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Compatibility Questions - 4L60E - TransGo & Sonnax Parts
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I have a question for the pros! I have been reading many many posts on different forums and been trying to absorb all the information that clinebarger and Dana of PBA have out there as I can tell you guys are a wealth of knowledge so let me first say that I really appreciate you guys. There are many other folks on this forum including a Frank that comes to mind also. Between this forum, transmission bench, PerformaBuilt and other great sources I’ve studied my butt off. Unknowingly to all you guys I have been able to study and answer many questions I have had based on the information you guys have donated online.
This summer I decided to take the 4L60E from my 1997 Blazer I drive during winter apart for a refresh and as a fun project. No issues with the transmission, it’s behind a 4.3L V6 and 4WD drivetrain. I just had to rebuild the engine @ 250,000km so figured the transmission wasn’t far behind being an issue eventually. I am an automotive technician by trade but I’d be lying to you if I said my day job is rebuilding transmissions. Very seldom do I get the opportunity to do this type of work although I thoroughly enjoy it. Not being in a rush, I carefully disassembled, studied as I took it apart, and carefully took the time to understand and inspect every piece. Fortunately I have a full workshop at home and all the tools needed to do this type of work and only had to buy a couple clutch spring compressors and a transmission hook to make this process a breeze.
My intention was simple - do an OEM rebuild but study and find the known problems and try to improve on anything I can to build the most reliable unit possible.
Upon disassembly I did not find any real concerns, did all the appropriate air checks on disassembly and thoroughly inspected hard parts etc. Carefully checked the input drum to shaft area for leaks also. Reverse drum surface where band rides was shockingly perfectly straight and true so was able to reuse that which was a bonus. I determined the unit was untouched since it left the GM assembly plant some years ago.
After much inspection and research I determined this was the best assortment of parts to build something reliable, with a quicker shift time that was still comfortable to daily drive. All parts sourced via my local Transtar in Calgary, Alberta:
Remanufactured Stock Converter
Replacement Reaction Hub (Found excess spline wear where hub enters ring gear)
“The Beast” sunshell (OE unit showed evidence that spline shaft was not long from breaking off)
Transtar Rubber/Paper Kit
Exedy Friction Module (Could not find a Borg Warner module but the quality and design of the Exedy Kit appeared to be as close to OEM or BW)
Steel Friction Module
BW Hi-Energy OE Width 2-4 Band
7 x .080” BW Hi-Energy Frictions for 3/4
6 x 0.076” 700R4 Steels for 3/4
ACDelco apply and backing plate for 3/4
Blue Hi-Perf Bonded steel pistons and caged overrun spring assembly
Bushing Kit along with some sonnax and durabond wider and PTFE coated bushings individually for certain known problem areas (pump, rear sun gear, etc)
New Torrington bearings
New thrust washers
New pump kit with rotor, slide, vanes, etc
TransGo Low-RPM No Yoyo Kit for pump
TransGo SK Kit Series L
Sonnax Pinless Accumulators (FWD, 1-2 & 3-4)
Sonnax Torlon Checkballs
New TransGo Seperator Plate
ACDelco A & B Shift Solenoids
All Rostra Electronics & Harness for all other electrical components (I replaced EVERYTHING)
Borg Warner 29 Element Sprag & New Low Roller
Sonnax 3-4 Replacement Release Springs
Sonnax O-Ring End Plug Kit
Sonnax FWD & REV abuse valve kits
TransGo 0.500” Boost Valve (originally I purchased a Sonnax 0.490” O-Ring Boost valve kit but I could not for the life of me get it installed without tearing the o rings even after bore prepping so I got scared of losing an o ring in pump and decided to change directions)
Corvette servo kit
Installed a Case saver vs factory spring clip
I think that is all however I may be missing something. Last night I finished case assembly. Pretty well all stock besides the updated sunshell design and a few aftermarket bushings more or less. TransGo mods to 13V PWM pump (boost valve and no yo-yo kit). I found on another forum I believe it was Clinebargers 7-Plate clutch stack using 4L60E 0.080” frictions and 700R4 0.076” steels and really liked that setup and with OEM sized 4L60E snap ring, apply plate, backing plate and #7 apply ring it was as he said bang on around 0.025-0.030” clearance which I thought was just awesome. Anyways, the case turned out awesome, all my clutches ended up bang on, all my capsulated check ***** and other items to inspect tested great. I ended with 0.016” input shaft end play and just couldn’t be happier. I also stacked my converter, pump, reverse input and input drum up outside the case before install and air checked it @ pump ports and it all turned out great.
