Rebuilt A518 very weak forward gears.

[mperryb]

The instructions for the shift kit said to take the line pressure regulator spring all the way till its flush with the inside edge of the spring retainer. Than it said in 2 turns for stock engines and 4 turns for high horsepower engines. I started with 2. Dropped the pan and turned it in another 2. By in I mean adjusting the spring "Tighter" or pushing the outer edge of the spring closer to the valve body. I don't remember if it was CW or CCW. I just assumed "in" was more pressure.
By the way the Transgo shift kit instructions are terrible.

[mperryb]

i suppose if the threads are normal than tightening the screw (which is what i did) is clockwise. Ill get under there in the morning and double check. THANKS, I'm dumb

[cmann250]

Caleb, the front and rear clutch pistons use ell shaped lip seals and the grooves are ell shaped also, you'd really have to work at it to install them upside down.

If I'm remembering right, I almost installed them backwards with the lip pointing the wrong way. I assume the pack wouldn't engage all the way if that's the case. I've forgotten a lot of the details

[ellis93]

. Mperry, you sure you turned the line pressure screw the right way, it needs to go counter clockwise to raise the line pressure.

Didn't even cross my mind to ask

[txs]

Caleb, if you managed to get the seals on backwards you wouldn't get any apply at all, even a small cut on one of them will slip to beat the band.

[mperryb]

Nevermind I DID increase the line pressure on the second try.

[mperryb]

Ok guys I got it torn out and took a peek inside and found this.


Nice wear mark on the piston ring



The reverse clutches are burned up



With a nice concave to them, not sure If you can see it in this pic or not.


When I was first inside the transmission I found this metal seal ring to be broken. I replaced it with the one supplied in my rebuild kit which happened to be teflon


I downloaded the ATSG manual so ill be reading through that tonight but any advise would be lovely.

What the heck did I do wrong?

[ellis93]

If all of that was out of that one drum,that's the foward clutch. Looks like too much clearance to me. Piston may have traveled too far and cut a lip seal and it was game over from there.

[mperryb]

according to the tech trans manual thats the rear clutch.
[URL=http://s1219.photobucket.com/user/mperryb/media/IMG_1865.jpg.html][/URL



And how about that seal ring on the input shaft, the teflon one. The metal one just sounds like a better idea to me. Should they both be teflon? I didn't get a chance to dig into that piston to see if the seal was torn or anything like that. Ill check today.

Thanks

[ellis93]

Call it what you want,doesn't make any difference....it comes on in any forward movement. look in the diagram that I posted up,it's named there as forward clutch and I explained why.
As for your rings....I use the steel every time. I've talked with other builders that like them...so it's a tomato,tamoto thing. I've heard some say that the metal rings can wear grooves in the surface it rides against and they like the plastic because they believe the wear into the surface to seal better,idk.

All that being said I don't think the rings are your issue. I think you should pull that piston out and inspect the lip seals on it. I think one has been cut from clearance issues.

What is your stack up like on your plates?

[mperryb]

I hear ya on the drum nomenclature and it makes sense.
My current burned stack up is 3 frictions and 2 steels. I am seeing in the ATSG manual has 4 frictions and 3 steels. I tried to put in 4 and 3 and it didn't seem to fit. Maybe I did it wrong, maybe my frictions and steels were too thick, though I though I measured them.

The outer piston has a few nicks in random spots. When I removed the piston it was fully seated.

So it seems I didn't have enough frictions and steels which lead to the piston traveling too far and getting damaged?

[ellis93]

Correct that clearance is what is screwing you up. you could probably use factory plates and fictions and be fine there. It never releases anyhow.

[mperryb]

so fancy pants steels and frictions are pointless in that clutch pack? I do still have the factory stuff and it looks fine.
I just need to find those piston seals.

Thanks for your help and dealing with my questions.

[ellis93]

That's what I believe man.....everyone has their own opinions. Bunch of folks are running stock steels and stock like frictions and shoving lots of power thru them. Heck I just use the high energy raybestos (sp?) clutches. I have used the altos and fancy steels a lot in turbo 350 and 400 trans,some in a few 727 for people but don't really get into the whole hot rod diesel trans thing. I'm currently beating on a 47rh (618),I built for a guy before I bought the engine and trans from him, and It has the high energy clutches and factory replacement bands. No issues and it has over 20k on it.

[txs]

I would second the use of stocker parts in the rear clutch, it never shifts while you are in the forward gears. I call it the rear clutch because that's what chryco called it, from year one, (1962). Most of your tranny shop people call it the forward clutch, but I worked at KTP for 33 years, so I will call it a rear clutch till I go to the grave. The suppliers of tranny shop tools have a really neat seal roller for the rear clutch lip seals, its a round sheet of semi stiff plastic, works great.