rebuilding a trans question on parts

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mopardemon340

mopardemon340

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soon ill be rebuilding a 904 trans to go into my demon.. looking at the rebuild kit and bands i can get bands and discs that are smooth or grooved.. what the benefit of one over the other? also how does the reverse wound spring make a difference then a standard spring in the direct. i was also told that i can tighten up the clearance in the direct more then what the books states.. any opinion on this..
 
mopardemon340 said:
soon ill be rebuilding a 904 trans to go into my demon.. looking at the rebuild kit and bands i can get bands and discs that are smooth or grooved.. what the benefit of one over the other? also how does the reverse wound spring make a difference then a standard spring in the direct. i was also told that i can tighten up the clearance in the direct more then what the books states.. any opinion on this..
Click to expand...

Go by what the rebuild book saids
 
I like to have 0.012 - 0.015 clearance per friction in both clutches. i.e. if there are 5 frictions in the high/rev. clutch then I aim for a clearance of 0.060 - 0.075. I've seen forward clutches where the piston travel was so big that the piston wore a groove in the front planet carrier. The tolerances in the FSM are huge so I like to keep to the bottom end of the scale. The frictions with the waffle pattern are for the front (high/reverse) clutch. As this is a so called "shifting clutch" it helps disperse trans fluid out of the clutch quicker when it is not engaged. The rear (forward) clutch is not a shifting clutch because it is engaged as long as the vehicle is moving forward as it's name suggests. The reverse wound spring is an advantage at very high RPM. The standard wound spring will start to compress at high engine revs which will cause the high/rev. clutch to drag eventually toasting it.
 
KickDown said:
I like to have 0.012 - 0.015 clearance per friction in both clutches. i.e. if there are 5 frictions in the high/rev. clutch then I aim for a clearance of 0.060 - 0.075. I've seen forward clutches where the piston travel was so big that the piston wore a groove in the front planet carrier. The tolerances in the FSM are huge so I like to keep to the bottom end of the scale. The frictions with the waffle pattern are for the front (high/reverse) clutch. As this is a so called "shifting clutch" it helps disperse trans fluid out of the clutch quicker when it is not engaged. The rear (forward) clutch is not a shifting clutch because it is engaged as long as the vehicle is moving forward as it's name suggests. The reverse wound spring is an advantage at very high RPM. The standard wound spring will start to compress at high engine revs which will cause the high/rev. clutch to drag eventually toasting it.
Click to expand...
thank you.. im looking to make it as tight as i can since it will be attached to 500hp.. if my clearances arent as tight as they can be where can i get new snap rings?. should i replace the bushings and should i get new thrust washer and also tighten up the input shaft play? lastly what is everyone using to align the front pump when putting it back together?
 
A&A transmission sells snap rings of different thickness....I would replace at least the tail shaft bushing...front drum bushing and the pump bushing....if the thrust washers are worn...replace them...
 
mopardemon340 said:
lastly what is everyone using to align the front pump when putting it back together?
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The way I do this is, after checking pump gear clearance I put both halves of the pump together with the bolts finger tight then back the bolts off half a turn. Then I carefully fit the pump into the empty case. Once it sits I snug all the bolts up from inside the case. I then remove the pump & torque the bolts to 20 Nm.
 
i have an alignment band....

then I side the pump on to the converter
 
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