Need Help; 904 Transmission Front Pump Install

[customsportsman]

Hi Fellas (and ladies)
First time transmission builder here, but longtime engine builder and motorhead. Transmission is my 1969 A-904 out of my 1969 Fury. Transmission was slow going into reverse. Decided to do a rebuild, and am following the shop manual and the Tom Rand transmission book. Up to now, all has gone smoothly. For the life of me, I cannot get the pump to drop in. I heard the "clunk" when the rear clutch assembly fell into place, and if you look at the photo, I believe I have the front clutch assembly properly seated also. I disassembled the pump as per the instructions, cleaned everything, re-lubed everything, replaced the slip rings. I used a large hose clamp ( I don't have the tool) to do my best to align the pump halves before torquing them. I tightened the band to align everything, then loosened it when the pump was in place. But...this sucker will NOT drop in. Can anybody offer any advice on what I might be doing wrong? I tried a couple of LIGHT love taps to no avail. BUT...even just dropping it in requires the slide hammer to get it back out. IF alignment of the pump halves is the issue, how do you guys do it?
any help is greatly appreciated.

 

[MoPar~Man]

See also:

A904 front pump install problems 63 Dart GT

Hello after rebuilding my A904 I ran into problems installing the front pump, I torqued the bolts to the correct 20nm as specified but then after that I can't turn the input shaft and the output shaft can only be turned with a bar/ lever. I have the correct clearances in the clutch packs, I...

www.forabodiesonly.com

 

[customsportsman]

See also:

http://[URL]https://www.forabodieso...ront-pump-install-problems-63-dart-gt.319713/

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Thanks for sending the link. I saw this video on Saturday and gave this a try. I can only get a couple of threads on each bolt. With the aluminum threads I am afraid to tighten those bolts, as I don't want to pull the threads in the aluminum housing.

 

[MONC440]

I have had a few go in hard but yours sounds excessive. Did you replace the sealing rings on the pump housing (the part that slides into the front clutch) if so make sure that they are installed properly.

If you can’t figure it out you could bring it up to me, I’m about an 1.5 hours from you just south of Jackson. I have rebuilt many 727’s and 904’s. I have helped other FCBO members in the past.

 

[customsportsman]

so I think I found the smoking gun. I pulled the clutches out and the input shaft. I then separated the oil pump case into the two pieces, and removed the pump gears. The bottom section drops into the housing cavity very nicely. the top half however, doesn't want to go. I took a very very fine Scotch-Brite, and just wet polished around the outside of the top part of the pump housing. The top of the housing still binds. I looked for nick's in the aluminum case cavity and no smoking gun there either. How the hell could this thing have gone together in 1969?

 

[493mike]

so I think I found the smoking gun. I pulled the clutches out and the input shaft. I then separated the oil pump case into the two pieces, and removed the pump gears. The bottom section drops into the housing cavity very nicely. the top half however, doesn't want to go. I took a very very fine Scotch-Brite, and just wet polished around the outside of the top part of the pump housing. The top of the housing still binds. I looked for nick's in the aluminum case cavity and no smoking gun there either. How the hell could this thing have gone together in 1969?

I always put the front pump half in the case bore facing the rear and then the rear half, using the case bore for alignment. Install all the bolts and snug them up, pop the assembly out and torque the pump bolts. Always worked for me.
Mike