Jump to content
Ultimate Subaru Message Board

Recommended Posts

ok newbie here

i searched the post so far and havent found an answer to my ? .so heres the story i purchased a 92 legacy L w/2.2 ltr wagon to replace my mom's 81 with 300k which is slowly falling apart. im an auto tech here in Wa state and this car came into our shop with a badly slipping automatic transmission ,customer didnt want to fix it so i offered to buy it ,also spoke to local subaru tech and he told me 90-94 transmissions had problems but that i could put a 95-97 in the car as long as i swapped the diff as well.so i purchased a trans from local slavage yard requesting that i got the diff out of the same car ,well when parts arrive invoice shows they are from different cars and i pulled the fill plug on diff and counted teeth and it was another 3.90 so called back and requested a 4.11 diff which they sent . so heres my ? the wagon had a 3.90 diff in it (as per tag on diff) with old bad trans . the only info i could find showed 95 legacy autos had 4.11 diffs and i thought i could spin the wheels while locking one axle front and rear ,mark and watch the tires on the other side and see if they spin at the same rate .but after reading about the 4wd system i come to find there is no way to lock into 4wd ,the trans ecu controls lockup by wheel slip via speed sensors . so how do i know definatively that i have the right tranny and diff combination? (by the way i did put the 4.11 in the car but havent driven it yet) i want to know i have the right ratio so i dont damage anything. i have vin for all vehicles if that would help.

thanks in advance

Angus

Share this post


Link to post
Share on other sites

Then 92-94 autos were a little weird....they had the 3.90 final drive ratio for some reason, while the 90-91's had the 4.111.

 

What year & model did the rear diff & transmission come out of?

 

I have info on the 99, and it says that the autos in the 2.2 had 4.111, while autos in the 2.5 had 4.444.

 

About the only way I know of to verify would be to drain the oil out of the front diff, shine a light in there, and count the teeth on the sun gear and pinion gear. Even then, I don't know if that's definitely because the fsm shows that the sun & pinion gear tooth # is the same on the 2.2 & 2.5.

 

So I'm not really sure. If you can post what model & year car you got your parts from, that might be a start.

Share this post


Link to post
Share on other sites

this may be a little tricky, but could be done with a helper and wouldn't take that long for two people that know what they are doing. (a lift would be really nice) turn the front wheel and count the number of rotations of the front wheel and the number of rotations of the rear output shaft (or rear tire). i know there's a power split between front and rear on an automatic, but i think the revolutions should be comparable with the car on a lift. the center diff *may* get in the way, but if your count doesn't verify 3.9 or 4.11 then you know the center diff was the problem. does that makes sense? you'll get one of three answers - 3.9, 4.11 or some bogus answer because of the center diff. but i think it will work.

Share this post


Link to post
Share on other sites
this may be a little tricky, but could be done with a helper and wouldn't take that long for two people that know what they are doing. (a lift would be really nice) turn the front wheel and count the number of rotations of the front wheel and the number of rotations of the rear output shaft (or rear tire). i know there's a power split between front and rear on an automatic, but i think the revolutions should be comparable with the car on a lift. the center diff *may* get in the way, but if your count doesn't verify 3.9 or 4.11 then you know the center diff was the problem. does that makes sense? you'll get one of three answers - 3.9, 4.11 or some bogus answer because of the center diff. but i think it will work.

 

There is no center diff with the older style automatic transmissions, so there is no way to do what you described. If it were a MT, or the newer VTD transmissions, you could probably do something similar because they have a center differential.

Share this post


Link to post
Share on other sites

jack it up, turn the engine by hand in teh gear that is straight through..........oh ************, its an automatic.

 

 

OK, I got it..

 

 

put a manual in!

 

those things have hte elctromagnetic lock up right? it senses slip and then dumps power to the rear..... i like the drain plug idea... its a good one.

Share this post


Link to post
Share on other sites

ok as stated car is a 5/92' legacy w/2.2 vin 4s3bj6325n7925300

 

new transmission came out of a 95 legacy vin4s3bd635xs7222837

new diff out of a 91 legacy w/o turbo vin 4s4bj63c3m7912029 and has sticker with 4.11 on rear cover plate

 

i drove car home last night with no problems and no codes flashed on the "power" indicator but im not sure if it compares speed sensors and can set a code for the diff ratio's being wrong

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×