One for Eric, no forward drive on rebuilt trans

Hi Guys,

Replaced the transmission on a friends 2001 today. Picked up a rebuilt -004 model velvet drive on ebay cheap. Box looked as new externally and had all the red plastic blanking plugs in it. As I was replacing a box with blown reverse clutches (accidently put in reverse, WOT while tied to the dock) I thought I'd split the box and check the reverse clutch pack. Inside the box it all looked as new so I reassembled and set the pump rotation.

Fitted box and filled with fluid. No it selects reverse ok but wold not select forward when at idle. I pulled the box, checked the pump direction, removed and check the valve assembly etc and same issue.

I then gave the engine a good rev holding the revs up around 4k for 10-15 secs, then let it back down to idle and it would select forward/reverse at idle. It spins the output at idle in neutral but no shaft connected and I can stop with my fingers easy enough.

So my question is could it have been an air lock? I've swapped trans before and not had an issue ike this. Never needed to bleed/prime the oil pump. Eric can you shed any light on the matter?

Thanks in advance!

Ahhh does this mean I need to tear the trans apart? I suggested the rebuilt box as it meant we could be back on the water quicker than getting the parts to replace the reverse clutches on the old box.

Eric, very much looking forward to your opinion.

This forum is great. I've not been on here for a year or two as I sold my 2001 and Tique and it's the same old faces :)

I've not water tested yet as I need some new bolts as the previous trans had the threads for the mounts drilled and helicoiled. I guess they had siezed solid and as such the threads don't match the new box. Being UNC I can't pop to the local hardware store as we're all metric over here. Really 5/8unc and all that? Give me a nice M12 thread anyday!

It engages forward/reverse with no issue now and I've given it some revs in gear and doesn't make and strange noises but there is no load on the box.

I've never been inside the forward clutch pack on a velvet drive but I'm well versed with the reverse clutch pack as I've replaced a fair few. The missing snap ring sounds about right as I've read a thread on MC owners and a guy had the same issue. Eric hooked him up but he never said what the problem was down to.

Didn't replace the damper plate as it looked like new and they are not cheap over here. The previous owner of this 2001 had spent a lot on it and I suspect he'd put a new damper plate in when he'd had the engine/box out for stringer work. (It's a saltwater boat and there was no corrosion on the damper so it's reasonable to say it wasn't that old)

you got it working?

Damn it's not working anymore :( Hopefully you can help Eric.

It's been fine all summer and now it won't dis-engage drive (enter neutral) unless the engine RPM's are below 600. Above that and it fully enguages forward drive even with the selector in neutral.

Shift from forward to reverse is fine, no slipping and everything else is ok.

So to clarify, with the engine rpm wound right back to 500rpm it sits in neutral fine. Blip the throttle and it actually engages drive. This is not a fwd clutch drag issue as you can actually hear it select drive.
It's not a cable or control issue as they are disconnected.

I still have the old tranny so I was thinking of putting the control valve from it into this box as to me it seems more like a valve issue rather than a clutch issue. Maybe a bit of crud blocking a bypass port?

As always Thanks in advance.