Problems after trans rebuild

[94TrnsAm]

Just rebuilt the 4l60e, put it into gear and it tugs, moves then feels like a reengagment, or stutter. Third gear is the only gear, i get second if i manually downshift. no first at any time, starts in 3rd Any thoughts or comments may help

[Kevin - Blown 95 TA]

Just rebuilt the 4l60e, put it into gear and it tugs, moves then feels like a reengagment, or stutter.I cannot feel any shift and beleive its starting in second gear. I installed trans go hd shift kit and did a soft parts rebuild.

Any thoughts or comment smay help

Do you really expect some one to diagnose a home rebuilt automatic transmission with a shift kit over the internet ?

I would start with the basic stuff like confirm the programming (if any), make sure the correct fluid is at the right level, solenoids are all hooked up correctly, see how it behaves in manual, then go through the shift kit and the servos including the one on the side of the tranny, if you can't find anything then you're going to have to yank it out and take it down to the tranny shop and listen to some rebuild guy lecture you about working on stuff you know nothing about.

[94TrnsAm]

trans

I dont expect somone to come along and tell me whats wrong, I was just looking for some input on what may cause the problem, I am fairly positive it is all in the valve body. Also this post may help another do it yourself'er down the road. I don't look for answers on here i look for posibilities and theories.

[fastTa]

Sounds like your 4L60E may be going into Limp Mode.

Do a search for "Limp Mode". I just recently explained briefly what Limp Mode is in another thread. It should give you a start. Let me know, and I can explain it in more detail if you like.

[94TrnsAm]

trans

I agree, I just spoke with a Trans go tech and he also implied limp mode. He first had me check the ignition fuse underhood(for trans) and then told me to pull codes. I plan on getiing a scan tool soon and doing so. Limp mode can be caused by a bad electrical connnection or componant, I will check your thread right now, Thanks!

[94TrnsAm]

trans

Ok, took it for another ride today with the scan tool, got code 28..fluid pressure switch assembly fault, atsg manual describes some of the problems I have related to this. It seems that I have no convertorock up in fourth, and loss of first gear(will not auto downshift from a stop, the car will if I manual downshift and step on it, 1/2 shift is good . When the transmission was cooler it seemed to perform better.
Any comments and thought may help, I will most likly be dropping the pan, but where I should go from there is what i need to figuire out. I will test the fliud pres. soliniod and inspect valve, any other ideas?

[fastTa]

If you aren't getting any VSS or TFT DTC's, and you are able to manually select a gear, and you are getting a type of PSA(sometimes referred to as the TFP sensor) circuit malfunction DTC, then it is likely that it is actually a faulty or clogged PSA sensor. This may or may not be related to the TCC being commanded "off". Usually the TCC being commanded off is because of a low "slippage" being detected within the converter. It also sounds as if the trans is intermittently going into 'limp mode'.

Once you pull the trans pan, look for a sensor that has 5 wires running to it. These 5 wires run to 5 individual little fluid manifolds each having an integrated sensor. These 5 little manifold's are what tells the PCM which gear range the actual valvebody is in by sensing fluid pressure within a certain section of the valvebody. According to Alldata, it is held in place by means of 3 10mm bolts and 2 8mm's.

The most common reason for failure of internal sensors and switches in automatic transmissions is debris. I'm sure you already know, but you have to be exremely careful and have an impeccably clean work area. This is why even with my level of experience, I still to this day leave all my auto trans work to the pros.

Just one more thought. I have seen an abnormally high trans fluid level throw a PSA circuit and/or sensor DTC as well.

[Kevin - Blown 95 TA]

I think the worst thing about working on an automatic transmission while it is still in the car is that it NEVER stops dripping fluid on you the whole time. As far as the Transgo kits are concerned, the instructional tape doesn't match the instructions exactly, and my one call to tech line got me an answer that was contradictory to what the Helms manual said, so you kind of take a chance putting those things in. Those kits are also grossly overengineered. Yet, a lot of guys have done it successfully, including me. I think one thing a transmission builder hates worse than anything else, though, is to have to go through a transmission that somebody tried to put a kit in. They have the advantage of putting the trans on a special dyno to make sure it works before installing it in a car, but I have found that some of them aren't too sharp about electronic controls.

My last time of working on the valve body was a near disaster of gigantic proportions. I was installing the vacuumm modulator kit and some other parts of my shift kit with the car on ramps, and the damn thing fell on me because I didn't have the brake set or the wheels chocked - BIG MISTAKE. I had time to turn sideways so my head wouldn't get popped like a grape and the weight of the car fell on my shoulders. First thought I was dead, then trapped, then broken shoulder, then I pulled myself out and figured I was lucky to get away with a couple separated shoulders. DONT LET THAT HAPPEN TO YOU Cleaned up the mess, put the car back together and it ran great. 7 check balls all gotta be in the right place, too

[94TrnsAm]

trans

Interesting, while I had the board out, 5 wire connector, I tested each by means of the atsg manual, but I don't doubt they could cause problems. there are so many sensor that are interelated. Fluid level is good, I will pull the pan sunday most likly, thanks for all the advice its great so far hopefully i can find the issue.

[Kevin - Blown 95 TA]

Interesting, while I had the board out, 5 wire connector, I tested each by means of the atsg manual, but I don't doubt they could cause problems. there are so many sensor that are interelated. Fluid level is good, I will pull the pan sunday most likly, thanks for all the advice its great so far hopefully i can find the issue.

I was dissapointed in the ASTG manual- it is just a bunch of excerpts from the Helms manual. Understanding how an electronically controlled tranny works is a lifetime effort, so don't feel bad if it takes you a few tries. Not to mention that to do a performance build you have to use a bunch of aftermarket parts and different heights for the clutch packs than the manual shows - stuff like that, so it's no easy thing for the DIY guy to know all that stuff.

[94TrnsAm]

trans

Agreed, the breakdowns helped the most.

[94TrnsAm]

trans

replaced the pressure switch assembly, no change, car basically only has third gear...i guess i will pull the valve body and look for error. not sure where to go no, no other fault codes

[94TrnsAm]

found problem

Well i dropped the valve body back down and went over everything. I found i had the shift solinoid clips in the wronge spot but i don't think this was the problem. I also found the converter valve sparing was incorrect, I think this was my major problem. I reinstalled the vale body and pan an could feel the difference as soon as I put it in gear. The car shift great and holds well inn every gear, what a relief, Thanks for all the help, my next diy mod is the rear end! oh boy