onevoice

Had a slow 1-2 shift during light throttle, not any rpm flare up, but just much slower than other 4l60e's I am acquainted with. Installed a Transgo shift kit and now the 1-2 shift is great, but the 2-3 shift that was perfect before now has noticeable flare up when accelerating at anything more than gently. I have read several threads about soft 2-3 shifts but none seem to fit my after shift kit install problem. Vehicle is an 02 Silverado with a 5.3, 55k miles. Anyone have ideas about what part of the shift kit I need to undo, or what to check?

Thought I would update this in case anyone is searching and comes across this in the future. Thanks to Dana at PBA the problem is now fixed, apparently was a shift timing issue. I'm not sure I understood exactly what caused it, combination of seals, internal leakages, and clutch pack clearances in combination with the shift kit. Dana sent me PM and had me call him, after discussion of the problem, he said a corvette servo would cure it and sent me one to install. Hot damn, now it works great. Many thanks.

onevoice

Thats interesting, I used one shim, and it seemed like the adjustment was done like the crappy directions indicated. I can remove it easily, I guess I'll start there. Any other suggestions?

chargedvx6

I think the shim is for the 1-2 accumulator and won't effect the 2-3 shift. Did you use a new seperator plate when you did the kit? There is a chance that a hole was missed or drilled under spec if that's the case. The 2-3 shift could be the problem, what is this drilled to?

onevoice

I drilled the holes to the specified sizes, using the smaller size if there was a choice, ie the 1-2 shift hole was .082 and the 2-3 shift was .093.

I am very confident that I did all holes as specified, I marked all the holes, drilled them and checked it again.

jxaxsxoxn

iTrader: (2)

There are big gold shims that go in the servo, and smaller fender washer looking spacers that go in the accumulator.

There is no 'as specified' sometimes you have to drill to get it to shift where you like it. The reason being is that each transmission has different clutch clearances since GM specs are a range not a specific number like you'd find in a performance rebuilt trans.
Plus other variables with the vehicle.

How many shim/washers did you put in the accumulator? (1-2 obviously since thats all the kit has you put shims in).
Need to make changes with the 3rd feed, band release holes.

onevoice

I used one shim in the servo, and one spacer in the accumulator.

I guess I am mostly confused that the 2-3 shift got worse. What would cause a change in the wrong direction? I assume line pressure was raised, and the size increase in the 2-3 hole was to increase flow, why a slower clutch apply?

PBA

In the Attached Thumbnail, under the word Separator Plate in the drawing, go under the letter "P" in Plate . Just below that you drilled the band release hole to .093" as per instructions. Reduce the size to .080". This should fix it.

chargedvx6

That means there is still a problem causing this out pf character performance though doesn't it? Could it be an incorrect spring in the kit or broken spring?

8a8mfh

iTrader: (3)

PBA helped me out with this when I had the same problem. Please take the advice given, if you keep asking unrelated questions sometimes people will give up trying to help.

I put the transgo HD2-B kit in and it made third worse, third was weak from the factory.
I got the mechanical part set up and left it. I then screwed around with the seperator plate hole sizes, I don't know how many times I had the vb off but I wanted it to be perfect, not just good enough.
I ended up buying a new transgo plate and starting over with smaller holes.
Your problem is with the servo IMO, it's applied in second. During the 2-3 shift it releases, and the 3-4 clutch comes on. This all has to happen at the right time, and as long as your band adjustment and 3-4 clutch clearance is ok it can all be fine tuned with the feed hole sizes in the seperator plate.
If all this doesn't happen at the right time your band may release too soon, before the 3-4 clutch comes on and you have a delay in shift there, I believe this is why PBA is telling you to make the band release hole smaller. This will give 3-4 time to come in before second releases.

BTW notice on the instructions it says for professional use only...this is why, it's also why you think the instructions suck because you don't fully understand them. This doesn't mean you can't learn, just take the advice given.

onevoice

Thanks, thats what I was looking for.

onevoice

I appreciate the explanation, but no it doesn't say ANYWHERE that it is for professional use only, maybe your directions are different. I used to write instructions and checkout procedures, I'll stick by my description of these as crappy. I'll be out of town a few days before I can get to it, but I'll let anyone interested know how it works when I make the change. Thanks.

