Rebuilt trans; No 3 or 4 shift

[Adam Whitman]

Rebuilt and sat on a shelf for several years, so the builder is long gone.

Finally installed it, and 1 and R worked just fine. It took a little bit of driving before the 1-2 started working but the shift feels good. It freewheels in 1 & 2 when decelerating in D, but engine brakes when in 3,2,1. I assume the Band is engaged in the manual gears. TV is not stuck.

Should I pull it or check the valve body and check for ?? What should I be looking for in pressures?

I seem to recall it being mentioned that something like this happens if one of the lip seals on a drum or servo isn't carefully installed and the lip folds over on the install. But that was a long time ago and I don't know where to look.

Who has the best trouble shooting manual? GM, ATRA, ATSG, CKPerf?

 

[Steve V]

Adam- get the ATSG book. You can pull the valvebody and air check 3rd and 4th real easy. If you put it in OD and drive what happens?

 

[Steve V]

Rebuilt and sat on a shelf for several years, so the builder is long gone.

Finally installed it, and 1 and R worked just fine. It took a little bit of driving before the 1-2 started working but the shift feels good. It freewheels in 1 & 2 when decelerating in D, but engine brakes when in 3,2,1. I assume the Band is engaged in the manual gears. TV is not stuck.

Should I pull it or check the valve body and check for ?? What should I be looking for in pressures?

I seem to recall it being mentioned that something like this happens if one of the lip seals on a drum or servo isn't carefully installed and the lip folds over on the install. But that was a long time ago and I don't know where to look.

Who has the best trouble shooting manual? GM, ATRA, ATSG, CKPerf?

1st gear is the sprag
2nd gear is the band
3rd is direct clutch-band is pushed off
4th/OD is 4th clutch and direct

Reverse is LO/REV and 3rd clutch--so if you have reverse you've got some 3rd oil. There's a lip seal inside that drum that seals one way and leaks the other way.

Pressures should be 250+ close to 300 is engine is stout.

 

[Adam Whitman]

1st gear is the sprag
2nd gear is the band
3rd is direct clutch-band is pushed off
4th/OD is 4th clutch and direct

Reverse is LO/REV and 3rd clutch--so if you have reverse you've got some 3rd oil. There's a lip seal inside that drum that seals one way and leaks the other way.

Pressures should be 250+ close to 300 is engine is stout.

Thanks, Steve!

If I put it in 3 or 4, I just get 1, then the 1-2 shift as expected. There's no slipping or other issues; the 3 and 4 shift just never come. Reverse feels good as do 1, 2 and 1-2 shift.

Do you think I could be so lucky to have a stuck valve or two from the trans sitting dry-stored for so long, or other valve body problem? With both 3 and 4 out it doesn't sound like it's that seal for the 3rd drum. Unless there is more than one problem :/

 

[Steve V]

Thanks, Steve!

If I put it in 3 or 4, I just get 1, then the 1-2 shift as expected. There's no slipping or other issues; the 3 and 4 shift just never come. Reverse feels good as do 1, 2 and 1-2 shift.

Do you think I could be so lucky to have a stuck valve or two from the trans sitting dry-stored for so long, or other valve body problem? With both 3 and 4 out it doesn't sound like it's that seal for the 3rd drum. Unless there is more than one problem :/

That could be it, is your TV cable adjusted too tight? Unless the trans sat unsealed I wouldn't think is valve sticking.

 

[David Husek]

Do you think I could be so lucky to have a stuck valve or two from the trans sitting dry-stored for so long, or other valve body problem? With both 3 and 4 out it doesn't sound like it's that seal for the 3rd drum. Unless there is more than one problem :/

If the VB had oil in it when built and never run, small amounts of trans oil will get acidic and gel. It shows dark orange in color. It will stick valves. I would pull the VB and the governor and check/clean every valve. Also air check all clutches for apply.

It could be starting in second from too much TV pressure at idle and not making the 4th shift. Get a gauge on the trans before doing anything. When the oil gets warm, the valves could start to free up, but 4th can still be an issue.

Any questions, feel free to give a call

 

[Adam Whitman]

I pulled the pan and checked the TV for sticking and the governor/spring first thing and both looked fine. TV is adjusted per factory. It's taking off in first and has a nice firm 1-2 shift. I drove it about 10-15 miles hoping it would warm up and loosen a stuck valve if that was the problem and no dice. I unhooked the TV and drove it nice and easy but still no shift past 2.

