Chapter 2: In Which We Await Fixed Driveshafts and Kill Time by Overhauling an AW4 Because we Think We are Invincible Now
Yeah, so I successfully(?) overhauled ONE stinking transmission and now I think I'm going to put the local trans shops out of business or something. My XJ buddy has given me waaaaay more hours of help than I've given him, so this is me repaying to favors. He's at a week of summer camp with my kids (and his kids and a bunch of other kids) so I'm gonna attempt to do his trans while he's gone (he is aware of this).
First thing I notice is that it's grimy as all get out. I'd love to have the case looking nice for him but with his driving style it's probably wasted effort. Second thing I notice is that the AW4 is much heavier. 3rd thing is that all the external components are o-ring fittings with a bolt hold down bracket. Very different from the 904 (32RH). Component-wise it's more or less the same on the underside; valve body, some accumulator pistons, only the pistons don't have lock rings holding them in which is a welcome change. The rotating assembly has more pieces but it's all basically the same stuff as the TJ trans. Snap rings, clutches, drums, planetary sets, etc. Unfortunately the pump puller bolt hole is a different thread so I can't get it out tonight.
Fourth thing I notice is that the fluid in here looks like extremely thin motor oil. It is dark brown, but much more runny than motor oil. The AW4 takes Dextron III/Mercon, but I assumed it was also reddish in color. It was leaking that color bad on the trail and we assumed his motor was shot. Upon closer review the trans pump seal (or do we call it the torque converter seal?) is obliterated and the torque converter is a lot noisier than it probably should be. In typical XJ fashion he wanted to just replace the seal & send it, but with it already out & me willing to do the work, it only makes sense to tear it down and get all that black fluid out. And then who knows what we'll find?!
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I guess it does have a reddish tint in that light, but I'm here to tell you it's dark brown. Doesn't smell burnt, but if this is the first overhaul then it has 240k miles on the clutches, and the last couple thousand have been some hard miles, let me tell you. We have a big trip at the end of August so it's probably just as well our transmissions spit the bit when they did. Would've been a long ride home given that we don't trailer our jeeps.
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