fresh 904 rebuild, not shifting

[mopar0166]

i rebuilt my transmission recently and finally after a reinstall  and getting it back to the point to run, i had no gears, it wouldn't shift into any gear.  i had a local transmission guy help and i kept checking the fluid and it seemed to be good.  Also i put in 5 solid quarts of new fluid and it has a Hugh's performance torque converter (2000-2200 stall).  The transmission shift level seemed to go into each gear OK (PRND21) any ideas?     

[mopar0166]

 

[Stormin]

Could be anything. I would speculate that the front pump is not picking up the fluid. Remove one of the cooler lines from the radiator and observe if fluid pumps out when you start the engine. Could be simple like a bad filter; however this is not likely.

What is highly likely is the engagement of the torque convertor to pump which is tricky on 904s. Was there a 3/8 gap between the torque convertor and flywhell when the trans was installed? If there was no gap the convertor was not in the pump.

You may have the wrong torque converter. Pre '67 TQs used a 19 spline hub and '67 and later used a 24 spline hub.

Hope this helps.

Norm

[mopar0166]

If the torque converter was the wrong spline count would it still fit ok ?  Im o not sure about the gap but it looked correct when i was bolting it up?  I am intereested in taking a line off to see if its pumps though!!   great suggestion If you think of anything else let me know

[mopar0166]

TORQUE CONVERTER - A904 (TF6) 1968-on All 6 cylinder
and 273/318 V8 w/27 spline input 2000 stall series


BTW -its a 69 charger with a 1969 904 orignal to car

[mopar0166]

"A-904 transmissions from their inception until 1967 have 18 splines in the input shaft. Non-lockup transmissions from 1968 have 27 splines."  - found on allpar.com

[mopar0166]

Well my buddy just called to tell me to drop the trans again, fun times !

[mopar0166]

Yeah im not giving up that easy, I knwo its gotta be something simple

[mopar0166]

Could this be a torque converter / flexplate issue ? 

[mopar0166]

DO you think if i ran in park or other gear besides N that it just didnt build pressure yet?

[John_Kunkel]

Like I suggested on the "other forum", monitor the fluid level; if the level rises after sitting awhile and doesn't go down with the engine running in Neutral the pump isn't turning.

[Cooter]

Only 5 qts of fluid? In a totally "Rebuilt" trans? I'm thinking if the pump was turning, it would take somewhere in the neighborhood of around 7-10 qts. to fill it all the way up from "Rebuilt"....

Sounds like your buddy was dead on..Pull it out and get it rebuilt professionally.

[mopar0166]

Yeah ill be dropping the transmission Friday night, even though i think it maybe a pump issue it may also be the aftermarket torque converter not engaging the pump correctly as well.  The trans was rebuilt professionally, i just got to do most of the work with the supervision of my buddy who does this stuff for a living.  I trust his abilities way over any of the local shops.  Plus their prices are sky high for classic cars.  thanks everyone for the advice and guidance.   

[mopar0166]

any ever have the ears shear off the pump, thus the pump doesnt work?

[John_Kunkel]

it may also be the aftermarket torque converter not engaging the pump correctly as well. 

Not very likely. Broken pump drive tangs is pretty common on initial startup though.

[mopar0166]

how do you avoid this from happenining again, im still taking the trans back out but everything ive tested points to the pump.  I ordered one to be on the safe side but would rather not break this one.  thanks again for your help!!!!!!!!!!

[mopar0166]

well it doesnt seem that they broke as i thought?   now what

[mopar0166]

it wasnt pumping and the input shaft it hard to spin as well ?  Any ideas

[mopar0166]

Ill be performing pressure tests tonight to rule out some other things   

[mopar0166]

Air tests passed, its ether the valvle body or pump, still thinking pump

[mopar0166]

Everything works fine, its all fixed up

[Stormin]

So what was the issue with the trans?

[mopar0166]

replaced the pump, the old one looked to be fine inside.   Also pulled the front drum and found a broken ring clip. replaced that.  and once the assembly was done i could tell the difference in how it felt.  Air tests all passes on the bench , do i installed it.  Now , this part people may hate but i put the old torque converter because we knew it worked. the new one who knows.  sure enough i started the car and i got a hissing sound, well it was the rubber line from the cooling hard line to the rad.  it was rubbing against the crank pulley and cut right through it.  so even though it was a grind to clean it all up and replace the line i new i had a working pump and good pressure.  Once all fixed up and the cooling lines positively secured i started it up again and it quickly wanted more fluid.  once topped off i ran it through all the gears and it worked great.  I do know have to road test the car and finish the monday details but i think I'm in good shape now.  I also had some help from the guys over at the Abody forum which helped me because i was a novice at transmissions.  it helped me to relay information to my buddy who built the trans.  This helped to fix the issue sooner.  it could of been a few minor things that ended up being the issue.   A 904 isn't the easiest trans to get parts for but at least ill be on the road this summer and wont have to wait for the big block stuff to get done.   Thanks again everyone for your feedback.