in my area.


I'd strongly recommend you get the following parts:

-Central Valvebodies AFL valve
- Sonnax end-plug kit
- Sonnax Boost valve
-Sonnax TCC valve
-Sonnax oversized Pressure Regulator valve.

-Block your 4th accumulator

 

If cores were available I would do that. I live in Finland in the EU. There was a half disassembled 4L65E for sale and I had already made a deal with the guy that I was gonna buy it and pick it up in a few days, but he sold it to a backyard rebuilder who was faster to pick it up.
There are non for sale, I have asked around and had an ad to buy one also but nothing. If there is one in a junkyard they are prohibitively expensive.

There is a message in the thread about the valve body, it has a lot of good stuff installed but also a problem with 3-4 relay/4-3 sequence valve vacuum tests.

There aren't that many trans shops in the whole country who do these transmissions. No one wants to fix the valve body I have. I was asking around if any shop / rebuilder had the tooling to install the SONNAX Oversized 4-3 Sequence Valve 77964-14K

One transmission shop just insisted on me sending the valve body in, no estimate or anything, just insisting that they can't estimate a price or anything because they don't know what is wrong with it. I pressed for an estimate for that particular job of installing
the Sonnax kit I mentioned. The reply I got was "we don't do these jobs based on customer instructions or diagnoses if that is the case you should just finish the job yourself" that is some customer service for you! They would have sold me a rebuilt VB for $750 though...

So I am looking at the possibility that I have to send it to the US to get that kit installed, or get another rebuilt and tested one. Or just use it as it is. One option I would like to try with it is to find another stock valve itself that is maybe less worn and see if I get better results with it.

 

Me too, I would not be using that transmission for a good expensive build. Lots of junk there. Need to check that case real good.

 

It's not that bad, most of the parts I would replace anyway for a high performance rebuild, (sun shell, reverse drum). The other parts, a little grinder or file will clean up the parts that the bolts in the wrong location burred up. The only parts left that are questionable are in the gear set. If the pinion gears don't have a lot of slop in them from what the pics show I wouldn't worry too much about the nicks on a few of the gears, if you are having such a hard time finding replacements. Here in the States, it's easy to get good used gear sets.

Definitely replace those sprag races and the sprag itself. There again not a part that is unusual to replace on a rebuild.