8a8mfh

iTrader: (3)

If it's in a blue box it says it somewhere.
It almost sounds like you have the kit in the yellow box with the video.
You have a 4L60E HD2-B?
I'll admit that I've installed several transgo kits and it seems the instructions for each kit are different even though the kits are exactly the same.
You should see the instructions for a TH400 1&2 kit, or 700 2&3 kit.

onevoice

Pulled everything apart today and rechecked everything, all parts of the kit were installed correctly, so I pulled the valve body and welded up and redrilled this hole. I can tell a little improvement but it is still quite noticeable when accelerating briskly. Before I did this mod, I called Transgo and they suggested adding the second shim in the servo, I did this first because it was easy to get to, but didn't notice any improvement.

When I put this together I used dexron 6, could this have any impact?

Anyone have any more suggestions?

8a8mfh

iTrader: (3)

Take all the shims out of the servo. Adding them will make the band travel less. You have a good 1-2 shift meaning the band doesn't need to be shimmed, in fact it needs to release sooner, the shims are preventing that to a small degree.

I'd drill 3rd to .106 and take the trans apart to install the rest of the kit and while I was in there install an improved 3-4 clutch and run the clearance at .030, and put in a beast sunshell.
I did all this at 32,000 on my trans. Do a search here and see how many people have the 3-4 clutch go out and describe it as a flare during 2-3, slow 2-3, or no 2-3 shift at all.
That means the 3-4 clutch is a weak point, we all know that.

Your shift kit has parts to be installed in the forward drum-right under the 3-4 clutches.
You're already having a 2-3 flare.
I'm not a sponsor and I'm not trying to sell you anything.

PBA

If you put in 2 and the band clearance is to tight, you will burn up the band. The shims keep the band travel to a minimum, and that is what you want. With minimum travel, (the band is the 3rd accumulator) the oil that is used to release the band is kept to a minimum, and then all of the oil can be used to apply the 3-4 clutches. Since you want this fixed without taking the transmission apart, there is more thing that you can do to force more oil to the 3-4 clutches. The (BR) band release hole that you brought down in size, has a checkball right next to it, plug the check ball hole, (I use an aluminum plug here) and leave out the checkball. By doing this you are eliminating one more leak in this circuit. I do this in almost all of my modified Shift kits that are going into a transmission with stock 3-4 clutch setup. By the way how did the transmission oil look when you went to install the kit? Any clutch/band material on the bottom of the pan away from the magnet?

onevoice

No way I'm pulling this tranny, it was shifting fine 2-3 before the shift kit went in. This isn't my hotrod, it's my daily driver truck with a stock 5.3. All I wanted was a firmer 1-2 shift, now I have a problem. If I knew all the original hole diameters, I would have put it all back stock and threw this damn shift kit in the trash.

onevoice

The fluid looked fine, and there was no metal or clutch material in the pan. It only had 55k miles and has never pulled anything, or been raced. I am a little hesitant to keep changing any more holes without knowing exactly what I am doing. What I would really like to know is what does the shift kit do that made the shift worse? It was perfect before. I would really like to remove everything except the changes that deal with the 1-2 shift. Hell, I'd rather live with it the way it was than now.

I also think the dexron 6 is a possibility, but everything I have read is that it is compatible with and better than dexron 3.

I am pretty frustrated that I spent the money for the shift kit, a dozen quarts of dex 6 and a bunch of time under the truck to go from an annoyance to a real problem.

8a8mfh

iTrader: (3)

There are stamped letters on the plate, use these to get a new stock one, get rid of the shift kit parts. If all you want is a more firm 1-2 shim or block the 1-2 accumulator.

chargedvx6

Just buy a stock plate and swap it over for the drilled one.

PBA

A Corvette servo is on the way, this most likely will solve it.