I'm going to be away from home for a week but agree the next steps will be a pressure gauge. That should tell me if I'm going to need the ATRA manual if it's likely beyond pulling the valve body and freeing up a stuck valve.

Thanks, both of you guys, I will keep you posted when I get back onto this. My hair is looking forward to the ATF.

 

[Steve V]

I pulled the pan and checked the TV for sticking and the governor/spring first thing and both looked fine. TV is adjusted per factory. It's taking off in first and has a nice firm 1-2 shift. I drove it about 10-15 miles hoping it would warm up and loosen a stuck valve if that was the problem and no dice. I unhooked the TV and drove it nice and easy but still no shift past 2.

I'm going to be away from home for a week but agree the next steps will be a pressure gauge. That should tell me if I'm going to need the ATRA manual if it's likely beyond pulling the valve body and freeing up a stuck valve.

Thanks, both of you guys, I will keep you posted when I get back onto this. My hair is looking forward to the ATF.

Good info. So that tells us forward clutch, the low sprag, and the band are working. Keep us posted.

 

[Adam Whitman]

Good info. So that tells us forward clutch, the low sprag, and the band are working. Keep us posted.

Hm, so what does that leave for problems in the power-flow? Seems there would have to be multiple problems or could direct clutch cause both?

Now on the hunt for a local pressure gauge setup. And the ATSG manual so I can start looking at fluid flow and the troubleshooting guide.

 

[Steve V]

Hm, so what does that leave for problems in the power-flow? Seems there would have to be multiple problems or could direct clutch cause both?

Now on the hunt for a local pressure gauge setup. And the ATSG manual so I can start looking at fluid flow and the troubleshooting guide.

Yes it certainly could. 4th applies on top of direct. But you have reverse which uses direct too.

 

[Adam Whitman]

Yes it certainly could. 4th applies on top of direct. But you have reverse which uses direct too.

OK, so direct is unlikely too. Reverse feels every bit as solid as 1 and 2. If direct clutch were having issues it sounds like it should show up there, too. This is at least giving me small hope that the valve body isn't happy for some reason. Better than R&R and disassemble the trans.

 

[Steve V]

OK, so direct is unlikely too. Reverse feels every bit as solid as 1 and 2. If direct clutch were having issues it sounds like it should show up there, too. This is at least giving me small hope that the valve body isn't happy for some reason. Better than R&R and disassemble the trans.

Pull valvebody and air check the unit, inspect the valvebody. If inconclusive pull it.

 

[Adam Whitman]

Pull valvebody and air check the unit, inspect the valvebody. If inconclusive pull it.

ATRA book bought on ebay and on its way!

 

[Adam Whitman]

received the ATSG book today. That was a short read. The troubleshooting guide is short, no guidance on pressures, pressure tap location, nothing. Although it looks like a decent reference if I decide to take it apart and disassemble/ reassemble. The only common issue I can find for no 3 and 4 is something with the center-support.

Steve, you gave me all of that needed info above, plus pressure diagnosis! Thank You again. OK, going to see about borrowing a pressure gauge and hose (and a half dozen other chores).

 

[Adam Whitman]

Finally got this thing apart to look at it. Amazingly it appears that the simple problem was the problem; the 2-3 shift valve was stuck tight. I broke it loose and it seems to be fine now.

Used the search and found where the 2 omitted check ball locations are. I counted but forgot to photo where they were before I started. DOH!

 

[Adam Whitman]

Update:
Several other gummed orange stuck valves and a little rust just as Dave Husek described.

Cleaned valves and will scrub out the valve body this morning. Also discovered it has a Sk 200-4r shift kit (thanks to the included tag) with a broken 2-3 throttle valve spring; sure wish I had the instruction sheet as they apparently don't have them on their website anymore. Guess I won't be putting it all back together today.

 

[Gary Durden]

I found the instruction sheet with a simple Google search.

 

[Adam Whitman]

I found the instruction sheet with a simple Google search.

When? As mentioned, I have read in older posts that TransGo at one time had instructions on their website; to the best of my reading abilities, this is no longer true. I've looked using several different search terms and search engines. Nothing. I will be proud to humbly bow to your interweb abilities if you will kindly post a current link to the instructions.

 

[Gary Durden]

https://www.google.com/search?q=sk+...i=s3RzWaqaIIHhmQHwt6DAAw#imgrc=JoCJdwpf3BN4uM:

 

[Gary Durden]