Need help from the experts here. I'm trying to find a new 1-2 accum piston , and the only place that has any only has one that looks just like the 3-4 one (metal, lots of little circles around the edge.). Its part number is A74927 where the plastic one on the car is an A74927B, anyone know if it will work? I don't want to get stuck trying it if it wont work at all.

 

The metal one will replace the plastic one.

 

It seems like the hole is much bigger though. I looked it up and it seems that one it a .235" and the other is .308". Should I just track down the bigger pin?

 

No I ment the metal one for the 1-2 will replace the plastic one but no sounds like what they have is the 4th accum it will not interchange, Ask them it they have the pinless accum for it then there will be no issue at all.

 

No, do not try to use a different pin. You need an aluminum 1/2 piston.

I can get them to you if need be.... call me tomorrow if you need me to! I'll get what you need out tomorrow.

g

 

Well, the issue here was I needed it today, as tomorrow is when I have to tear into it. The one I have looks similar to the 3-4 piston but is not the same part number. I guess I'll find out the hard way tomorrow.

EDIT: I found the problem, they gave me the early 4L60E 1-2 accum piston that had the large bore pin. Any way to make it work? (The trans can explode for all I care as long as it will run for 2 or 3 weeks.)

 

I dont see much way to make it work unless you can find the early 4l60e/700r4 accum housing

 

Whats the difference between the two?

 

Pin size but the large pin will not fit the late accumulator

 

Okay, hoping to get a reply to this quickly. I have the accumulator apart, and there is no spring inside of it. Just two small sleeves that were around the pin, which appear to have blocked the piston from moving at all. Is this normal? I have a new spring with the new piston, should I put that in or leave the sleeves in there.

 

Some one had blocked the accumulator I would put the springs in and take out the little sleeves if not it will rattle your teeth when it shifts at any throttle and possibly break stuff

 

Okay thanks, it looks very weird to me, and confirms my suspicions that someone has messed with the tranny before.

 

I put everything back together annnnd...... no second gear any more. It doesnt even try it. It has everything but second.

 

Anyone know how it is possible to lose 2nd gear even with selecting it manually? It just runs 1st still. And its only 2nd, R, 1, 3, D, lockup all works.

 

Well asuming the acumulator was assembles properly right hole size for the housing used, I would have to assume there may be some issue with the band/servo . What was the symptom ou were trying to fix to start with. With the stock accume having stop spacers instead of a spring its very possible the band of servo may actually be broken. I would look at the servo next ,

 

Well, I did that. The servo looked fine to me just the same as it did before. The band looks ok too from what I can see. Plus, if there was a problem with the band would 4th work? It doesnt even attempt to use 2nd gear. The original problem was that 1st and 2nd stopped working, the car would start in 3rd, after a WOT 1-2 run. But then the car would try it and make some rumbles and rev a bit before it went to 3rd. The 1-2 accum piston was in 3 pieces when I took it out. The car drives PERFECTLY except for no 2nd, it does a very clean 1-3-4 shift.

 

Hm in that case I would revist the accum did ou fine the right piston for it ? And thats correct on the band with 4th. So as I said we are back to the accum and the second servo.

 

Yeah I got the right piston, it straightened up 1st gear really nicely. What should I look for on the 2nd servo? Would it show any symptoms of being messed up when its driving? It doesnt look like it is burning anything up, the fluid was nice and red.

 

Well it posible the seal is damaged or that the center is broken out of it , hen you get it out take a few pictures of it and post and we will see what we can see.

 

roger, thanks for all the help.