Front clutch on bw 35 P6 3500

#1
I am changing out the wearable material in my gearbox and have fitted it back in car. However i have no drive forward or reverse. I had forgotten to hook up the manual control valve to the gear selector. Fixed that and expected my gearbox to work. No ...still no drive. The only thing now i can think of is i replaced my front clutch with a set of 4 inner friction and 4 outer steel plates as that is what i counted when i removed the old ones. I now remember reading here that the front clutch packs are 3 or 5 of each plate. Have i put in one too many ? And would this cause my problem?
 

harveyp6

Well-Known Member
#3
IIRC it's 5 friction plates and 4 flat steels.

If you don't fit the manual control valve to the selector lever what can happen is that the front clutch can drag all the time, and that will burn it out in a very short time.
 
#4
IIRC it's 5 friction plates and 4 flat steels.

If you don't fit the manual control valve to the selector lever what can happen is that the front clutch can drag all the time, and that will burn it out in a very short time.
I am sure thats what went back into it because i only have one steel plate left on the bench out of a pack of 5I only ran it on my car lift for aprox 20 seconds about three times while checking the oil levels. And also checked the front servo was set ok . Would you think that would strip the clutch or band?
 

harveyp6

Well-Known Member
#5
Probably a minutes running in total wont burn the clutch out even if it was dragging. Did it feel like it wanted to drive forwards in either PARK or NEUTRAL?

TBH if you have no drive at all the chances are you're going to have to take the box out again anyway.
 
#7
No drive at all and checked everything fitted as it should before fitting it. I will be taking it down again i know. The only thing i can think of now is the new Forward clutch diaphram spring seems to be very stiff compared to the one i removed. how much pressure does the forward clutch piston create as it would would need to be a lot to compress the spring and clutch plates.
 
#9
not sure aprox 4-5 litres. filled it than ran it through all the gears , dipped and topped up then ran again. And repeated again until dipstick had oil level correct.
 
#10
Did you change the forward sun shaft sealing rings?
Are you sure all the fluid supply pipes are fitted into the valve body corectly ?
Did you measure the end float at the input shaft ?
What type of fluid filter was fitted, and if you replaced it was it of the same type?
 
#11
Did you change the forward sun shaft sealing rings?
Are you sure all the fluid supply pipes are fitted into the valve body corectly ?
Did you measure the end float at the input shaft ?
What type of fluid filter was fitted, and if you replaced it was it of the same type?
I didn't replace the sealing rings . And the did seem to be the same diameter as the shaft , would a good set of seals be a slightly larger dia?
All the pipes are fitted snug. when i tapped them in they made a different noise when fitted all the way in.
Didnt measure the float end of the input shaft. Is that the piece that sticks out of the pump assembly. If so it looked the same as when i took it out probably 1.5 inches
And it was the new type filter and i replace the same.
What do you think?
 
#14
Er.. measuring stuff helps/
The cars takes about 8 litres of fluid. Five or six probably won't get enough oil to enough things to make them work. Most of that eight litres is in the pipework, pan and torque converter. Try some more fluid before pulling it to bits again...It has to be high enough to get sucked into the inlet in the pan and the first four litres will head off into the torque converter but only after the pan is full enough.
 
#15
Er.. measuring stuff helps/
The cars takes about 8 litres of fluid. Five or six probably won't get enough oil to enough things to make them work. Most of that eight litres is in the pipework, pan and torque converter. Try some more fluid before pulling it to bits again...It has to be high enough to get sucked into the inlet in the pan and the first four litres will head off into the torque converter but only after the pan is full enough.
Yes I agree will check the a few more times. i didn't measure anything as there was good oil in the torque converter already, but i will run and check levels again. cheers
 

harveyp6

Well-Known Member
#19
The rear band strut may have not been located correctly and broken the band, but the rear band will only give you a loss of REVERSE and engine braking in "1", it won't affect forward drive in any other way.
 
#20
The rear band strut may have not been located correctly and broken the band, but the rear band will only give you a loss of REVERSE and engine braking in "1", it won't affect forward drive in any other way.
The rear band strut was fine as it was still in place when i removed the valve chest. I am thinking that the front clutch piston might have a faulty one way valve also but i haven't looked at that yet
 
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