Sorry for dragging on this post but just figured I’d give a short story of where I’m at and what I’ve done. It’s been a lot of fun.
My concerns:
Today I did my servo install and ran into some issues but feel I may have resolved my concerns here. It originally had the I believe 553 second apply piston from factory so I opted for the 093 corvette second apply and left the 4th apply piston as stock. I modded it as described in the TransGo SK kit. I will add that I used the OEM 2 ring servo pin which I removed, found no issue with the bore wear or pin itself and that the encapsulated check ball was good. Read mixed opinions about the Sonnax check ball and decided against adding that component. What I found was that with the single gold shim provided by TransGo for the servo assembly installed, the band seemed to be grabbing the reverse input drum and it would not spin freely with servo not applied. I will add that I had the case supported in my hook vertically (input shaft up/output shaft down) so as to not side load the drum while installing and setting up servo. Upon removal of shim, the drum spins freely with servo released and the band begins grabbing when the servo cover is depressed to approximately 0.040” (measured with dial indicator) and continues to grab further until 0.100”. So I am getting 0.100” of servo cover travel until pin is fully applied and no longer moves the band. The single gold shim that TransGo provided measured about 0.055”. The TransGo instructions are quite vague as far as the importance of this shim. I went down to my local GM dealer and borrowed the Kent Moore tool for checking the pin to take an extra precaution and found that the line was directly in the middle of the sight window with the OEM tool @ the 98 inch pounds they say to apply the pin to so I felt this was not an issue with the pin at this point. My thoughts were to try to get my band adjustment closer to the 0.075” of the 0.075-0.125” specification as of course the band will break in over time and that tolerance should in theory increase slightly.
My question here is: does it sound like I have the band adjustment set correctly WITHOUT the provided shim, is it common that the shim is not needed and do I need to worry about this? By my calculations my servo pin travel is exactly in the middle of GMs spec without the provided shim. I got these measurements with the pin only using the GM tool and also with servo assembled and a dial indicator on the servo cover itself.
I am now at the valve body and shift kit stage here after which is the finish line of this project. Of course I know that valve body modifications can be the most critical and that’s why I have decided to stop and think about the best way to cross this bridge.
I first started with the 3-4 pinless accumulator from Sonnax which was a no brainer, OEM spring installed and went together as per instructions with no concerns.
I’m now working on the 1-2 accumulator. I have the “2nd design” housing and piston as described in TransGo’s instruction manual and removed 2 stock springs sitting between housing and piston. The Sonnax Pinless accumulator of course comes with no springs. I staked the appropriate sized ball in the housing with a T45 socket. I found that the TransGo kit came with 3 springs which they recommend using in this accumulator. My issue is that I am concerned about the compatibility of the Sonnax Piston and the TransGo springs? The middle of the 3 springs seems as though it would sit on the very outside of the machined and raised centre in the Sonnax Piston and I have concerns that it could break if it has any ability to move off centre when installed. I found online only 1 example of a person installing it this way (On YouTube) but no context and no feedback or information regarding shift feel, reliability, compatibility etc. Would it be best to use the 2 x OEM springs, the 3 x TransGo springs or I also know that Sonnax make a purple spring for this location also?
My last step will be drilling the valve body and I am wondering if I should be following the SK kit directions exactly with this build or if there is a more optimum sizing I should be following?
Additionally I will add that I did NOT install the orifice cup plugs in the reverse piston as mentioned in the TransGo SK kit as I had read on many forums that this is not necessary on a late 4L60E and I confirmed I had the later casting number piston as described in the ATSG manual I have. Was this something I should have done or am I OK there?
And my other question while it’s fresh in my head is the Sonnax end plugs w / o rings. Should they be only installed in the 2 x locations mentioned in their installation guide? Or can I use them in all locations with end plugs. Also I bought complete FWD/REV abuse valve kits from Sonnax and I know that the TransGo kit includes a check ball for the one valve assembly but I am assuming I should disregard that check ball and just install the Sonnax valves as outlined in their instructions?
Any feedback is greatly appreciated, sometimes in my career I find myself in periods of mild boredom and this has been a great project to reignite my flame and get my brain working although I will be the first to admit I do have a tendency to overthink things sometimes. If this transmission turns out really great as I hope it will I am thinking about buying up local cores to continue building as a hobby as this has been a lot of fun!!
