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OK, here goes. 

 

Have a bad driver side front diff oil seal. Doing the CVs while I'm at it. 

 

Background- had a center diff bearing fail (shatter) 20K ago, split the tranny, found the bearing fragments and replaced no problem (also found some other old fragments of hardened metal from something else which failed and was repaired prior to my owning it). Kept the old seals and slid the halves back over the diff seals. Did not reset the backlash with the differential side retainers when it went back together (pops reassembled while I was at work, he couldn't help himself).

 

Must I pull the trans to do this job like the manual calls out, or can I simply pull the side retainer, swap the seal & O-ring and reinstall the side retainer to the same exact point (indexing its original position/turns)?

 

If I must pull the trans its all good, have all the necessary tools/equipment. 

Edited by poolskaterpt
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If you have the replacement seal in hand, just hold it up and compare to the installed one. If you can see all the seal, you can pull it straight out. 

 

Some of the reference data on MT vs AT transmissions get it mixed up. AT transmissions are inside, MT transmissions install outside. What does your trans side plates do? My Chiltons was wrong as usual, Checking with the seal next to it confirmed the problem. No way it was going to come out on my AT, the side plate had to. I left them alone until they leak, the car needed to get back on the road. 

 

No need to pull the trans, just count the turns and lock it back down in the same place the retainer did. Mark with a paint pen or whiteout to check. Pulling the trans is major mojo work, avoid it unless absolutely necessary. 

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You do not have to pull the trans. Just be sure to mark the retainer well and count how many rotations it takes to remove it.

 

Clean the area around the retainer and the output stub as well as you can before removing the retainer. Wire brush it to get any dirt/grit out of the groove between the retainer and case, and make sure no grit can fall into the retainer bore while you're working.

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The side plates sets the preload and backlash on the front diff so they are important.

 

I'm going to mark them well an count the turns out to be able to reset them. Pulling the seal straight out would be next to impossible as the drive splines prevent getting purchase on a rear surface to pull it.

 

Thanks Fairtax and Tirod

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If you have the replacement seal in hand, just hold it up and compare to the installed one. If you can see all the seal, you can pull it straight out. 

 

Some of the reference data on MT vs AT transmissions get it mixed up. AT transmissions are inside, MT transmissions install outside. What does your trans side plates do?

 

This isn't true for new gens.

 

They ALL install from inside the retainer

 

Old 3spd automatic Loyales/GLs/BRats/etc......they install from outside just pry out old push in new.

 

But again......all 4eat atuomatics, and all 5spds.......they install from inside the cup.....And yes....It's fine to mark, remove, and reinstall to the same place the cup for seal replacement.  1 side at a time.

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Gloyale said it a little more clearly than I.

Yes, these seals are done differently than most other cars, but they generally do not pose a problem because the stub shafts allow axle replacement without disturbing the seals.

 

Personally I've only seen one that was leaking, and it was on a transmission I had taken apart to replace the mainshaft bearings on. I just didnt get the stub and seal clean enough before putting the case halves back together. It started leaking about 6 months later.

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  • 2 weeks later...

So I yanked one side at a time with meticulous indexing, changed the seals but now that the retainer plates are back in the shafts just do not turn quite right. Get a cyclic binding/increase resistance then free spinning with each revolution. Looking at pulling the tranny out to set the preload and backlash- does anyone know the mass/weight of special tool weight that gets placed on the passenger side when servicing according to the manual?

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Fairtax,

That thing is clean as a whistle. Degreaser with wire brush prior to full pressure washing... It's really clean. I just don't think the counting the turns out method was quite accurate enough, one tooth's worth of rotation spans the entire adjustment tolerance range for the backlash.

 

I'm going to pull the tranny, just need to know how much the dang "weighted special tool" that gets placed on the passenger side weighs. Don't want to buy the dang tool

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You don't need to do that.

 

Install the cup back to the spot you marked it.  Done.

 

I never use the special tool.  if anything, pull the drain plug, and put your finger in the hole and wiggle the ring gear back and forth against the pinion......it should barely rock a tiny amount.  about .010" or .25mm.  If there is a big play or non at all adjust.

 

Myself and my customers have put 200k+ combined miles diffs I've serviced....and I've never used the "special tool".  A deflection gauge is helpful but it's not hard to feel a .010 gap.

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I know I can get the backlash set with the dial indicator, my concern is the preload on the driver side being excessive and that is why reinstalling the passenger side for backlash to the previous mark has resulted in binding.

 

Risk to pinion or ring gear bearings?

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I know I can get the backlash set with the dial indicator, my concern is the preload on the driver side being excessive and that is why reinstalling the passenger side for backlash to the previous mark has resulted in binding.

 

Risk to pinion or ring gear bearings?

 

If you put both back to the marks....there is no problem.

 

There shouldn't be any "preload" at all on the ring gear while doing this..

 

Feeling the cup binding a bit as you thread it in is normal......especially if you didn't use a new o-ring and lube it up.

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I just changed one and it worked fine.  I pin punched it and then tighten it until I felt resistance - tight, it was about 1 3/4 teeth.  It was just a nice way to confirm the count.  Count as you turn it back in and take it to tight and then back it up to the marks.

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