Pump destroyed and converter hub cracked....thinking slide failure

[Steve V]

Here's how I check rotor clearence in the pump. I did a write up on it on my Facebook page last week. Use shim stock, very cheap, and a piece of glass or granite block. Stack shim rotor and pump up, see if the rotor is free, has drag, or is bound up.

The pump I was working on was from a name brand vendor and was way too loose. Hence why I do all my own builds/work and somehow landed up doing this as a full time job...lol

 

[Mike T]

Cool idea! Just happen to have a piece of my wife's granite . Thanks everyone for contributing and keep the info coming so we all can learn a new trick or two. I need things simplified to absorb it.......never been good with hundreds of pages of technical manuals. Pics and straight to the point is the way for me.

 

[Mike T]

Here is a pic of the pump with the torque converter installed so that those that don't know can see how the veins move in and out of the rotor. Note how the veins on the RT side are pushed out and veins on the LT are in. As the converter turns the rotor the veins move in sort of an elliptical motion.

 

[INEEDAGN]

A standard 9x12 granite surface plate is actually very cheap and allows you to flat sand anything that fits on it using a standard sheet of sandpaper. I went a bit crazier and wanted an 18x24 which was heavy enough to need truck freight. Freight was higher than the plate and was the same money whether I bought one or two plates. So it was like $220 shipped for one or $300 for two. I bought two. Found large sheets of sandpaper and now I have a course and a fine grit stone as well as a 9x12 with nothing glued to it for general purpose (like pinewood derby projects ). They are ridiculously handy and I'd do the exact same again in a heartbeat. Flat sand every part of the pump and the valve body and accum housing etc and can tell you if a pressure plate is warped in seconds. Ive never tried to adjust pump clearance by flat sanding the housing yet but with enough elbow grease I'm sure I could. Then you have manifold flanges and the upper plenum that gets warped at the bolt holes and creates a vac leak etc.

they get buried quick on top my toolbox though...forces me to clean it off occasionally.

 

[77 cruiser]

FWIW glass isn't always flat, I bought a piece of shelving glass 1/2 in. thick, & it was bowed. I assume from being used as a shelf.

 

[McHaggis]

FWIW I've just finished putting my trans together last night, once again. Recently I was giving it a wee blast and had just changed into 4th when I hit a bump at the bottom of a dip. I was watching the trans pressure and it dropped to 50psi so I got off it real quick and limped it home. This is the 2nd time I've broken the pump slide. Cracked it through the pivot pin area both times. Both times no damage to anything else. This time I replaced the slide with a new 10 vane slide David Husek sent me but reused by GM 7 vane rotor. This time I also replaced the vanes and rings but last time I just reused them. I was going to replace the 4th gear frictions and steels but these were in great condition so back in they went.
To me it seems likely the OP's rotor took everything out.

So...Why are these slides breaking so often? Who else it having this issue?

 

[INEEDAGN]

What slide spring setup were you using?

 

[McHaggis]

What slide spring setup were you using?

Me? The dual setup that was in the built up pump that Dave Husek built for me back 5-6 years.

 

[Mike T]

Here's how I check rotor clearence in the pump. I did a write up on it on my Facebook page last week. Use shim stock, very cheap, and a piece of glass or granite block. Stack shim rotor and pump up, see if the rotor is free, has drag, or is bound up.

The pump I was working on was from a name brand vendor and was way too loose. Hence why I do all my own builds/work and somehow landed up doing this as a full time job...lol

How are you ultimately getting the correct clearance? One of the guys in our Buick club said in his old service manual GM had rotors available of varying thicknesses in .0005 increments.

 

[77 cruiser]

When Bruce's post was a sticky he mentioned that.
Where did his post go?

 

[Steve V]

How are you ultimately getting the correct clearance? One of the guys in our Buick club said in his old service manual GM had rotors available of varying thicknesses in .0005 increments.

I mix and match with rotors I have on hand. When I run out I am screwed. They are not available anymore.

 

[Mike T]

Maybe surface the pump housing and cut slide down?

 

[INEEDAGN]

Worst case scenario you machine the pump housing surfaces to match the rotor and slide you are using. I'm curious as to what's all out there for rotor and slide options as I've never really looked. I've got a decent stash of parts and a few cores so I'm comfortable as a hobby builder but we all need to keep our eyes peeled for cheap cores because unlike the Chevy crowd, no one else is keeping any of these around.

Edit: deleted half the book I wrote. I get carried away when I type

 

[Mike T]

CK list a billet 10 vein rotor or a 10 vein billet kit but it doesn't appear to come with a slide, seems like the slide is an area of concern.

The CK billet rotor is silver and another company on ebay list a billet rotor that is dark looking so they must be from different manufacturers.
FWIW some of the rotors on ebay claim to fit the 700,4l60 and 2004r so they are representing them as interchangeable. Have not heard that before so it may be worth looking into.

 

[Mike T]

Thirteen vein said to be interchangeable

 

[INEEDAGN]

The parts are interchangeable but if the aftermarket only has one thickness you'll still be adjusting clearance by changing the pump body dimension. I guess I took for granted that you could find a billet slide with the rotor.

 

[INEEDAGN]

When Bruce's post was a sticky he mentioned that.
Where did his post go?

That thread is still here you just have to search for it. I think they finally unstuck it because it's a 15 year old thread and some of it is dated info and some was just opinion to begin with.

 

[jthomas]

Avoid 13 vane. Causes pressure irregularities and more prone to break.

 

[Mike T]

If you have to use your current method remove the slide and remove the metal ring and o ring out of the slide and retest I bet it's holding your "straight edge" up off the pump body and throwing you off

As it turns out Sir you are 100% correct in your analysis! Slide seal was holding it up and now we're@ .0015, I will follow up with other measurement but pump housing is looking a lot better now.

 

[Mike T]

Measured the exploded rotor and the possible replacement and they are the same, both look identical so I'm a little reluctant to use it fearing the same fate.