Bandit_ky

Had my trans rebuilt last week. Originally lost 2nd and 4th no other issues. Ordered a master kit with upgraded frictions, sonnax 3rd accumulator valve kit, beast sunshell, all new solenoid and harness (as delco), 13 vane pump.
installed trans and no 3rd or 4th. Call my builder and he finds the check ball for 3rd accumulator is on table not over sonnax valve. Install that and bam 3rd gear but no 4th. I also found wrong orings on 2-4 servo so I replaced those. All solenoid show proper on off sequences when shifting...4th is commanded but makes no attempt to shift. Tcc is engaging and will disengage with brake pedal apply. He says internal issue with something I ordered. I have already found 2 .mistakes he made and am looking for suggestions/ info before I take it back to him.
any help is appreciated just don't know a ton about auto trans and i feel his mind is made up he did nothing to cause this issue.

coryforsenate

iTrader: (1)

Considering he already screwed up really basic things during your rebuild, what is his basis for accusing the parts you ordered (and good parts at that) of having manufacturer defects? It sounds like he's brushing you off and hoping you just go away while he pockets your money. You may have to threaten (hopefully a threat would be enough) small claims or other legal action to get him to fix his mistakes or refund your money.

performabuilt

iTrader: (25)

Remove the servo and post a picture of it as installed

Bandit_ky

Can do. Plan on pulling trans tonight. I double checked the servo install and made sure everything was correct with long side of 4th servo up and the intermediate housing had the finned side up but I will pull and post to make sure before I pull trans out

clinebarger

Make sure the 4th servo bleed hole on the pan rail isn't full of RTV or blocked by the gasket. Applying shop air to the bleed should actuate the band.

mrvedit

Since 4th gear is a combination of 2nd and 3rd gears, assuming you have 2nd and 3rd, the lack of 4th is nearly always a servo problem. I do recall one thread in which a valve body problem caused the lack of 4th. Several valves move for 4th gear - the 3-4 Relay and adjacent 4-3 sequence valve and the 3-4 shift valve. However I doubt that is your problem.
One more thing to check is the servo end play. With a ruler next to it, press on the servo cover with a crowbar and estimate how much it moves. Usually excessive end play (more than about .150") is caused by a worn band and usually 2nd gear is lost before 4th, but I recall a few threads where the OP lost 4th before losing 2nd.

Bandit_ky

He tore trans back down and discovered burnt 3 4 clutches. He said due to binding of the springs in the drum. Replaced 3 4 clutches he said good to go. Still same symptom as before. He says valve body issue any thoughts ?

performabuilt

iTrader: (25)

Hmm No 4th is simple no 4th the band is not applying . Mentioned above are the valves used but I agree this is not likely unless a lot of debris . I have seen on the 3-4 shift valve with the Transgo HD23 FULL MANUAL where it says to replace a spring and does not tell you to discard the other on can cause no 4th but I do not see where you installed a transgo kit. If the small ring on the second servo is missing or damaged it can cause a no 4th condition.
Clearance would be the most likely issue as mentioned use a crowbar to push in on the servo cover vehicle not running and have someone turn the drive shaft it should stop and not turn in one direction but continue to turn in the other and you should have to push in no further than the thickness of the ring that holds the servo in.
Other causes would be the servo sealing rings on the 4th servo itself missing or damaged. "
This is all I can think of you stated the servo assembled correctly as far as positions.

Bandit_ky

Got fed up going back and forth with my trans guy. Swapped a valve body out of a core I had and now everything works. I assume he either put something back together wrong when he disassembled the valve body, or a piece of metal lodged a valve, or the list goes on. But it's fixed now...thanks for the info everyone. I now know way more about this trans than I ever wanted to.

mrvedit

Well I (and PerformaBuilt) thought that a valve body problem was unlikely, but I'm glad I mentioned it as a possibility. Wish I knew which of those valves was the problem for the next time.
Knowing more about this trans than you ever wanted to should give you peace of mind. Now instead of "god I hope the trans doesn't blow", it more of "well I could probably fix it".
Thanks for following up with the solution; many people don't do that and leave us hanging. I learn more from these follow-ups than I do from the very few trans I actually touch.

Bandit_ky

I am taking the valve body back to my builder so he can see if it's his fault or if metal stuck a valve when the 3 4 pack fried. I will update when he let's me know what happened.

erickk120

This is such a great place to drop my sponge (brain) and absorb all this transmission black magic. I've learned quite a bit just from reading from you guy's posts. I will be attempting a 4l60e rebuild myself soon.

performabuilt

iTrader: (25)

My guess would be the 3-4 relay we do see this valve stuck on occasion on old cores or cores that have had a lot of debris in them when doing refurbish and clean up. though rare on running units