Preload/End Play Questions

[c2ypt1c]

Hey guys, I'm planning to do an awd conversion but wanted to beef up the trans internals while it's out. This will be my first time digging in to a transmission so I want to make sure I understand everything before I start. My main concern is with the preload and end play:

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From my understanding, end play is the additional space (if any) between the crushed solder and the case. So if the solder measures 0.055, and I wanted 0.001 of end play, would I use a 0.054 spacer/shim?

For preload, I'm pretty confused on what it is exactly...is it the opposite of end play? So if I wanted 0.007 preload, would I use a 0.062 spacer/shim?

 

[doesitonall4rs]

you got it exactly correct sir.

However depending on your ultimate powergoals I would look into preloading the intput shaft instead of setting endplay keeps everything nice and tight. Also if you have it all apart might as well send out the gearset for shotpeening and weld the center diff.

 

[c2ypt1c]

Yeah that's actually what I was planning on doing, shotpeening and welded center diff. And for the preload/endplay specs, I plan on following twicks' advice: Gearbox shimming expert needed#19

Nice, thanks for confirming

Also I noticed from the above thread, Tim repeatedly mentions worn bearings:

In this circumstance, you are reusing worn bearings, and that may be the issue; they may be out of spec causing your measurement variations that are significant.

Anyone know if he is referring to the outer races from the service manual (highlighted in yellow)?

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Or is it the roller bearings on the shafts themselves?

 

[hotrodssnova]

He's talking about the tapered roller bearings. They wear together, so you can't just buy the races. And don't mix them up when you take the shafts out. They have to go back together with the bearing it was with. If you're getting the gears done, they will replace the bearings while they are taking things apart.

 

[doesitonall4rs]

OP when you buy the tapered roller bearings they already come with the outside bearing race. Thats why if you look for part numbers it will drive you crazy as to why you cant find the outer race separately, because it is packaged with the bearing!

The tapered roller bearing presses onto the shafts, or center diff. And the the outer bearing race presses into either the bell housing or endcase depending on which bearing you are replacing. I personally like to replace both the bellhousing side bearings/races and the endcase side bearings/races everytime i put together a transmission. Mainly because I shim mine pretty aggressively and there is no point to have OLD 20+ year old bearings having to take extra load

 

[BoostedBeaver]

I went through this a few years back. I documented the process that I used in these posts. Hopefully it helps you.

http://www.dsmtuners.com/threads/1990-eagle-talon-sleeper.427853/

 

[c2ypt1c]

Oh wow, you guys rock! Thank you so much.

 

[bastarddsm]

Make sure you use some really soft solder and put the case completely together with all the bolts torqued to spec. Otherwise the shim specs you get will be all wonky.

 

[luv2rallye]

And do the solder measurements 3 times to see if consistent and use the average. One time I found a solder I was using expanded sometimes when it was removed which gave me erroneous measurements. And you'll find dealers won't have most spacer/shims (and never in stock). You'll end up having to get them from a tranny rebuilder like twicks69 or Jacks.