See here my stock housing, stock springs and stock piston. See here the Sonnax Pinless 1-2 Accumulator & 3 x TransGo SK springs. See here the middle spring with the Sonnax Pinless Accumulator. After using some force I found the spring fits very tightly around the machined and raised centre on the inside of the piston. Is this OK?
See here my concern - the middle / intermediate spring of the 3 included with TransGo’s kit also just barely has a landing on the inside edge of the housing. Seems a little iffy as if it became even the slightest bit misaligned you would think it would break? To note: this is how TransGo instructs you to install it when using a factory 2nd design piston. See the included instructions in my kit here. SK 4L60E Series L
Ahhh and now I just noticed on the very last page of the SK Kit that the TransGo 3-4 accumulator directly contradicts the Sonnax Pinless instructions also. So I guess when I said previously that the 3-4 accumulator was a no brainer… I lied! See here:
1st off on the accumulators follow Sonnax's instructions. On the 1-2 accumulator use the factory spring or the Sonnax purple spring.
On the Sonnax end plugs, it's been a while since I have built a 60e but I think that they will only fit in a few locations, but it won't hurt to install them wherever they will fit.
You don't have a factory 3-4 clutch clearance so; a tighter band clearance would help with the 2-3 shift timing. .050 to .070 is recommended. I use the Sonnax extralong servo pin in every unit I rebuild. It allows you to set the band clearance to your exact specifications.
You are correct with leaving the TransGo check ball out of the Sonnax FWD & REV abuse valve kits. Whenever I am mixing kits I normally stick to the instructions for the assembly I am working on. (Exp. FWD abuse valve or pin less accumulators)
One last thing go conservative when drilling the separator plate, especially the 2nd feed hole. You can all ways come back and make them bigger if you want the shift to be a little firmer.
Thank you @bbond105 for chiming in on this topic. I appreciate your insight. I was leaning towards strictly following Sonnax’s instructions so I’m glad to hear that.
As far as the band goes does it sound like I am checking/measuring clearance correctly? As mentioned the pin does have 0.100” of travel until it is applied so much so that you can look in through the valve body and see the pin/band is no longer moving. However, I do start to see enough band application from 0.040” onwards that the drum then becomes bound and will not turn. I am guessing TransGo includes that shim to help take up tolerance without swapping pins however their instructions do say to absolutely not use their shim AND grind down the pin in combination so I would say the Sonnax Pin is the only way to go unless I went with an OE No Groove Pin which would yield me only an additional 0.005” so likely not. In theory if I’m seeing band apply with my current pin @ 0.040” I could likely add about 0.020” of pin safely (in comparison to the current pin length) using a Sonnax pin. Too bad TransGo doesn’t include multiple shims as they do in other kits as a 0.020” shim may have worked.
Are there any other valve body modifications I should consider to ensure adequate shift timing in relation to my tighter 3-4 stack up?
Also any opinions on my parts selection - things that you would add or change for a relatively stock build?
On the 4th accumulator piston. Install the spring first as mentioned in the Shift kit instructions. This virtually eliminates the 4th gear accumulation, which is fine here.
What letter is on the 2nd accumulator bushing? "C" or "CX" are the best for getting a good 1-2 shift at part to medium throttle when using the Corvette servo, large boost valve, and this TransGo Shift kit. I do not like the pinless accumulator setup for the 1-2 accumulator. I use the aftermarket accumulator piston (from Transtar) with the much longer pin bore and the hardened aftermarket pin, that will prevent unnecessary leaks and pin bore wear. This way you can use the TransGo three spring setup with either 1-2 accumulator housings that come with the 4L60E's.
The small check ball from TransGo for the forward abuse valve, is to prevent a harsh neutral to forward engagement when at a high rpm idle when cold.
There should be little to no difference in drag when turning the output shaft backwards (the hard way) with the 2-4 servo setup installed, as compared to the servo not installed.
You want minimum band clearance, as it will increase some when the band is broken in.
You could take measurements now on the pin travel now and in about 50 - 100 miles, recheck it. If the band clearance has changed to the high side of the recommended band clearance. Then you could reduce it by adding the TransGo (.055" +/- .003") shim, if desired.
The Borg Warner Hi-Energy 2-4 band takes at least 50 miles to break in.
You want the band surface on the reverse input drum to be flat and smooth as possible. A mirror finish is best.
Never install the two restrictor plugs from TransGo in the reverse input piston. As this will not allow the oil behind the piston to escape due to centrifuge, when at high rpm in the top of first and third gear. This will ruin the reverse input clutches and steels over time.
