2000 Subaru Forester L - Possible Torque Bind?

[ImpulseGundam]

I recently acquired a 2000 Subaru Forester L, with 115k miles. We've only had it for 2 days, and we noticed something really weird. We were at a Subaru dealership for coolant, an oil filter, and some gear oil. However, because it was Labor Day, they were closed. As we were backing up to leave, it seemed to stutter a lot, and stuttered when we made some tight turns. It would stutter the most when backing up. I figured it must be one of the differentials, and my brother agreed. He concluded it could be a torque bind. We still have to flush the coolant, put new engine oil, and put gear oil. BTW, does having almost no gear oil affect this problem?

[AWDfreak]

You forgot to mention it's the 5-speed manual and that the front gear oil was at minimum. Well, I'm not sure about the front diff gear oil since you checked it on a surface I doubt was level ground...

[porcupine73]

It could be torque bind, on the MT's generally it happens from running mismatched tires (Such as putting new on the front or rear only, or getting a flat and replacing only one tire), improper towing such as towing with the front wheels off the ground but the rears on the ground, running with a soft or flat tire for a really long time, etc. Getting stuck in snow and spinning the tires like crazy for too long could probably do it too.

 

In the MT's, it damages the silicone fluid in the center differential that transfers the power to the rear wheels. The fluid gets thick and then when overheated too much it stays thick, and then there's your torque bind.

 

Changing the gear oil will make zero difference in the MT for torque bind, since that silicone fluid is a separate fluid sealed inside the trans and it is not serviceable.

[porcupine73]

Also, just throwing this out there, if the timing belt hasn't been done yet, it is overdue, and there's a number of things that should be done at the same time. Just mentioning it because that is an interference engine.

[AWDfreak]

Also, just throwing this out there, if the timing belt hasn't been done yet, it is overdue, and there's a number of things that should be done at the same time. Just mentioning it because that is an interference engine.

 

According to the previous owner, it has already been done. BTW, I am ImpuleGundam's brother.

 

In addition to already-said problems, there seems to be an odd whine, with a whine directly related to wheel speed. I don't know if it's a transmission or a bad CV/wheel bearing, but it's quite annoying.

[porcupine73]

Sounds good. It's great to have Subaru brothers on the board. I wish my brother liked Subaru but he is a Ford man. sigh. Anyway, not sure on the whine, with the AT the whine is known that is the final reduction gear drive, but for the MT not sure. If the MT was run low on gear oil it might have blued up some of the gears in there and made some whine. Or maybe lifting the wheels off the ground and shaking them to check for looseness and spinning them while holding the coil spring to see if there is anyway oddness there.

[idosubaru]

for the whine i'd check/change the front diff gear oil (auto trans), ATF (auto), or MT gear oil (manual trans obviously). Hopefully the front diff doesn't have issues, they can whine.

[idosubaru]

change the MT gear oil.

 

it's possible that that torque bind and low oil have compromised the front diff, but let's hope not. if it's at minimum that that's not bad - but it's not a great sign either. oil is going somewhere or being lost. why? and was it ever run even lower than just minimum? front diffs don't typically loose oil at all...i think a lot of folks never even change it!

 

torque bind on a manual trans is annoying and also needs to be fixed (VLSD needs replaced) since it does put strain through the entire drivetrain. it can be done without dropping the trans. if it's completely failed you can pull the rear half of the driveshaft and just run it in FWD until you get it fixed.

 

not rotating tires properly, running mismatched tires, or improper towing (two wheels off the ground) will cause this. be sure to not do these things once you get it repaired.

[AWDfreak]

change the MT gear oil.

 

it's possible that that torque bind and low oil have compromised the front diff, but let's hope not. if it's at minimum that that's not bad - but it's not a great sign either. oil is going somewhere or being lost. why? and was it ever run even lower than just minimum? front diffs don't typically loose oil at all...i think a lot of folks never even change it!

 

torque bind on a manual trans is annoying and also needs to be fixed (VLSD needs replaced) since it does put strain through the entire drivetrain. it can be done without dropping the trans. if it's completely failed you can pull the rear half of the driveshaft and just run it in FWD until you get it fixed.

 

not rotating tires properly, running mismatched tires, or improper towing (two wheels off the ground) will cause this. be sure to not do these things once you get it repaired.

 

 

Thankfully the Forester L doesn't have the VLSD, the Forester S does. I don't know about the tires, but all 4 tires are brand new, and all the same exact type.

 

Just last night I checked the tire pressures and set them to the recommended pressures (29PSI front, 26PSI rear). There wasn't a huge difference in pressure (no more than a 3 to 4 PSI difference side-to-side or front-to-back).

[porcupine73]

Good that the new tires are matching. However in the past, it may have been run with mismatched tires.

 

For the VLSD we are talking about the one in the center diff inside the manual trans, which, if the vehicle is AWD, it has. There might be differences in which models had or didn't have the limited slip rear differential (which uses the same silicone viscous fluid principal as the one in the MT, and can be damaged similarly).

[idosubaru]

Thankfully the Forester L doesn't have the VLSD, the Forester S does. \

i think we need to clarify, we're talking about the transmission not the rear differential. you're talking about the rear differential which is not the issue at all here.

 

Transmission - your forester (all of them) have a VLSD *CENTER* differential.

 

Rear Differential has the VLSD/Open S verses L model distinction, but we're not talking about the rear diff.

 

With 5MT torque bind it is your *center* differential that is failing, which is part of the transmission. Reread my post again and maybe it'll make more sense in light of that.

[AWDfreak]

i think we need to clarify, we're talking about the transmission not the rear differential. you're talking about the rear differential which is not the issue at all here.

 

Transmission - your forester (all of them) have a VLSD *CENTER* differential.

 

Rear Differential has the VLSD/Open S verses L model distinction, but we're not talking about the rear diff.

 

With 5MT torque bind it is your *center* differential that is failing, which is part of the transmission. Reread my post again and maybe it'll make more sense in light of that.

 

Yeah, I was quite sleepy when I replied, thanks for clarification.

 

I of course know that the center differential is a VLSD (on MT). (I thought you were talking about the rear VLSD, but that's what lack of sleep can do to one's thinking...) The center diff being locked is what may be causing the front and rear wheels to be "fighting" during tight turning, hence my suspicion for the torque bind. We just wanted to confirm if you guys would've thought the same.

 

 

Anyways, the Forester is going to be serviced at the local Subaru dealer, we'll have them verify it since I'm still such a newcomer to Subies (despite much reading on USMB and other Subaru boards).