2004r shifting dillema

[Douglee]

Purchased a KCF 200 4r from a salvage yard and rebuilt myself with a Trans-go shift kit using the ATSG manual. It went into my 1979 Chevy Corvette. Used the proper TV cable bracket(Bowtie overdrives), shift detent(Shiftworks) and followed all instructions for set up and pressure checks before driving. Everything checks out except it won't shift into fourth gear. One through three is fine, good shift points, manual downshifts work, but no overdrive. I tried raising the rear wheels and running it up over 100MPH, no overdrive. I dropped the pan and valve body, pulled all the valves and cleaned and lubed, made sure no hang-ups of valves, reassembled and tried again, no luck. Tried moving the shift lever while driving 60ish so it was just a hair shy of going into neutral, still no overdrive. Only thing seems odd to me, while driving with shifter in OD position(while still in third gear), when I downshift to 3rd, it goes into 2nd gear. When I downshift into 2nd, it stays in second, and when I downshift into 1st, it downshifts into 1st. Can somebody help point me in the right direction? Ideas? Things to check? Thanks in advance.
Doug

 

[chris718]

There is a fourth gear pressure tap on the outside of the trans.Get it up to 60 mph on jack stands or lift with tv cable disconnected and blow air into the port to see if it shifts.Report back,also try screwing a gage in there and make sure you have no pressure before test @ 60mph.Report back results.

 

[Douglee]

Thank you for the reply. I did a double-take on the words '4th gear pressure tap' because I have not seen that before. The ATSG picture of the shifter shaft incorrectly identifies it as the line pressure tap on the trans. The Bowtie information calls for a check on the line pressure tap located above and slightly forward of the shifter shaft, where I took the line pressure readings initially. Where is the 4th gear pressure tap located? And by the info I now have, it is safe to have this opened while running with no danger of having a gusher of fluid? Do I have a helper run it up while I apply air pressure? or just blast it with air first to see if something dislodges and take it for a test drive? I will report back when I know what to do. And thank you.

 

[chris718]

Its there on the rear of the case if you look.Passenger side.I said to disconnect cable so you are at lo pressure.Check for pressure there first,if there is non the valve body isnt asking for a shift.If there is there isa a hydraulic leak in the circuit from the shift valve.Have someone in the car run it up and keep the blower rubber tip pushed in the hole .After 3rd gear shifts put air into the port and you will feel it shift if the clutch circuit is good.

 

[Douglee]

Thanks for the reply. I'll try what you said and report back.

 

[Douglee]

Well, finally got to make a couple checks on jackstands and what I found was : with the TV cable connected, at the 4th gear pressure tap, had no pressure until after being in 3rd, then 60lbs pressure. Tried manual shifting, 1st - nothing, 2nd - nothing, 3rd - nothing, then shift to OD, 60lbs. pressure Same thing with the TV cable disconnected, nothing, nothing, nothing, then 60lbs pressure. Zero pressure until manually shifted into OD, then pressure, or 60 lbs. after it shifts through the lower grears when in OD. Any idea why it won't shift into OD?

 

[1936fordturbo]

I have the same TransGo kit and same problem. I have not done any pressure testing yet, I am to ticked off. Mine was assembled by a guy that knows how to rebuild these transmissions.

 

[Douglee]

Already the end of May? I've thought about my shifting dillema for a while now and what I have concluded is this: I should have air pressure checked the OD clutches before assembling the valve body. The ATSG manual seems vague compared to CK Performance's 2004r manual. Now I will have to pull the trans and perform some air pressure checks to find the source of my hydraulic leak in the OD circuit. Great book Chris! Thanks for bringing that info to the masses.

 

[Douglee]

OK. took out the trans, removed the VB and applied 60lbs. of air to the OD clutch circuit and the piston pops up and retracts as normal with no leaks. Now I'm stumped. Why won't it shift into OD?

 

[Douglee]

OK. took out the trans, removed the VB and applied 60lbs. of air to the OD clutch circuit and the piston pops up and retracts as normal with no leaks. Now I'm stumped. Why won't it shift into OD?

Would it help me to receive a reply if I lied and said the trans is going into a Buick GN?

 

[TexasT]

Would it help me to receive a reply if I lied and said the trans is going into a Buick GN?

Doesn't matter what you put it in.

Have someone in the car run it up and keep the blower rubber tip pushed in the hole .After 3rd gear shifts put air into the port and you will feel it shift if the clutch circuit is good.

Did you do this? The trans case itself could have a leak.