On the 4th accumulator piston. Install the spring first as mentioned in the Shift kit instructions. This virtually eliminates the 4th gear accumulation, which is fine here. I am assuming here you’re saying to install the pinless piston as described in the TransGo SK instructions?
What letter is on the 2nd accumulator bushing? "C" or "CX" are the best for getting a good 1-2 shift at part to medium throttle when using the Corvette servo, large boost valve, and this TransGo Shift kit. I do have a CX bushing and was planning on using the suggested blue/56oz spring from the TransGo SK kit as recommended for V6/093/CX configuration.
I do not like the pinless accumulator setup for the 1-2 accumulator. I use the aftermarket accumulator piston (from Transtar) with the much longer pin bore and the hardened aftermarket pin, that will prevent unnecessary leaks and pin bore wear. This way you can use the TransGo three spring setup with either 1-2 accumulator housings that come with the 4L60E's. Do you think then I should pause what I’m doing and toss the Sonnax kit for the 1-2 and order those pieces from Transtar? Of course I have already staked the ball in the housing so I’d have to source a new housing as per my OCD. Otherwise I could install the Sonnax kit as per there instructions and move on?
The small check ball from TransGo for the forward abuse valve, is to prevent a harsh neutral to forward engagement when at a high rpm idle when cold. To clarify does the Sonnax Abuse Valve kit with the different valve and spring combat this issue or should I use the checkball in addition to the different valve?
There should be little to no difference in drag when turning the output shaft backwards (the hard way) with the 2-4 servo setup installed, as compared to the servo not installed. Correct no difference in drag either way with servo removed or servo installed and released WITHOUT gold TransGo shim installed however with this shim installed and servo installed and released I could not get the reverse input drum to turn freely.
You want minimum band clearance, as it will increase some when the band is broken in.
You could take measurements now on the pin travel now and in about 50 - 100 miles, recheck it. If the band clearance has changed to the high side of the recommended band clearance. Then you could reduce it by adding the TransGo (.055" +/- .003") shim, if desired.
The Borg Warner Hi-Energy 2-4 band takes at least 50 miles to break in. I’m currently thinking of purchasing an extra long Sonnax pin and grinding to achieve 0.060-0.070” servo cover travel before I install and break in Trans is this a good starting point/solution to this? Otherwise - being currently @ 0.100” of pin travel, if the band were to break in and that measurement change to 0.125” approx, then at that point I may be able to bring that down to 0.070” with the shim alone?
You want the band surface on the reverse input drum to be flat and smooth as possible. A mirror finish is best. Definitely flat and smooth but I was unable to get a mirror / polished finish I just cleaned it up as best I could with some extremely fine scotch brite until I had a nice uniform finish.
Never install the two restrictor plugs from TransGo in the reverse input piston. As this will not allow the oil behind the piston to escape due to centrifuge, when at high rpm in the top of first and third gear. This will ruin the reverse input clutches and steels over time. I had read in another thread where you mentioned this which was why I decided against making this change so I thank you on that one!
Thank you @PBA Dana for chiming in! I’ve read a lot of your stuff very helpful!! I added some stuff above in Bold to respond to you.
This morning I had my coffee and inspected the Seperator plate and suggested changes from TransGo SK instructions. Here is what I found:
First I compared to the original plate and noticed two differences that I am unsure are a big deal or not? TransGo 46-96 Plate is what I purchased and I did confirm I have the 2nd type 3-2 valve. Based on what I can tell this is the correct plate for my 1997MY transmission.
See picture below, I believe I have it labelled correctly but let me know if I screwed that up. Notice I marked the holes based on what TransGo SK recommends but I have yet to actually modify the plate at all so some holes are labelled what I intended to drill but no changes made to it as of yet.
I noticed that the “3-4 clutch” hole #27 on my ATSG manual seems to have came predrilled / enlarged by TransGo in comparison to the original plate.
I also noticed that the “Apply (Reg Apply)” #6 on my ATSG manual has a rectangular window where as my original plate had a hole in its place. My paper/rubber kit came with 2 sets of gaskets. 93-00 and 01-up. Being a 1997 I naturally chose the 93-00 gaskets and noticed that the 93-00 gaskets have the same hole as seen on the OEM plate but the 01-up gaskets have the rectangular window that the TransGo plate had. Upon inspection of my valve body casting as shown in the paperwork that came with the gaskets - I do have a 93-00 style casting. Is this window variation at the reg apply going to be an issue??
