C4 problems

[k-star]

Ok i did some work on a C4 for a customer it is in a 37 ford street rod.... i did not do a complete rebuild. he told me the trans was just done maybe 10,000 miles ago and it worked fine.I found very little debris in the pan, no metal or bushing material. I changed the tail bushing, he had to short of a drive shaft in it ,And i pulled the pump and changed the converter bushing because the converter hub had a gouge in it and it messed up the bushing. he asked me to put a shift kit in so i used a trans-go # sk4-71.

He calles me tonight and it's not working right. I go over to his place and we go for a ride. Well he tells me he bought a B&M converter from summit and it came packaged in the wrong box. He called B&M and they assured him it was the correct converter, but it had the 7/16 holes in it and according to the chart only the 3000 stall converters have the big bolts????

So when he pulls out the thing revs like a clutch is slipping but it does move foward. I got it back and checked the line pressures.And there is never a good feeling shift but the car never went over 3000 rpms either. I do know that the rated stall is the flash rpm and the car will move under a much lower rpm....

here is what i got all readings are with 16" of vacuum and a 700 rpm idle

park 80 psi
reverse 90 psi
neu 70 psi
drive 80 psi
d2 80psi
d1 80/90 psi gauge pulses some

Then with the vacuum un-hooked same idle rpm

park 170 psi
rev 90 psi
n bounce between 150 psi and 180 psi
same for drive
D1 and D2 was 90psi

So i think the modulator circut is working......

When you put it in any gear it moves (loads the car) like it is engaging into gear like any normal transmission.

The engine is a totally stock 302 with like a 3:08 rear gear,,,

My question,,, if this is in fact a 3000 stall converter would it act like this????
I cannot come up with anything i did that would cause this to happen, Or could it be a bad converter????frankly i am lost as what to do?????

Any ideas are welcome....

Keith

[Hutch]

The pressures look ok except for the mod disconnected reverse pressure. It seems low but at this point im sure its not the problem.
It really sounds like he has a converter that is just too high stall . I have had some that flashed to 3000 and drove away nicely at 2200 and some others that were supposed to be 3000 and were closer to 4000, which makes for a pretty lousy cruiser.
The incresed stall will also make all the shifts feel mushy until you get well above the coupling point of the converter.

If the car feels sloppy in fwd and reverse (high stall) then you can be pretty much assured that the slipping feeling your getting is from too much stall speed.

Hope this helps ,Hutch

[k-star]

Thanks hutch,

I think i am going to have him take it out and get a stock converter. while it's out i am going to go through the entire trans to make sure there is nothing else wrong. He told me it worked before but you know how the stories can change????

It does act the same weather it's in reverse or drive...

I have run stock converters in cars that neede 2500 stalls and witness how they act, but i have never seen what a 3000 stall would do it a stock application.....

Keith