ok heres the run down..

a month or two ago I lost 3-4 gears which I know is VERY common. So I got a "performance" rebuild kit and rebuilt the tranny and put 9 Alto eagle red clutches in the 3-4 clutch pack (instead of factory 6), and a kevlar band. Also I went ahead and put a fuddle 4000 stall along with it

I have had the car back together for almost two weeks now (maybe 800 miles)and last night I lost 3-4 gears again. WTF?? I also got a shift solenoid sticking code the night before the trans went out. I cleared the code and never saw it again.

I followed all data (109 pages) step by step and had an ASE master technition help me rebuild this thing (he has done several in the past). So I am ruling out a bad rebuild to be the culprit.

The question is what CAUSES the 3-4 gears to go out on these trannys?? What upgrade can I do or part to change to solve this issue?? Is it heat? Could a vacuum leak cause the vacuum modulation to not shift into 3rd right and cause the trans to slip until the point of no return?

The few possibilities that I can think of are...
1. If a vacuum leak is the culprit, I think the MAP sensor could be leaking on the fast 90 (cause the damn hole is too big) I used silicone, but it is possible to be leaking

2. Heat. I really want to rule this out simply b/c I lost 3-4 before I put a stall in and I really dont think a factory converter will cause too much heat.

3. Also highly doubted is that I had HPE tune my car AFTER the intake(4 months ago) and they turned torque modulation off and turned up the shift points and shift firmness. So MAYBE?? the tune is knocking out my transmission. After they tuned it my 1-2 shift would actually turn me sideways if I was turning in a intersection, but the 2-3 was soft as hell?? The tires would bark at 1/4 throttle on the 1-2 shift, and be soft into third. Even after rebuild it was like this.

4. shift solenoid sticking?

One final thought is that the day I got my car done I took it up to HPE to lower the shift points some and decrease the shift firmness (because of the 1-2 violent shifts)

If anyone can please put some advise in this from either experience or knowledge please do. Other wise I am either gonna burn the bitch to the ground or put a t-56 in it

 

the trans go high rev spring kit will help keep the 3-4 clutch from burning up. but with a soft 2-3 shift I'd like to believe that there could be a pressure leak somewhere. did you install a shift kit when you rebuilt it? many of the common problems like code 1870, soft shifts, bump shifts and other problems can be fixed or reduced by installing a trans-go kit.

 

so a trans go kit and a spring kit?? what springs are needing to be replaced? Part number?

 

The Trans Go will help keep the unit together, as mentioned. To a point, the quicker the shift the less time it spends burning up your clutches/bands.

 

please tell me you put a trans cooler on your tranny when you installed the stall...

you may have just burnt it up by heat in a week. it's very possible with no cooler on a stalled car - ESPECIALLY A 4000!

 

The springs that need to be replaced are in the input drum spring cages.They do come in the transgo hd- kit This might help but it sounds like you have something else going on. I would check your input shaft and see if it is loose/floating. Somewhere in your trans it sounds like you are loosing pressure or that circuit. Might be something as simple as a cut seal. You will have to get it apart and see what happened. Take your time and you might just find it. You can always put it in a create and send it to us. At least when it leaves it is dyno tested and built by builders that specialize in your application. Good luck, Vince.

 

I am really leaning toward a t-56. just need to find a donor car. That would be so much easier.

 

i just remembered something.. the number 7 checkball will cause a slipping 2-3 shift and is pretty common to have happen on a 4l60e. the way to check it is to lay the case on its back and pour trans fluid into the #7 cavity and see if it leaks into the inside of the case. if thats the case it would explain why you have a soft 2-3 shift and burned up clutches. if thats not the problem then you will need to check seals and stuff.

 

A soft 2-3 shift might have something to do with the 4K stall verter. Also, the life of the 3-4 clutches is directly related to line pressure. Simple air pressure checks during the assembly would help pin point leaks and potential problems. Line pressure checks after the install will also help identify problems. Listen to Vince. Give him a call. A spin on his dyno will tell him everything he needs to know about your problem. (wish I had a dyno )

Mec

 

For the DIY, this is a must.

 

i just take out the ball and capsule for the 3rd accumulator and block it off with a 41te park pawl cup plug makes 3rd nice and firm

 

Does it make it feel like 2nd? My 3rd feels kinda crappy, and "hits" harder than the other gears instead of smoothly changing. Feels sort of clunky.

 

yeah it makes 3rd hit good. it also helps keep the 3-4 pack from burning up do to leaky ball and crap.....with that if you set the 3rd pack clearance to about .025 it will shift fast and firm you will likey....3rd uses the servo as an accumulator if you pull out the ball and capsule and block it off then 3rd has no cushion ....you have to push the plug all the way to the top of the case though...the window has to stay open and below the srvo has to be open also

 

That describes mine pretty well, there is no "cushion" feel when going into 3rd, it "hits" instead of sliding in real fast like 2nd. Personally I don't like it, and it kinda shocks the drivetrain a bit.

 

lol....there is not much you can do if that has been done if you pull the servo out and look in there you can tell if it has been done......just look to see if the ball cage is still ion the window if not then it has been blocked off.........when it was built they could have done a mod to the accum spring also which makes it harder...but if it is banging 3rd then i belive it has been removed and plugged.......on mine i usually block the 1-2 and the 2-3 accumulator but i like that