Jump to content
Ultimate Subaru Message Board

99 SUS automatic transaxle backlash adjustment


Recommended Posts

Hi Gang - 

I admit I didn't conduct any research before jumping in and changing out the right hemorrhaging transaxle seal on my daughters 99 SUS.  Meaning, I didn't mark the outter transaxle seal cup before spinning it off.  I know it is not properly seated and there is more 'wiggle' in the axle than before.  When it came out, it was a little stiff but it moved and gradually came out.  After the seal was inserted, the cap screwed in nicely but stiffened up and I chipped off a couple of teeth trying to seat it.  So I put it back together and took it for a test ride.  What bothers me is how loose it is and it doesn't want to tighten up any more but I can feel the lip that is protruding, I feel it has at least half to 3/4 turn left.

So, a couple of questions -

Is there a special tool or socket like gismo to allow for tightening?  Or a special procedure or what technique do you recommend?

And is there a way to adjust the backlash into tolerance by myself or is it worth a couple of hours of shop time by the local subaru repair shop for a $1500 car?

Thanks,

Ken

Link to comment
Share on other sites

best bet is to pay a trans/4WD or other shop that knows how to do backlash and bearing preloads.  or get all the equipment to do that yourself.  this isn't something you want to guess on or "get close"....and i'm pretty forgiving when it comes to doing things "by the book".

another issue is you will quite literally find no one well versed in this.  i don't know that anyone will tell you "yeah you can get it real close - i've done it a bunch of times...do this", or "yeah I do the proper dial gauges for subaru's all the time and can tell you this...".   you'll be sifting anecdotal comments mostly with very little experience...not very good teachers or stats behind that. 

there is a special tool - it's not readily available and expensive.  most people make one - there's like a generic GM one that can easily be made to work or make one out of a large socket and some welding/cutting.

when i did this, i was in the same boat, it started making noise but it did take about 20,000 miles before it finally got really bad and locked up.

 

 

Edited by idosubaru
Link to comment
Share on other sites

I use a set of right angle needle nose pliers to turn the bearing carrier.

If you're concerned that it's not done up tight enough I'd be lifting the wheel on that side, gearbox in neutral and while applying gentle pressure with the needle nose pliers in the direction to tighten up as you rotate the lifted wheel in the same direction.

You can't over tighten this really unless you're reefing on it with a bar and a suitable attachment. The pressure you apply will be playing against the other bearing carrier that by the sounds of things hasn't been touched. 

So you should be able to get this sorted for trouble free running for years to come ;)

if it still feels loose after this fix I'd say there's another issue or you're being highly critical of the vehicle since you did the work yourself (I used to be like this too).

Cheers

Bennie

  • Like 1
Link to comment
Share on other sites

I feel for you, because I did the exact same thing. Eventually after about 5 years the trans slowly got noisier & noisier. Had a junk yard one installed because I didn't want her to get stranded. But after the fact, I stumbled on a guy here in forums, sorry I forget his name for credit, but he always before removing ring, would see how tight he could get it, and noticed a pattern where they would tighten 2 notches. So if one forgets to mark, tighten all the way & back off 2 notches. Personally I might go for 3 because I'd rather have a tad loose than to heat up & bind.(make a tool because too many broken tabs is not a good thing) I would do it this way if the other side was not touched, because I'm not sure if they push against one-another.

Link to comment
Share on other sites

Since you only removed one side, the other side should be in the correct position for the lash to be OK still. And when it comes to differential carrier bearings, tighter is typically better. To the point that differential shops will use case spreaders to get more shims in the carrier bearings for additional pre-load. Roller bearings like pre-load. They do not like to be loose, and when the case expands it's going to expand at twice the rate of the carrier because aluminium has twice the coefficient of thermal expansion. I wouldn't sweat it too much just get it tight. Make sure that the carrier is centered and gravity isn't pulling it down and keeping you from getting it seated. 

GD

Edited by GeneralDisorder
  • Like 1
Link to comment
Share on other sites

Thanks for everyone's input, I really appreciate it.  As an update, I tightened up the carrier plate till it was really tight using a hammer and modified large screwdriver.  Had the car lifted, wheel off the ground and kept turning it, wiggling the inner CV up and down.  It feels about right but the other side CV is a little too loose for me.  It also doesn't appear to be in the same position where it was when I loosened it.  I planned to talk to the local subaru mechanic about him finishing the job however he was killed in a motorcycle accident about 10 days ago, may Joe rest in peace. :mellow:

Moving forward, I plan to make a tool and drive it.  About once a week, will check things out and maybe try adjusting it.  I have this next week off and hope to talk to a retired subaru mechanic about this.  I am curious about what the shop manual says about adjusting this?  I imagine there are dial indicator tolerances and other measurable 'things' to get it perfect. 

The reality, this car has 170k miles and isn't in great shape but serves an important need as local transportation around our small town for my HS daughter.  We hope to keep an eye on this and I may find another mechanic I trust.  The nearest dealership is in the next state, 2 hours away and they will screw you every chance they can, I hate doing any business with them.  The best option may be to purchase a replacement transaxle from the wrecking yard?  I don't think I want my daughter taking this car to college next year and be 6 hours away if she needs a vehicle rescue. 

Thanks again and if you have any other suggestions or thoughts, please let me know - my mind reading skills are bad, just ask my wife.

Ken

  • Like 1
Link to comment
Share on other sites

they'll give plenty whining noises before they fail so I would just drive it and if you don't have noises within a year you likely got it fine.  

i was in the same position, having counted but forgot - didn't right it down - and went to install and couldn't remember if it was 6,7, or 8 turns, i guessed wrong and started making noise within a month and deteriorated after 16,000 miles of driving.  

Link to comment
Share on other sites

yeah swap in another transmission is what most people do.  car-part.com 

or swap a used front diff from another trans.  transfer everything from the donor trans and you'll "retain" the backlash and preload.  one person on this forum did that a few years ago. 

or replace the parts necessary inside the diff:
Bearings - at least one bearing in the front diff is like $80-$100.  
Front diff gear set is like $800 in parts. 

figure $500 - $1,000 in labor to split the cash and do the work if you're paying someone to do it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...