The hole size selections I made were the minimum recommendation given by TransGo where applicable.
When setting the band clearance, I install the servo and cover without rings and seals. Then I put a dial indicator on the servo cover and zero the dial. Then I will push the cover in as hard as I can by hand and the travel on the dial indicator is your band clearance.
When setting the band clearance, I install the servo and cover without rings and seals. Then I put a dial indicator on the servo cover and zero the dial. Then I will push the cover in as hard as I can by hand and the travel on the dial indicator is your band clearance.
Ok gotcha then I am set at 0.100” currently. I should tighten that up I’d imagine.
The gold ring that comes in the SK kit is for taking up clearance on higher mileage units if installing a "kit" without pulling out the transmission.
I have never used it. I always have used the Sonnax pin and grind down what I need to achieve my clearance. I did however use a factory pin once but needed less clearance and welded the end of the pin and ground it down to achieve what I was after as I didnt have time to wait for a Sonnax pin or longer factory pin. Worked well also.
The gold ring that comes in the SK kit is for taking up clearance on higher mileage units if installing a "kit" without pulling out the transmission.
I have never used it. I always have used the Sonnax pin and grind down what I need to achieve my clearance. I did however use a factory pin once but needed less clearance and welded the end of the pin and ground it down to achieve what I was after as I didnt have time to wait for a Sonnax pin or longer factory pin. Worked well also.
OK that makes sense I will hopefully have Sonnax pin for tomorrow! Thank you
So to update, I’ll have a Sonnax extra long pin tomorrow and plan to size that to see around 0.060” servo travel? Is that a reasonable plan to set forth considering I have a new band? Provided I can see the reverse input drum spin when servo released at that adjustment?
Also I went to flip the 3-4 pinless accumulator over as shown in TransGo instructions but found that neither the OEM or Yellow TransGo spring sit flat on the case side when installed in that orientation as only about 3/4 of the circumference is flat and there is a couple spots where the casting won’t allow the spring to sit nice and flat?
Also didn’t like the way the 3 x TransGo springs stacked up in my 1-2 accumulator housing so opted for the 2 x OE Springs.
To summarize I followed Sonnax’s instructions for all the accumulators as I didn’t like the fitment any other way. Am I crazy? Or is this fine for a basically stock rebuild??
So to update, I’ll have a Sonnax extra long pin tomorrow and plan to size that to see around 0.060” servo travel? Is that a reasonable plan to set forth considering I have a new band? Provided I can see the reverse input drum spin when servo released at that adjustment?
Also I went to flip the 3-4 pinless accumulator over as shown in TransGo instructions but found that neither the OEM or Yellow TransGo spring sit flat on the case side when installed in that orientation as only about 3/4 of the circumference is flat and there is a couple spots where the casting won’t allow the spring to sit nice and flat?
Also didn’t like the way the 3 x TransGo springs stacked up in my 1-2 accumulator housing so opted for the 2 x OE Springs.
To summarize I followed Sonnax’s instructions for all the accumulators as I didn’t like the fitment any other way. Am I crazy? Or is this fine for a basically stock rebuild??
As said in post #6, follow Sonnax's instructions. Or plug the 4th accumulator feed and leave the accumulator bore empty.
As said in post #6, follow Sonnax's instructions. Or plug the 4th accumulator feed and leave the accumulator bore empty.
Copy that I will be following their instructions for sure thank you @bbond105 !
Any thoughts on my Seperator plate variations between my original plate and the TransGo one I purchased? The 3-4 clutch I can understand why they made bigger but the reg apply window is the only area that is a concern for me ? @bbond105
Copy that I will be following their instructions for sure thank you @bbond105 !
Any thoughts on my Seperator plate variations between my original plate and the TransGo one I purchased? The 3-4 clutch I can understand why they made bigger but the reg apply window is the only area that is a concern for me ?@bbond105
@FranksCustomTrans is better qualified to answer that question than I am.
@bbond105 See in red circle - on TransGo plate there is a rectangular window which I noticed is as per normal on the 2001+ gasket set however on my original plate and gaskets for 93-00 this window is actually a circle? Confirmed I have correct 97 valve body casting already
That may not be the correct plate. I am not very good at knowing which parts are interchangeable from year to year. It may be best to wait for someone more knowledgeable in this area to chime in.
07-20-2024, 05:35 PM
Compatibility Questions - 4L60E - TransGo & Sonnax Parts 
