Drivetrain backlash?

[McDave]

I just bought a '93 Loyale 2wd with 165k miles. It's in very nice shape and the 3 speed auto tranny was rebuilt 50k miles ago. Runs great other than some lifter noise on the right bank.

 

I notice in the transition between on and off the throttle there seems to be a lot of slack in the driveline. If it were a rear wheel drive car I would say there is too much backlash in the ring and pinion. Does this apply to these fwd cars too? Is this common to Subarus and/or is it something I should be concerned about? I'm getting ready to change out the leaking axle seals in the diff and wonder if I need to address this issue at the same time.

 

PS I'm not getting any noise out of the CV joints when turning corners so can I assume they aren't the cause of the slack?

[idosubaru]

my first guess is not CV related so i think you're good to rule that out for now too. if it were 4WD i'd say your rear differential bushings needed replaced. but since it's not i'd guess your transmission mounts are shot. since it was rebuilt though i'd at least check to make sure everything is mounted and snugged up properly/tight. after that you'll want to check the rear trans cross member bushings.

 

since your ticking seems isolated to one side - change your oil OFTEN. these have HLA's - hydraulic valve lash adjusters. they are fantastic because they never need adjusting (like lots of other cars), but they do get noisy if the oil isn't changed frequently.

 

if it gets bad enough some oil additives may alleviate the problem if it's related to varnished/gummed up HLA's. start with a can of seafoam in the oil and move up to some ATF if it's really bad. no matter what though continue to change it frequently.

[McDave]

my first guess is not CV related so i think you're good to rule that out for now too. if it were 4WD i'd say your rear differential bushings needed replaced. but since it's not i'd guess your transmission mounts are shot. since it was rebuilt though i'd at least check to make sure everything is mounted and snugged up properly/tight. after that you'll want to check the rear trans cross member bushings.

 

since your ticking seems isolated to one side - change your oil OFTEN. these have HLA's - hydraulic valve lash adjusters. they are fantastic because they never need adjusting (like lots of other cars), but they do get noisy if the oil isn't changed frequently.

 

if it gets bad enough some oil additives may alleviate the problem if it's related to varnished/gummed up HLA's. start with a can of seafoam in the oil and move up to some ATF if it's really bad. no matter what though continue to change it frequently.

 

Looking back through the records I see the axles were replaced 40k miles ago, so I agree, not the problem. I'll have someone rock the car between drive and reverse while I watch the mounts and bushings. Those rear bushings do sound suspect based on the symptom.

 

As for the lifters, I see they recently resealed the oil pump, so that likely rules that out. Records show the oil has been changed regularly, though they often stretched it out to 5k miles. I have some MMO in it now. If my a/c parts would ever show up I could start putting some miles on the car to see if that takes care of the tapping. Otherwise my next step appears to be to remove the cam tower for a good cleaning and inspection.

 

I saw mention here that someone rebuilds lifers for $8ea. Could one of you point me towards this person? At nearly $50 a pop for new ones, I think having them rebuilt (if needed) would be a better choice.

 

Thanks for the tips GG.

[idosubaru]

okay if the axles were replaced i would definitely make a mental note of that now, don't forget it! after market replacement axles suck really bad. they fail and cause problems all time, doesn't matter where you buy them from. the only solid source for axles is Subaru or MWE, don't buy them from any store.

 

good luck checking those trans mounts, they are easy to replace.

 

if you use the words "rebuild hlas" in the search function, the second thread has the link to the place that rebuilds them. i think they're even cheaper than $8 each. definitely the way to go.

[McDave]

Mizpah Precision is the place and you're right, only $4.50 exchange or $6.00 without cores. You probably couldn't mail your old ones to them for less than $1.50ea these days.

 

Thanks again!

 

PS Mental noted about aftermarket axles, although our shop hasn't had any problems with the New aftermarkets that we've been using the past few years. But then again Subarus are rare out here.