velvet drive 71c question

briandarf wrote: Is this because theres no fluid pressure to 'engage' anything?? -Brian

Correct

They turn together likely due to fluid sheer forces and sticktion within the forward clutch pack. It's not in gear, they slip as soon as there is enough torque difference.
Maybe your forward pack is on the loose side.
You did shim it, yes?

uh oh.. shims???? I just put in new what ever I took out. I id see somewhere that youre supposed to measure the play between the big basket and its monster 'C'clip, but measuring that gap is so arbitrary and clumsy,- It seemed like nonsense.- you could read many different measurements, + or- .2 " at different points- so I didnt bother going down that rabbit hole.
The fluid shear force is good news to me- I was hoping for an answer like that.

So- why would you need to shim, if all the plates are new?- wouldnt 'shimming' only be necessary when adjusting old clutch plates because of wear reducing the plates thickness?

Thanks again.

It seems the shims are due to the forward piston only has so much throw, and can run out of usefull throw while you still have friction material available.
Depending how the stack adds up and plate type used, can be right on, or leave excess play.

I don't think at all your build will frag, but maybe you will get 10 or 15 seasons instead of 20+, just being arbitrary

The procedure is in the manual in the reference section

Well, it seems like you're now maybe wondering if this thing was put together right or if there's too much clearance in the forward clutch pack.

Way too many unknowns and too little info for somebody to tell you that

By the way, that manual in the reference section for earlier 71C's doesn't show the snap ring for shimming the clutch pack in the exploded view or list it in the parts list or give any shimming instructions.

Later on in the production of the 71C this snap ring showed up along with manuals that cover the measuring of the clearance. Most all 71C's didn't have or need that snap ring

Maybe you used a later manual that has that section and skipped over it.

By 1989 that tag on your transmission probably says 10-17-004 as a guess and not AS1-71C

If you had an extra snap ring left over, it might be time to worry, but if you didn't and that snap ring wasn't there to begin with you're probably OK if the clutch plate material was the same.

If you're worried you could bench test it to see that it engages and shifts from neutral to forward and reverse but that wouldn't tell you much about slipping under load.

If you're replacing the damper plate, the old splined female center section welded to a pulley driven by a belt and a gas engine or electric motor works good for this as long as you spin the transmission in the right direction.

I know one slightly deranged individual who uses his riding mower with a horizontal shaft engine and a bracket to hold the transmission to do this   

Some people say they do it with a 1/2 inch drill, but it's a good way to smoke that drill unless it's a big beefy boy drill.

And..............if you're not replacing the damper plate, somebody is bound to ask why, since this is the perfect time.

In the link below to a PCM engine manual from the CCF reference section the back section deals with the transmission and has the shimming info

link

woodyelc wrote: The snap ring that they are talking about was only used in the 72c gears

Then I guess you can explain the link below, see page 275,276

link

Ok so thick metal end plate drops in the forward drum first then you stack your 5 frictions and 4 steel plates for a 71c or 10-17.. if it’s a 72c or a 10-18 then it’s 7 friction and 6 steel after that you drop the other thick metal end plate and use the thicker of the 2 snap rings to hold the clutch pack. Assy your forward piston and press it into the forward clutch drum then use the remaining snap ring to hold forward piston into drum

72c is snap ring first the thick end plate then clutch stack up followed by thick end plate then snap ring, forward piston the final snap ring

I use only Genuine B/W bronze friction plate which are .060 thick and genuine B/W steels which are .068.. and I always use new pressure plates...if the clearance isn’t correct I have assortments of different thickness steel plates to achieve the proper clearance

If I have to shim I do use alto steels and yes you are correct I use alto red eagle friction plates but only as an upgrade for engines over 400hp

Alto overhaul kits will have the same thickness friction plates and steel plates as B/W as for prices alto is around 30% less then B/W but in the B/W clutch kit you get new end pressure plates which makes the B/W in my mind a better deal since the entire clutch stack is brand new

yes I can get genuine velvet drive clutch kits, seal and gasket kits, oil pumps , most internal parts new...

and I have just about anything in stock like cases planetary gears input shafts but they will all be good used parts

Also have tons of PCM parts in stock in good used condition besides clutch drums