urb0123

Putting my trans back together and after putting in the 2-4 servo I checked to see if the still turned both ways and it didn't. So I've been tearing it down and putting it together in different ways trying to figure out what is binding.

I'm to the point that I've left out the input drum as well as the 2-4 band and servo. The second I screw the pump in that hard locks to the right.

My theories are that either the pump is too tight in the , or that the is pinched between the sun shell and pump.

Theory 1 - The pump is too tight in the reverse drum.
When I pull the pump out it always brings the reverse drum with it. I have to use two prybars, one on each side, to pry them apart. When they are together I can get the pump to spin inside the , but it is really hard. Should the pump come out of the trans without the reverse drum? Should they spin more freely?

Theory 2 - The reverse drum is pinched between the sun shell and pump.
When I seat the reverse drum into the sun shell, there is about an 1/8 inch of clearance between the shelf the pump bolts into and the top of the . Once I assemble everything I can't see or tell if the pump is touching the top of the drum or not. The inner race that the sun shell sits on at the other end sticks up about 1/4" beyond the sprag. Should the inner race be seated more fully into the sprag?

Thank you in advance!(With more thank you's for help to come!)

clinebarger

You sure the 3-4 clutches are fully laced? When the 3-4's are fully splined...The input drum will have endplay between it & the reverse input drum, The reverse input will be resting on the sunshell & the input drum will fall past that.

urb0123

Thank you clinebarger

I left the input drum with the 3-4 clutches out to try to isolate the problem.

bbond105

The reverse drum should slide on to the pump easily and spin easily when mount on the pump.

98CayenneT/A

A video that may help.

start video at 33 min mark

close up of mine seated

urb0123

Awesome, that helps a lot.

Yeah, mine doesn't do anything easy. In order to "spin" my pump on top of the reverse drum, I have to put a prybar in the splines of the reverse drum to hold it still and use both hands on the pump to get it to turn in about 30 degree increments. It's really bad.

I think tonight I'm going to somehow get it separated and try it again without the teflon seals. If it still misbehaves I'll have to suspect the stator, reverse drum bushings, or reverse drum.

Thank you!

urb0123

98CayenneT/A

That video helps a lot, there's no way in hell you can yank my pump stator out of the reverse drum or spin it like that without the reverse drum moving too.

bbond105

Most likely the bushing in the reverse drum is too tight on the pump. Did you replace the bushing in the reverse drum, replace the reverse drum or replace the pump or pump stator?

urb0123

"Most likely the bushing in the reverse drum is too tight on the pump. Did you replace the bushing in the reverse drum, replace the reverse drum or replace the pump or pump stator?"

Yes, that's exactly what's going on. I replaced every bushing. They came with the kit and I figured what the hell.

I pulled the stator seals off and put the pump in the reverse drum last night. It still binds up. I flipped the drum over and put the stator in the bottom of the drum. It doesn't seat all the way into the bottom reverse drum bushing but it goes in far enough to tell me it's fine. The top bushing on the other hand is horrific.

I can't believe I didn't consider the bushing as a possibility. I had a similar problem with the sun gear bushing. The bushing would fit fine on the shaft before I put it in but once I pounded the bushing in, the shaft no longer fit. I went through three of the sonnax sun gear bushings before I got it in right. What I ended up doing was sanding off .1mm from the outside of the bushing before I put it in. I'll probably do the same with this one. Maybe I'm bottoming them out and adding another whack or two for good measure?

mrvedit

It does sound like a rare problem of a bushing being too tight.

Also, I have not seen any mention of input shaft end play.
As you begin to tighten the pump bolts, confirm there is end play. With the bolts tight, the spec is for .015 to .035 end play.

urb0123

Thread necro, sorry.


I ended up sanding off a tenth of a millimeter from the outside of the bushing and it all fit and worked correctly after that.

And yes, there was end play even when it bound up. I can't remember how much but it was pretty close to the tight end of the limit.

Thank you all!